(211c) A Heuristic-Based Model for Gasification-Based Plants with Flexible Feedstock/Product in Carbon Constrained Scenarios

Gasification is one of the most versatile thermochemical conversion technologies for carbonaceous feedstocks. The inherent feedstock flexibility of gasification technology as well as the broad range of end use products makes it an attractive option in coal and biomass conversion. The commercially available technologies for pre-combustion CO₂ capture from syngas are extremely capital intensive. The economic impact of a carbon tax on a gasification based plant significantly depends on the quality of feed, technology, and application of interest.

In this study, the impact of the sulfur, ash, moisture content, and heating value are considered for a wide range of coals and biomass. Heuristics, continuous and discrete design variables and cost functions are used to build various modules for major process units including gasification island, acid gas removal, water gas shift reactor, and application specific processes. A heuristic-based algorithm is used to identify the near-optimum modules (nodes) of gasifier and downstream subsystems to determine the process route with the maximum net present value under various carbon tax schemes for a given set of inputs and constraints.

This model examines a myriad of alternative pathways to determine the most economical match of carbonaceous feedstock composition, gasifier choice, and syngas processing subsystems to a process application of interest including electricity, hydrogen, methanol and Fischer-Tropsch hydrocarbon production.