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Optimizing support acidity of NiMo catalysts for increasing the yield of benzene, toluene and xylene in tetralin hydrocracking

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Frontiers of Chemical Science and Engineering 2024年第1期18卷 71-84页

作者： Feng Chen Jianing Huo Liang Zhao Jinsen Gao Chunming Xu State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China

To enhance the yields of benzene,toluene,and xylene in tetralin hydrocracking,the effect of the support acid properties of NiMo catalysts on hydrocracking performance of tetralin were investigated in this study.NaY zeolites were modified by hydrothermal treatment to form USY zeolites at different temperatures and adjust the type and amount of acid.In addition,H-Beta was loaded into the USY to further adjust the acidic properties of the catalysts.The result shows that when the total B acid content of the catalyst is maintained between 150 and 200μmol·g^(-1),the total acid amount is maintained between 1.7 and 1.9 mmol·g^(-1),and the L/B(L and B acids)ratio is maintained between 1.5 and 2,the catalysts have favorable performances on tetralin hydrocracking.Under this condition,the catalysts have a yield of benzene,toluene,and xylene higher than 30 wt%and a selectivity for benzene,toluene,and xylene higher than 35%.The tetralin conversion is greater than 85 wt%.The AB6 catalyst obtains the best hydrocracking effect with the conversion of tetralin reaching 90.24 wt%,the yields of benzene,toluene,and xylene reaching 33.58 wt%,and the selectivity of benzene,toluene,and xylene reaching 37.21%,respectively.

关键词： hydrocracking tetralin benzene toluene and xylene acid properties reaction pathways

An optimized approach for estimating benzene in ambient air within an air quality monitoring network

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Journal of Environmental Sciences 2022年第1期34卷 164-174页

作者： David Galán-Madruga Jesús P.García-Cambero Atmospheric Pollution Area National Center for Environment HealthCarlosⅢHealth Institute28220 MadridSpain Toxicology Area National Center for Environment HealthCarlosⅢHealth Institute28220 MadridSpain

benzene is a carcinogenic air pollutant for which European legislation has set an annual limit and criteria for the number of fixed monitoring sites within air quality networks(AQMN).However,due to the limited number of fixed sites for benzene measurement,exposure data are lacking.Considering the relationship between benzene levels and other variables monitored within an AQMN,such as NO_(2),O_(3),temperature,solar radiation,and accumulated precipitation,this study proposes an approach for estimating benzene air concentrations from the related variables.Using the data of the aforementioned variables from23 fixed stations during 2016-2017,the proposed approach was able to forecast benzene concentration for 2018 with high confidence,providing enriched data on benzene exposure and its trends.Moreover,the spatial distribution of the estimated versus the most representative benzene levels was quite similar.Finally,an artificial neural network identified the most representative fixed benzene monitoring sites within the AQMN.

关键词： Ambient air Air quality network benzene NO_(2)/O_(3)ratio Meteorological variables Prediction model

Catalytic degradation of benzene over non-thermal plasma coupled Co-Ni binary metal oxide nanosheet catalysts

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Journal of Environmental Sciences 2023年第10期132卷 1-11页

作者： Zhi Jiang Dongxu Fang Yuting Liang Yaoyu He Hisahiro Einaga Wenfeng Shangguan Research Center for Combustion and Environmental Technology Shanghai Jiao Tong UniversityShanghai 200240China Department of Energy and Material Sciences Faculty of Engineering SciencesKyushu University6-1 Kasuga KoenKasugaFukuoka 816-8580Japan

Non-thermal plasma(NTP)has been demonstrated as one of the promising technologies that can degrade volatile organic compounds(VOCs)under ambient condition.However,one of the key challenges of VOCs degradation in NTP is its relatively low mineralization rate,which needs to be addressed by introducing catalysts.Therefore,the design and optimization of catalysts have become the focus of NTP coupling catalysis research.In thiswork,a series of two-dimensional nanosheet Co-Ni metal oxides were synthesized by microwave method and investigated for the catalytic oxidation of benzene in an NTP-catalysis coupling system.Among them,Co_(2)Ni_(1)O_(x)achieves 60%carbon dioxide(CO_(2))selectivity(SCO_(2))when the benzene removal efficiency(REbenzene)reaches more than 99%,which is a significant enhancement compared with the CO_(2)selectivity obtained without any catalysts(38%)under the same input power.More intriguingly,this SCO_(2)is also significantly higher than that of single metal oxides,NiO or Co_(3)O_(4),which is only around 40%.Such improved performance of this binary metal oxide catalyst is uniquely attributed to the synergistic effects of Co and Ni in Co_(2)Ni_(1)O_(x)catalyst.The introduction of Co_(2)Ni_(1)O_(x)was found to promote the generation of acrolein significantly,one of the key intermediates found in NTP alone system reported previously,suggest the benzene ring open reaction is promoted.Compared with monometallic oxides NiO and Co_(3)O_(4),Co_(2)Ni_(1)O_(x)also shows higher active oxygen proportion,better oxygenmobility,and stronger low-temperature redox capability.The above factors result in the improved catalytic performance of Co_(2)Ni_(1)O_(x)in the NTP coupling removal of benzene.

