Char Co <sub> 2 </ Sub> Gasification Reactivity Tga

With the rapid development of Chinese economy, the demand for energy is increasing. Oil and natural gas resources are inadequate seriously, and the situation that coal is used as the main energy will last for a long time in our country. It's imminent to develop clear coal technology instead of outdated domestic technology.A coupling technology of coal catalytic pyrolysis and coal char gasification to produce synthesis gas is a new way to improve the situation. An important issue proposed in this way is how to improve coal char reactivity of gasification more economical and effectively, which is the purpose of this research. Tongchuan bituminous coal, Xinjiang long flame coal, Yunnan brown coal, demineralization coal and coal residues from ultrasonic extraction were investigated by TGA in the aim of finding out the effect of different factors on coal char gasification reactivity.The effect of different conditions on gasification reactivity of coal char was investigated in this paper. Under low gasification temperature, the experimental results showed that the reactivity of coal char made in low temperature was much higher than that of the coal char made in high temperature, while it was opposite at high gasification temperature. It was in favor of enhancing the reactivity of coal char at fast heating rate in pyrolysis. The temperature 900℃of pyrolysis is a boundary, the reactivity of the coal char from higher temperature was controlled by the temperature of pyrolysis and residence time, and that was controlled by residence time if the pyrolysis temperature of coal char was lower.In the research of the gasification reactivity about ultrasonic extraction residues, it was found that the extraction ratio was greatly improved after ultrasonic treatment. Generally, the gasification reactivity of ultrasonic extract residues char is much higher than that of raw coal char or non-ultrasonic extract residues char. With the treatment under high power ultrasonic, the reactivity of the residues char is enhanced remarkable, and the difference of the reactivity under different power decrease as the time. The reactivity under ultrasonic treatment is increased with time, but the effect of time is restricted in a certain extent. As ultrasonic treatment could greatly improve the extract ratio, the pore ratio and specific surface area were also enhanced at the same time, which would increase the gasification reactivity. Nevertheless, small molecules in coal were extracted, which could lower the reactivity of extract residues in some condition.The effect of coal ash on gasification reactivity of char is complex because the component of the ash is very complex. In general, the ash of Tongchuan bituminous coal could catalyze the gasification reaction in low temperature, while the reactivity of demineralization coal char is much higher than that of the raw coal char in high gasification temperature. Furthermore, the phenomena of "preposed gasification" is caused by coal ash and the active matter of coal char, and it is weaken and even disappear in defect of one of them. The gasification reactivity of ultrasonic extraction residues is very sensitive to demineralization, and it is decreased serious with demineralization.Kinetic parameters of some coal char were computed in this paper, and the parameters conformed to the experiment phenomena and conclusion.