Hydrogen Production by Catalytic Gasification of Coal in Supercritical Water

Abstract

A high-throughput batch reactor system was designed for hydrogen production by catalytic gasification of bituminous coal in supercritical water. The experimental system was made up of six subsystems with the same parameters, which was designed with a maximum temperature and pressure of 750 °C and 30 MPa, respectively. The system ensures that a maximum of six series experiments are conducted at the same time, which promotes the efficiency of the experimental work. In this study, the experiments were conducted under different operational conditions: temperature of 600–750 °C, pressure of 23–25 MPa, feed concentration of 5–20 wt %, reaction time of 4–15 min, and K2CO3 addition rate of 0–200 wt %. The effects of operational conditions were examined. The results obtained show that the carbon gasification efficiency (CE) and gasification efficiency (GE) increased with decreasing feed concentration and increasing temperature, reaction time, and K2CO3 addition rate. The addition of K2CO3 promoted the gasification reactivity significantly. CE and GE in the catalytic case were about 1.7 and 2 times that in the non-catalytic case, respectively. Kinetic information on catalytic gasification of coal in supercritical water was experimentally investigated. The activation energy and pre-exponential factor obtained were 59.47 ± 4.87 kJ/mol and 43.89 ± 1.82 min–1, respectively.