白松木屑半焦与褐煤共气化过程中的协同效应

对白松木屑在200、300和400 ℃下马弗炉烘焙预处理制得半焦，与胜利褐煤进行共气化研究. 傅里叶变换红外（FTIR）光谱分析表明，200和300 ℃制得白松木屑半焦中主要含有―C―O―、―CH₃和―OH三种官能团，而400 ℃制得白松木屑半焦和褐煤结构相似，主要含有―C=C―、―C=O和―OH三种官能团，因此，随着预处理温度升高，生物质半焦中的官能团从单键转换成双键. 然后通过热重分析仪和固定床反应器对所制得的松木屑半焦、褐煤单独气化以及它们的共气化进行比较，两者的实验结果相吻合. 随着制备松木屑半焦的温度升高，生物质半焦单独气化的产气率也不断提高；200和400 ℃制得的松木屑半焦与褐煤共气化时具有协同作用，而且400 ℃半焦与褐煤共气化的产气率、碳转化率和协同效率均大于200 ℃半焦的；300 ℃半焦与褐煤共气化不存在协同作用，相反，它们之间存在抑制作用. 结合热重分析和固定床实验，推断协同气化主要是热解阶段松木屑半焦中碱金属和氢原子作用的结果.

Synergy Effect in Co-Gasification of Lignite and Char of Pine Sawdust

Pine sawdust was torrefied at 200, 300, and 400 ℃ in a muffle furnace, and used with Shengli lignite for co-gasification. Fourier transform infrared (FTIR) spectroscopy indicated that the pine sawdust torrefied at 200 and 300 ℃ contained the functional groups C―O―, ―CH₃, and ―OH, while the pine sawdust torrefied at 400 ℃ was similar to lignite, containing the functional groups ―C=C―, ―C=O, and ―OH. That is, when the torrefaction temperature of the pine sawdust increased, the single bonds in functional groups were converted to double bonds. After torrefaction, individual gasification and co-gasification of the lignite and pine sawdust chars were studied and compared in a thermogravimetric analyzer and fixed-bed reactor. It was found that both experimental results were consistent. The gas yield of pine sawdust char by individual gasification was higher when the pretreatment temperature was increased. Co-gasification of pine sawdust torrefied 200 and 400 ℃ with lignite had a positive effect on the product gas yield, carbon conversion, and synergetic efficiency, and the synergetic effects for sawdust torrefied at 200 ℃ were less than those for sawdust torrefied at 400 ℃. In contrast, pine sawdust torrefied at 300 ℃ had some inhibitory effects for co-gasification with lignite. Considering both the thermogravimetric analysis and fixed bed experiments, it is concluded that the synergetic effects can be attributed to the alkali metal and the hydrogen atomin the pine sawdust chars occurring at the pyrolysis stage.