Process Study on Hydrogen Production from Co-Gasification of Biomass Fuels

A 20 MW co-gasification plant integrated with a power plant may represent an attractive solution for a realistic starting scenario based on hydrogen economy. In this work, a process model is developed and a methodological procedure applied to the co-gasification of biomass/coal blends for optimizing the conditions to produce hydrogen. A detailed model of the gasifier is crucial for evaluating the effects of the operating parameters (share of biomass in the feed and flow rates of oxygen and steam) and optimizing the production of hydrogen as well as the efficiency of the entire process with the energetic demand of all units. Although the low values obtained, the efficiency can be improved by adding the terms due to the integration with the power plant. Heat recovery and steam production significantly increase the global efficiency. Further improvements would be obtained from an economic and environmental analysis, to take into account the use of CO2 neutral fuels and additional improvements associated to the integration with the power plant (fuel storage, emission treatment, utilities) and to advanced process configurations (e.g. comprising the CO2 capture and sequestration). At the basis of these analyses the optimization of the operating conditions is fundamental in any case.