ZSM-5 with hierarchical pore structure was synthesized by a simple two-step hydrothermal crystallization from silica fume without using any organic ammonium templates.The synthesized ZSM-5 were oval shaped particles w...ZSM-5 with hierarchical pore structure was synthesized by a simple two-step hydrothermal crystallization from silica fume without using any organic ammonium templates.The synthesized ZSM-5 were oval shaped particles with a particle size about 2.0 μm and weak acid-dominated with proper Brønsted(B)and Lewis(L)acid sites.The ZSM-5 was used for catalytic co-cracking of n-octane and guaiacol,lowdensity polyethylene(LDPE)and alkali lignin(AL)to enhance the production of benzene,toluene,ethylbenzene and xylene(BTEX).The most significant synergistic effect occurred at n-octane/guaiacol at 1:1 and LDPE/AL at 1:3,under the condition,the achieved BTEX selectivity were 24%and 33%(mass)higher than the calculated values(weighted average).The highest BTEX selectivity reached 88.5%,which was 3.7%and 54.2%higher than those from individual cracking LDPE and AL.The synthesized ZSM-5 exhibited superior catalytic performance compared to the commercial ZSM-5,indicating potential application prospect.展开更多
Catalytic co-cracking of Fischer–Tropsch(FT) light distillate and methanol combines highly endothermic olefin cracking reaction with exothermic methanol conversion over ZSM-5 catalyst to produce light olefins through...Catalytic co-cracking of Fischer–Tropsch(FT) light distillate and methanol combines highly endothermic olefin cracking reaction with exothermic methanol conversion over ZSM-5 catalyst to produce light olefins through a nearly thermoneutral process. The kinetic behavior of co-cracking reactions was investigated by different feed conditions: methanol feed only, olefin feed only and co-feed of methanol with olefins or F–T distillate. The results showed that methanol converted to C2–C6 olefins in first-order parallel reaction at low space time, methylation and oligomerization–cracking prevailed for the co-feed of methanol and C2–C5 olefins, while for C6–C8 olefins,monomolecular cracking was the dominant reaction whether fed alone or co-fed with methanol. For FT distillate and methanol co-feed, alkanes were almost un-reactive, C3–C5 olefins were obtained as main products, accounting for 71 wt% for all products. A comprehensive co-cracking reaction scheme was proposed and the model parameters were estimated by the nonlinear least square method. It was verified by experimental data that the kinetic model was reliable to predict major product distribution for co-cracking of FT distillate with methanol and could be used for further reactor development and process design.展开更多
Co-cracking is a process where the mixtures of different hydrocarbon feedstocks are cracked in a steam pyrolysis furnace, and widely adopted in chemical industries. In this work, the simulations of the co-cracking of ...Co-cracking is a process where the mixtures of different hydrocarbon feedstocks are cracked in a steam pyrolysis furnace, and widely adopted in chemical industries. In this work, the simulations of the co-cracking of ethane and propane, and LPG and naphtha mixtures have been conducted, and the software packages of COILSIM1 D and Sim CO are used to account for the cracking process in a tube reactor. The effects of the mixing ratio, coil outlet temperature, and pressure on cracking performance have been discussed in detail. The co-cracking of ethane and propane mixture leads to a lower profitability than the cracking of single ethane or single propane. For naphtha, cracking with LPG leads to a higher profitability than single cracking of naphtha, and more LPG can produce a higher profitability.展开更多
The catalytic cracking of bio-oil is important to produce aromatic hydrocarbons,which can partially replace gasoline or diesel to greatly reduce carbon emissions from transportation.To further promote the formation of...The catalytic cracking of bio-oil is important to produce aromatic hydrocarbons,which can partially replace gasoline or diesel to greatly reduce carbon emissions from transportation.To further promote the formation of aromatic hydrocarbons,this work studied the effects of the preparation method and the acid strength of Ga_(2)O_(3)/HZSM-5 on catalytic cracking of the bio-oil distilled fraction systematically.The preparation method of Ga_(2)O_(3)/HZSM-5 had an important effect on its