Books
Sunil K. Maity, Kalyan Gayen, Tridib Kumar Bhowmick
Sustainable production of hydrocarbon biofuels from biomass, fuels that are fully compatible with existing internal combustion engines, will allow the global transport economy to transition to a sustainable energy source without the need for capital-intensive new infrastructures. Hydrocarbon Biorefinery: Sustainable Processing of Biomass for Hydrocarbon Biofuels presents a comprehensive and easy to understand consolidation of existing knowledge for the production of hydrocarbon biofuels from biomass. Three major areas for the conversion of biomass to hydrocarbon biofuels are addressed: i) Chemical and thermochemical conversion processes, ii) Biological and biochemical conversion processes, and iii) Conversion processes of biomass-derived compounds. Additionally, the book includes process design, life cycle analysis of various processes, reaction engineering, catalysts, process conditions and process concepts, and is supported with detailed case studies. The economic viability of each process is specifically addressed to provide a clear guide for the economic development of future hydrocarbon biofuels. Hydrocarbon Biorefinery: Sustainable Processing of Biomass for Hydrocarbon Biofuels offers an all-in-one resource for researchers, graduate students, and industry professionals working in the area of bioenergy and will be of interest to energy engineers, chemical engineers, bioengineers, chemists, agricultural researchers, and mechanical engineers. Furthermore, this book provides structured foundational content on biorefineries for undergraduate and graduate students.
Kalyan Gayen, Tridib Kumar Bhowmick, Sunil K. Maity
Microalgae can be future resource for industrial biotechnology. In current energy crisis era, microalgae are under tremendous research focus for the production of biodiesel due to their high photosynthetic efficiency, growth rate and high lipid content compared to territorial plants. However, the large-scale production of algal biomass and downstream processing of harvested algae towards bio-fuels are facing several challenges from economic viability perspective. Apart from bio-fuels, the microalgae synthesize number of bio-molecules such as pigments (e.g., chlorophyll, carotenoid), protein (e.g., lectin, phycobiliprotein), and carbohydrates (e.g., agar, carrageenan, alginate, fucodian) which are available in the various forms of microalgal products. Therefore, developing a strategy for large-scale production and use of algal biomass for the co-production of these value-added macromolecules is thus imperative for the improvement of the economics of algal biorefinery.
In the above context, this book covers three major areas (i) commercial-scale production of bio-molecules from microalgae, (ii) sustainable approach for industrial-scale operation, and (iii) optimization of downstream processes. Each of these sections is composed of several chapters written by the renowned academicians/industry experts. Furthermore, in this book, a significant weightage is given to the industry experts (around 50%) to enrich the industrial perspectives.
We hope that amalgamate of fundamental knowledge from academicians and applied research information from industry experts will be useful for forthcoming implementation of a sustainable integrated microalgal biorefinery. This book highlights following.
Explores biomolecules from microalgae and their applications
Discusses microalgae cultivations and harvesting
Examines downstream processing of biomolecules
Explores sustainable integrated approaches for industrial scale operations
Examines purification techniques specific for microalgal proteins, Omega 3 fatty Acids, carbohydrates, and pigments
Nanobiotechnology Applications of Nanomaterials in Biotechnology, Medicine and Healthcare
Tridib Kumar Bhowmick, Kaylan Gayen, Sunil Kumar Maity
CRC Press 2024. ISBN 9781032303871 , https://doi.org/10.1201/9781003305583
This book covers topics related to drug delivery, biomaterials, drug design, formulation development, nanoscience, and nanotechnology. It describes the fundamental concepts in nanotechnology and their different applications in biotechnology to solve engineering challenges and generate new areas of technological development. Nanobiotechnology: Applications of Nanomaterials in Biotechnology, Medicine, and Healthcare covers vast application areas that include medical science, material science, pharmaceutical science, and environmental science. Section 1 presents recent research updates on the different nanomaterials, which are promising in different medical and biotechnological applications. Applications of nanomaterials as bone replacement orthopedic implants have revolutionized the treatment of orthopedic surgery. Nanostructured polymeric materials have gained immense research attention as therapeutic carriers for the precise delivery of drugs at targeted sites. Nanocellulose is recognized as a promising green nanomaterial due to its renewability and abundance in nature. Scientific topics on the most recent scientific and technological advances and applications of different nanostructured materials are presented in this section. Section 2 focuses on the novel synthesis methods that are used extensively and promising for large-scale production of inorganic and nanostructured materials. Section 3 covers the applications of nanotools in the treatment of different diseases, including cancers and genetic diseases. The increasing use of nanotechnology will bring changes in the manufacturing processes of nanomaterials. The applications of nanomaterials in the field of medical imaging and molecular detection are presented in section 4. This book will be useful for students, researchers, scientists, academicians, and industrial manufacturers to understand the importance and applicability of nanomaterials in the field of biotechnology and medical science.
Book Chapters
Importance of Nanomaterials for Biological Applications
Bhabatush Biswas, Kalyan Gayen, Sunil K. Maity, Tarun Kanti Bandyopadhyay, and Tridib Kumar Bhowmick
In: Tridib Kumar Bhowmick, Kaylan Gayen, Sunil Kumar Maity (eds), Nanobiotechnology Applications of Nanomaterials in Biotechnology, Medicine and Healthcare.
CRC Press 2024. ISBN 9781032303871 , https://doi.org/10.1201/9781003305583
Nanomaterials are unique materials whose dimension ranges from 1 to 100 nm. Nanomaterials have been the cardinal research focus in medical and biological applications due to their unique properties. These features led to unprecedented developments in the applications of nanomaterials in disease targeting, therapeutics delivery, gene delivery, and healthcare diagnostic functions. Several nanostructures exhibited great potential due to their multifaceted properties, including high surface area-to-volume ratio, electroactivity, low toxicity, biocompatibility, doping ability, scalable and economical manufacturing process, and fluorescence and functionalization properties. Particulate matters in the form of minerals, herbs, metals, animal, and chemical products have been used in traditional medicine (Ayurveda, Siddha, Unani, and Traditional Chinese medicine) from ancient times. This chapter thus discusses the efficacy of these traditional medicines in light of the emerging scientific understanding of the role of nanomaterials in the delivery of therapeutics and related applications. The chapter also highlights varieties of nanomaterials (carbon, metal, polymeric, ceramic, lipid, etc.), which are under current research focus for their application in the biomedical field. This chapter further presents their significance in therapeutic delivery, gene therapy, disease targeting, photodynamic/photothermal therapy, bioimaging, biosensors, and tissue engineering applications.
Technological advancements in the production of green diesel from biomass
Sudhakara R. Yenumala, Baishakhi Sarkhel, and Sunil K. Maity
In: Aslam, M., Shivaji Maktedar, S., Sarma, A.K. (eds) Green Diesel: An Alternative to Biodiesel and Petrodiesel. Advances in Sustainability Science and Technology. Springer Nature 219–248, 2022. https://doi.org/10.1007/978-981-19-2235-0_7
Diesel-range hydrocarbons derived from biomass have similar chemical compositions and physicochemical properties with petroleum-derived diesel, known as green diesel. Green diesel also meets the American Society for Testing and Materials (ASTM) specification ASTM D975. Green diesel is thus compatible with existing petroleum pipelines, storage tanks, fuelling stations, and diesel engines. Currently, green diesel is produced from non-edible tree-born oils and lignocellulose biomass. Hydroprocessing of oils and fats, biomass-to-liquid, and a combination of fast pyrolysis and hydrodeoxygenation of bio-oil, are some of the thermochemical processes used to produce green diesel. While commercial technologies are available for producing green diesel from oils and fats, these technologies are suffering from the challenges of the dearth and high cost of feedstock. On the contrary, lignocellulosic biomass is abundant and inexpensive. However, the technologies for converting lignocellulosic biomass to green diesel are in the developing stage. This chapter presents the existing and upcoming hydropyrolysis technologies for converting lignocellulosic biomass to green diesel.
Keywords: Hydroprocessing; Green diesel; Pyrolysis; Hydrodeoxygenation; Non-edible oils; and Biomass.
Hydrocarbon biorefinery: A sustainable approach
Alekhya Kunamalla, Swarnalatha Mailaram, Bhushan S. Shrirame, P Kumar, SK. Maity
Academic Press, Elsevier 2022, 1-44.
A sustainable hydrocarbon biorefinery is crucial to reduce dependency on petroleum. This chapter presents different types of biomass with their availability and chemical structure, various biorefinery approaches, and a diverse range of biofuels. The sugar and starch, triglycerides, and lignocellulose are traditional biorefineries. These biorefineries produce a vast range of oxygenated biofuels (biodiesel, bioethanol, biobutanol, and dimethyl ether) and fuel-additives (γ-valerolactone, alkyl levulinates, furanic compounds, and glycerol acetals). On the other hand, a hydrocarbon biorefinery produces biofuels similar to current transportation fuels, known as hydrocarbon biofuels. These biofuels are compatible with existing refinery facilities. This biorefinery is thus vital to circumvent huge capital investment. This chapter presents a comprehensive overview of three different routes of hydrocarbon biorefinery: chemical and thermochemical, biological and biochemical, and conversion of biomass-derived compounds. This chapter further provides an overview of the role of heterogeneous catalysis in the hydrocarbon biorefinery.
Keywords: Biomass; Biorefinery; Hydrocarbon biorefinery; Hydrocarbon biofuels; Heterogeneous catalysis
Pankaj Kumar, Deepak Verma, Malayil Gopalan Sibi, Paresh Butolia, Sunil K. Maity
Academic Press, Elsevier 2022, 97-126.
Catalytic hydrodeoxygenation of triglycerides is a prominent technology in hydrocarbon biorefinery for producing diesel-range biofuels, named green diesel. The triglycerides are fatty ester of glycerol associated with three long-chain fatty acids. While the triglycerides are generally composed of C8-C24 fatty acids, the majority of the fatty acids are in the diesel range (C16 and C18). The removal of oxygen from triglycerides thus produces green diesel. Therefore, the present chapter provides an overview of the hydrodeoxygenation of triglycerides. The process involves a combination of hydrogenation, hydrodeoxygenation, and decarbonylation reactions. This chapter also covers the impact of metal-based catalysts and process conditions on the reaction mechanism and composition, fuel properties, and yield of green diesel. The fuel characteristics of green diesel demonstrate that it can be used directly in an unmodified combustion engine. This chapter further covers the commercial status and economic viability of this technology.
Keywords: Biomass; Green diesel; HDO; Heterogeneous catalysts; Hydrocarbon biorefinery
Advances in the conversion of methanol to gasoline
Jyoti Prasad Chakraborty, Satyansh Singha, Sunil K. Maity
Academic Press, Elsevier 2022, 177-200.
Methanol-to-gasoline (MTG) process is a sustainable approach for producing gasoline-range hydrocarbon biofuels. It can also mitigate the challenges associated with crude oil, such as environmental pollution, scarcity and cost of fossil-derived fuels, and political instability in major crude oil-producing countries. MTG process starts with the production of syngas, followed by conversion of syngas to methanol and production of gasoline from methanol. This chapter summarized the various feedstock used for producing methanol, including biomass and carbon dioxide. MTG process started way back in 1978 when the first plant was installed in New Zealand. Since then, significant technological advancement has been witnessed in the MTG process. This chapter thus presents progress in the MTG process. Specifically, the effect of characteristic features of zeolites and various process variables on the MTG process are elaborated. The reaction mechanism and industrial processes are also discussed briefly.
