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Production of octyl levulinate biolubricant over modified h-zsm-5:Optimization by response surface methodology

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Journal of Energy Chemistry 2014年第4期23卷 535-541页

作者： Kakasaheb Y.Nandiwale Sunil K.Yadava Vijay V.Bokade Catalysis and Inorganic Chemistry Division CSIR-National Chemical Laboratory Pune-411008 India University Institute of Chemical Technology North Maharashtra University Jalgaon-425001 Maharashtra India

The present study highlighted the use of modified h-zsm-5 （Meso-hZ-5） as heterogeneous catalyst for the synthesis of octyl levulinate biolubricant by catalytic esterification of biomass derived renewable levulinic acid （LA） with n-octanol. The process variables such as catalyst loading （X1）, n-octanol to LA molar ratio （X2） and reaction temperature （X3） were optimized through response surface methodology （RSM）, using Box-Behnken model. Analysis of variance was performed to determine the adequacy and significance of the quadratic model. The yield of octyl levulinate was obtained to be 99% at optimum process parameters. The developed quadratic model was found to be adequate and statistically accurate with correlation value （R2） of 0.9971 to predict the yield of octyl levulinate biolubricant. The study was also extended on the validation of theoretical and experimental data, including catalyst reusability.

关键词： biolubricant esterification h-zsm-5 levulinic acid octyl levulinate response surface methodology

Ethylbenzene disproportionation and p-xylene selectivity enhancement in xylene isomerization using high crystallinity desilicated h-zsm-5

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Chinese Journal of Chemical Engineering 2018年第1期26卷 116-126页

作者： Marjan Farshadi Cavus Falamaki Chemical Engineering Department Mahshahr CampusAmirkabir University of TechnologyMahshahr 415Iran Chemical Engneering Department Amirkabir University of TechnologyTehran 15875-4413.Iran Petrochemical Center of Excellence Amirkabir University of TechnologyTehran 15875-4413Iran

Desilication accompanied with minimum loss of crystallinity effect of a high alumina zsm-5 zeolite on the isomerization reaction of ethylbenzene/xylene mixtures has been considered.Desilication was assessed through XRF,XRD,FTIR,TEM,nitrogen adsorption/desorption,Nh_3-TPD,^(29)Si and^(27)Al MAS NMR analytical techniques.Desilication was accompanied with the creation of super acid sites.There exists a limit(Si/Al molar ratio of9.67)for keeping high crystallinity and obtaining improved catalytic performance.Desilication promotes ethylbenzene conversion by disproportionation and trans-alkylation reactions while the same reactions are limited for the xylene isomers.The p-xylene approach to equilibrium improves by more than 7% at 400℃ and a WhSV of 2 h^(-1)for the optimum sample with respect to the parent zeolite.At the same conditions,the optimum sample exhibits the maximum ethylbenzene conversion of 89%,i.***.more than 40%w.***.t.of the parent zeolite.however,the xylene yield decreases only 3%.

关键词：二甲苯异构化 h-zsm-5 异构化反应 Nh3-TPD 解吸附作用 FTIR 催化性能氧化铝

Catalytic performance of hierarchical h-zsm-5/MCM-41 for methanol dehydration to dimethyl ether

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Journal of Energy Chemistry 2013年第5期22卷 769-777页

作者： Yu Sang hongxiao Liu Shichao he hansheng Li Qingze Jiao Qin Wu Kening Sun School of Chemical Engineering and the Environment Beijing Institute of Technology

Micro-mesoporous composite molecular sieves h-zsm-5/MCM-41 were prepared by the hydrothermal technique with alkali-treated h-zsm-5zeolite as the source and characterized by scanning electron microscopy,transmission electron microscopy,energy dispersive spectroscopy,X-ray diffraction,N2 adsorption-desorption measurement and Nh3 temperature-programmed desorption.The catalytic performances for the methanol dehydration to dimethyl ether over h-zsm-5/MCM-41 were evaluated.Among these catalysts,h-zsm-5/MCM-41 prepared with NaOh dosage (nNa/nSi) varying from 0.4 to 0.47 presented excellent catalytic activity with more than 80%methanol conversion and 100%dimethyl ether selectivity in a wide temperature range of 170—300℃,and h-zsm-5/MCM-41 prepared with nNa/nSi=0.47 showed constant methanol conversion of about 88.7%,100% dimethyl ether selectivity and excellent lifetime at 220℃.The excellent catalytic performances were due to the highly active and uniform acidic sites and the hierarchical porosity in the micro-mesoporous composite molecular sieves.The catalytic mechanism of h-zsm-5/MCM-41 for the methanol dehydration to dimethyl ether process was also discussed.

