二苯乙烯对秸秆纤维素超临界乙醇裂解转化液化产物的影响  

Effects of diphenylethene on products produced during cornstalk cellulose liquefaction in supercritical ethanol

作　　者：黎巍[1] 刘志威[1] 解新安[1] 孙娇[1] 樊荻 魏星[1] 

机构地区：[1]华南农业大学食品学院,广东广州510642

出　　处：《燃料化学学报》2017年第9期1064-1073,共10页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(21576107);广东省科技计划(2014A010106024)项目资助~~

摘　　要：以1,1-二苯乙烯(DPE)为阻聚剂,采用高压反应釜对玉米秸秆纤维素进行超临界乙醇液化,探究DPE浓度(用量)和反应温度对纤维素裂解碎片转化成液化产物的影响。结果表明,DPE浓度增加,挥发分收率降低了25.4%,生物油收率增加了19.9%,收率最高达39.8%,纤维素转化率有所下降;反应温度升高,纤维素转化率迅速增加到85.5%,挥发分也急剧升高,生物油收率最高为34.6%。GC-MS结果显示,生物油主要包括酮类、酯类、烃类等平台化合物以及较多的联苯化合物。DPE浓度过高,结合大量的纤维素裂解片段(乙基、羟基、甲基、氢等)形成联苯类化合物产生较强的空间位阻效应,使得纤维素裂解及活性片段转化成平台化合物的反应受到抑制,两者之间是一个竞争过程;温度升高,乙醇自由基活性增强,其对纤维素裂解的促进作用逐渐超过DPE对纤维素裂解的抑制作用,平台化合物收率有所升高。With 1,1-diphenylethene（DPE） as the polymerization inhibitor,the effects of DPE concentration（dosage） and reaction temperature on the active fragments transforming to liquefaction products during cellulose liquefaction in supercritical ethanol were investigated using an autoclave.As the DPE concentration increases,the yield of volatile compounds decreases by 25.4%,while the yield of bio-oil increases to 39.8%,and the cellulose conversion rate decreases gradually.With the increasing of reaction temperature,the cellulose conversion rate reaches to 85.5% sharply and the volatile compounds also increases fastly,but the maximum bio-oil yield drops to 34.6%.GC-MS analysis shows that ketones,esters,alkanes,alcohols,acids and the DPE derivatives are dominant platform chemicals in the bio-oil.A lot of active fragments（such as CH3CH2-,HO-,H-,CH3-,etc.）produced from cellulose pyrolysis in supercritical ethanol are trapped by a higher concentration of DPE to form DPE derivatives,which has a strong steric effect on the fragments transforming to platform chemicals.With the increasing of temperature,the enhanced pyrolysis of cellulose by ethanol radicals is more significant in comparison with the inhibition of DPE,resulting in an improvement in the content of platform chemicals.

关 键 词：二苯乙烯 秸秆纤维素 超临界乙醇 裂解 平台化合物 

分 类 号：TK6[动力工程及工程热物理—生物能]