关键词： benzene Nonthermal plasma Catalysis Cobalt metal oxide Nickel oxide Binary metal oxide

Interaction analysis of the influence of different factors and benzene exposure on workers' alanine aminotransferase

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China Medical Abstracts(Internal Medicine) 2024年第1期41卷 20-20页

作者：李培 Instit Occup Health Tianjin Dis Contr&Prev CenterTianjin 300011

Objective To investigate the main factors that influence ALT abnormalities in workers exposed to benzene.Methods In June 2022,data of 613 enterprises with benzene hazards and 585 enterprises with nonbenzene hazards in Tianjin in 2021 were collected,and occupational health examination data of 13 018 workers with benzene exposure and 13 018 workers with non-benzene exposure were collected,and the region.

关键词： benzene analysis alanine

Enabling tandem oxidation of benzene to benzenediol over integrated neighboring V-Cu oxides in mesoporous silica

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Chinese Journal of Chemical Engineering 2023年第3期55卷 236-245页

作者： Mengting Liu Xuexue Dong Zengjing Guo Aihua Yuan Shuying Gao Fu Yang School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Chemistry and Chemical Engineering Liaocheng UniversityLiaocheng 252000China State Key Laboratory of Materials-Oriented Chemical Engineering Nanjing Tech UniversityNanjing 210009China

The direct tandem oxidation synthesis of benzenediol from benzene could simplify or even avoid the separation and purification of reaction intermediates, which is promising but challenged because of the further required immediate consecutive activation of intermediate phenol. In this work, a synergistic benzene tandem-oxidation catalyst that V-Cu bimetallic oxides modified nanoporous silica(VCu-NS)was constructed via a facile assembly strategy which involves addictive negative anion citric acid mediating the intercalation of metal-citric acid chelate in mesopore of silica and subsequent thermal calcination inducing dual-metal active site formation. Such a tactic could make amorphous VOxspecies well covered on the surface of mesopore, and ultrafine copper oxide particles surrounded and neighbored by highly dispersed VOxwith strong interplay in mesopore, which was comprehensively confirmed by various characterizations. Benefiting from the unique V-Cu neighboring effect, the desorption of formed phenol over the catalytic site might be restricted therefore easily further activated by the formed reactive oxidative species, 3VCu-NS shows synergetic tandem-oxidation catalytic activities for benzene towards benzenediol with a selectivity of 57%. The result allows optimal 3VCu-NS to be a promising catalyst for benzenediol synthesis from benzene.

关键词： Catalysis Molecular sieve benzene Synergetic effect Tandem oxidation

Alkylation of benzene with carbon dioxide to low-carbon aromatic hydrocarbons over bifunctional Zn-Ti/HZSM-5 catalyst

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Frontiers of Chemical Science and Engineering 2022年第3期16卷 384-396页

作者： Xiangyu Liu Yanling Pan Peng Zhang Yilin Wang Guohao Xu Zhaojie Su Xuedong Zhu Fan Yang Engineering Research Center of Large-Scale Reactor Engineering and Technology Ministry of EducationEast China University of Science and TechnologyShanghai200237China Department of Product Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai200237China

Alkylation of benzene to value-added,high octane number and low toxic toluene and xylenes provides a way to lower benzene content in gasoline pool,and is hence a method to promote fuel quality.On the other hand,CO_(2) accumulation in the atmosphere causes global warming and requires effective route for its valorization.Utilization of CO_(2) as a carbon source for benzene alkylation could achieve both goals.Herein,alkylation of benzene with CO_(2) and H2 was realized by a series of low-cost bifunctional catalysts containing zinc/titanium oxides(Zn/Ti oxides)and HZSM-5 molecular sieves in a fixed-bed reactor.By regulating and controlling oxygen vacancies of Zn/Ti oxides and the acidities of HZSM-5,benzene conversion and CO_(2) conversion reached 28.7%and 29.9%respectively,along with a total selectivity of toluene and xylene higher than 90%.In this process,more than 25%CO_(2) was effectively utilized and incorporated into the target products.Moreover,the mechanism of the reaction was analyzed and the course was simultaneously traced.CO_(2) was transformed into methanol firstly,and then methanol reacted with benzene generating toluene and xylene.The innovation provides a new method for upgrading of fuels and upcycling the emissions of CO_(2),which is of great environmental and economic benefits.

