(445c) Process Synthesis of Hybrid Coal, Biomass, and Natural Gas to Liquids (CBGTL) Via Fischer-Tropsch Synthesis, ZSM-5 Catalytic Conversion, Methanol Synthesis, Methanol-to-Gasoline, and Methanol-to-Olefins/Distillate Technologies

Thermochemical conversion of biomass or coal to liquid hydrocarbons can proceed via syngas intermediate, followed by either the Fischer-Tropsch (FT) process or via methanol intermediate. Thermochemical conversion of natural gas generally occurs through indirect liquefaction using an autothermal reactor. A recent review of hybrid and single feedstock energy processes can be found in [1]. A coal, biomass, and natural gas to liquids (CBGTL) thermochemical superstructure was recently developed [2-9] that incorporates various technologies, unit operating conditions, and stream interconnections. A process synthesis mathematical model was proposed to determine the process topology that can produce fuels at the lowest levelized cost [4, 6-8]. The hydrocarbon conversion route was primarily based on a combination of Fischer-Tropsch processes operating at multiple temperature levels, using either iron or cobalt catalysts.

This superstructure is expanded to include conversion from syngas to fuels via methanol intermediate, followed by the methanol-to-gasoline and methanol-to-olefins/distillate technologies to produce gasoline, diesel, and kerosene. The hydrocarbons can be upgraded to fuel quality in a standard upgrading section akin to the operation of petroleum refineries, or through catalytic conversion over ZSM-5 catalysts. Formulated as a mixed-integer nonlinear optimization problem (MINLP), the process synthesis problem is solved with simultaneous heat, power, and water integration.

Case studies are presented to investigate the trade-offs between the Fischer-Tropsch and methanol routes, along with detailed parametric analysis on the effect of plant capacities on the technology selection and optimal topologies. These examples elucidate the process topological differences and their effect of the overall system cost, the process material/energy balances, and the well-to-wheel greenhouse gas emissions.

[1] C.A. Floudas, J. A. Elia, R. C. Baliban (2012) Hybrid and Single Feedstock Energy Processes for Liquid Transportation Fuels: A Critical Review. Comp. Chem. Eng. 41:24-51.

[2] R. C. Baliban, J. A. Elia, C. A. Floudas (2010) Toward novel biomass, coal, and natural gas processes for satisfying current transportation fuel demands, 1: Process alternatives, gasification modeling, process simulation, and economic analysis. Ind. Eng. Chem. Res. 49:7343-7370.

[3] J. A. Elia, R. C. Baliban, C. A. Floudas (2010) Toward novel biomass, coal, and natural gas processes for satisfying current transportation fuel demands, 2: Simultaneous heat and power integration. Ind. Eng. Chem. Res. 49:7371-7388.

[4] R. C. Baliban, J. A. Elia, C. A. Floudas (2011) Optimization framework for the simultaneous process synthesis, heat and power integration of a thermochemical hybrid biomass, coal, and natural gas facility. Comp. Chem. Eng. 35:1647-1690.

[5] J. A. Elia, R. C. Baliban, X. Xiao, C. A. Floudas (2011) Optimal energy supply network determination and life cycle analysis for hybrid coal, biomass, and natural gas to liquid (CBGTL) plants using carbon-based hydrogen production. Comp. Chem. Eng. 35:1399-1430.

[6] R. C. Baliban, J. A. Elia, V. Weekman, C. A. Floudas (2012) Process synthesis of hybrid coal, biomass, and natural gas to liquids via Fischer-Tropsch synthesis, ZSM-5 catalytic conversion, methanol synthesis, methanol-to-gasoline, and methanol-to-olefins/distillate technologies. Submitted for publication.

[7] R. C. Baliban, J. A. Elia, C. A. Floudas (2012) Simultaneous process synthesis, heat, power, and water integration of thermochemical hybrid biomass, coal, and natural gas facilities. Comp. Chem. Eng. 37:297-327.

[8] R. C. Baliban, J. A. Elia, R. Misener, C. A. Floudas (2012) Global Optimization of a MINLP Process Synthesis Model for Thermochemical Based Conversion of Hybrid Coal, Biomass, and Natural Gas to Liquid Fuels. Comp. Chem. Eng. In press. DOI:10.1016/j.compchemeng.2012.03.008

[9] J. A. Elia, R. C. Baliban, C. A. Floudas (2012) Nationwide Supply Chain Analysis for Hybrid Feedstock Energy Processes with Significant CO₂ Emissions Reduction. AIChE Journal. Submitted for publication.