Keywords: Biomass; Methanol; Gasoline; ZSM-5 catalyst; Reaction mechanism
Biomass, Biorefinery, and Biofuels
S Mailaram, Pankaj Kumar, Alekhya Kunamalla, Palkesh Saklecha, SK Maity
Academic Press, Elsevier 2021, 51-87.
Biomass is the only carbon-neutral renewable resource for the sustainable production of biofuels. There are three types of biofuels: traditional, hydrocarbon, and fuel additives. Traditional biofuels, such as biodiesel, bio-ethanol, and bio-butanol, contain oxygen in their structure and are therefore limited to mixing with transportation fuels. Hydrocarbon biofuels are similar to existing transportation fuels and well-suited with unmodified combustion engines. This chapter covers various routes for the production of the hydrocarbon biofuels, such as hydrodeoxygenation (HDO) of triglycerides, fast pyrolysis followed by HDO of bio-oil, Fischer–Tropsch synthesis, oligomerization of bio-olefins, and HDO of condensed products from C–C bond forming reactions. Several biomass-derived compounds are also suitable for mixing with transportation fuels to a certain extent, known as fuel additives: γ-valerolactone, furanic compounds, 5-ethoxymethylfurfural, alkyl levulinates, glycerol acetal, and dimethyl ether. This chapter describes the production of these fuel additives from methanol and platform chemicals.
Keywords. Bio-ethanol; bio-butanol; biodiesel; hydrocarbon biofuel; fuel additive
Biofuels from triglycerides: A review
S Mailaram, P Kumar, SK Maity
Nova Science Publishers, Inc., New York 2020, 1-27. ISBN: 978-1-53618-134-0
This chapter gives an overview of the various thermochemical routes for the conversion of triglycerides to biofuels. The transesterification, thermal and catalytic cracking, and hydrodeoxygenation are the main thermochemical processes for manufacturing biofuels from triglycerides. The transesterification of triglycerides with methanol produces fatty acid methyl esters, known as biodiesel. The thermal and catalytic cracking of triglycerides produces hydrocarbons in the range of gasoline, jet fuel, and diesel. The cracking routes are, however, associated with the drawback of low yield of biofuel and catalyst deactivation due to the coke deposition on the catalyst. The hydrodeoxygenation is the most potential route to convert triglycerides to diesel-range hydrocarbons, known as green diesel. In this route, the oxygen is eliminated as water and CO. The green diesel is also fully compatible with the existing diesel engine. This chapter provides a detailed description of these processes, including operating conditions, reaction mechanism, catalysts, and techno-economic feasibility.
Keywords: Biodiesel; Green diesel; Transesterification; Hydrodeoxygenation.
Biorefinery Polyutilization Systems: Production of green transportation fuels from biomass
P Kumar, M Varkolu, S Mailaram, A Kunamalla, SK Maity
Academic Press, Elsevier 2019, 373-407.
The green transportation fuels (green gasoline, green diesel, and green jet fuel) (GTF) derived from biomass are quite similar to the petroleum-derived transportation fuels and compatible with existing petroleum refinery infrastructures and combustion engines. The present chapter provides an outline of the various routes for the production of GTF from biomass. In general, the biomass is converted to GTF through thermochemical, chemical, biochemical, and platform chemical-based routes. The current chapter presents an outline of thermochemical conversion processes such as biomass gasification, liquefaction, and pyrolysis and chemical conversion process such as hydrodeoxygenation of triglycerides. The ethanol to gasoline and butanol to gasoline are two important biochemical conversion processes for the production of GTF and discussed in the present chapter. The present chapter also provides an outline of the production of GTF and fuel additives from the platform chemicals such as 5-hydroxymethylfurfural, furfural, and levulinic acid.
Keywords: Hydrocarbon biorefinery; Green transportation fuels; Fast pyrolysis; Hydrodeoxygenation of triglycerides; Ethanol to gasoline; Butanol to gasoline; Platform chemicals
Integrated approach for the sustainable extraction of carbohydrates and proteins from microalgae
S Sarkar, MS Manna, SK Maity, TK Bhowmik, K Gayen
CRC Press, Taylor & Francis Group 2019, 27 pages
Microalgae possess plenty of useful metabolites (broadly carbohydrate, proteins, pigments, and lipids) that can be converted into commercially useful products. Microalgal cells contain a large quantity of structural and functional carbohydrates, as well as bio-functional proteins and peptides. Downstream processing of these individual metabolites from microalgae, however, incurs higher costs compared to other sources. Hence, an integrated extraction approach is becoming essential for commercialization. The microalgae possess a thick cell wall and thus require an additional pre-treatment prior to extraction. The cell disruption of microalgae is an energy-intensive process and thus influences the economics of the overall process significantly. On the other hand, proteins are prone to denaturation under severe conditions, for example, high temperature, extreme pH, and high shear. Therefore, the cell-disruption method should be carried out under mild conditions to retain the native functionality and structure of the proteins. The merits and demerits of different mild cell-disruption methods for integrated processes such as bead milling, ultrasonication, pulse electric field, and enzymatic treatment are discussed in this chapter. Selective extraction of individual metabolites in a sequential manner from the biomass has been demonstrated as a useful approach. Both proteins and carbohydrates are soluble in polar solvents. Consequently, both of these are extracted by aqueous solvents, simultaneously followed by their separation into different fractions. Aqueous two-phase separation and three-phase partitioning are the efficient liquid–liquid extraction techniques to obtain proteins and carbohydrates from the microalgal biomass. Integration of membrane separation with aqueous co-extraction of carbohydrates and proteins is another potential approach for this purpose.
Process development for hydrolysate optimization from lignocellulosic biomass towards biofuel production
A Mazumder, SK Maity, D Sen, K Gayen
Nova Science Publishers, Inc., New York 2014, 41-76. ISBN: 978-1-63463-187-7.
The renewable biofuels derived from lignocellulosic biomass (LCB) through hydrolysis is a promising alternative of fossil fuel and it creates carbon balance of the ecosystem by recycling the emitted CO2 into biomass production. LCB mainly comprises of cellulose, hemicellulose and lignin with a small percentage of pectin, protein, extractive and ash. Prior to hydrolysis of LCB, pretreatment can be performed by different methods namely physical (e.g. mechanical reduction, pyrolysis and extrusion), chemical (e.g. acid, alkaline, oxidative pretreatment and ozonolysis), physiochemical (e.g. steam pretreatment and ammonia fiber explosion (AFEX)) and biological pretreatment. The pretreatment process is one key step to remove lignin and hemicellulose attributing to an improvement in the LCB hydrolysis efficiency. Enzymatic hydrolysis is preferred over acid hydrolysis that produces inhibitory products (e.g. furfural, hydroxymethylfurfural (HMF), acetic acid, formic acid and levulinic acid) of subsequent fermentation process. Different detoxification methods (physical, chemical and biological) are employed to remove the inhibitors. However, enzymatic hydrolysis rate and yield depend on several factors such as concentration and quality of substrate, pretreatment methods, cellulase enzymes and reaction conditions (e.g. temperature, pH and mixing). Upcoming amalgamated techniques with both hydrolysis and fermentation, such as separate enzymatic hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF), non isothermal simultaneous saccharification and fermentation (NSSF), simultaneous saccharification and co-fermentation (SSCF), simultaneous saccharification, filtration and fermentation (SSFF), two chamber bioreactor separated by a membrane filter, and consolidated bioprocessing are the key areas that require detailed analysis for further technology improvement prior to commercialization of hydrolysis process.
Publications
Bhushan S. Shrirame and Sunil K. Maity
Catalysis Today 2024, 442, 114917. https://doi.org/10.1016/j.cattod.2024.114917
Sustainable aviation fuel (SAF) is essential for achieving carbon neutrality in the transportation sector. This study elucidates the production of SAF range C9-C15 branched alkanes by hydrodeoxygenation (HDO) of C15 furanic precursor derived from 2-methylfuran and furfural via hydroxyalkylation-alkylation reaction. HDO reaction was performed using high surface area mesoporous NiMo-ZrO2 composite catalysts that exhibited high selectivity to central SAF alkanes (C13-C14). Deoxygenation follows a complex reaction network involving furanic double bond saturation and furan-ring opening reactions in series, followed by the cascade of HDO, dehydroformylation, and C-C bond cleavage. The present investigation enlightens the impact of calcination temperatures and metal (Mo and Ni) contents on structural stability, physicochemical properties, and catalytic performance of NiMo-ZrO2. Both Ni and Mo stabilized the tetragonal ZrO2 phases with improved surface area. The catalytic activity proliferated with rising calcination temperature till 873 K due to the enrichment of Mo-O-Zr acidic species and deteriorated beyond this temperature owing to the generation of crystalline MoO3/Zr(MoO4)2 species. NiMo alloy formation was enhanced, and concurrently, acidity was reduced with increasing Mo content. 30 wt% MoO3-containing catalyst showed the best catalytic activity due to the proper balance between acidity and NiMo alloy. Oxygenate conversion was boosted by increasing NiO addition up to 15 wt% due to the enhanced Ni and NiMo alloy formation and decreased at 20 wt% owing to the evolution of catalytically inactive bulk metal oxide species. Catalytic cracking was prominent at elevated reaction temperatures, with significant amounts of C13 alkane.
Abishek R. Varma, Bhushan Shrirame, Siddharth Gadkari, Kumar Raja Vanapalli, Vinod Kumar, Sunil K. Maity
Butanediols are versatile platform chemicals that can be transformed into a spectrum of valuable products. This study examines the techno-commercial feasibility of an integrated biorefinery for fermentative production of 2,3-butanediol (BDO) from sucrose of sugarcane (SC), followed by chemo-catalytic upgrading of BDO to a carbon-conservative derivative, methyl ethyl ketone (MEK) with established commercial demand. The techno-economics of three process configurations are compared for downstream MEK separation from water and co-product, isobutyraldehyde (IBA): (I) heterogeneous azeotropic distillation of MEK-water and extractive separation of (II) MEK and (III) MEK-IBA from water using p-xylene as a solvent. The thermal efficiency of these manufacturing processes is further improved using pinch technology. The implementation of pinch technology reduces 8% of BDO and 9–10% of MEK production costs. Despite these improvements, raw material and utility costs remain substantial. The capital expenditure is notably higher for MEK production from SC than BDO alone due to additional processing steps. The extraction based MEK separation is the simplest process configuration despite marginally higher capital requirements and utility consumption with slightly higher production costs than MEK-water azeotropic distillation. Economic analysis suggests that bio-based BDO is cost-competitive with its petrochemical counterpart, with a minimum gross unitary selling price of US$ 1.54, assuming a 15% internal rate of return over five-year payback periods. However, renewable MEK is approximately 16–24% costlier than the petrochemical route. Future strategies must focus on reducing feedstock costs, improving BDO fermentation efficacy, and developing a low-cost downstream separation process to make renewable MEK commercially viable.
