Analysis of the Influence of CO2 and H2O on Coal Rapid Gasification Reactivity

In order to discuss the production of syngas CO and hydrocarbons (HCs) and the effect of water on coal gasification reactivity, the　gasification and combustion characteristics of coal were tested in a CO2 enrichment environment (O2 concentration≤10%) using a self-made CO2 laser beam with a 200 °C/s rapid heating system by changing the heating rate, oxygen concentration and moisture content of coal samples. The experimental results show that with the increase of heating temperature in the process of coal gasification and combustion, the mass loss of coal sample and the output of syngas increases continuously, and the relationship between the mass loss of coal sample and the transformed gas environment is air atmosphere>CO2-rich atmosphere> N2-rich atmosphere. On the other hand, in a CO2-rich gas environment, with the increase of heating temperature, the production of CO gas and HCs gas at 5%O2 concentration is relatively large. In addition, it is found that the amount of CO gas generated is relatively reduced, while the amount of HCs generated is relatively increased. This result shows that during the gasification and combustion of coal in CO2 enriched gas environment, the generation of CO gas mainly depends on O2 concentration, while the generation of HCs mainly depends on H2O.