Co-Production of Electricity and Hydrogen from Coal and Biomass Gasification

This work addresses the techno-economic and environmental analysis of an Integrated Gasification Combined Cycle power plant (IGCC) of 308 MW, of gross power, giving particular attention to co-gasification and co-production of electricity and H-2. Products, sub-products and effluents distributions are estimated by means of an ad-hoc developed superstructure for conceptual design of syngas generation and treatment, delivering preliminary flowsheets targeted to co-production. The resulting multi-objective optimization problem evaluates the trade-off between the cost of energy (COE), the total energy efficiency of the plant and the environmental impact evaluated through Impact 2002+ indicator. Sixteen scenarios are considered: 4 different feedstock's combined with 4 alternative plant topologies; electricity generation from syngas, electricity generation from H-2, and purified H-2 production from flue gas in a Pressure Swing Adsorption (PSA) unit in the Combined Cycle (CC). The case studies environmental boundary has been drawn from cradle to gate. The Pareto Frontiers (PF) for the Key Performance Indicators (KPIs) trade-off evaluation reveals that the scenario with petcoke as feedstock and H-2 production with PSA flue gas profit is the best one in terms of efficiency maximization and COE minimization. Scenario with residual biomass without PSA flue gas profit is the best in terms of environmental impact.