Recent Advances in Bio-based Production of Top Platform Chemical, Succinic acid: An Alternative to Conventional Chemistry
Vinod Kumar, Pankaj Kumar, Sunil K. Maity, Deepti Agrawal, Vivek Narisetty, Samuel Jacob, Gopalakrishnan Kumar, Shashi Kant Bhatia, Dinesh Kumar, Vivekanand Vivekanand
Biotechnology for Biofuels and Bioproducts 2024, 17, 72.
https://doi.org/10.1186/s13068-024-02508-2
Succinic acid (SA) is one of the top platform chemicals with huge applications in diverse sectors. The presence of two carboxylic acid groups on terminal carbon atoms makes SA a highly functional molecule than can be derivatized into a wide range of products. The biological SA production route is a cleaner, greener, and promising technological option with huge potential to sequester the potent greenhouse gas, carbon dioxide. The recycling of renewable carbon of biomass (an indirect form of CO2), along with fixing CO2 in the form of SA, offers a carbon-negative SA manufacturing route to reduce atmospheric CO2 load. These attractive attributes mandate a paradigm shift from fossil-based to microbial SA manufacturing, as evidenced by several commercial-scale production of bio-SA in the last decade. The current review article scrutinizes the existing knowledge and covers SA production by the most efficient SA producers, including several bacteria and yeast strains. The review starts with the biochemistry of the major pathways accumulating SA as an end product. It discusses the SA production from a variety of pure and crude renewable sources by native as well as engineered strains with details of pathway/metabolic, evolutionary, and process engineering approaches employed for enhancing TYP (titer, yield, and productivity) metrics. The review is then extended to recent progress on separation technologies to recover SA from fermentation broth. Thereafter, SA derivatization opportunities via chemo-catalysis are discussed for various high-value products, which are only a few steps away. The last two sections are devoted to the current scenario of industrial production of bio-SA and associated challenges, along with the author's perspective.
Suksun Amornraksa, Chanin Panjapornpon, Sunil K Maity, Malinee Sriariyanun, Atthasit Tawai
Computers & Chemical Engineering 2024, 108735.
https://doi.org/10.1016/j.compchemeng.2024.108735
This study proposes an adaptive optimal predictive control (AOPC) for the upflow anaerobic sludge blanket (UASB) reactor with recirculation, employing a PDE-ODE system. Effectively addressing complexity and uncertainties associated with Danckwerts-boundary conditions and biomass distribution, an analytical model predictive control scheme incorporates adaptive set points and compensators. By dynamically adjusting multiple manipulated inputs, including the feed flow rate and recirculation-to-feed ratio, the controller achieves precise effluent concentration control. The robustness of the control system is investigated through fluctuations in inlet concentrations (15–30 %) and variations in bacterial growth rates (10–30 %). The control performance index, ISE, indicates that the AOPC-based control system outperforms the PI controller by 28–150 times for inlet concentration variations and 3–84 times for growth rate changes. With a settling time of 1–3 days, the proposed system excels over the conventional controller, which consistently struggles to maintain the target, emphasizing its inherent robustness.
Rendra Hakim Hafyan, Jasmithaa Mohanarajan, Manaal Uppal, Vinod Kumar, Vivek Narisetty, Sunil K. Maity, Jhuma Sadhukhan, Siddharth Gadkari
Energy Conversion and Management 2024, 301, 118033.
In this study, an advanced decarbonization approach is presented for an integrated biorefinery that co-produces bioethanol and succinic acid (SA) from bread waste (BW). The economic viability and the environmental performance of the proposed BW processing biorefinery is evaluated. Four distinctive scenarios were designed and analysed, focusing on a plant capacity that processes 100 metric tons (MT) of BW daily. These scenarios encompass: (1) the fermentation of BW into bioethanol, paired with heat and electricity co-generation from stillage, (2) an energy-optimized integration of Scenario 1 using pinch technology, (3) the co-production of bioethanol and SA by exclusively utilizing fermentative CO2, and (4) an advanced version of Scenario 3 that incorporates carbon capture (CC) from flue gas, amplifying SA production. Scenarios 3 and 4 were found to be economically more attractive with better environmental performance due to the co-production of SA. Particularly, Scenario 4 emerged as superior, showcasing a payback period of 2.2 years, a robust internal rate of return (33% after tax), a return on investment of 32%, and a remarkable net present value of 163 M$. Sensitivity analysis underscored the decisive influence of fixed capital investment and product pricing on economic outcomes. In terms of environmental impact, Scenario 4 outperformed other scenarios across all impact categories, where global warming potential, abiotic depletion (fossil fuels), and human toxicity potential were the most influential impact categories (−0.344 kg CO2-eq, −16.2 MJ, and −0.3 kg 1,4-dichlorobenzene (DB)-eq, respectively). Evidently, the integration of CC unit to flue gas in Scenario 4 substantially enhances both economic returns and environmental sustainability of the biorefinery.
Bread waste valorization: A review of sustainability aspects and challenges
Rendra H. Hafyan, Jasmithaa Mohanarajan, Manaal Uppal, Vinod Kumar, Narisetty Vivek, Sunil K. Maity, Jhuma Sadhukhan, Siddharth Gadkari
Frontiers in Sustainable Food Systems 2024, 8, 1334801.
Bread waste (BW) poses a significant environmental and economic challenge in the United Kingdom (UK), where an estimated 20 million slices of bread are wasted daily. BW contains polysaccharides with great potential for its valorization into building block chemicals. While BW valorization holds tremendous promise, it is an emerging field with low technology readiness levels (TRLs), necessitating careful consideration of sustainability and commercial-scale utilization. This review offers a comprehensive assessment of the sustainability aspects of BW valorization, encompassing economic, environmental, and social factors. The primary objective of this review article is to enhance our understanding of the potential benefits and challenges associated with this approach. Incorporating circular bioeconomy principles into BW valorization is crucial for addressing global issues stemming from food waste and environmental degradation. The review investigates the role of BW-based biorefineries in promoting the circular bioeconomy concept. This study concludes by discussing the challenges and opportunities of BW valorization and waste reduction, along with proposing potential strategies to tackle these challenges.
Abhishek R Varma, Bhushan S Shrirame, Sunil K Maity, Deepti Agrawal, Naglis Malys, Leonardo Rios-Solis, Gopalakrishnan Kumar, Vinod Kumar
Chinese Journal of Catalysis 2023, 52, 99-126.
The current era is witnessing the transition from a fossil-dominated economy towards sustainable and low-carbon green manufacturing technologies at economical prices with reduced energy usage. The biological production of chemical building blocks from biomass using cell factories is a potential alternative to fossil-based synthesis. However, microbes have their own limitations in generating the whole spectrum of petrochemical products. Therefore, there is a growing interest in an integrated/hybrid approach where products containing active functional groups obtained by biological upgrading of biomass are converted via chemo-catalytic routes. The present review focuses on the biological production of three important structural isomers of C4 diols, 2,3-, 1,3-, and 1,4-butanediol, which are currently manufactured by petrochemical route to meet the soaring global market demand. The review starts with justifications for the integrated approach and summarizes the current status of the biological production of these diols, including the substrates, microorganisms, fermentation technology and metabolic/pathway engineering. This is followed by a comprehensive review of recent advances in catalytic upgrading of C4 diols to generate a range of products. The roles of various active sites in the catalyst on catalytic activity, product selectivity, and catalyst stability are discussed. The review also covers examples of integrated approaches, addresses challenges associated with developing end-to-end processes for bio-based production of C4 diols, and underlines existing limitations for their upgrading via direct catalytic conversion. Finally, the concluding remarks and prospects emphasise the need for an integrated biocatalytic and chemo-catalytic approach to broaden the spectrum of products from biomass.
Venkata Chandra Sekhar Palla, Debaprasad Shee, Sunil K. Maity, Srikanta Dinda
Acs Omega 2023, 8, 43739–43750.
Sustainable production of gasoline-range hydrocarbon fuels from biomass is critical in evading the upgradation of combustion engine infrastructures. The present work focuses on the selective transformation of n-butanol to gasoline-range hydrocarbons free from aromatics in a single step. Conversion of n-butanol was carried out in a down-flow fixed-bed reactor with the capability to operate at high pressures using the HZSM-5 catalyst. The selective transformation of n-butanol was carried out for a wide range of temperatures (523–563 K), pressures (1–40 bar), and weight hourly space velocities (0.75–14.96 h–1) to obtain the optimum operating conditions for the maximum yields of gasoline range (C5–C12) hydrocarbons. A C5–C12 hydrocarbons selectivity of ∼80% was achieved, with ∼11% and 9% selectivity to C3–C4 paraffin and C3–C4 olefins, respectively, under optimum operating conditions of 543 K, 0.75 h–1, and 20 bar. The hydrocarbon (C5–C12) product mixture was free from aromatics and primarily olefinic in nature. The distribution of these C5–C12 hydrocarbons depends strongly on the reaction pressure, temperature, and WHSV. These olefins were further hydrogenated to paraffins using a Ni/SiO2 catalyst. The fuel properties and distillation characteristics of virgin and hydrogenated hydrocarbons were evaluated and compared with those of gasoline to understand their suitability as a transportation fuel in an unmodified combustion engine. The present work further delineates the catalyst stability study for a long time-on-stream (TOS) and extensive characterization of spent catalysts to understand the nature of catalyst deactivation.
Kumar Raja Vanapalli, Rajarshi Bhar, Sunil K. Maity, Brajesh K. Dubey, Sandeep Kumar, Vinod Kumar
Science of the Total Environment 2023, 905, 167051.
Bread waste (BW), a rich source of fermentable carbohydrates, has the potential to be a sustainable feedstock for the production of lactic acid (LA). In our previous work, the LA concentration of 155.4 g/L was achieved from BW via enzymatic hydrolysis, which was followed by a techno-economic analysis of the bioprocess. This work evaluates the relative environmental performance of two scenarios - neutral and low pH fermentation processes for polymer-grade LA production from BW using a cradle-to-gate life cycle assessment (LCA). The LCA was based on an industrial-scale biorefinery process handling 100 metric tons BW per day modelled using Aspen Plus. The LCA results depicted that wastewater from anaerobic digestion (AD) (42.3–51 %) and cooling water utility (34.6–39.5 %), majorly from esterification, were the critical environmental hotspots for LA production. Low pH fermentation yielded the best results compared to neutral pH fermentation, with 11.4–11.5 % reduction in the overall environmental footprint. Moreover, process integration by pinch technology, which enhanced thermal efficiency and heat recovery within the process, led to a further reduction in the impacts by 7.2–7.34 %. Scenario and sensitivity analyses depicted that substituting ultrapure water with completely softened water and sustainable management of AD wastewater could further improve the environmental performance of the processes.
