Experimental Study On The Effects Of Biomass Characteristics Of Agricultural Residue Straw On Its Rapid Pyrolysis Process And Product Distribution

China is rich of agricultural wastes,but the utilization efficiency is low.Rapid pyrolysis technology can accomplish the conversion of waste biomass resources to liquid fuels,but its unstable chemical properties limit its application as high-quality fuel.In order to lower the technical difficulty of follow-up refining process and perform the large-scale utilization of agricultural wastes and the enrichment of pyrolysis products with high addendum value,it is necessary to understand the reaction mechanism.In view of this,the relationship between the characteristics of biomass raw materials,pyrolysis process,product distribution and multi-material mixed pyrolysis are studied systematically in this paper.Firstly,the effect of the difference of biomass material characteristics on pyrolysis kinetics was studied.The results show that the different content of the components led to a certain difference in weightlessness behavior in the pyrolysis of straw,and the straw with high content of cellulose shows high weightlessness rate and narrow reaction interval,and the higher ash content is beneficial to obtain more residue,and the higher hemicellulose content corresponds to the lower initial pyrolysis temperature.Secondly,the effects of biomass raw material characteristics on product distribution,typical pyrolysis product generation and yield were studied.The results showed that the distribution of hydrothermal pyrolysis products of straw biomass tended to be consistent,and there were differences in the yield of typical products.The precipitation of levoglucose and glycolaldehyde is related to the content of cellulose in materials.The higher the hemicellulose content,the easier it is to precipitate 2-sugar aldehyde and acetic acid at lower temperatures,and the higher the yield.The straw with high content of lignin precipitats phenols products in a larger temperature range and had the highest yield.Finally,the pyrolysis process of mixed biomass of agricultural straw was explored.The results show that the cross coupling between the components has an effect on the pyrolysis behavior.The inhibitory effect of ash on the maximum weightlessness rate of mixed pyrolysis was stronger than the interaction between cellulose and lignin.Straw with high hemicellulose content can pyrolyz at lower temperatures.Hemicellulose and lignin all inhibit the formation of levoglucose,and reducing the content of ash of straw can effectively improve the yield of levoglucose.Cellulose has a good selectivity to 2-furfural and acetic acid production,and its promoting effect becomes stronger with the increase of cellulose content.However,the increase of cellulose proportion has weakened the effect of precipitation of phenols products.