基于Diels-Alder化学合成煤基高能量密度燃料的模型物反应研究
Model compounds reaction of coal based high energy density fuel based on Diels-Alder chemical synthesis
-
摘要: 选取基于煤基油中轻质芳烃为前驱体化学合成高能量密度燃料的工艺过程为研究对象,利用轻质芳烃模型化合物,研究了其Diels-Alde化学合成高能量密度燃料过程的反应机理与催化原理。结果表明,在分子筛催化剂作用下,以苯、甲苯、二甲苯和四氢萘等芳烃为前驱体可与降冰片烯发生Diels-Alde化学合成,生成具有多个封闭环平面组成的立体分子构型的高能量密度燃料。其转化率分别为85.2%,93.1%,99.0%和98.3%,选择性分别为95.2%,93.5%,95.5%和15.3%,轻质单环芳烃(BTX)具有优异的选择性和反应性;MCM-22催化剂因具有较大的孔结构和适度的酸性,其反应活性高于ZSM-5,SAPO-34和ZSM-35催化剂;增加反应时间和升高反应温度均有利于Diels-Alder合成反应。通过轻质芳烃模型物化学合成制备的高能量密度燃料具有较高的密度和能量密度,分别为0.941 8 g/cm3和43.79 MJ/L,远高于石油基和煤基喷气燃料。煤基石脑油经过催化重整后,可得到富集轻质芳烃组分,其单环芳烃(BTX、苯、甲苯、二甲苯)含量高达71.05%,另外,仍可通过柱层析或萃取精馏等先进的分离富集技术,进一步提高轻质芳烃组分富集度。因此,以煤基石脑油为起始原料,通过催化重整或柱层析分离后,得到的富集轻质芳烃组分完全可作为前驱体化学合成真实体系下的煤基高能量密度燃料。Abstract: The process of Chemical Synthesis of High Energy Density Fuel based on light aromatics from coal-derived oil was investigated. Using light aromatic hydrocarbon model compounds,the reaction mechanism and catalytic princi- ple of Diels-Alde chemical synthesis of high energy density fuel were studied. The results show that aromatics such as benzene,toluene,xylene and tetralin as precursors can be synthesized by Diels-Alder reaction with norbornene over Ze- olite Catalyst. High energy density fuel with a stereoscopic configuration of multiple closed ring planes was generated.The conversion rates were 85. 2% ,93. 1% ,99% and 98. 3% ,respectively,and the selectivity was 95. 2% ,93. 5% , 95. 5% and 15. 3% respectively. Thus BTX-aromatics has excellent selectivity and reactivity. MCM-22 catalyst has larger pore structure and moderate acidity,and its reactive activity is higher than that of ZSM-5,SAPO-34 and ZSM-35 catalysts. The increases of reaction time and high temperature are favorable to the synthesis of Diels-Alder reaction. The high energy density fuel produced by the chemical synthesis of light aromatic model compounds has higher density and energy density,and the density is 0. 941 8 g / cm3 and energy density is 43. 79 MJ / L,respectively,which are much higher than those of petroleum-based and coal-based jet fuels. After the catalytic reformation of coal based naphtha,the concentration of light aromatic hydrocarbons can be obtained. The content of BTX,benzene,toluene and xylene is up to 71. 05% . In addition,the enrichment of light aromatic hydrocarbons can be further improved by the advanced separa- tion and enrichment techniques such as column chromatography or extractive distillation. Therefore,using the coal- based Naphtha as a starting material,after the catalytic reformation or column chromatography separation,the enriched light aromatic hydrocarbon components can be used as the precursor of coal-based high energy density fuel based on Diels-Alder Chemical Synthesis.