热解温度对生物质炭碳保留量及稳定性的影响

热解温度对生物质炭碳保留量及稳定性的影响
李飞跃;汪建飞;谢越;李贺;李孝良;李粉茹
【期刊名称】《农业工程学报》
【年(卷),期】2015(31)4
【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KMnO4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℃/minin 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 (KMnO4) 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, thehydrogen (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 feedstock, the -C-O and O-CH3 groups did not exist and the aliphatic-CH gradually disappeared while more aromatization were shown by new aromatic compounds with the increasing of pyrolysis temperature based on FTIR analysis. Biochar yield decreased with the rise
of the pyrolysis temperature from 79.1% at 200℃ to 19.4%at 700℃. The carbon retention, defined as the proportion of the original carbon, which was from plant photosynthesis and sequestrated the CO2 in feedstock from atmosphere, was retained in the biochar after the pyrolysis, and also decreased with the rise of the pyrolysis temperature from 69.4% to 11.0%, all of which indicated that high pyrolysis temperature aggravated carbon loss. However, high pyrolysis temperature strengthened the carbon stability, and especially for biochar derived from 500℃, the carbon loss of biocharoxidated by K2Cr2O7and KMnO4 were 10.4% and 1.66%, respectively, which were smaller than the other biochars derived from other pyrolysis temperatures. There was significant negative correlation between pyrolysis temperature and the yield and carbon retention of biochar, while there was significant positive correlation between pyrolysis temperature and biochar stability. The stability of biochar in real soil and the optimal temperature of biochar for maximizing its carbon sequestration capacity need to be researched in the future.
【总页数】6页(P266-271)
【作者】李飞跃;汪建飞;谢越;李贺;李孝良;李粉茹
【作者单位】安徽科技学院城建与环境学院，凤阳 233100; 上海交通大学环境科学与工程学院，上海 200240;安徽科技学院城建与环境学院，凤阳 233100;安徽科技学院城建与环境学院，凤阳 233100;安徽科技学院城建与环境学院，凤阳233100;安徽科技学院城建与环境学院，凤阳 233100;安徽科技学院城建与环境学院，凤阳 233100
【正文语种】中文
【中图分类】S156.2
【相关文献】
1.热解温度对生物质炭性质及其在土壤中矿化的影响 [J], 赵世翔;姬强;李忠徽;王旭东
2.热解温度与碱金属对生物质热解碳烟氧化活性的影响 [J], 李艳;谭厚章;刘原一;王学斌
3.热解温度和生物质类型对生物炭吸附U(VI)性能的影响 [J], 吕鹏;王光辉;王冰;胡德玉
4.不同热解温度对生物质炭8种元素含量的影响 [J], 孙小飞;陈智伟;李宇轩;马红亮;高人;尹云锋
5.生物质炭与氮肥配施对植烟土壤微生物量碳、氮和碳氮比的影响 [J], 王欢欢;任天宝;元野;刘德育;匡岗;李树峰;刘国顺
因版权原因，仅展示原文概要，查看原文内容请购买。