Bhushan S. Shrirame, Abhishek R. Varma, Swagat Sabyasachi Sahoo, Kalyan Gayen, Sunil K. Maity
Biomass and Bioenergy 2023, 177, 106943
Glycerol is a low-value by-product in biodiesel industries and an important platform chemical in biorefinery with vast derivative potentials. 1,2- and 1,3-Propanediol (PDO) are vital polymer precursors. Valorizing glycerol to PDOs is thus a promising approach for producing renewable chemicals and improving the economics of biodiesel industries. Therefore, this work demonstrated the techno-economic feasibility of PDOs for 100–2000 metric tons per day glycerol feed rate. 1,2-PDO was produced by selective hydrogenolysis of glycerol, while microbial batch and fed-batch fermentation of glycerol was considered for manufacturing 1,3-PDO with the co-production of 2,3-butanediol and ethanol. Pinch analysis was applied for process integration that reduced utility demands by around 19% for 1,2-PDO and 12–16% for 1,3-PDO. However, utilities were still major operating costs in these processes. Besides, utility consumptions and capital expenditures were considerably higher for 1,3-PDO by batch fermentation than 1,2-PDO due to low glycerol concentration (50 g/L). 1,3-PDO production cost (USD 3.42/kg) by batch fermentation was thus much more than 1,2-PDO (USD 0.98/kg). The minimum unitary selling price was USD 1.15 for 1,2-PDO and USD 4.90 for 1,3-PDO (batch) for 8.5% rate of return and five years payback period. However, the microbial 1,3-PDO produced by fed-batch fermentation was economically viable, with USD 0.78 and USD 1.02 as unitary production costs and minimum selling price.
Swarnalatha Mailaram, Vivek Narisetty, Sunil K. Maity, Siddharth Gadkari, Vijay Kumar Thakur, Stephen Russell, Vinod Kumar
Sustainable Energy & Fuels 7, 2023, 3034-3046.
Lactic acid (LA) is a vital platform chemical with diverse applications, especially for biodegradable polylactic acid. Bread waste (BW) is sugar-rich waste biomass generated in large quantities in residential and commercial operations. Recently, we evaluated the potential of BW for LA production by Bacillus coagulans under non-sterile conditions. This work presents a techno-economic and profitability analysis for valorizing 100 metric tons of BW per day to alleviate environmental pollution with concurrent production of LA and biomethane. We compared two fermentation approaches: acid-neutral (Scenario I) and low pH (Scenario II). Traditional esterification with methanol, followed by hydrolysis of methyl lactate, was employed for downstream separation to obtain polymer-grade LA. High-pressure steam was generated from solid debris via anaerobic digestion to complement energy demands partly. Energy consumption was further attenuated by process integration using pinch technology, with around 15% and 11% utility cost savings for Scenario I and II, respectively. These processes were capital-intensive, with 42–46% of LA production cost stemming from direct and indirect costs. Utilities were the major cost-contributing factor (19–21%) due to energy-intensive water evaporation from dilute fermentation broth. Due to additional processing steps, capital investment and operating costs were slightly higher in Scenario I than in Scenario II. LA manufacturing cost was thus more for Scenario I ($2.07 per kg) than Scenario II ($1.82 per kg). The minimum LA selling price for Scenario I and II were $3.52 and $3.22 per kg, respectively, with five-year payback periods and 8.5% internal rates of return. LA was slightly more expensive for decentralized BW processing than the market price.
Bikash Ranjan Tiwari, Rajarshi Bhar, Brajesh Kumar Dubey, Sunil K. Maity, Satinder Kaur Brar, Gopalakrishnan Kumar, Vinod Kumar
ACS Sustainable Chemistry & Engineering 2023, 11 (22), 8271–8280.
Microbial production of 2,3-butanediol (BDO) has received considerable attention as a promising alternate to fossil-derived BDO. In our previous work, BDO concentration >100 g/L was accumulated using brewer’s spent grain (BSG) via microbial routes which was followed by techno-economic analysis of the bioprocess. In the present work, a life cycle assessment (LCA) was conducted for BDO production from the fermentation of BSG to identify the associated environmental impacts. The LCA was based on an industrial-scale biorefinery processing of 100 metric tons BSG per day modeled using ASPEN plus integrated with pinch technology, a tool for achieving maximum thermal efficiency and heat recovery from the process. For the cradle-to-gate LCA, the functional unit of 1 kg of BDO production was selected. One-hundred-year global warming potential of 7.25 kg CO2/kg BDO was estimated while including biogenic carbon emission. The pretreatment stage followed by the cultivation and fermentation contributed to the maximum adverse impacts. Sensitivity analysis revealed that a reduction in electricity consumption and transportation and an increase in BDO yield could reduce the adverse impacts associated with microbial BDO production.
Techno-Economic Analysis of 2,3-Butanediol Production from Sugarcane Bagasse
Siddharth Gadkari, Vivek Narisetty, Sunil K. Maity, Haresh Manyar, Kaustubha Mohanty, Rajesh Banu Jeyakumar, Kamal Kishore Pant, Vinod Kumar
ACS Sustainable Chemistry & Engineering 2023, 11(22), 8337–8349.
Sugarcane bagasse (SCB) is a significant agricultural residue generated by sugar mills based on sugarcane crop. Valorizing carbohydrate-rich SCB provides an opportunity to improve the profitability of sugar mills with simultaneous production of value-added chemicals, such as 2,3-butanediol (BDO). BDO is a prospective platform chemical with multitude of applications and huge derivative potential. This work presents the techno-economic and profitability analysis for fermentative production of BDO utilizing 96 MT of SCB per day. The study considers plant operation in five scenarios representing the biorefinery annexed to a sugar mill, centralized and decentralized units, and conversion of only xylose or total carbohydrates of SCB. Based on the analysis, the net unit production cost of BDO in the different scenarios ranged from 1.13 to 2.28 US$/kg, while the minimum selling price varied from 1.86 to 3.99 US$/kg. Use of the hemicellulose fraction alone was shown to result in an economically viable plant; however, this was dependent on the condition that the plant would be annexed to a sugar mill which could supply utilities and the feedstock free of cost. A standalone facility where the feedstock and utilities were procured was predicted to be economically feasible with a net present value of about 72 million US$, when both hemicellulose and cellulose fractions of SCB were utilized for BDO production. Sensitivity analysis was also conducted to highlight some key parameters affecting plant economics.
Alekhya Kunamalla, Sunil K.Maity
Fuel 332, 2023, 125977
Green biofuels are equivalent to hydrocarbon-based motor fuels and compatible with existing refinery infrastructures and combustion engines. Therefore, sustainable production of green biofuels is essential to circumvent the construction of expensive biorefinery infrastructures. This study thus presents the production of green jet fuel from biomass-derived furanic compounds via hydroxyalkylation-alkylation (HAA) reaction coupled with hydrodeoxygenation (HDO) of the C15 biofuel precursor. MoO3-promoted ZrO2 is a promising solid acid catalyst with excellent thermal stability. The HAA reaction of 2-methylfuran with furfural was thus investigated over a novel MoO3-promoted mesoporous ZrO2 catalyst. This work elucidated the role of calcination temperature and MoO3 loading on the structural variation of MoO3-promoted mesoporous ZrO2 and the evolution of acid sites. The highest acid density and consequently best catalytic performance was observed at 873 K calcination temperature with 20 wt% MoO3 loading. About 85 % 2-methylfuran conversion was achieved over 1.25 g of this optimum catalyst at 2:1 2-methylfuran/furfural mole ratio, 323 K, and 5 h. The HAA reaction was further investigated at various reaction temperatures, catalyst loadings, and 2-methylfuran/furfural mole ratios to obtain optimum reaction conditions. HDO of biofuel precursor was examined over Co/γ-Al2O3 catalyst at various reaction temperatures, initial hydrogen pressure, and Co metal loading on γ-Al2O3 to understand the reaction mechanism and identify the optimum reaction conditions. HDO of biofuel precursor progressed through successive furan ring saturation and opening reactions, followed by a combination of HDO, decarbonylation, and cleavage of tertiary-carbon bonds. C9-C15 alkanes were observed as products, with C11 and C14 hydrocarbons being dominant at 573 K and 30 bar. The elevated hydrogen pressure and reaction temperature boosted the conversion of oxygen-containing intermediate compounds at the cost of CC cracking reactions. The conversion of oxygen-containing intermediate compounds was enhanced with rising Co metal loading on γ-Al2O3 up to 20 wt% due to the enhancement of metal dispersion.
Swarnalatha Mailaram, V. Narisetty, V.V. Ranade, V. Kumar, Sunil K. Maity*
Industrial & Engineering Chemistry Research 2022, 61(5), 2195-2205.
2,3-Butanediol (BDO) is a versatile platform chemical with great potentials as the precursor for various value-added derivatives across different industrial sectors. This work thus presents a techno-economic feasibility study for microbial BDO production from C5 and C6 sugars derived from brewers’ spent grain (BSG). Water-soluble carbohydrates obtained from pretreatment were further utilized for the biogas generation. Besides, the solid residue generated after fermentation and biogas were used to generate high-pressure steam and electricity. The process integration was carried out using pinch technology for various BDO titers and plant capacities. The pinch analysis helped in the reduction of hot and cold utility consumption by about 34% and 18%, respectively. The minimum hot and cold utility consumption was 4.59 MW and 10.97 MW for 100 MT BSG per day with 100 g/L BDO titer, respectively. The cooling water consumption was decreased, and electricity generation was increased with increase in BDO titer while BDO production cost reduced marginally. For 100 MT BSG per day, the BDO production cost was US$1.84, US$1.76, and US$1.74/kg for BDO titers of 80, 100, and 120 g/L, respectively. However, the unitary BDO production cost was only US$1.07 for 2000 MT BSG per day. For 100 g/L BDO titer, the minimum selling price was US$3.63 and US$2.00/kg of BDO for 100 and 2000 MT BSG per day, respectively, with 8.5% return on investment and five years as the payback period.
SwarnalathaMailaram and Sunil K.Maity*
Fuel 2022, 312, 122932.
n-Butanol has emerged as a potential biofuel and promising feedstock for organic chemicals. This study presents a techno-economic comparison of dual liquid–liquid extraction (LLE) with distillation for manufacturing 10,000 MT bio-butanol per annum from corn, sugarcane, and lignocellulose biomass using pinch technology. The energy consumption per kg of bio-butanol was lower in dual LLE than distillation. However, the dual LLE involves the complex recovery of extractants with high capital investment and utility consumption. The bio-butanol production cost was thus slightly higher for dual LLE than distillation. Despite the high capital investment, the bio-butanol production cost was much lower for lignocellulose biomass than corn and sugarcane due to cheaper feedstock and higher co-product credit. The production cost was, however, higher for corn compared to sugarcane due to higher feedstock cost, additional enzymatic hydrolysis step, and extra cost for enzymes and nutrients. The production cost per kg of bio-butanol from corn, sugarcane, and lignocellulose biomass was USD 1.50, USD 1.11, and USD 0.65 for distillation and USD 1.59, USD 1.19, and USD 0.74 for dual LLE, respectively. The feedstock contributed 53–70% of the production cost with ∼130%, ∼60%, and ∼40% contribution of co-product credit for lignocellulose biomass, sugarcane, and corn, respectively. The profitability analysis was further carried out to obtain the minimum bio-butanol selling price.
Alekhya Kunamalla, Bhushan S. Shrirame and Sunil K. Maity*
Energy Adv., 2022, 1, 99-112.