catalytic activity:the Ga_(2)O_(3)/HZSM-5 prepared by physical mixing showed the low dispersion of active phases and poor pore structure,resulting in its insufficient activity and severe coke deposition;the Ga_(2)O_(3)/HZSM-5 prepared by precipitation exhibited the higher activity,while many polycyclic aromatic hydrocarbons unfavorable for the subsequent utilization were in the oil phase;the Ga_(2)O_(3)/HZSM-5 prepared by impregnation showed the highest activity and 35.5%(mass)selectivity of the oil phase,including 80.3%monocyclic aromatic hydrocarbons and 12.0%polycyclic aromatic hydrocarbons.The Brønsted acidity of Ga_(2)O_(3)/HZSM-5 decreased with Si/Al ratio,leading to the decline in reactant conversion,oil phase selectivity and quality.Meanwhile,the polymerization between monocyclic aromatic hydrocarbons and oxygenates was promoted to produce many polycyclic aromatic hydrocarbons and even coke,causing catalyst deactivation.展开更多
Abstract Acetic acid was selected as the model compound representing the carboxylic acids present in bio-oil. This work focuses the co-cracking of acetic acid with ethanol for bio-gasoline production. The influences o...Abstract Acetic acid was selected as the model compound representing the carboxylic acids present in bio-oil. This work focuses the co-cracking of acetic acid with ethanol for bio-gasoline production. The influences of reaction temperature and pressure on the conversion of reactants as well as the selectivity and Conaposition of the crudegasoline phase were investigated. It was found that increasing reaction temperature benefited the conversion of reactants and pressurized cracking produced a higher crude gasoline yield. At 400 ℃ and 1 MPa, the conversion of the reactants reached over 99% and the selectivity of the gasoline phase reached 42.79% （by mass）. The gasoline phase shows outstanding quality, with a hydrocarbon content of 100%.展开更多
基金supported by the National Natural Science Foundation of China(22078076)Guangxi Natural Science Foundation(2020GXNSFAA159174)the Opening Project of National Enterprise Technology Center of Guangxi Bossco Environmental Protection Technology Co.,Ltd(GXU-BFY-2020-005).
文摘ZSM-5 with hierarchical pore structure was synthesized by a simple two-step hydrothermal crystallization from silica fume without using any organic ammonium templates.The synthesized ZSM-5 were oval shaped particles with a particle size about 2.0 μm and weak acid-dominated with proper Brønsted(B)and Lewis(L)acid sites.The ZSM-5 was used for catalytic co-cracking of n-octane and guaiacol,lowdensity polyethylene(LDPE)and alkali lignin(AL)to enhance the production of benzene,toluene,ethylbenzene and xylene(BTEX).The most significant synergistic effect occurred at n-octane/guaiacol at 1:1 and LDPE/AL at 1:3,under the condition,the achieved BTEX selectivity were 24%and 33%(mass)higher than the calculated values(weighted average).The highest BTEX selectivity reached 88.5%,which was 3.7%and 54.2%higher than those from individual cracking LDPE and AL.The synthesized ZSM-5 exhibited superior catalytic performance compared to the commercial ZSM-5,indicating potential application prospect.
文摘Catalytic co-cracking of Fischer–Tropsch(FT) light distillate and methanol combines highly endothermic olefin cracking reaction with exothermic methanol conversion over ZSM-5 catalyst to produce light olefins through a nearly thermoneutral process. The kinetic behavior of co-cracking reactions was investigated by different feed conditions: methanol feed only, olefin feed only and co-feed of methanol with olefins or F–T distillate. The results showed that methanol converted to C2–C6 olefins in first-order parallel reaction at low space time, methylation and oligomerization–cracking prevailed for the co-feed of methanol and C2–C5 olefins, while for C6–C8 olefins,monomolecular cracking was the dominant reaction whether fed alone or co-fed with methanol. For FT distillate and methanol co-feed, alkanes were almost un-reactive, C3–C5 olefins were obtained as main products, accounting for 71 wt% for all products. A comprehensive co-cracking reaction scheme was proposed and the model parameters were estimated by the nonlinear least square method. It was verified by experimental data that the kinetic model was reliable to predict major product distribution for co-cracking of FT distillate with methanol and could be used for further reactor development and process design.
