Research on Coal Pyrolysis Property for Polygeneration Technology

A circulating fluidized bed heat-power-gas-tar polygeneration technology has been developed which is based on the property of coal pyrolysis. To study the effect of temperature and coal type on pyrolysis behavior, the pyrolysis process of four different types of coal was investigated by TG-FTIR. The results showed that, at the heating rate of 25°C/min, pyrolysis process could be divided into four stages, namely drying stage, preheating stage, primary pyrolysis stage and secondary pyrolysis stage. Primary pyrolysis process was described as first-order reaction model and kinetic parameters were calculated by Coats-Redfern method at different temperature ranges. TG-FTIR coupled with kinetic analysis revealed the formation mechanism and variation of gas products, such as CO, CO₂, CH₄, during pyrolysis process. Pyrolysis laws provided a reference for achieving the target gas products by controlling temperature and selecting suitable coal type during polygeneration process.