Abstract: The paper studied the effects of carbonization temperature on biochar yield and the physicochemical properties from wheat-straw improved the application of wheat-straw biochar,in order to further expound the mechanism of action of wheat straw biochar.The effects of different carbonization temperatures(100,200,300,400,500,600,700,800℃)on wheat-straw biochar yield and the physicochemical properties (porosity condition,the content of total carbon and inorganic carbon,CEC content,oxygen-containing functional group,pH and FTIR) were studied through mionectic carbonization with the heating rate of 20℃/min. Fourier transform infrared spectrometer was used to obtain infrared spectra and the reasons for the changes of biochar physicochemical properties were analyzed.The wheat-straw of low temperature carbonization was acidic,after 400℃,was alkaline. The degree of wheat straw biochar carbonized increased with the increased of carbonization temperature, and the yield decreased from 91.32% to 18.52% in 100-400℃. In the carbonization process,the wheat-straw biochar porosity increased,the structure was loose. Pore size,specific surface area and specific pore volume showed first increased and then decreased trend,and all reached the maximum at 400℃,were 6.675 m²/g,13.992 nm,0.015 cm³/g respectively.In 200-400℃,the content of organic carbon was high. The content of CEC was maintained at a high level in 400-800℃,between 69.13-84.35 cmol/kg.The analysis of infrared spectrum and surface oxygen functional groups showed that,with the increase of pyrolysis temperature,the degree of aromatization of wheat-straw biochar increased,and the structure became more stable. The carbonization temperature of wheat-straw is more ideal at about 400℃.

Key words: Wheat-straw, Pyrolysis temperature, Biochar, Biochar yield, Physicochemical properties

CLC Number: 

• S210

• X610