热解温度对生物质炭碳保留量及稳定性的影响  

Effects of pyrolysis temperature on carbon retention and stability of biochar

作　　者：李飞跃[1,2] 汪建飞[1] 谢越[1] 李贺[1] 李孝良[1] 李粉茹[1] 

机构地区：[1]安徽科技学院城建与环境学院,凤阳233100 [2]上海交通大学环境科学与工程学院,上海200240

出　　处：《农业工程学报》2015年第4期266-271,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(21107070);安徽省科技攻关项目(1301032151);安徽省自然科学基金项目(1508085QD74);安徽科技学院自然科学研究项目(ZRC2013373)

摘　　要：以核桃壳为生物质炭生产原料,研究热解温度（200-700℃）对生物质炭产率、元素组成、表面官能团分布及其稳定性的影响,以期探明生物质炭基本性质随热解温度变化的规律,为全面了解生物质炭固碳减排效果提供理论参考。结果表明,生物质炭的C含量随温度升高而增加,H和O元素含量却随温度升高而降低。此外,生物质炭的H/C和O/C随着温度增加而减少。生物质炭的产率及碳保留量随着温度的升高而降低。红外光谱分析结果表明,经过热解核桃壳原材料分子中所含的-C-O和O-CH3基团消失,随着热解温度升高,生物质炭中的烷烃基团-CH逐渐减少,芳香化程度逐渐升高。500℃制备生物质炭的K2Cr2O7和KMn O4氧化碳损失量均最低,分别为10.4%和1.66%。相关分析表明,生物质炭的产率、碳保留量及稳定性与热解温度之间均具有显著相关关系。Turning biomass wastes into biochar under the conditions of low temperature and limited oxygen has recently proven to be a promising approach for long-term carbon sequestration. However, the ultimate carbon sequestration efficiency of biochar depends not only on the feedstock type and production condition, but also on the environmental conditions of soil. In order to reveal the effects of pyrolysis temperature which is main parameter of biochar production condition on carbon retention and biochar stability, and provide more information for further improvement of carbon sequestration potential by turning biomass into biochar, the characteristics of biochar derived from walnut shell under lab condition were analyzed. During a typical slow pyrolysis process, the biochar was heated at a speed of approximately 20℃/min in a Muffle Furnace under limited oxygen and held at 200-700℃ for 2 h; then, biochar yield, elemental composition, functional groups distribution using Fourier transform infrared spectroscopy（FTIR） analysis and its chemical stability determined by potassium dichromate（K2Cr2O7） and potassium permanganate（KMn O4） oxidation methods, were all analyzed. The results showed that the carbon（C） content of biochar increased with the rise of the pyrolysis temperature from 54.0% at 200℃ to 83.7% at 700℃, on the contrary, the hydrogen（H） and oxygen（O） contents decreased with the rise of the temperature from 6.31% to 2.22% for H content and 45.1% to 10.6% for O content, respectively. Moreover, the H/C and O/C, usually used as two indexes to estimate carbon aromaticity for biochar, also decreased with the rise of the pyrolysis temperature from 1.25 to 0.32 for H/C and 0.54 to 0.09 for O/C, respectively, which indicated the carbon aromaticity of biochar was strengthened with the rise of the pyrolysis temperature, which is beneficial for the improvement of biochar stability. After the pyrolysis of walnut shell, especially when pyrolysis temperature was above 200℃, compared to the feedsto

关 键 词：热裂解 温度 碳 化学氧化 碳固定 生物质炭 

分 类 号：S156.2[农业科学—土壤学]