Measurements of Gasification Characteristics of Coal and Char in CO_2-Rich Gas Flow by TG-DTA

摘要

Pyrolysis, combustion, and gasification properties of pulverized coal and char in CO_2-rich gas flow were investigated by using gravimetric-differential thermal analysis (TG-DTA) with changing O_2%, heating temperature gradient, and flow rate of CO_2-rich gases provided. Together with TG-DTA, flue gas generated from the heated coal, such as CO, CO_2, and hydrocarbons (HCs), was analyzed simultaneously on the heating process. The optimum O_2% in CO_2-rich gas for combustion and gasification of coal or char was discussed by analyzing flue gas with changing O_2 from 0 to 5%. The experimental results indicate that O_2% has an especially large effect on carbon oxidation at temperature less than 1100℃, and lower O_2 concentration promotes gasification reaction by producing CO gas over 1100℃ in temperature. The TG-DTA results with gas analyses have presented basic reference data that show the effects of O_2 concentration and heating rate on coal physical and chemical behaviors for the expected technologies on coal gasification in CO_2-rich gas and oxygen combustion and underground coal gasification.