A study of the in-situ CO2 removal pyrolysis of Chinese herb residue for syngas production.

The in-situ CO2 removal pyrolysis of Chinese herb residue was studied by thermodynamic equilibrium simulation and experimental methods. The effects of temperature, pressure, and CaO loading on the gas composition, heating value and yield were determined. The simulation results indicate that the heating value of product gas increases with the increase of Ca/H and pressure, and slightly decreases with the increase of temperature. The simulation results were verified by the experiments conducted with a micro fixed-bed reactor. Under the simulated reaction conditions including atmospheric pressure, reaction temperature of 700 °C and the Ca/H of 0.65, the CO2 in the product gas was effectively removed, resulting the syngas with a high heating value. The product gas was mainly composed of H2, CO, CO2 and CH4 with the contents of 47.52, 22.04, 9.01 and 14.02 respectively by experiment. And the lower heating value of the product gas reached 18.1 MJ/Nm3.