Phát Minh của Người Việt - Lê Văn Mão

Từ trái qua phải: GS Lê Văn Thới, GS Lê Văn Mão, Bà Chung Mai Liên.

Hình chụp năm 1969

Hai Ông Bà Lê văn Mão

(trước Chùa Ấn Độ ở Toronto)

Profile of the AC3B technology

Direct catalytic liquefaction of lignocellulosic biomass into fuels & chemicals.

The new Biomass-to-Hydrocarbons (BtH) process

Inventor: Professor Raymond LE VAN MAO,

Professor Emeritus, Concordia University, Department of Chemistry and Biochemistry, Laboratory of Industrial

Catalysis, Montreal (Quebec) H4B 1R6 Canada

Biomass raw materials that can be used for the process: wood/forest/agricultural residues, perennial grasses (switch grass, arundodonax), municipal wastes, by-products and wastes of the pulp and paper industry, peat, algae, etc.

I- Technology based primarily on direct catalytic liquefaction of lignocellulosic biomass materials:

Summary:

This technology (called the AC3B technology) consists of a sequence of two steps: a direct catalytic liquefaction of biomass followed by a catalytic up-grading of some of the products previously obtained.

The first catalytic step produces ethyl esters of three carboxylic acids and a limited number of other oxygenates. By using a special homogeneous catalytic system, the total product yield increases from 30 wt% (normal acidic hydrolysis/ethanolysis) to more than 70 wt% [1-3].

The second catalytic step converts, over ZSM-5 zeolite based catalysts, an ether by-product and some selected esters/oxygenates previously obtained into hydrocarbons with yields close to 100%...

The final products are: gasoline, light olefins & paraffins, diesel additive and other chemicals of high commercial values. By just varying the composition of the feed of the second step, several product spectra are obtained, thus providing to the AC3B technology a high production flexibility.

Particularly interesting (for the petroleum industry) is the version Biomass-to-Hydrocarbons (BtH) that aims at producing BTX aromatics-rich gasoline, light olefins (ethylene, propylene and butenes) and some LPG-grade paraffins.

Some technological aspects:

1. Direct catalytic conversion of biomass (Scheme 1: Reactor I or R I):

The biomass material is first submitted to a controlled oxidative cracking in ethanol/water medium. A (dilute) mineral acid, a Fenton’s reagent (hydrogen peroxide and transition metal-ions), a polymerization inhibitor are the active species for this general conversion step.

2. The products of the previous conversion are separated by distillation (Scheme 1: DIST).

3. Catalytic up-grading of DEE (Scheme 1, Reactor II or R II):

Diethyl ether (DEE), a by-product of the main conversion step, is converted into commercially valuable hydrocarbons over a zeolite-based catalyst. It is found that, over ZSM-5 zeolite catalysts, DEE not only is readily converted into hydrocarbons but also, when co-fed with other oxygenates, promotes deoxygenation of these compounds into hydrocarbons without the need of a hydrogen-donating solvent or hydrogen provided by an external supply.

4. Optionally: Ethanol regeneration by catalytic hydration (Scheme 1’, Reactor III or R III, Shell technology):

C₂-C₄ hydrocarbons, coming from reactor R II and containing ethylene, propylene and some butenes, are hydrated into ethanol and C₃/C₄ alcohols. These alcohols are then sent to DIST (distillation): such (regenerated) ethanol when recycled to reactor R I, contributes to a very significant reduction of the amount of ethanol consumed by the entire process.

Production flexibility of the technology:

Many options are available depending on the products of the general conversion step (R I) that are co-fed with DEE and subsequently sent to reactor R II. Each option leads to a different spectrum of the final products.

a) Version 1 ( Scheme 1):

Only DEE [or DEE + very minor products of R I (methanol + 2-furfural)] is sent to R II.