This study presents manufacturing jet fuel-range (C9-C15) hydrocarbon biofuels from 2-methylfuran and furfural. The process involves hydroxyalkylation-alkylation reaction, followed by hydrodeoxygenation of the C15 fuel precursor. Hydroxyalkylation-alkylation reaction was investigated under various cation exchange resin loading, furfural/2-methylfuran molar ratio, and reaction temperatures. Hydroxyalkylation-alkylation reaction results were further corroborated by an appropriate kinetic model. Hydrodeoxygenation proceeds via the sequential furan ring-hydrogenation and ring-opening reactions, followed by the combination of dehydroformylation, hydrodeoxygenation, and cracking reactions. The dehydroformylation reaction was the leading pathway over Ni/γ-Al2O3 catalyst, forming mainly C14H30 alkane. The oxygenates conversion was boosted with rising hydrogen pressure, Ni metal content on γ-Al2O3, and reaction temperatures. Both hydrodeoxygenation and hydrogenation reactions proliferated at elevated hydrogen pressure with the enrichment of the C15 alkane and ring-opening and ring-hydrogenation products. The cracking, ring-opening, and ring-hydrogenation reactions were promoted at elevated reaction temperatures with a significant amount of lighter alkanes.
M Varkolu, Alekhya Kunamalla, SAK Jinnala, P Kumar, Sunil K Maity*, D Shee
International Journal of Hydrogen Energy 2021,46, 7320-7335.
This study presents steam reforming of n-butanol to synthesis gas using high surface area mesoporous Ni–CeO2–ZrO2–SiO2 composite catalysts. The reaction proceeds through a combination of dehydrogenation, dehydration, and cracking reactions with propanal, butanal, and C2–C4 hydrocarbons as intermediate compounds. The ceria forms a solid solution with zirconia, promotes dispersion of nickel, and enhances oxygen storage/release capacity. The carbon conversion to synthesis gas (CCSG) and hydrogen yield are thus enhanced with increasing CeO2/ZrO2 mole ratio up to 1:2 and decreased slightly for higher mole ratios. The CCSG and hydrogen yield are also boosted by increasing the amount of nickel in the catalyst up to 20 wt%. 1:2 CeO2/ZrO2 mole ratio and 20 wt% nickel content are thus deliberated as optimum. The optimum catalyst exhibits stable catalytic performance for about 30 h time-on-stream. The study further presents the effect of temperature and steam/carbon mole ratio on n-butanol steam reforming.
Keywords: Bio-butanol; Mesoporous Ni–CeO2–ZrO2–SiO2; Steam reforming; Synthesis gas
Techno-economic Analysis for Production of Biodiesel and Green Diesel from Microalgal Oil
S Mailaram, N Dobhal, SK Maity*
Springer Proceedings in Energy 2021, 1465-1475.
Microalgae has massive potential for the production of biofuels. Thermochemical conversion of microalgal oil is the potential route to produce diesel-range biofuels. This work provides the process design using Aspen Plus and economic analysis for transesterification and hydrodeoxygenation of microalgal oil to produce biodiesel and green diesel, respectively. In the present study, the microalgal oil derived from Nannochloropsis salina is considered as feedstock. Capital, operating expenses and the manufacturing cost of the biodiesel and green diesel have been estimated for various plant capacities ranging from 0.05 to 0.15 million metric ton microalgal oil per annum. The effect of plant capacity and different cost-contributing factors on the manufacturing cost of biodiesel and green diesel has also been studied. The manufacturing cost of diesel oil-equivalent biodiesel and green diesel was USD 4.425 and USD 4.294 per kg, respectively, for 0.125 million metric ton microalgal oil per annum.
Keywords:Techno-economic analysis Microalgal oil Biodiesel Green diesel
VCS Palla, D Shee, and SK Maity
ACS Sustainable Chem. Eng. 2020, 8, 40, 15230–15242.
The production of aromatics from biomass is very much essential to address the sustainability issue of human civilization. The present work proposed a novel process for aromatics production from n-butanol (BTA) using various solid acid catalysts (HZSM-5, H-β, and γ-Al2O3) in a high-pressure fixed-bed reactor. γ-Al2O3 is associated with Lewis acid sites only and hence selective toward butylenes. H-β showed lower selectivity toward aromatics and benzene–toluene–ethylbenzene–xylene (BTEX) compared to HZSM-5 because of rapid catalyst deactivation. The selectivity to aromatics was strongly dependent on the silica/alumina (Si/Al) mole ratio of HZSM-5. The highest selectivity to aromatics was observed over HZSM-5 (Si/Al = 55) because of the presence of an optimum quantity of Brønsted acid sites and organic radicals. The aromatics and BTEX selectivity improved with increasing operating pressure up to 20 bar and reduced slightly at higher pressure. The aromatics and BTEX selectivity, however, declined with increasing weight hourly space velocity (WHSV) and enhanced with increasing temperature up to 623 K. The maximum aromatics selectivity was 49.2% with 29.4% BTEX over HZSM-5 (Si/Al = 55) under optimum reaction conditions: 20 bar, 623 K, and 0.75 h–1 WHSV. A comprehensive reaction mechanism was further delineated correlating variation of product distribution obtained over a broad range of process conditions.
Hydrodeoxygenation of karanja oil using ordered mesoporous nickel-alumina composite catalysts
SR Yenumala, P Kumar, SK Maity*, D Shee
Catalysis Today 348, 2020, 45-54.
This study presents a systematic investigation of hydrodeoxygenation (HDO) of karanja oil over ordered mesoporous nickel-alumina composite catalysts. These catalysts were prepared by the evaporation-induced self-assembly method. The catalysts showed the ordered mesoporous structure up to 15 wt% nickel content in the catalyst. The mesoporous structure, however, became disorder beyond this nickel content. The catalysts were associated with catalytically active dispersed tetrahedral (or octahedral) coordinated nickel aluminate with strong interaction with alumina and a negligible amount of catalytically poor extra-framework nickel. The mesoporous nickel-alumina composite catalysts thus demonstrated superior catalytic activity compared to mesoporous alumina and γ-Al2O3 supported nickel catalysts. Wide ranges of linear paraffins (C14-C22) were formed in the reaction with C17 alkane as the main product. The conversion of oxygenates was enhanced with the rise in initial hydrogen pressure and nickel content in the catalyst without affecting product distribution much. The cracking of heavy hydrocarbons was, however, significant at elevated reaction temperatures, resulting in high selectivity to C17 alkane. For the optimum nickel loading of 20 wt%, the conversion of oxygenates was almost 100% with about 70 wt% C17 alkane and 15 wt% each lower and higher than C17 alkanes at 633 K and 2 h reaction time.
Keywords: Mesoporous nickel-alumina catalyst; Evaporation-induced self-assembly method; Composite catalyst; Hydrodeoxygenation; Karanja oil; Green diesel
Pankaj Kumar, Sunil K. Maity*, D Shee
Chemical Engineering Communications 207, 2020, 904-919.
The calcination temperature (Cal-Temp) plays a vital role in the performance of supported metal catalysts. In this work, the alumina supported Ni, NiMo, Co, and CoMo catalysts were prepared at different Cal-Temp. The catalysts were characterized by various techniques to identify the catalytically active different surface species to correlate their role in the hydrodeoxygenation of stearic acid. With increasing Cal-Temp, the metal dispersion was increased for Ni, NiMo, and CoMo catalyst (up to 973 K) and decreased for Co catalyst. With increasing Cal-Temp, the catalytic activity was thus increased for Ni and NiMo catalyst and decreased for Co catalyst. The activity of CoMo catalyst was, however, enhanced with rising Cal-Temp up to 973 K and declined slightly after that. The optimum Cal-Temp for Ni, NiMo, Co, and CoMo catalyst was found to be 1023 K, 973 K, 773 K, and 973 K. The reaction followed the decarbonylation route over active metallic centers (Ni and Co) and the HDO route over oxophilic M2+⋅MoO2 (M = Ni/Co) and reducible cobalt oxide species. The C17 alkane was thus the principal product over Ni catalyst, whereas C18 alkane was the primary product over CoMo and NiMo catalyst. In contrast, both C17 and C18 alkanes were significant over Co catalyst.
Keywords: Calcination temperature; Green diesel; Hydrodeoxygenation; Ni, NiMo, Co and CoMo catalyst; Stearic acid
Sudhakara Reddy Yenumala, Pankaj Kumar, Sunil K Maity*, D Shee
Bioresource Technology Reports 7, 2019, 100288.
NiMo-alumina catalysts with a small quantity of Mo showed ordered mesoporous structure. For 4.3 mmol total metals content, mesoporous structure, however, became disorder for 1.7 mmol and higher Mo content. The C18 alkane was the leading product among hydrocarbons (C15–C22) formed during hydrodeoxygenation of karanja oil. The catalytically active NiMo complex and Mo oxide species with lower oxidation states were substantial in NiMo catalysts with the modest quantity of both Mo and Ni and relatively small for the other two extremes. The catalytic activity and selectivity to C18 alkane were thus enhanced with the rise in Mo content up to 3.4 mmol. The catalytic activity was also improved with growing total metals content and temperature. The optimum catalyst (0.9 mmol Ni and 3.4 mmol Mo) showed the complete conversion of oxygenates with 13 wt% < C18, 75 wt% C18, and 12 wt% > C18 alkanes at 340 °C and 4 h reaction.
Keywords: Green diesel; Hydrodeoxygenation; Karanja Oil; NiMo-alumina; Mesoporous catalysts
Near-Room-Temperature Synthesis of Sulfonated Carbon Nanoplates and Their Catalytic Application
Devarakonda Damodar, Alekhya Kunamalla, Mohan Varkolu, Sunil K. Maity, and Atul S. Deshpande
ACS Sustainable Chem. Eng. 2019, 7, 15, 12707–12717.
We demonstrate a unique one-pot synthesis approach to obtain sulfonated carbon nanoplates having elongated hexagonal morphology (S-ECN). The S-ECN was synthesized by dehydration of recrystallized sucrose and sodium chloride mixed crystals with concentrated sulfuric acid under ambient conditions. No additional heat treatment or elaborate experimental setup was necessary to obtain graphitic carbon nanoplates. Scanning electron microscopy (SEM) studies showed that the presence of NaCl and recrystallization conditions played a crucial role in crystal habit modification of sucrose during recrystallization. Consequently, initial morphology of sucrose crystals was largely preserved in resultant carbon nanostructures. X-ray diffraction, Raman spectroscopy, and transmission electron microscopy studies showed that S-ECN was partially graphitic with wider interplanar spacing compared to standard graphite. The elemental analysis (CHNS) and Fourier transform infrared (FTIR) spectroscopic studies confirm the presence of sulfur in the form of −SO3H group. The catalytic performance of the S-ECN was studied for hydroxyalkylation–alkylation (HAA) reaction of 2-methylfuran with furfural to produce C15 oxygenated hydrocarbon. The S-ECN showed up to 90% conversion of 2-methylfuran. Additionally, an empirical kinetic model was developed to obtain rate constant of HAA reaction and to correlate 2-methylfuran conversion under various reaction conditions. The experimental results matched reasonably well with the calculated 2-methylfuran conversion.
Keywords: Sucrose, Recrystallization, Dehydration, Sulfonated carbon nanoplates, Catalytic activity
Swarnalatha Mailaram and Sunil K. Maity*
Journal of Renewable and Sustainable Energy 11, 2019, 025906.
