Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, People's Republic of China.
Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, People's Republic of China.
Bioresour Technol. 2015 Jan;176:15-22. doi: 10.1016/j.biortech.2014.10.157. Epub 2014 Nov 4.
Wet and dry torrefaction of corncobs was conducted in high-pressure reactor and tube-type reactor, respectively. Effect of wet and dry torrefaction on chemical structure and pyrolysis behavior of corncobs was compared. The results showed that hemicellulose could be effectively removed from corncobs by torrefaction. However, dry torrefaction caused severe degradation of cellulose and the cross-linking and charring of corncobs. X-ray diffraction analysis revealed that crystallinity degree of corncobs was evidently enhanced during wet torrefaction, but reduced during dry torrefaction as raising treatment temperature. In thermogravimetric analysis, wet torrefied corncobs produced less carbonaceous residues than raw corncobs, while dry torrefied corncobs gave much more residues owing to increased content of acid insoluble lignin. Pyrolysis-gas chromatography/mass spectroscopy analysis indicated that wet torrefaction significantly promoted levoglucosan yield owing to the removal of alkali metals. Therefore, wet torrefaction can be considered as a more effective pretreatment method for fast pyrolysis of biomass.
玉米芯的湿、干热解分别在高压釜和管式炉中进行。对比了湿、干热解对玉米芯化学结构和热解行为的影响。结果表明，热解可以有效地从玉米芯中去除半纤维素。然而，干热解会导致纤维素严重降解以及玉米芯的交联和碳化。X 射线衍射分析表明，在湿热解过程中，玉米芯的结晶度明显提高，而在干热解过程中，随着处理温度的升高，结晶度降低。在热重分析中，湿热解玉米芯比原玉米芯产生的碳质残留物少，而干热解玉米芯由于酸不溶木质素含量增加而产生更多的残留物。热解-气相色谱/质谱分析表明，由于碱金属的去除，湿热解显著促进了左旋葡聚糖的生成。因此，湿热解可以被认为是生物质快速热解的一种更有效的预处理方法。
