不同产地水稻秸秆制备生物炭结构特征及其理化性质

以江苏丹阳、黑龙江哈尔滨产地水稻秸秆为原料,采用限氧裂解法,在不同温度(300,500,700℃)下制备生物炭,利用SEM电镜扫描、元素分析、比表面积测定、傅里叶红外光谱(FTIR)、XRD衍射等分析手段对两产地生物炭结构特征进行全面表征和比较分析。结果表明:1)裂解温度升高,丹阳生物炭和哈尔滨生物炭各项理化性质表现出大体一致的变化趋势。2)裂解温度升高,两产地生物炭均呈现产率下降,pH增大,C含量升高,比表面积和总孔容增大,芳香化程度增加的趋势;丹阳生物炭中C含量低于哈尔滨生物炭;700℃丹阳生物炭孔隙结构发育程度最高。在300,500℃的制备温度下,丹阳生物炭的芳香族C-C、芳香族C—H含量明显高于哈尔滨生物炭,500,700℃的制备温度下丹阳生物炭的SiO_2、KCl含量高于哈尔滨生物炭。

STRUCTURAL AND PHYSICO-CHEMICAL PROPERTIES OF BIOCHARS PREPARED FROM DIFFERENT RICE STRAW

In this paper,we prepared a series of bio-chars by using rice straw from Harbin in Heilongjiang,and Danyang in Jiangsu.By limiting oxygen cracking condition and controlling pyrolysis temperatures (300,500,700 ℃),we got 6 different bio-chars.SEM,element analysis,BET special surface,Fourier Transform Infrared Spectroscopy,X-ray diffraction and other analytical methods were utilized to analyze the structure,elements contents,morpology,special surface area,pore size,surface functional groups,mineral content,etc.The results showed that:1) With an increase of pyrolysis temperature,yielding rates,pH values,carbon content,specific surface area,aromatic properties,mineral content and other physico-chemical properties showed a trend similar in Danyang bio-chars and Harbin bio-chars.2) Under the same pyrolysis temperature,the structural characteristics and physico-chemical properties of Danyang and Harbin were different.With an increase of pyrolysis temperature,the yield of Harbin bio-chars and Danyang bio-chars decreased,the pH,carbon content,specific surface area and total pore volume increased,aromatic properties also increased.The content of carbon in Danyang bio-chars was lower than that in Harbin,and the pore structure of Danyang bio-chars in 700 ℃ was the most developed.In the 300 ℃ and 500 ℃,Danyang bio-chars aromatic (C =C、C-H) framework were significantly higher than Harbin bio-chars.At 500 ℃ and 700 ℃,the SiO2 and KCl content in Danyang bio-chars was higher than Harbin bio-chars.