关键词： hierarchical porosity h-zsm-5 composite molecular sieve methanol dehydration dimethyl ether

Formaldehyde intermediate participating in the conversion of methanol to aromatics over zinc modified h-zsm-5

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Journal of Energy Chemistry 2021年第3期30卷 174-178页

作者： Youming Ni Wenliang Zhu Zhongmin Liu National Engineering Laboratory for Methanol to Olefins Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina Dalian National Laboratory for Clean Energy Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina

Metal-modified h-zsm-5 has a high selectivity of aromatics in methanol to aromatics(MTA)reaction,which is often attributed to the metal promoting the aromatization of intermediate olefins.however,the effect of methanol dehydrogenation on aromatics formation over these catalysts is rarely studied.here,we report that hChO,which is formed by methanol dehydrogenation over Zn/h-zsm-5 prepared by Zn impregnation,can participate in the synthesis of aromatics.Methanol conversion can produce more aromatics than olefins(propylene or ethylene)conversion over Zn/h-zsm-5,indicating the conventional MTA pathway including methanol-to-olefins and olefins-to-aromatics is not complete.Moreover,an MTA mechanism including the conventional pathway and the methanol and hChO coupling pathway is systematically proposed.

关键词： Methanol Formaldehyde Aromatics Zn h-zsm-5

Effect of Pd or Ir on the catalytic performance of Mo/h-zsm-5 during the non-oxidative conversion of natural gas to petrochemicals

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Journal of Natural Gas Chemistry 2008年第4期17卷 337-343页

作者： Ahmed K.Aboul-Gheit Ahmed E.Awadallah Salah M.El-Kossy Abdel-Lateef h.Mahmoud Process Development Division Egyptian Petroleum Research Institute Faculty of Science Department of ChemistryMNF University Ageeba Petroleum Co.

Natural gas conversion to petrochemicals, principally, benzene, naphthalene, toluene, as well as ethylene under non-oxidative conditions was examined in a fixed bed flow reactor at 700 ℃ and gaseous hourly space velocity （GhSV） of 1500 ml·g ^-1·h^-1 at time-on-stream ranging from 5 rain to 4 h using catalysts containing 6.0%Mo/h-zsm-5 promoted with Pd or Ir metal. The catalysts were characterized by XRD, TPD, and TGA. The addition of Pd or Ir to 6%Mo/h-zsm-5 catalyst promoted ethylene production but inhibited the cyclization reaction to aromatics owing to the strong interaction between these noble metals and the framework Al species, which were attached to the acid sites during the impregnation process. Coke deposition on the catalysts was found to decrease upon addition of 0.5wt% of Pd or Ir to 6%Mo/h-zsm-5 catalyst owing to the hydrogenating activity of these metals.

关键词： natural gas methane benzene ethylene molybdenum Pd Ir h-zsm-5

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固体酸催化合成二丙二醇和三丙二醇的研究

化学工业与工程 2024年第4期 45-54页

作者：汪宝和段晨飞张照邦马静朱璟天津大学化工学院绿色合成与转化教育部重点实验室

在固体酸催化作用下，对环氧丙烷（PO）与丙二醇（PG）合成二丙二醇（DPG）和三丙二醇（TPG）进行了研究。研究表明h-zsm-5分子筛催化活性明显高于h-13X分子筛，消除了内外扩散的影响后，建立了h-zsm-5分子筛催化作用下的反应动力学模... 详细信息

在固体酸催化作用下，对环氧丙烷（PO）与丙二醇（PG）合成二丙二醇（DPG）和三丙二醇（TPG）进行了研究。研究表明h-zsm-5分子筛催化活性明显高于h-13X分子筛，消除了内外扩散的影响后，建立了h-zsm-5分子筛催化作用下的反应动力学模型，利用数值分析法确定了反应动力学常数。实验结果表明，计算值与实验值吻合较好。通过反应动力学数学模型优化了反应条件，为二丙二醇和三丙二醇的工业化生产提供了基础的物性数据。采用X射线衍射、N2吸附和脱附测试、吡啶吸附红外光谱（Py-FTIR）等方法分别对新制备的和使用过的催化剂进行了表征，并对失活原因进行了初步探索。

关键词：环氧丙烷(PO) 丙二醇(PG) 二丙二醇(DPG) 三丙二醇(TPG) h-zsm-5 反应动力学

h-zsm-5分子筛催化4-MBP与甲醇甲基化的反应机理(英文)

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物理化学学报 2015年第1期31卷 56-66页

作者：李玲玲 JANIK J.Michael 聂小娃宋春山郭新闻辽宁科技学院冶金工程学院辽宁本溪117004 大连理工大学化工学院精细化工国家重点实验室PSU-DUT联合能源研究中心辽宁大连116024 宾夕法尼亚州立大学能源与矿物工程系能源研究所 PSU-DUT联合能源研究中心美国宾夕法尼亚16802 宾夕法尼亚州立大学化学工程系美国宾夕法尼亚16802 佐治亚理工学院化学与生物工程学院美国亚特兰大30332-0100

