生物质焦油的特性及其去除方法的研究现状

生物质焦油是阻碍生物质热化学转化技术发展的瓶颈问题。只有全面正确的了解焦油的性质和特点,才能选择最合适的去除方法。介绍生物质焦油的特性,并将焦油的成分分类,最后介绍了目前国内外去除焦油的方法,为进一步研究提供参考。     

生物质焦分形维数计算

采用压汞法的实验数据,计算两种分形模型下生物质焦样的分形维数。其中根据Menger海绵模型计算得到的分形维数Dm的值在2．7～3．1之间,基于热力学关系的分形模型计算得到的分形维数Dr的值在2．7～2．9之间。分析认为第二种模型更好的描述了焦样的孔隙结构,Dr的值比Dm的值更为合理。实验结果表明,分形维数与生物质种类有关,树叶焦样的分形维数整体上大于稻壳焦样的分形维数。生物质焦样的平均孔径与分形维数有关。总的来看,同一生物质焦样的分形维数随着平均孔径的增大而减小。     

北京地区生物质能利用工程现状及政策建议

介绍了北京地区可利用的生物质资源量,生物质能利用工程的发展现状,从整体和个体角度阐述了北京地区生物质能利用存在的问题,最后从管理、技术、产业发展等方面对北京市扩大生物质能利用提出了针对性的对策和建议。     

国内外生物质能源政策对比研究

介绍了国内外发展生物质能源的政策状况和特点,并对其进行了比较与分析。指出相对于生物质能源发展较快的国家,我国相关政策还不够健全和完善。最后对我国生物质能源政策提出了建议。     

生物法制取纤维素乙醇技术

以纤维素为原料生产燃料乙醇,由于其原料来源广泛及环保效益良好而被认为是最有前景的生产燃料乙醇的方法之一。在阐述我国发展纤维素乙醇必要性的基础上,综述了纤维素乙醇的浓酸水解、稀酸水解、酶水解及生物质合成气等发酵工艺及研究进展。分析了各工艺优缺点,并讨论了各工艺过程需要解决的关键技术问题,展望了纤维素乙醇的产业化前景。     

Recent advances in the catalytic pyrolysis of biomass

Biomass is considered as a renewable and alternative resource for the production of fuels and chemicals, since it is the only carbon and hydrogen containing resource that we can find in the world except for fossil resources, capable of being converted to hydrocarbons. The pyrolytic liquefaction of biomass is a promising way to convert biomass to useful products. This paper briefly surveys the present status of the direct catalytic pyrolysis for the liquefaction of biomass. The direct use of catalysts could decrease the pyrolysis temperature, increase the conversion of biomass and the yield of bio-oil, and change the distribution of the pyrolytic liquid products then improve the quality of the bio-oil obtained. The fact that biomass is in solid state present great challenges for its conversion and for the effective use of catalysts due to the bad heat transfer characteristics and bad mass transfer properties. These barriers appeal for the development of a new catalyst and new catalytic process as well as the integration of both. Process design and process intensification are of significant importance in the catalytic conversion of biomass.     

Biochemical methane potential (BMP) of solid organic substrates: evaluation of anaerobic biodegradability using data from an international interlaboratory study

BACKGROUND: This paper describes results obtained for different participating research groups in an interlaboratory study related to biochemical methane potential (BMP). In this research work, all experimental conditions influencing the test such as inoculum, substrate characteristics and experimental conditions were investigated. The study was performed using four substrates: three positive control substrates (starch, cellulose and gelatine), and one raw biomass material (mung bean) at two different inoculum to substrate ratios (ISR). RESULTS: The average methane yields for starch, cellulose, gelatine and mung bean at ISR of 2 and 1 were 350 ± 33, 350 ± 29, 380 ± 42, 370 ± 36 and 370 ± 35 mL CH₄ g^?1 VS_added, respectively. The percentages of biotransformation of these substrates into methane were 85 ± 8, 85 ± 7, 88 ± 9, 85 ± 8 and 85 ± 8%, respectively. On the other hand, the first‐order rate constants obtained from the experimental data were 0.24 ± 0.14, 0.23 ± 0.15, 0.27 ± 0.13, 0.31 ± 0.17 and 0.23 ± 0.13 d^?1, respectively. CONCLUSION: The influence of inocula and experimental factors was nearly insignificant with respect to the extents of the anaerobic biodegradation, while the rates differed significantly according to the experimental approaches. Copyright © 2011 Society of Chemical Industry     

生物质与煤共燃研究(Ⅰ)生物质的低温热解

介绍了生物质与煤共燃的研究流程及其主要的研究方法，通过对三种主要农业剩余生物质（锯屑，谷壳和花生壳）热解过程中的失重率变化，物理性质变化，工业分析变化，元素分析变化和发热量变化的研究发现，三种生物质在热解温度220℃-300℃，热解时间30min-60min下进行低温热解时，热解过程主要受热解温度控制，受热解时间控制较弱，随热解温度升高，热解时间延长，生物质的热失重率逐渐升高，生物质逐渐变得易于研磨。在工业分析上挥发分逐渐减少，固定碳及灰分不断提高，水分含量大幅下降；在元素分析上O元素的含量不断下降，C元素的含量不断上升，从而发热量不断增加，研究表明，当热解温度为270℃-300℃时，热解生物质的各项性质可与煤接近。     

生物质焦油裂解催化剂制备及其催化裂解性能

以萘为生物质焦油模型化合物 ,在以白云石为载体制备的 Ni基催化剂上进行了催化裂解实验研究 ,对催化剂的制备技术、活性、积炭失活性能和再生方式进行了实验分析。结果表明 :在 70 0℃的裂解温度、重量空速 0 .8L· h-1的反应条件下 ,萘的单程转化率可达 95 %,以饱和湿空气为再生气流 ,在程序升温的条件下烧碳 ,催化剂再生时间短 (<0 .5 h) ,与同温度的热裂解相比催化裂解更有利于萘的深度裂解 .     

生物质与煤共燃研究(Ⅱ)燃烧性质分析

对低温热解生物质和煤共燃的燃烧性质进行了研究。在热解温度300℃，热解时间30min下对三种生物质（锯屑、谷壳和花生壳）的热解产品、长焰煤、无烟煤、热解锯屑和长焰煤混样（1：10）、热解锯屑和无烟煤混样（1：10）七个样品的燃烧热重分析发现：热解生物质的燃烧性能相近，组成结构相似，主要分为挥发分释放燃烧阶段和焦炭燃烧阶段，分别位于30℃－400℃和400℃－500℃之间，其出现分别较煤的温度低；长焰煤与热解锯屑混燃可以有效地降低着火温度，而热解锯屑与无烟煤混燃时，由于燃烧性质差异较大，是分别燃烧，不产生协同效果；热解锯屑与长焰煤、无烟煤共燃能够有效地提高煤的着火性能，在总体燃烧性能上，虽然热解锯屑明显好于长焰煤和无烟煤，但混合后对其改变不大。