Hydrodeoxygenation (HDO) of vegetable oil is a potential technology for the production of green diesel for direct application in unmodified combustion engines. This study provides the conceptual process design for HDO of karanja oils by two different routes: (i) direct HDO of vegetable oils (direct HDO) and (ii) HDO of fatty acids derived from hydrolysis of vegetable oils (two-step HDO). Pinch analysis was carried out to obtain energy targets and the maximum level of heat recovery and to design the heat exchange network. An economic analysis was then performed using USD 0.5 per kg as the retail price of karanja oil. The production costs of green diesel were estimated as USD 0.84 per kg and USD 0.798 per kg for direct and two-step HDO, respectively, for an optimum plant capacity of 0.12 × 106 metric ton per annum of karanja oil. The analysis was further extended to understand various cost-contributing factors and the effect of feedstock and the price of co-products on the manufacturing costs of green diesel. A discounted cash flow analysis was carried out to determine the minimum selling price of green diesel.
Pankaj Kumar, Sunil K Maity, Debaprasad Shee
ACS omega 2019, 4, 2833-2843.
The hydrodeoxygenation (HDO) of vegetable oil and fatty acid is extremely important for the sustainable production of diesel-range hydrocarbons. The present work depicts the role of Ni/Mo (mole) in the performance of alumina-supported NiMo catalysts for the HDO of stearic acid. Both Ni and NiMo alloy coexist in the NiMo catalysts depending on the Ni and Mo content. With increasing Ni/Mo (mole), the NiMo alloy content in the catalyst increases with the simultaneous decrease in the Ni content. The activity of NiMo catalysts thus enhances with increasing Ni/Mo (mole). The reaction follows a decarbonylation route over Ni sites and a HDO route over NiMo alloy species. C17 and C18 alkanes are thus observed as the dominating hydrocarbon product over Ni and NiMo alloy-rich catalysts, respectively. The activity of the NiMo catalyst further enhances with increasing reaction temperature and metal (Ni + Mo) loading. The selectivity to alkanes was, however, not affected by metal loading. A suitable kinetic model was further established based on the reaction mechanism to relate the kinetic data.
Sudhakara Reddy Yenumala, Sunil K. Maity*, D Shee
Reaction Kinetics, Mechanisms and Catalysis 120, 2017, 09–128.
The present work provides a systematic study to delineate the reaction mechanism and develop a mechanistic kinetic model for the hydrodeoxygenation (HDO) of triglycerides (TG) over alumina supported nickel catalyst. The HDO of 1:2 molar mixtures of tripalmitin and tristearin was studied in a batch reactor over a wide range of process conditions. The results showed that TG instantaneously converted to respective fatty acids. The fatty acids further converted to the fatty aldehydes. The fatty aldehydes, then, rapidly converted to alkanes by two parallel reaction pathways. The decarbonylation of fatty aldehyde (RP-I) was the dominating route compared to the reduction of the fatty aldehyde to fatty alcohol followed by its dehydration and hydrogenation (RP-II). A mechanistic kinetic model was developed based on the observed reaction pathway to correlate the experimental results. The rate constants for the conversion of palmitic acid and stearic acid to alkanes were matched closely with each other thereby demonstrating that HDO is independent of fatty acid chain length. The developed kinetic model was further validated using experimental data at various hydrogen-to-nitrogen mole ratios in the gas phase. Furthermore, the rate constants obtained for various catalyst loadings were correlated by a linear equation with zero intercept.
Keywords:Triglyceride; Hydrodeoxygenation; Reaction mechanism; Kinetics; Nickel-alumina
Vishnu P. Yadav, Sunil K. Maity*, D Shee
Indian Chemical Engineer 59(2), 2017, 117-135.
The etherification of glycerol with ethanol is a novel process to utilise low-value by-product (glycerol) of the biodiesel industry to produce ethers of glycerol suitable for use as fuel additive or solvent. The etherification of glycerol with ethanol was investigated under the liquid phase in a high pressure batch reactor using two different types of commercial solid acid catalyst (zeolites and strongly acidic cation exchange resin (CER)). The CER showed superior catalytic activity over H-beta zeolite. The diethyl ether was observed as major product at high ethanol-to-glycerol mole ratio. The product selectivity diverted towards ethers of glycerol with decreasing ethanol-to-glycerol mole ratio. Among ethers of glycerol, glycerol monoethyl ether was the major product of the reaction. The reaction mechanism for etherification of glycerol with ethanol was delineated based on experimental observations. The reaction rate increased with increasing catalyst loading and temperature without affecting selectivity to the products significantly. The apparent activation energy of glycerol and ethanol was 25.1 and 26.6 kcal/mol, respectively. An empirical kinetic model was developed to correlate experimental data at different temperatures. The conversion of the reactants calculated from the kinetic model matched reasonably with experimental data.
Conversion of n-butanol to gasoline range hydrocarbons, butylenes and aromatics
Venkata Chandra Sekhar Palla, D Shee, Sunil K Maity
Applied Catalysis A: General 526, 2016, 28-36.
Sustainable production of hydrocarbon transportation fuels and building-block chemicals from biomass is extremely important to circumvent the development of capital-intensive new infrastructures for automobile sector and petrochemical industry. The present investigation is thus focused on selective conversion of n-butanol to gasoline range transportation fuel, and butylenes and aromatics building blocks in single step. Systematic investigation was carried out in a fixed-bed reactor over HZSM-5 catalyst at atmospheric pressure for clear identification of temperature and weight hourly space velocity (WHSV) window to maximize the yield of various products. The present article additionally provides the mechanistic insights for the formation of various products from n-butanol.
Keywords: n-Butanol; Gasoline; Aromatics; Butylenes; HZSM-5.
Sudhakara Reddy Yenumala, Sunil K. Maity*, D Shee
Catalysis Science & Technology 6, 2016, 3156-3165.
Abstract. Production of hydrocarbon transportation fuels from triglycerides is extremely important to reduce dependency on limited fossil fuels. The present article provides a systematic examination of hydrodeoxygenation (HDO) of karanja oil (KO) in a semi-batch reactor over supported (γ-Al2O3, SiO2, and HZSM-5) nickel catalysts. The catalysts were associated with both dispersed and bulk nickel/nickel oxide depending on the extent of nickel loading and nature of the support. Virgin KO is composed of ~76 wt% C18 fatty acids with ~15 wt% oxygen. HDO of KO resulted in a wide range of alkanes (C10–C22) with n-heptadecane being the major one. Transformation of KO into alkanes proceeds through three distinct routes: HDO, catalytic cracking, thermal cracking, or their combination. Highly acidic catalysts (HZSM-5 and Ni/HZSM-5) promote catalytic cracking leading to formation of a large amount of lighter alkanes. The cracking reaction becomes significant over the γ-Al2O3 supported nickel catalyst with ≤15 wt% nickel loading at elevated temperatures. A strong metal–support interaction favored the HDO pathway over the γ-Al2O3 supported nickel catalyst with ≥20 wt% nickel loading. About 80 wt% of KO was converted to the liquid product with physicochemical properties comparable with light diesel oil.
Vimala Dhanala, Sunil K. Maity*, D Shee
RSC Advances 5, 2015, 52522–52532.
The production of synthesis gas from bio-isobutanol in an integrated biorefinery is a novel approach for its downstream conversion to hydrocarbon fuels and organic chemicals. The present article provides a systematic examination of the structure–activity correlation of various supported transition metal catalysts, xMS (x mmol metal, M (Ni, Co, and Mo) supported on S (Al, Si, and Zr for γ-Al2O3, SiO2, and ZrO2 respectively)) for steam reforming (SR) of bio-isobutanol. The activity of the catalyst was strongly influenced by metal-support interaction as reflected by metal dispersion, metal crystallite size, and extent of bulk metal/metal oxide. The catalytic activity increased in the order of 4.3NiZr < 4.3NiSi < 4.3NiAl and 4.3MoAl < 4.3CoAl < 4.3NiAl. 7.3CoAl exhibited consistent catalytic activity up to 12 h of time-on-stream. The hydrogen yield was boosted with rise of temperature and steam-to-carbon mole ratio (SCMR) with concurrent drop of selectivity to methane. The selectivity to CO reduced with increasing SCMR and decreasing temperature. Furthermore, spent catalysts were characterized to elucidate the effect of metal and support on the nature of coke formed and chemical transformation of the catalyst during SR.
Vimala Dhanala, Sunil K. Maity*, and D Shee
Journal of Industrial and Engineering Chemistry 27, 2015, 27, 153-163.
Present work provides a systematic investigation of oxidative steam reforming (OSR) and comparisons with steam reforming (SR) of isobutanol over γ-Al2O3 supported nickel catalysts. Catalysts characterization results demonstrated that majority of nickel oxide was present as dispersed NiAl2O4. The hydrogen yield and selectivity to CO and methane were somewhat lesser for OSR compared to SR. The H2/CO mole ratio in the range of 8–10 was observed under the experimental conditions. The experimental results were matched well with equilibrium products compositions. The spent catalysts were further characterized to elucidate chemical and morphological changes of the catalysts during SR and OSR.
Keywords: Oxidative steam reforming; Thermodynamic equilibrium analysis; Bio-butanol; Synthesis gas; Ni/γ-Al2O3
Opportunities, recent trends and challenges of integrated biorefinery: Part I
Sunil K. Maity*
Renewable and Sustainable Energy Reviews 43, 2015, 1427-1445.
Sustainable production of energy, fuels, organic chemicals and polymers from biomass in an integrated biorefinery is extremely important to reduce enslavement on limited fossil fuels. In the present article, the biomass was classified into four general types based on their origin: energy crops, agricultural residues and waste, forestry waste and residues and industrial and municipal wastes. The article further elucidates the chemistry of various types of biomass used in the biorefinery. The biorefinery was classified into three broad categories based on the chemistry of biomass: triglyceride, sugar and starchy and lignocellulosic. The article further presents a comprehensive outlines of opportunities and recent trends of each type of biorefinery. A brief overview of original and revised list of platform chemicals, their sources from biomass and derivative potentials were also articulated. The article also provides comparisons of different types of biorefinery, broad challenges and availability of biomass. Furthermore, the article provides an overview of hydrocarbon biorefinery for production of hydrocarbon fuels and building block chemicals from biomass.
Keywords: Biorefinery; Biomass; Bio-fuels; Platform chemical; Lignocellulose; Starch
Opportunities, recent trends and challenges of integrated biorefinery: Part II
Sunil K. Maity*
Renewable and Sustainable Energy Reviews 43, 2015, 1446-1466.
Availability of cost-competitive biomass conversion technologies plays crucial role for successful realization of biorefinery for sustainable production of fuels and organic chemicals from biomass. The present article provides an outline of opportunities and socio-techno-economic challenges of various biomass processing technologies. The biomass processing technologies were classified into three broad categories: thermochemical, chemical and biochemical. This review article presents an overview of two potential thermochemical conversion processes, gasification and fast pyrolysis, for direct conversion of lignocellulosic biomass. The article further provides a brief review of chemical conversion of triglycerides by transesterification with methanol for production of biodiesel. The highly productive microalgae as an abundant source of triglycerides for biodiesel and various other fuels products were also reviewed. The present article also provides an outline of various steps involved in biochemical conversion of carbohydrates to alcoholic bio-fuels, bio-ethanol and bio-butanols and conversion of nature׳s most abundant aromatic polymer, lignin, to value-added fuels and chemicals. Furthermore, an overview of production of hydrocarbon fuels through various biomass processing technologies such as hydrodeoxygenation of triglycerides, biosynthetic pathways and aqueous phase catalysis in hydrocarbon biorefinery were highlighted. The present article additionally provides economic comparisons of various biomass conversion technologies.
