Steam Gasification of Refuse-Derived Fuel with CaO Modification for Hydrogen-Rich Syngas Production

Steam gasification of refuse-derived fuel (RDF) for hydrogen-rich syngas production was investigated in a lab-scale gasification system with CaO modification. A simulation model based on Aspen Plus was built to study the characteristics and the performance of the RDF gasification system. The influences of gasification temperature, steam to RDF ratio (S/R), and CaO adsorption temperature on the gas composition, heating value, and gas yield were evaluated. Under the gasification temperature of 960 degrees C and S/R of 1, H-2 frication in the syngas increased from 47 to 67% after CaO modification at 650 degrees C. Higher syngas and H-2 yield were obtained by increasing both S/R and gasification temperature. However, as the CaO adsorption temperature increased, a lower H-2 fraction was obtained due to the limitation of the CaO adsorption capacity at high temperatures. The highest H-2 fraction (69%), gas yield (1.372 m(3)/kg-RDF), and H-2 yield (0.935 m(3)/kg-RDF) were achieved at gasification temperature of 960 degrees C, S/R of 2, and CaO modification temperature of 650 degrees C. The variation trends of simulation results can match well with the experiment. The deviation was mainly because of the limitation of contact time between the gasification agent and RDF, uneven temperature distribution of the reactors, and the formation of tar during the experiment.