Integration of coal and biomass gasification process with fuel cell system for small scale industrial CHP applications

摘要

Clean syngas from coal or biomass gasification could be used for a series of applications such as power generationand production of hydrogen, substitute natural gas, liquid fuels and chemicals.Currently, Sotacarbo is engaged in a series of experimental tests in its pilot platform, which includes a fixed-bedair-blown gasifier equipped with complete syngas treatment line for hydrogen production and power generation basedon an internal combustion engine. But it is under evaluation the possibility to equip the plant with a high efficiency fuelcell system directly fed by clean syngas.This study analyses the possibility to apply the Sotacarbo coal and biomass gasification technology for highefficient power generation in a small-scale combined heat and power (CHP) industrial system by a potential integrationof the gasification process itself with a molten carbonate fuel cell (MCFC) system.The mass and thermal balances of the gasification and syngas treatment processes (the pilot plant is equipped witha catalytic COS hydrogenation system followed by a zinc oxides-based hot gas desulphurization process; this systemallows a final H_2S concentration lower than 1 ppm by volume, compatible with the fuel cell specifications) have beenevaluated on the basis of the experimental data collected during the gasification and hot gas desulphurization tests. Inparticular, according to the results obtained from about 1350 hours of experimental tests in the Sotacarbo plant, coalgasification process is characterized by a relatively high cold gas efficiency, whereas raw syngas composition andproperties strongly depend on the feedstock and the specific operating conditions. On the other hand, the performanceof the MCFC fuel cell stack has been assessed by developing a mathematical model based on thermodynamicelectrochemicalanalysis.