基金Supported by the National Natural Science Foundation of China(21276078)Shanghai Key Technologies R&D Programe(12dz1125100)+1 种基金Natural Science Foundation of Shanghai(13ZR1411300)Shanghai Leading Academic Discipline Project(B504)
文摘Co-cracking is a process where the mixtures of different hydrocarbon feedstocks are cracked in a steam pyrolysis furnace, and widely adopted in chemical industries. In this work, the simulations of the co-cracking of ethane and propane, and LPG and naphtha mixtures have been conducted, and the software packages of COILSIM1 D and Sim CO are used to account for the cracking process in a tube reactor. The effects of the mixing ratio, coil outlet temperature, and pressure on cracking performance have been discussed in detail. The co-cracking of ethane and propane mixture leads to a lower profitability than the cracking of single ethane or single propane. For naphtha, cracking with LPG leads to a higher profitability than single cracking of naphtha, and more LPG can produce a higher profitability.
基金This work was supported by the Innovative Research Groups of the National Natural Science Foundation of China(51621005).
文摘The catalytic cracking of bio-oil is important to produce aromatic hydrocarbons,which can partially replace gasoline or diesel to greatly reduce carbon emissions from transportation.To further promote the formation of aromatic hydrocarbons,this work studied the effects of the preparation method and the acid strength of Ga_(2)O_(3)/HZSM-5 on catalytic cracking of the bio-oil distilled fraction systematically.The preparation method of Ga_(2)O_(3)/HZSM-5 had an important effect on its catalytic activity:the Ga_(2)O_(3)/HZSM-5 prepared by physical mixing showed the low dispersion of active phases and poor pore structure,resulting in its insufficient activity and severe coke deposition;the Ga_(2)O_(3)/HZSM-5 prepared by precipitation exhibited the higher activity,while many polycyclic aromatic hydrocarbons unfavorable for the subsequent utilization were in the oil phase;the Ga_(2)O_(3)/HZSM-5 prepared by impregnation showed the highest activity and 35.5%(mass)selectivity of the oil phase,including 80.3%monocyclic aromatic hydrocarbons and 12.0%polycyclic aromatic hydrocarbons.The Brønsted acidity of Ga_(2)O_(3)/HZSM-5 decreased with Si/Al ratio,leading to the decline in reactant conversion,oil phase selectivity and quality.Meanwhile,the polymerization between monocyclic aromatic hydrocarbons and oxygenates was promoted to produce many polycyclic aromatic hydrocarbons and even coke,causing catalyst deactivation.
基金Supported by the National Natural Science Foundation of China(51276166)the National Science Technology Supporting Plan Through Contract(2011BAD22B06)+1 种基金the Zhejiang Provincial Natural Science Foundation(R1110089)the Program for New Century Excellent Talents in University(NCET-10-0741)
文摘Abstract Acetic acid was selected as the model compound representing the carboxylic acids present in bio-oil. This work focuses the co-cracking of acetic acid with ethanol for bio-gasoline production. The influences of reaction temperature and pressure on the conversion of reactants as well as the selectivity and Conaposition of the crudegasoline phase were investigated. It was found that increasing reaction temperature benefited the conversion of reactants and pressurized cracking produced a higher crude gasoline yield. At 400 ℃ and 1 MPa, the conversion of the reactants reached over 99% and the selectivity of the gasoline phase reached 42.79% （by mass）. The gasoline phase shows outstanding quality, with a hydrocarbon content of 100%.
