摘要
以农业废弃物水稻秸秆为原料,采用限氧裂解法不同温度(300℃、400℃、500℃、600℃、700℃)下制备生物炭,利用SEM电镜扫描、比表面测定、傅里叶红外光谱、元素分析等现代分析手段对生物炭的结构、形貌、比表面积、孔径、表面官能团和元素含量等理化特性指标进行分析表征.结果表明:随着热解温度的升高,产率和挥发分比例下降,灰分含量升高,p H值增大,含碳量上升,N、H、O含量下降,H/C、O/C、(O+N)/C下降,这表明生物炭芳香性增强,亲水性和极性减弱.生物炭具有丰富的孔隙结构,随着温度升高,孔隙数量增加,孔结构发育更加完全.稻秆生物炭孔结构主要为中孔,且随着热解温度的升高,平均孔径变小,比表面积有所增大,在600℃达到最大.红外光谱结果显示,随着裂解温度升高,水稻秸秆中烷烃基缺失,甲基(—CH3)和亚甲基(—CH2)逐渐消失,而芳香族化合物增加,芳香化程度增强.
In this paper, we prepared a series of bio-chars by using rice straw under the limited oxygen cracking condition and the different pyrolysis temperatures including 300℃ , 400 ℃, 500 ℃ , 600 ℃ and 700 ℃. SEM, BET specific surface, Fourier Transform Infrared Spectroscopy, element analysis and other analytical methods were utilized to analyze the structure, morphology, specific surface area, pore size, surface functional groups, the contents of elements and other physical or chemical characteristics of biochars. The results show that with an increase of pyrolysis temperature, both the yields and the volatile matter ratios decrease, while the ash contents, pH and carbon content increase. Through the element analysis, the carbon contents show a significant increase with increasing pyrolysis temperature, while the contents of the other elements including nitrogen, hydrogen and oxygen decrease, and the values of H/C, O/C and （O＋N）/C are also reduced, indicating that the aromatic properties of the bio-char increases, while the hydrophilicity and the polarity are both weakened. The results of SEM show that the biocham have rich pore structure, with more complete pore structure with increasing the pyrolysis temperature. The specific surface area results reveal that the hole structure of the bio-char from rice straw is mainly mesoporous, and the average pore size decreases but the BET specific surface area increases with an increase of pyrolysis temperature, in addition, the maximum BET specific surface area of the bio-ehar is shaped under 600 ℃. The FTIR results exhibit that the functional groups on the surface of the carbonized rice straw can be changed, so that the paraffin base is missed, both methyl（--CH3 ）and methylene（--CH2 ）gradually disappear, the aromatic compounds increase and the aromatic degree is enhanced as pyrolysis temperature increases.
出处
《环境科学学报》
CAS
CSCD
北大核心
2016年第5期1757-1765,共9页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.41161035
41461042)
江西省重大生态安全问题监控协同创新中心资助项目(No.JXS-EW-03)
江西省教育厅科技计划项目(No.GJJ14242)~~
关键词
稻秆
生物炭
裂解温度
特性
rice straw
bio-chars
pyrolysis temperature
characteristics