关键词： carbon dioxide benzene alkylation bifunctional catalyst mechanism

Numerical simulation of benzene transport in shoreline groundwater affected by tides under different conditions

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Frontiers of Environmental Science & Engineering 2022年第5期16卷 83-95页

作者： Mahsa Kheirandish Chunjiang An Zhi Chen Xiaolong Geng Michel Boufadel Department of Building Civil and Environmental EngineeringConcordia UniversityMontrealQC H3G 1M8Canada Center for Natural Resources Department of Civil and Environmental EngineeringNew Jersey Institute of TechnologyNewark NJ 07102USA

The release and transport of benzene in coastal aquifers were investigated in the present study.Numerical simulations were implemented using the SEAM3D,coupled with GMS,to study the behavior of benzene in the subsurface of tidally influenced beaches.The transport and fate of the benzene plume were simulated,considering advection,dispersion,sorption,biodegradation,and dissolution on the beach.Different tide amplitudes,aquifer characteristics,and pollutant release locations were studied.It was found that the tide amplitude,hydraulic conductivity,and longitudinal dispersivity were the primary factors affecting the fate and transport of benzene.The tidal amplitude influenced the transport speed and percentage of biodegradation of benzene plume in the beach.A high tidal range reduced the spreading area and enhanced the rate of benzene biodegradation.Hydraulic conductivity had an impact on plume residence time and the percentage of contaminant biodegradation.Lower hydraulic conductivity induced longer residence time in each beach portion and a higher percentage of biodegradation on the beach.The plume dispersed and the concentration decreased due to high longitudinal dispersivity.The results can be used to support future risk assessment and management for the shorelines impacted by spill and leaking accidents.Modeling the heterogeneous beach aquifer subjected to tides can also be further explored in the future study.

关键词： Numerical simulation benzene Transport and fate Shoreline Groundwater Tide

The influence of pore structures and Lewis acid sites on selective hydrogenolysis of guaiacol to benzene over Ru/TS-1

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Green Energy & Environment 2022年第5期7卷 1014-1023页

作者： Yingying Xin Zhaoxia Zheng Zhicheng Luo Chengzhen Jiang Shaofeng Gao Zhihao Wang Chen Zhao Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai200062China Jinan Shengquan Group Share Holding Co. Ltd.Jinan250204China

Here,we report a Ru/TS-1 catalyst for selective hydrogenolysis of guaiacol to benzene in the aqueous phase at conditions of 240℃ and 0.2 MPa H2,achieving a benzene yield of 86% with a hydrogenolysis rate of 103.1 mmol g^(-1) h^(-1).It was found that Silicalite-1(MFI type) with suitable pore sizes supported Ru nanoparticles(NPs) favored for hydrogenolysis of guaiacol,whereas de-aluminated Ru/HBEA,Ru/HY and Ru/MWW(without acidic sites) accelerated the parallel reactions of hydrogenation of aromatics.In addition,Ru NPs located at the orifice of Silicalite-1 was proved to be more electron-deficient and active than Ru NPs on the outer surface,as evidenced by CO-IR characterization and activity tests on Ru/Silicalite-1(with and without templates).Moreover,Br?nsted acid sites(BAS) on Ru/MFI highly promoted the hydrogenation rates of aromatics,while Lewis acid sites(LAS) on Ru/TS-1 and Ru/MFI led to a linear increase of guaiacol hydrogenolysis rate to benzene,probably due to the enhanced absorbance capability of guaiacol and phenol on the LAS of MFI.Thus,pore structure properties of MFI coupled with abundant LAS(TS-1) as well as Ru NPs on the orifice of pores of TS-1 construct a promising catalyst for achieving efficient aromatic hydrocarbons from selective hydrogenolysis of lignin.

关键词： benzene hydrogenation catalyst

Study on Coconut Shell Activated Carbon Temperature Swing Adsorption of benzene and Formaldehyde

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Journal of Renewable Materials 2022年第12期10卷 3573-3585页

作者： Zhiguang Yang Gaojun Yan Xueping Liu Zhengyuan Feng Xinfeng Zhu Yanli Mao Songtao Chen Zhisheng Yu Ruimei Fan Linlin Shan Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology Henan University of Urban ConstructionPingdingshan467036China College of Resources and Environment University of Chinese Academy of SciencesBeijing100085China College of Basic Medical Sciences Xinxiang Medical UniversityXinxiang 453003China

Adsorption can be used to recover effectively the volatile organic gases(VOCs)in the exhaust gas from factories through using an appropriate adsorption bed.Due to form a physical or chemical bond,adsorption occurs between the porous solid medium and the liquid or gas multi component fluid mixture.The regeneration capa-city of the adsorbent is as important as the adsorption capacity and it determines the economics of the adsorption system.The regeneration of adsorbent can be realized through changing the pressure or temperature of the system.Here,activated carbon samples from coconut shell were prepared and characterized.benzene or formal-dehyde in the mixed air was used as the adsorption object,and the adsorption experiment was carried out in a U-shaped bed.Discussed how adsorption was affected by activated carbon type,adsorbate and temperature.The results show that oxidation modifed activated carbon can increase the adsorption effect of form aldehyde,but will reduce the ad sorption effect of benzene,because their ad sorption mechanism is different.At 30℃,the saturated adsorption apacity of AC-0 for benzene is 437.0 mg/g.and that of AC-1 for formaldehyde is 670.5 mg/g.In the experimental range,it is found that the adsorption capacity increases with the decrease of temperature,and their changes are very consistent with the ftted ExpDecay1 function.

关键词： Activated carbon adsorption benzene formaldehyde oxidation modification