The final products are: ethyl levulinate + ethyl formate + ethyl acetate + diethyl succinate + hydrocarbons (without option R III = BTX aromatics-rich gasoline + C₂-C₄ olefins and paraffins).

b) Version 2:

DEE, when co-fed with all the oxygenates (products of R I) except for the ethyl levulinate, is sent into R II.

The final products are: ethyl levulinate + hydrocarbons (without option R III = BTX aromatics-rich gasoline + C₂-C₄ olefins and paraffins).

c) Version 3 (see following section 0: the Biomass-to-Hydrocarbons process (BtH)):

DEE, when co-fed with all product oxygenates of R I, is sent into R II.

Current performance of the process in the extraction of biomass:

As current performance (using pine or spruce wood sawdust / waste chips), more than 70% of the lignocellulosic biomass are liquefied, including a significant portion of the biomass lignin component.

No environmentally harmful solvent/reactant is used in this process where (homogeneous and heterogeneous) catalysis plays the main role. All unreacted solvents and the mineral acid used can be recovered and then recycled.

Preliminary feasibility study (done by Seneca Experts-Conseils Inc. - Engineering consultants) shows positive results in technology and environmental aspects, also suggesting good economical profitability [6].

Final products of the process and their potential commercial uses:

1) Ethyl levulinate:

a) Additive for diesel/biodiesel or jet fuel (blending agent to improve the quality of diesel: high energy content, improves cold flow properties, increases lubricity and reduces the emission of soot).

b) Octane booster for gasoline.

c) Heating oil (high energy content, eliminates soot, reduces greenhouse gas emission, improves cold flow properties).

d) raditional uses such as plasticizer for high polymers, flavouring and intermediates for perfumes and flavors).

2) Ethyl formate: solvent, flavour and fragrance agents, “safe” grain and fruit fumigant.

3) Ethyl acetate: universal organic solvent with low flammability.

4) Hydrocarbons: gasoline (aromatics-rich = premium), light olefins and LPG-grade paraffins.

5) Minor products: 2-furfural, methanol, C₃/C₄ alcohols, diethyl succinate and levulinic acid can be optionally converted into hydrocarbons when co-fed with DEE in the catalytic up-grading step.

Left over solid with high calorific properties (Lignin char or Cat-lignin): production of electricity, can be used as soil conditioner or as precursor of phenolic resins.

Current performance of the various versions of the AC3B technology (preliminary data as of November 15, 2013):

Consumption: 100 g of dried spruce wood waste and 68 g of ethanol.

Production:

1) Version 1 (117 g of final products):

42 g of ethyl formate + 25 g of ethyl acetate + 20 g ethyl levulinate + 32 g of hydrocarbons (same % as in the BtH process).

2) Version 2 (95 g of final products):

20 g of ethyl levulinate + 75 g of hydrocarbons (same % as in the BtH process).

3) BtH, Version 3 (90 g of hydrocarbons):

45 g of BTX aromatics-rich gasoline (25 wt% in aromatics) + 30 g light olefins (ethylene, propylene, butenes, same weight %) + 15 g LPG.

References:

• 1. R. Le Van Mao, A. Muntasar, D. Petraccone, H.T. Yan, “ AC3B Technology for Direct Liquefaction of Lignocellulosic Biomass: New Concepts of Coupling and Decoupling of Catalytic/Chemical reactions for obtaining a Very High Overall Performance”, Catalysis Letters (2012) 142: 667.

  2. R. Le Van Mao, Q. Zhao, G. Dima, D. Petraccone, “New Process for the Acid-Catalyzed Conversion of Cellulosic Biomass (AC3B) into Alkyl Levulinates and other Esters Using a Unique One-Pot System of Reaction and product Extraction” , Catalysis Letters (2011) 141: 271.

  3. R. Le Van Mao, “Catalytic conversion of ligno-cellulosic biomasss into fuels and chemicals”, U.S. Provisional Patent Application # 61/604,726, (February 29, 2012), and: R. Le Van Mao, WIPO/PCT WO 2013/127006 A1 (6 September 2013).

