Chirag Mevawala

Process Modeling and Techno-Economic Analysis of Thermo-Catalytic Dimethyl Ether  Synthesis and Microwave-Based Aromatics Production Technology from Shale Gas

Production of dimethyl ether (DME) and direct non-oxidative methane dehydro-aromatization  (DHA) to aromatics via conventional and microwave (MW)-assisted processes are investigated in this research. Plant-wide models of the shale gas to DME process with integrated CO2 capture via direct and indirect synthesis routes have been developed. Optimal parameter estimation, and  model validation are undertaken for various sections of the process including the pre-reforming  reactor, autothermal reforming reactor, DME synthesis reactors, CO2 capture units and  separation sections. A novel DME separation process has been developed for efficient separation  of DME, syngas, and CO2. Plant-wide techno-economic optimization is performed in an equation oriented environment for maximizing the net present value (NPV). Effects of key design parameters and investment parameters on the process economics have been evaluated. For the conventional as well as MW-assisted direct non-oxidative methane  dehydroaromatization (DHA) process, dynamic data reconciliation, parameter estimation, and  multi-scale, multi-physics dynamic fixed-bed reactor model development are undertaken. Due to  rapid coke formation, catalysts in the non-oxidative methane DHA reactors get deactivated. A model for the catalyst deactivation is proposed along with rate models for other DHA reactions.  An algorithm is developed by coupling an iterative direct substitution approach with an  optimization algorithm for optimal estimation of the initial state of the reactor and the kinetic  parameters using the in-house experimental data. For the MW-assisted reactor, the amount of  heat generated at specific catalyst sites has been modeled using Maxwell’s equation. For  integrating the Maxwell’s equation within the process model, a reduced order model is  developed. A 2-D multi-scale heterogenous industrial scale MW rector model is developed by  coupling the catalyst pellet level model with the reactor level model. In addition, plant wide models are developed, and techno-economic analysis of the conventional and MW-assisted  processes are performed.

• Mevawala C, Bai X, Hu J, Bhattacharyya D, “Plant-Wide Modeling and Techno-Economic Analysis of a Direct Non-Oxidative Methane Dehydroaromatization Process via Conventional and Microwave-Assisted Catalysis”, 336, 120795, Applied Energy, 2023

• Mevawala C, Bai X, Bhattacharyya D, Hu J, “Dynamic Data Reconciliation, Parameter Estimation, and Multi-Scale, Multi-Physics Modeling of the Microwave-Assisted Methane Dehydroaromatization Process”, 239, 116624, Chemical Engineering Science, 2021 

• Deng Y, Bai X, Abdelsayed V, Shekhawat D, Muley P D, Karpe S, Mevawala C,  Bhattacharyya D, Robinson B, Caiola A, Powell J B, van Bavel A P, Hu J, Veser G, “Microwave-Assisted Conversion of Methane over H-(Fe)-ZSM-5: Evidence for Formation of Hot Metal Sites”,  420, 129670, Chemical Engineering Journal, 2021 

• Mevawala C, Bai X, Kotamreddy G, Bhattacharyya D, Hu J, “Multi-Scale Modeling of a Direct Non-Oxidative Methane Dehydroaromatization Reactor with a Validated Model for Catalyst Deactivation”,  Industrial & Engineering Chemistry Research, 60, 4903-4918, 2021 

• Mevawala C, Jiang Y, Bhattacharyya D, “Techno-Economic Optimization of Shale Gas to Dimethyl Ether Production Processes via Direct and Indirect Synthesis Routes”,  Applied Energy, 238, 119-134, 2019 

• Mevawala C, Jiang Y, Bhattacharyya D, “Plant-Wide Modeling and Analysis of the Shale Gas to Dimethyl Ether (DME) Process via Direct and Indirect Synthesis Routes”, Applied Energy, 204, 163-180, 2017 

• Mevawala C, Bhattacharyya D, “Techno-Economic Analysis of Microwave-assisted Conversion Processes: Application to a Direct Natural Gas to Aromatics Process”, Chapter 16 in “Direct Natural Gas Conversion to Value-Added Chemicals”, Ed.  J. Hu and D. Shekhawat, 2020, CRC Press, Boca Raton, FL, USA 

• Mevawala C, Bai X, Hu J, Abdelsayed V, Shekhawat D, Bhattacharyya D,  “Direct Non-Oxidative Conversion of Shale Gas to Aromatics: Dynamic Data Reconciliation, Parameter Estimation, and Dynamic Modeling of a Fixed-Bed Reactor”, Virtual AIChE Annual Meeting, November 16-20, 2020 

• Mevawala C, Bai X, Hu J, Abdelsayed V, Shekhawat D, Bhattacharyya D,  “Dynamic Data Reconciliation, Parameter Estimation, and Plant-Wide Modeling of a Microwave (MW)-Assisted Direct Non-Oxidative Methane Dehydroaromatization (DHA) Processes”, Virtual AIChE Annual Meeting, November 16-20, 2020 

• Mevawala C, Hu J, Bhattacharyya D, “Techno-Economic Analysis of Direct Non-Oxidative Conversion of Shale Gas via Non-Thermal Microwave (MW) Plasma Catalysis”, Paper 570e, AIChE Annual Meeting, Pittsburgh, PA, October 28-November 2, 2018 

• Mevawala C, Jiang Y, Bhattacharyya D, “Plant-Wide Modeling, Techno-Economic Analysis and Optimization of the Shale Gas-to-Dimethyl Ether (DME) Process via Direct and Indirect Synthesis Routes”, Paper 578d, AIChE Annual Meeting, Minneapolis, MN, October 29-November 3, 2017 

• Mevawala C, Jiang Y, Bhattacharyya D, “Techno-Economic Analysis of Shale Gas-to-Dimethyl Ether (DME) Process via Direct Synthesis”, Paper 386c, AIChE Annual Meeting, San Francisco, CA, November 13-18, 2016