摘要
为了提高芳烃的选择性产率和减少催化剂的积碳,以生物基呋喃为原料,以甲醇为耦合试剂进行催化共热解,探讨工艺条件对芳烃的选择性产率的影响,同时对其转化路径以及催化剂的积碳进行分析。结果表明:呋喃与甲醇耦合协同催化共热解可以有效的提高芳烃的选择性产率,二者具有明显的协同效应,甲醇的添加促进了甲醇制烯烃(methanol to olefin,MTO)反应、Diels-Alder环加成反应以及苯烷基化反应的发生,高温促使多烷基化合物以及萘及其同系物选择性产率的增加;强酸性促进了甲醇的脱水以及Diels-Alder环加成反应;同时,羰基抑制了呋喃环和烯烃的Diels-Alder反应,而羟基的存在有效的促进了甲苯以及二甲苯的生成,因此,当采用HZSM-5(SiO2/Al2O3=25)为催化剂,当热解温度为500℃,催化温度为550℃,MF∶甲醇=1∶5,物质的进样量为0.2 mL/min时,其芳烃的选择性产率达到99.73%,积碳量达到11.06%,苯、甲苯、二甲苯以及乙苯的总含量达到40.49%,萘及其同系物的含量仅为10.15%,有效的提高了烷基苯的选择性产率。
The catalytic converter is an important approach to obtain high-value chemicals from biomass with HZSM-5 mesoporous catalyst.Furan can serve as a representative model compound for catalytic fast pyrolysis of raw woody biomass.A major drawback of the aromatization of bio-derived furans is how to improve aromatic yield and selectivity of specific aromatic production(e.g.,xylenes)and to reduce the formation of carbon deposits.So,to overcome its disadvantages,the effect of process conditions(pyrolysis temperature,catalytic temperature,weight hourly space velocity,furan species,2-Methylfuran(MF)to methanol ratio and silicon to aluminum ratio)on the product yield and selectivity of aromatics were investigated with bio-derived furans and methanol catalytic co-pyrolysis with HZSM-5 catalyst.Simultaneously,the catalytic conversion mechanism and catalyst deactivation was discussed with X-ray diffractometer(XRD),specific surface area and aperture distribution meter(BET)and scanning electron microscope(SEM).The coupling conversion of bio-derived furans and methanol was conducted in a continuous fixed bed reactor.MF was used as a probe molecule to identify the possible reaction pathways.The experimental results showed that the coupling catalytic co-pyrolysis of furan and methanol effectively improved the yield and selectivity of aromatic hydrocarbon.The aromatic yield from the coupling conversion of MF and methanol was about 1.45 times higher than that of the catalytic fast pyrolysis of only MF.There was a positive synergistic effect between furan and methanol.The addition of methanol promoted methanol-to-olefin(MTO)reaction,Diels-Alder cycloaddition reaction and alkylation of benzene/toluene.In the process of the reaction,dimethyl ether was the main intermediate product of methanol dehydration.The first dehydration of methanol produced dimethyl ether,and then dimethyl ether continued to dehydrate to produce ethylene.Ethylene and MF further underwent Diels alder cycloaddition reaction to produce aromatic hydrocarbons.Higher t
作者
郑云武
王继大
刘灿
林旭
卢怡
李文斌
郑志锋
Zheng Yunwu;Wang Jida;Liu Can;Lin Xu;Lu Yi;Li Wenbin;Zheng Zhifeng(National Joint Engineering Research Center for Highly-Efficient Utilization Technology of Forest Biomass Resources,Southwest Forestry University,Kunming 650224,China;College of Materials Science and Engineering,Southwest Forestry University,Kunming 650224,China;Xiamen Key Laboratory for High-valued Conversion Technology of Agricultural Biomass(Xiamen University),Fujian Provincial Engineering and Research Center of Clean and High-valued Technologies for Biomass,College of Energy,Xiamen University,Xiamen 361102,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2020年第2期275-283,共9页
Transactions of the Chinese Society of Agricultural Engineering
基金
云南省科技厅项目项目(2018FG001-054,2018FB071)
云南省教育厅教师类项目(2018JS325)
国家自然科学基金(31670599)。