  4. D.J. Hayes, S. Fitzpatrick, M.H.B. Hayes, J.R.H. Ross “The Biofine Process”, in Biorefineries – Industrial Processes and Products, Vol 1 (2006), Wiley-VCH, Germany, 139.

  5. P. Leprince, A. Chauvel, J-P. Catry, in Procédés de Pétrochimie, Ed. Technip Paris (1971) :Technology Shell for catalytic hydration of ethylene (p. 306).

  6. Seneca Experts-Conseils Inc., feasibility study, Technology of Biomass liquefaction by Prof. R. Le Van Mao, May 3^rd, 2013. Preliminary result: great potential for commercial profitability.

  7. R. Le Van Mao, Concordia University, unpublished results – bench scale investigations (June 2013); R. Le Van Mao, A. Muntasar, H.T. Yan, Petrochemistry 2013, San Antonio, TX (U.S.A.), Nov. 2013.

II- The Biomass-to-Hydrocarbons (BtH) process

The BtH process aims at producing, from all kinds of lignocellulosic biomass: gasoline and all the basic petrochemicals that are currently derived from conventional or unconventional petroleum sources (oil and gas) i.e. BTX (benzene, toluene, xylene) aromatics, light olefins (ethylene, propylene, butenes) and LPG-grade paraffins (ethane, propane, butane).

As shown in scheme BtH, there are two catalytic steps:

Reactor R I (Homogeneous catalysis) = Catalytic liquefaction of biomass, using an oxidative cracking method.

Reactor R II (Heterogeneous catalysis) = all the products of the previous biomass liquefaction are sent over the ZSM-5 zeolite catalyst onto which these oxygenates undergo deoxygenation into hydrocarbons.

The final products are: BTX aromatics-rich gasoline + C₂-C₄ olefins (ethylene, propylene, butenes, equal %) and LPG-grade paraffins.

This is a technologically quite simple, environmentally friendly and carbon-neutral process.

Note: To reduce the consumption of ethanol per weight of hydrocarbons produced, it is possible to add (to the feed entering reactor RII) R-OH (methanol or another oxygenate).

Scheme of the BtH (Biomass-to-Hydrocarbons) process

Biography:

Prof. Raymond Le Van Mao received his PhD in 1974 from the University of Lyon I (France). After post-doctoral studies in Paris and Milan (Italy), he worked until 1981 at the Basic Petrochemicals Research Centre, Montedison Corp. (Italy). In 1982, he became Associate Professor of Chemistry at Concordia University (Montreal, Canada). He is now Professor Emeritus. He holds 40 patents and is author/coauthor of more than 200 papers and technical reports in Heterogeneous Catalysis, Zeolites, Petroleum Chemistry and biomass conversion.

Ghi chú của tác giả bài AC3B Technology (LVM):

Bài này đã được tôi trình bày tại "World Congress on Petrochemistry and Chemical Engineering, San Antonio, Texas (U.S.A.), November 18, 2013".

Kỹ thuật AC3B biến chế các sinh khối (biomass) như là lá cây, rơm rạ, mạt cưa và cỏ thành những nhiên liệu như là dầu Diesel, xăng và các chất mà ta dùng để sản xuất vật liệu dẻo như là Polyethylene (PE), Polypropylene (PP), Polyvinyl Chloride (PVC), v.v..., cũng như các sợi và cao-su nhân tạo. Một đồng nghiệp cho rằng kỹ thuật AC3B, hoàn toàn dựa trên hiện tượng xúc tác, đã có thể biến chế phần lớn nhiên liệu và hóa chất như những nhiên liệu cho bởi dầu hỏa chỉ trong vòng vài giờ, trong khi đó Thiên Nhiên phải bỏ hàng triệu năm để tạo ra dầu hỏa.

Tôi cũng xin kính tặng bài này cho cố Giáo Sư Lê Văn Thới, người Thầy khả kính của tôi năm xưa.

Lê Văn Mão

Canada, 17-01-2014