Experimental Study On The Effect Of Disposable Catalysts For The Reactivity Of Coal Gasification

Coal gasification is the core technology of coal chemical industry.In recent years,the research of coal and biomass co-gasification and coal gasification disposable catalyst has been widely concerned.Spirit-based distillers'grains are rich in alkali metals and alkaline earth metals,which can be used as a disposable catalyst for coal gasification.Based on this,this study selected Guizhou spirit-based distillers'grains and anthracite coal as raw materials,using fixed-bed reactor to explore their co-gasification reaction characteristics from the point of view of carbon conversion and gas production.XRF,SEM-EDS,BET,XRD,and Raman characterization methods were used to explore the synergistic mechanism of the catalytic effect of distiller's grains on co-gasification reaction,which provided a theoretical basis for the efficient utilization of anthracite coal and spirit-based distillers'grains.The main contents and conclusions of this study are as follows:?1?The gas release rate and gas composition of anthracite and liquor distiller's grains mixed with steam at different mass ratios were studied.Different gasification temperatures and the effect of different ratios on the gasification reaction activity.The results show that with the increase of distillers'grains blending ratio,the instantaneous release rate of gas increases gradually,the H₂ component in syngas increases gradually,but the content of CO decreases gradually.With the increase of gasification temperature,the activity of gasification reaction increases gradually.When the distillers'grains are completely gasified into ash at the later stage of the reaction,the actual carbon conversion is higher than the theoretical carbon conversion,indicating that there is a synergistic effect.In addition,there is a nonlinear change between the blending ratio of raw materials and the composition of gas products,which also confirms the existence of synergistic effect.?2?Distillers'grains produce distillers'grains ash after gasification,and the co-catalytic effect of AAEMs in the ash is the reason for the synergistic effect.For this reason,the distillers'grains were ashing to eliminate the effects of volatile matter in distillers'grains and their physical and chemical structure on gasification,and the effects of different addition ratios were studied.Effect of distillers'grains ash on gas production characteristics and reaction activity in catalytic gasification process.The results showed that the gas release rate and carbon conversion rate increased with the increase of distillers'grains ash content,and the gasification activity increased with the increase of temperature.The synergistic effect is related to the content of distillers'grains and gasification temperature.the higher the content of distillers'grains,the stronger the synergistic effect;the higher the gasification temperature,the weaker the synergistic effect.?3?The catalytic mechanism of distillers'grains ash on coal gasification reaction and its effect on the evolution of physicochemical structure of coal char during gasification reaction were analyzed by SEM-EDS,XRF and Raman characterization.the results show that K and Ca elements in ash play a major catalytic role.The active sites of gasification reaction were added,the disorder of microcrystalline structure of coal char was enhanced,and the development of pore structure was promoted.The active intermediates C-[M]and C-[M_?O?]play the role of reduction and oxidation in gasification,and the formation of intermediate heterozygote C?O?also affects the gasification.In the gasification process,with the increase of carbon conversion,the graphitization degree of coal char deepens,and the carbon structure tends to order gradually.The surface of coal char has also undergone changes of density,porosity,agglomeration and destruction.The gasification reaction rate increased rapidly from the early stage to the middle and late stage,which also explained the catalytic effect of the main elements K and Ca in distillers'grains ash.