Keywords: Biorefinery; Bio-fuel; Pyrolysis; Microalgae; Bio-butanol; Green diesel
Kinetics of Hydrodeoxygenation of Octanol over Supported Nickel Catalysts: A Mechanistic Aspect
Venkata Chandra Sekhar Palla, D Shee, Sunil K. Maity
RSC Advances 4, 2014, 41612-41621.
Abstract. The hydrodeoxygenation (HDO) of 1-octanol as a model aliphatic alcohol of bio-oil was investigated in a continuous down-flow fixed-bed reactor over γ-Al2O3, SiO2, and HZSM-5 supported nickel catalysts in the temperature range of 488–533 K. The supported nickel catalysts were prepared by incipient wetness impregnation method and characterized by BET, XRD, TPR, TPD, H2 pulse chemisorption, and UV-vis spectroscopy. Characterization of supported nickel (or nickel oxide) catalysts revealed existence of dispersed as well as bulk nickel (or nickel oxide) depending on the extent of nickel loading and the nature of the support. The acidity of γ-Al2O3 supported nickel catalysts decreased with increasing the nickel loading on γ-Al2O3. n-Heptane, n-octane, di-n-octyl ether, 1-octanal, isomers of heptene and octene, tetradecane, and hexadecane were identified as products of HDO of 1-octanol. The C7 hydrocarbons were observed as primary products for catalysts with active metal sites such as γ-Al2O3 and SiO2 supported nickel catalysts. However, C8 hydrocarbons were primarily formed over acidic catalysts such as pure HZSM-5 and HZSM-5 supported nickel catalyst. The 1-octanol conversion increased with increasing nickel loading on γ-Al2O3, and temperature and decreasing pressure and WHSV. The selectivity to products was strongly influenced by temperature, nickel loading on γ-Al2O3, pressure, and types of carrier gases (nitrogen and hydrogen). The selectivity to C7 hydrocarbons was favoured over catalysts with increased nickel loading on γ-Al2O3 at elevated temperature and lower pressure. A comprehensive reaction mechanism of HDO of 1-octanol was delineated based on product distribution under various process conditions over different catalysts.
Kinetics of Hydrodeoxygenation of Stearic Acid Using Supported Nickel Catalysts: Effects of Supports
Pankaj Kumar, Sudhakara Reddy Yenumala, Sunil K. Maity*, D Shee
Applied Catalysis A: General 471, 2014, 28– 38.
The hydrodeoxygenation of fatty acids derived from vegetable and microalgal oils is a novel process for production of liquid hydrocarbon fuels well-suited with existing internal combustion engines. The hydrodeoxygenation of stearic acid was investigated in a high pressure batch reactor using n-dodecane as solvent over nickel metal catalysts supported on SiO2, γ-Al2O3, and HZSM-5 in the temperature range of 533–563 K. Several supported nickel oxide catalysts with nickel loading up to 25 wt.% were prepared by incipient wetness impregnation method and reduced using hydrogen. The catalysts were then characterized by BET, TPR, H2 pulse chemisorption, TPD, XRD, and ICP-AES. Characterization studies revealed that only dispersed nickel oxide was present up to 15 wt.% nickel loading on γ-Al2O3. The acidity of the supports depends on nickel loading of oxidized catalysts and increases with increasing nickel loading up to 15 wt.%. n-Pentadecane, n-hexadecane, n-heptadecane, n-octadecane, and l-octadecanol were identified as products of hydrodeoxygenation of stearic acid with n-heptadecane being primary product. The catalytic activity and selectivity to products for hydrodeoxygenation of stearic acid depends strongly on acidity of the supports. The maximum selectivity to n-heptadecane was observed with nickel supported γ-Al2O3 catalyst. A suitable reaction mechanism of hydrodeoxygenation of stearic acid was delineated based on products distribution. The conversion of stearic acid was increased with increasing reaction time, nickel loading on γ-Al2O3, temperature, and catalyst loading. Complete conversion of stearic acid was accomplished with more than 80% selectivity to n-heptadecane at reasonable reaction temperature of 563 K after 240 min of reaction using 15 wt.% Ni/γ-Al2O3 catalyst. An empirical kinetic model was also developed to correlate the experimental data.
Keywords: Hydrodeoxygenation; Stearic acid; Green diesel; Ni/γ-Al2O3; Modeling
Steam Reforming of Isobutanol for Production of Synthesis Gas over Ni/γ-Al2O3 Catalysts
Vimala Dhanala, Sunil K. Maity*, Debaprasad Shee
RSC Advances 3, 2013, 24521–24529.
Abstract. Bio-isobutanol has received widespread attention as a bio-fuel and a source of chemicals and synthesis gas as part of an integrated biorefinery approach. The production of synthesis gas by steam reforming (SR) of isobutanol was investigated in a down-flow stainless steel fixed-bed reactor (FBR) over Ni/γ-Al2O3 catalysts in the temperature range of 723–923 K. The NiO/γ-Al2O3 catalysts were prepared by the wet impregnation method and reduced in the FBR prior to the reaction. The surface area, metal dispersion, crystalline phase, and reducibility of the prepared catalysts were determined using BET, chemisorption, XRD and TPR, respectively. From the TPR studies, the maximum hydrogen consumption was observed in the temperature range of 748–823 K for all the catalysts. The presence of nickel species was confirmed through the characterization of the catalysts using powder XRD. The time-on-stream (TOS) studies showed that the catalysts remained fairly stable for more than 10 h of TOS. The conversion of carbon to gaseous products (CCGP) was increased by increasing the nickel loading on γ-Al2O3 and the temperature and by decreasing the weight hourly space velocity (WHSV). The hydrogen yield was increased by increasing the nickel loading on γ-Al2O3, the WHSV, the steam-to-carbon mole ratio (SCMR), and the temperature. The selectivity to methane decreased at high reaction temperatures and SCMRs. The selectivity to CO decreased with increasing SCMRs and decreasing temperatures. The work was further extended to the thermodynamic equilibrium analysis of the SR of isobutanol under experimental conditions using Aspen Plus, and the equilibrium results were then compared to the experimental results. A reasonably good agreement was observed between the trends in the equilibrium and the experimental results.
Thermodynamic Evaluation of Dry Reforming of Vegetable Oil for Production of Synthesis Gas
Sudhakara Reddy Yenumala, Sunil K. Maity*
Journal of Renewable and Sustainable Energy 4, 2012, 043120.
Abstract. The dry reforming (DR) is a promising technology for utilization of greenhouse gas, carbon dioxide, to produce synthesis gas for downstream synthesis of valuable chemicals and fuels. In this study, equilibrium of DR and autothermal dry reforming (ATDR) of vegetable oils was investigated by Gibbs free energy minimization method. The effects of various process variables of DR and ATDR of vegetable oils such as temperature (673–1273 K), carbon dioxide-to-carbon mole ratio (CCMR) (0.5–3.0), and oxygen-to-carbon mole ratio (OCMR) (0–1.0) were studied to obtain equilibrium products composition, thermodynamically promising operating conditions, and thermoneutral conditions of the process. The study revealed that insignificant amount of coke and compounds containing two or more carbon atoms were formed for both DR and ATDR of vegetable oils. The hydrogen yield was found to increase with increase in temperatures for DR of vegetable oil. At temperature 983 K and above, the hydrogen yield was found to increase with CCMR, reach maxima, and then decrease with further increase in CCMR. The carbon dioxide conversion and yield of CO and water were increased and yield of methane was decreased with increase in temperature. The yield of CO and water were increased and the conversion of carbon dioxide and yield of methane were decreased with increase of CCMR. For ATDR of vegetable oils, the reduced yield of CO and methane and enhanced yield of water and hydrogen (up to temperature of maximum hydrogen yield) were observed compared to that of DR. From critical analysis of the results of DR and ATDR of vegetable oil, the optimum conditions for maximum yield of hydrogen with very low yield of methane were determined as 1000–1050 K, CCMR of about 1, and oxygen-to-carbon mole ratio of 0.6–0.7. It was observed that about 80% hydrogen yield with 78–83 moles of CO and 0.2–0.6 moles of methane per mole of vegetable oil could be obtained under the optimum conditions.
Correlation of Solubility of Single Gases/Hydrocarbons in Polyethylene Using PC-SAFT
Sunil K. Maity*
Asia-Pacific Journal of Chemical Engineering 7, 2012, 406-417.
Abstract. The knowledge of solubility of gases and hydrocarbons in polymer has enormous importance in the design and development of reactor, polymer foaming, and membrane separation processes. In this work, the solubility of gases and hydrocarbons in polyethylene was correlated using a thermodynamic model based on perturbed‐chain statistical associating fluid theory (PC‐SAFT). The experimental solubility data of various gases such as ethylene, carbon dioxide, nitrogen, methane, and hydrocarbons of up to chain length of seven in both molten and semicrystalline polyethylene has been reviewed and the suitability of the developed model based on PC‐SAFT was then tested using the available solubility data in literatures for various gases and hydrocarbons. Furthermore, the optimum values of adjustable solvents‐solute binary interaction parameters (Kij) of PC‐SAFT at different temperatures have been estimated by regression of the PC‐SAFT model using experimental solubility isotherms. A suitable correlation of Kij with temperature was then developed using the estimated Kij at different temperatures. The solubility calculated from the developed model using the estimated Kij was then compared to the experimental results and a reasonably good correlation was observed.
Kinetics of Esterification of Ethylene Glycol with Acetic Acid using Cation Exchange Resin Catalyst
Vishnu P. Yadav, Sunil K. Maity*, Prakash Biswas, Raghubansha K. Singh
Chemical and Biochemical Engineering Quarterly 25(3), 2011, 359-366.
Abstract. The esterification of ethylene glycol with acetic acid was investigated in a batch reactor in presence of a strongly acidic cation exchange resin, seralite SRC-120, as catalyst in the temperature range of 333 to 363 K. The detailed kinetic study was performed to understand the effect of various process variables such as catalyst loading, ethylene glycol to acetic acid mole ratio, and temperature on conversion of reactants and selectivity to products. Further, two different kinetic models, empirical and kinetic model based on Langmuir-Hinshelwood-Hougen-Watson (LHHW) approach, were developed to correlate the experimental concentration versus time data. The kinetic parameters of the developed models were then estimated at different temperatures using non-linear regression technique based on modified Levenberg-Marquardt algorithm. The calculated results based on the estimated kinetic and equilibrium constants at different temperatures were then compared with the experimental values and LHHW-based model was found to fit the experimental data reasonably better compared to empirical kinetic model. The estimated rate constants at different temperatures of LHHW-based model were then used to estimate the activation energy and frequency factor of the rate constants.
Reforming of Vegetable Oil for Production of Hydrogen: A Thermodynamic Analysis
Sudhakara Reddy Yenumala, Sunil K. Maity*
International Journal of Hydrogen Energy 36, 2011, 36, 11666-11675.
