改性HZSM-5催化生物质与塑料热解制备芳烃和生物炭  

Preparation of aromatic and bio-char by pyrolysis of biomass and plastics catalyzed by modified HZSM-5

作　　者：郑云武[1,2] 王继大 刘灿 林旭[1,2] 卢怡 李文斌 郑志锋[1,3] 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)

机构地区：[1]林业生物质资源高效利用技术国家地方联合工程研究中心,西南林业大学,昆明650224 [2]西南林业大学材料科学与工程学院,昆明650224 [3]厦门市现代农业生物质高值化技术重点实验室(厦门大学),福建省生物质高值化技术工程研究中心(厦门大学),厦门大学能源学院,厦门361102

出　　处：《农业工程学报》2020年第17期190-201,共12页Transactions of the Chinese Society of Agricultural Engineering

基　　金：云南省科技厅项目(2018FG001-054,2018FB071,2017FG001-001,2017FG01(-022),2017FG001(-62));国家自然科学基金(31670599);国家重点研发项目(2019YFD1002404);云南省重大科技专项(2018ZG004);西南林业大学材料科学与工程学院“新境杯”科技创新基金(201903)。

摘　　要：为了进一步提升生物油的品质,该研究采用竹材和低密度聚乙烯(Low-Density Polyethylene,LDPE)为原料,采用金属氧化物和HZSM-5(HZ)为催化剂催化生物质共热解,探索生物质与塑料的混合比例、金属氧化物的种类(HZSM-5、CaO、MgO、CeO2、La2O3和SnO2)、HZSM-5和MgO的混合比例以及组合方式(分层模式和混合模式)对生物质催化共热解制备生芳烃和生物炭的影响,同时对其添加效果进行分析。结果表明:LDPE和金属氧化物的添加可以有效的促进生物质的转化,降低了生物油的产率(9.76%~23.96%),提高生物油的品质和生物炭的石墨化程度,二者具有明显的协同效果,MgO促进了烷基酚的形成,CaO促进了烯烃的转化,而La2O3和SnO2明显的促进是呋喃的生成。而且混合模式可以有效的提高芳烃的产率,当生物质:LDPE=1:1,HZSM-5:MgO=2:1时,芳烃含量最高为84.99%,苯、甲苯、二甲苯和乙苯(SBTXE)的总含量达到了60.09%,而甲苯和二甲苯含量分别达到了25.97%和16.91%,混合模式有效促进了苯、甲苯和二甲苯的选择性,分层模式有效促进了烷基苯的转化,且MgO的添加明显抑制了稠环芳烃的形成。Metal oxides are widely used in the formulations of the catalysts for catalytic pyrolysis of biomass,due to the large specific surface area,pore size,and suitable acidity.HZSM-5 was the best mesoporous catalyst for aromatics synthesis because of the best acidity.However,there are some problems,such as low target yield,catalyst coking and deactivation with solo the catalysts.In order to improve the quality of bio-oil,a catalytic co-pyrolysis vapor upgrading of bamboo sawdust and LDPE was conducted by a fixed bed reactor,further to investigate effect of bamboo to LDPE ratio(1:0,2:1,1;1,1:2,0:1)of pyrolysis and catalyst pyrolysis on product yield.This study also revealed the effect of metal oxide(including HZSM-5,CaO,MgO,CeO2,La2O3 and SnO2),the dual-catalyst bed of HZSM-5 and base catalysts,HZ to MgO ratio(HZ:MgO=5:1,2:1,1:1,1:2,1:5)and combination mode(layered mode and mixed mode)on the promotion of aromatic hydrocarbons and bio-char.In addition,an investigation was made to explore the synergistic effect,reaction mechanism,and process optimization.Experimental results illustrated that:the addition of LDPE and metal oxide can effectively promote the conversion of biomass,thereby to reduce the yield of bio-oil(from 36.82%to 9.76%~23.96%),and further to enhance the quality of bio-oil,and the graphitization degree of bio-char,indicating an obvious synergistic effect.Hydrogen-rich fragments that derived from LDPE can promote the Diels-Alder reactions of furans,and participate in the hydrocarbon pool reactions of non-furanic compounds.As a result,a high yield of hydrocarbons was achieved.Scum as the hydrogen donor,showed a significant synergistic effect with biomass to enhance the production of bio-oil and aromatic hydrocarbons,when the H/Ceff value exceeded 1.The maximum yield of aromatic hydrocarbons(89.32%)was obtained,when the optimal biomass to LDPE ratio was 1:2.MgO catalyst can facilitate the formation of phenol and alkylphenol.The MgO-based catalysts suppressed the formation of ethylene glycol,furans,carboxylic

关 键 词：催化剂 热解 塑料 协同影响 芳烃 生物炭 

分 类 号：TQ35[化学工程]