4,4'-二甲基联苯(4,4'-DMBP)是生产高性能聚合物材料的重要前驱体,可以通过4-甲基联苯(4-MBP)甲基化制得.本文采用"our own-N-layered integrated molecular orbital+molecular mechanics"(ONIOM)和密度泛函理论(DFT)方法研究h-zsm-5分子筛孔内4-MBP和甲醇择形甲基化的反应机理,考虑了分步和协同反应机理.分步机理的活化能低于协同机理.在两种反应机理中,4,4'-DMBP为动力学优先生成产物.过渡态择形的特征也使甲基化更容易生成4,4'-DMBP.在分子筛孔内,4-MBP异构化生成3-甲基联苯(3-MBP)的反应被抑制.在分子筛外表面,4-MBP异构化生成3-MBP比甲基化反应更有动力学优势,导致4,4'-DMBP选择性降低.对外表面进行改性将会抑制4-MBP异构化反应,并使反应在分子筛孔内进行,因此可以提高4,4'-DMBP的选择性.h-zsm-5催化择形和非择形反应的计算结果与实验现象一致.

关键词： ONIOM 甲基化甲醇 4-MBP h-zsm-5

h-zsm-5催化甲苯与碳酸二甲酯和甲醇甲基化的反应机理(英文)

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物理化学学报 2013年第7期29卷 1467-1478页

作者：李玲玲 JANIK J.Michael 聂小娃宋春山郭新闻大连理工大学化工学院精细化工国家重点实验室 PSU-DUT联合能源研究中心辽宁大连116024 宾夕法尼亚州立大学能源与矿物工程系能源研究所 PSU-DUT联合能源研究中心宾夕法尼亚州立大学化学工程系俄亥俄州立大学化工与生物分子工程系

对二甲苯是重要的石油化工产品之一,可以通过甲苯甲基化生产.本文采用"ourown-N-layered integrated molecular orbital+molecular mechanics"(ONIOM)和密度泛函理论(DFT)结合的方法,计算了h-zsm-5催化甲苯与碳酸二甲酯(DMC)和甲醇甲基化反应机理.考察了反应物吸附和产物脱附.描述了主要的中间物种和过渡态的结构.用计算的速率常数来估计甲苯甲基化反应的动力学活性.h-zsm-5催化的甲苯与DMC和甲醇甲基化的机理不同.甲苯和DMC甲基化包括DMC完全解离,接着甲基化生成二甲苯异构体.相比而言,在甲苯甲基化反应中,甲醇作为甲基化试剂的活性比DMC更好.甲苯和甲醇甲基化的分步反应路径和联合反应路径的本征活化能相似.在773K,分步反应路径的速率常数比联合反应路径更高.在甲苯和这两种试剂甲基化的反应中,生成对二甲苯为动力学优先,而间二甲苯为能量最低产物.我们的计算结果和实验观察到的现象一致.

关键词：密度泛函理论 ONIOM 甲苯甲基化碳酸二甲酯甲醇 h-zsm-5

苯和甲醇在h-zsm-5催化剂上甲基化的反应机理

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物理化学学报 2017年第4期33卷 769-779页

作者：李玲玲陈韧戴戬孙野张作良李晓亮聂小娃宋春山郭新闻辽宁科技学院冶金工程学院辽宁本溪117004 大连理工大学化工学院精细化工国家重点实验室PSU-DUT联合能源研究中心辽宁大连116024 宾夕法尼亚州立大学能源与矿物工程系能源研究所 PSU-DUT联合能源研究中心美国宾夕法尼亚大学城16802

采用"our own-N-layered integrated molecular orbital+molecular mechanics"(ONIOM)和密度泛函理论(DFT)结合的方法,在5T、12T、104T_9和104T_(12)h-zsm-5模型中研究了苯和甲醇甲基化的分步和协同机理。描述了中间体物种和过渡态的结构。考察了h-zsm-5催化剂Br?nsted(B)酸强度对苯和甲醇甲基化反应机理的影响。反应活化能结果表明,在B酸强度更强的h-zsm-5催化剂上,苯和甲醇甲基化反应更容易发生,反应活化能更低。随着B酸强度增强,分步机理的反应活化能比协同机理的反应活化能降低的更多。B酸强度增强对分步机理更有利。当分步机理成为主导反应路径时,分步机理中甲醇脱水步骤生成的甲氧基中间体进一步生成大体积烃类的副反应会导致h-zsm-5催化剂因积炭而失活。合理调变h-zsm-5催化剂的酸强度对提高催化剂的催化活性和稳定性有重要意义。

关键词：密度泛函理论 ONIOM 苯甲基化甲醇 h-zsm-5