Abstract. The vegetable oils are one of the promising renewable feedstock for production of hydrogen suitable for application in hydrogen based fuel cells for electrical power generation. In the present work, a thermodynamic equilibrium analysis of steam reforming (SR) and autothermal steam reforming (ATSR) of vegetable oils to synthesis gas was investigated by Gibbs free energy minimization method. The thermodynamic equilibrium analysis was performed considering the vegetable oils as a mixture of triglycerides containing three same fatty acid groups in the structure. The property method used for equilibrium analysis was first regressed using available physical and chemical properties of the considered triglycerides. The regressed property method was then used to calculate the equilibrium products composition. The effects of various parameters of SR of vegetable oils, temperature and steam-to-carbon ratio (SCR), on hydrogen yield and selectivity of CO and methane was studied in a broad range of temperature (573–1273 K) and SCRs (1–6). The optimum conditions for SR of vegetable oils were then determined for maximum hydrogen yield with very low selectivity of methane. The thermodynamic equilibrium analysis of ATSR of vegetable oils was then performed at different oxygen-to-carbon ratios and thermoneutral conditions were then determined for various operating conditions.
Keywords: Hydrogen; Vegetable oils;Thermodynamic analysis; Steam reforming; Autothermal steam reforming
Previous publications
Sunil K. Maity, Sujit Sen, Narayan C. Pradhan, A new mechanistic model for liquid–liquid phase transfer catalysis: Reaction of benzyl chloride with aqueous ammonium sulfide. Chemical Engineering Science 2009, 64(21), 4365-4374.
Sunil K. Maity, Narayan C. Pradhan, Anand V. Patwardhan, Reduction of p-Nitrotoluene by Aqueous Ammonium Sulfide: Anion Exchange Resin as a Triphasic Catalyst. Chemical Engineering Journal 2008, 141, 187–193.
Sunil K. Maity, Narayan C. Pradhan, Anand V. Patwardhan, Kinetics of Phase Transfer Catalyzed Reduction of Nitrochlorobenzenes by Aqueous Ammonium Sulfide: Utilization of Hydrotreater Off-gas for the Production of Value-Added Chemicals. Applied Catalysis B: Environmental 2008, 77, 418–426.
Sujit Sen, Sunil K. Maity, Narayan C. Pradhan and Anand V. Patwardhan, Utilization of Hydrogen Sulphide for the Synthesis of Dibenzyl Sulphide: Effects of Process Parameters on Conversion and Selectivity. International Journal of Chemical Sciences 2007, 5(4), 1569-1578.
Sunil K. Maity, Narayan C. Pradhan, Anand V. Patwardhan, Reduction of o-Nitroanisole to o-Anisidine by H2S-rich Aqueous Diethanolamine: A Novel Process for Utilization of H2S-laden Gas Streams. Chemical Engineering Science 2007, 62, 805-813.
Sunil K. Maity, Narayan C. Pradhan, Anand V. Patwardhan, Kinetics of Reduction of Nitrotoluenes by H2S-rich Aqueous Ethanolamine. Industrial & Engineering Chemistry Research 2006, 45, 7767-7774.
Sunil K. Maity, Narayan C. Pradhan, Anand V. Patwardhan, Reaction of benzyl chloride with ammonium sulfide under liquid–liquid phase transfer catalysis: Reaction mechanism and kinetics. Journal of Molecular Catalysis A: Chemical 2006, 250, 114–121.
Sunil K. Maity, Narayan C. Pradhan, Anand V. Patwardhan, Kinetics of the Reduction of Nitrotoluenes by Aqueous Ammonium Sulfide under Liquid-Liquid Phase Transfer Catalysis. Applied Catalysis A: General 2006, 301, 251–258.
Sanghamitra Barman, Sunil K. Maity, Narayan C. Pradhan, Alkylation of Toluene with Isopropyl alcohol catalyzed by Ce-exchanged NaX Zeolite. Chemical Engineering Journal 2005, 114, 39–45.
Ruchi Agarwal, Durga Prasad, Sunil Maity, Kalyan Gayen, Saibal Ganguly, Experimental Measurement and Model Based Inferencing of Solubility of Polyethylene in Xylene. Journal of Chemical Engineering of Japan 2004, 37 (12), 1427-1435.
Conference Presentations
Sunil K. Maity, Kalyan Gayen, Sirshendu De, Saibal Ganguly, Modeling and Simulation of Solid-Liquid Equilibrium: Model Validation Using Solubility Data and Sensitivity Study for Polyethylene System. 1st national Conference of Research Scholar and Young Scientists, Indian Institute of Technology, Kharagpur, India, 2004, P 28-34. PDF
Sunil K. Maity, Anand V. Patwardhan and Narayan C. Pradhan, Reaction of Benzyl Chloride with Aqueous Ammonium Sulfide under Liquid–Liquid Phase Transfer Catalysis. CHEMCON, Indian Institute of Technology, New Delhi, 2005. PDF
Sunil K. Maity, Narayan C. Pradhan, Anand V. Patwardhan, Phase Transfer Catalyzed Reduction of Nitrotoluenes by Aqueous Ammonium Sulfide: Kinetic Study. SCHEMCON, Indian Institute of Technology, Guwahati, 2005. PDF
Sunil K. Maity, Narayan C. Pradhan, Anand V. Patwardhan, Reduction of Nitrotoluenes by H2S-rich Aqueous Ethanolamine Solution: A Viable Alternative to Claus Process. 19th Canadian Symposium on Catalysis, May 14-17, 2006, Saskatoon, SK, Canada. PDF
Sunil K. Maity, Narayan C. Pradhan, Anand V. Patwardhan, Kinetics of Reduction of Nitrochlorobenzenes by Aqueous Ammonium Sulfide under Liquid–Liquid Phase Transfer Catalysis. CHEMCON, Ankleshwar, Gujarat, India, page-23, 2006. PDF
K. Ganapathi S. Naidu, Sunil K. Maity, Narayan C. Pradhan, Anand V. Patwardhan, Kinetics of Vapor-Phase Alkylation of Benzene with Isopropyl Alcohol over Commercial H-Mordenite Catalyst. CHEMCON, Ankleshwar, Gujarat, India, page-23, 2006. PDF
Sunil K. Maity, CH. Seetaram, Narayan C. Pradhan, Kinetics of Transalkylation of Diisopropylbenzenes with Benzene. CHEMCON, Ankleshwar, Gujarat, India, page-33, 2006. PDF
Sujit Sen, Sunil K. Maity, Narayan C. Pradhan and Anand V. Patwardhan, Utilization of Hydrogen Sulphide for the Synthesis of Dibenzyl Sulphide: Effects of Process Parameters on Conversion and Selectivity. National Conference on Frontiers in Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, India, 2007.
Vishnu P. Yadav, Rudra Palash Mukherjee, Kandi Bantraj, Sunil K. Maity,* Kinetic Modeling of Esterification of Ethylene Glycol with Acetic Acid. International Conference On Modeling, Optimization, And Computing (ICMOC 2010), West Bengal, (India), 28–30 October 2010.
Sudhakara Reddy Yenumala, Sunil K. Maity*, Thermodynamic Analysis of Steam Reforming of Vegetable Oil. International Conference on Recent trends in Renewable energy Resources, Indian Institute of Chemical Technology, Uppal Road, Hyderabad - 500 607, AP, INDIA, January 2011.
Vishnu P. Yadav, Sunil K. Maity, Debaprasad Shee, Etherification of Glycerol with Ethanol Using Cation Exchange Resin. CHEMCON, Dr. B.R. Ambedkar National Institute of Technology, Punjab, India, 27-30 December, 2012.
Vimala Dhanala, Sunil K. Maity, Debaprasad Shee, Vinod M. Janardhanan, Steam Reforming of Isobutanol for the Production of Synthesis Gas over Ni/Al2O3 Catalyst. CHEMCON, Dr. B.R. Ambedkar National Institute of Technology, Punjab, India, 27-30 December, 2012.
Pankaj Kumar, Sudhakara Reddy Yenumala, Sunil K. Maity, Debaprasad Shee Hydrodeoxygenation of Stearic Acid Using Supported Nickel Alumina Catalysts. CHEMCON, Dr. B.R. Ambedkar National Institute of Technology, Punjab, India, 27-30 December, 2012.
P.V. Chandra Sekhar, Debaprasad Shee, Sunil Kumar Maity, Hydrodeoxygenation of 1-Octanol. CHEMCON, Dr. B.R. Ambedkar National Institute of Technology, Punjab, India, 27-30 December, 2012.
Sudhakara Reddy Yenumala, Sunil K. Maity, Reforming of Vegetable Oil: A thermodynamic Equilibrium Analysis. International Conference on Advances in Chemical Engineering (ACE 2013), February 22-24, 2013, IIT Roorkee, India.
Vishnu P. Yadav, Sunil K. Maity, Debaprasad Shee, Utilization of glycerol: etherification with ethanol. International Conference on Advances in Chemical Engineering (ACE 2013), February 22-24, 2013, IIT Roorkee, India.
Vimala Dhanala, Sunil K. Maity*, Debaprasad Shee, Steam reforming of isobutanol for production of synthesis gas: Effects of metals. World Congress on Petrochemistry and Chemical Engineering, Hilton San Antonio Airport, United States 78216, November 18-20, 2013.
Vimala Dhanala, Sunil K. Maity*, Debaprasad Shee, Cobalt supported g-Al2O3 catalyst for steam reforming of isobutanol for production of synthesis gas. Seventh Tokyo Conference on Advanced Catalytic Science and Technology (TOCAT7) at Kyoto, Japan, June 1-6, 2014.
Venkata Chandra Sekhar Palla, Debaprasad Shee*, Sunil K. Maity, Hydrodeoxygenation of 1-Octanol over Supported Nickel Catalysts. Seventh Tokyo Conference on Advanced Catalytic Science and Technology (TOCAT7) at Kyoto, Japan, June 1-6, 2014.
SR Yenumala, SK Maity, D Shee, Hydrodeoxygenation of karanja oil for the production of green diesel. 64th Canadian Chemical Engineering Conference, Canada, October 19-22, 2014.
M Varkolu, SAK Jinnala, A Kunamalla, SK Maity, D Shee, Mesoporous Ni-CeO2-ZrO2-SiO2 composite catalyst for steam reforming of n-butanol. International Hydrogen & Fuel Cell Conference, Jodhpur, Rajasthan, India, December 9-11, 2018.
M Varkolu, SAK Jinnala, A Kunamalla, SK Maity, D Shee, Steam reforming of bio-butanol over mesoporous Ni-CeO2-ZrO2-SiO2 composite catalysts. International Conference on Catalysis Science, Engineering & Technology, Stockholm, Sweden, November 04-07, 2018.
P Kumar, SK Maity and D Shee, Hydrodeoxygenation of stearic acid over NiMo/γ-Al2O3 catalyst. 255th American Chemical Society Meeting, New Orleans LA, 18-22 March, 2018.
S Mailaram, SK Maity, Hydrodeoxygenation of karanja oil for the production of green diesel: process design with heat integration and economic analysis. AIChE Annual Meeting, Pittsburg, PA, October 28 - November 2, 2018.
SR Yenumala, SK Maity, D Shee, Production of green diesel from karanja oil using ordered mesoporous nickel-alumina composite catalyst. Applied Catalysis & Chemical Engineering, Dubai, UAE, April 08 - 10, 2019.
S Mailaram, N Dobhal and Sunil K. Maity*, Techno-economic Analysis for Production of Biodiesel and Green diesel from Microalgal oil. Conference: 7th International Conference on Advances in Energy Research (ICAER 2019), IIT Mumbai, India, 10 - 12 December 2019