Study on the pyrolysis characteristics of rape straw based on TG analysis

The paper is aimed at presenting the pyrolysis and pyrolysis products' producing characteristics of rape straw by using the method of TG and TG-FTIR with specified heating rates and particle sizes. The results show that the higher the heating rate was,the higher the starting pyrolysis temperature and the weight loss temperatures were,and the smaller the particle size was,the more beneficial to pyrolysis process it was. At the heating rate of 20 ℃ / min,with the hating temperature rising to 245. 15 ℃,the material began to appear sharp reaction,and later on reached the maximum pyrolysis rate at 342. 13 ℃,the maximum pyrolysis rate was 1. 09% / ℃. However,when the particle size reduced to 100 mesh,the maximum pyrolysis temperature reduced to 337. 98 ℃,meanwhile the maximum pyrolysis rate kept on 1. 087% / ℃. So for the sake of promoting the pyrolysis of rape straw,the small size state is strongly recommended.And via observation of electron microscopy before and after the pyrolysis,there would be found obvious change on the inner and outer layer of rape straw,a large number of wrinkles and crystal particulate matters would appear on the surface of the materials after the pyrolyzing. Although the pyrolysis of rape straw has different stages,the time when gaseous products of epidermis and inner core came out was consistent. The only obvious difference was that the absorption curve of epidermis had only one absorption peak while the absorption curve of inner core had two. At heating rate of 20 ℃ / min,the main gaseous products of epidermis and inner core during pyrolysis detected by the FTIR was H2O,CH4,CO2,CO and some carbonyl compounds,aromatic compounds, amine compounds in gasification state. Among these substances,CH4and CO are the main combustible gas generated by the straw gasification device,and aromatic compounds and amine compounds are widely used in chemical engineering and medicine.