To obtain high yields of monocyclic aromatic hydrocarbons with methyl side chains,such as toluene and xylene,methane(CH_(4))can be introduced into the hydrocracking of polycyclic aromatic hydrocarbons.CH_(4)can partic...To obtain high yields of monocyclic aromatic hydrocarbons with methyl side chains,such as toluene and xylene,methane(CH_(4))can be introduced into the hydrocracking of polycyclic aromatic hydrocarbons.CH_(4)can participate in the reaction,supply methyl side chains to the product,and improve product distribution.In this study,the hydrogenation reaction of polycyclic aromatic hydrocarbons over a carbonized NiMo/Hβcatalyst in a CH_(4)and hydrogen(H_(2))environment was investigated to study the promotional effect of CH_(4)on the hydrocracking of polycyclic aromatics.Under conditions of 3.5 MPa,380℃,volume air velocity of 4 h^(-1),gas-oil volume ratio of 800,and H_(2):CH_(4)molar ratio of 1:1,the conversion rate of naphthalene was 99.97%,the liquid phase yield was 93.62%,and the selectivity of BTX were 17.76%,25.17%,and 20.47%,respectively.In comparison to the use of a H_(2)atmosphere,the selectivity of benzene was significantly decreased,whereas the selectivity of toluene and xylene were increased.It was shown that CH_(4)can participate in the hydrocracking of naphthalene and improve the selectivity of toluene and xylene in the liquid product.The carbonized NiMo/Hβcatalyst was characterized by a range of analytical methods(such as X-ray diffraction(XRD),ammonia-temperature-programmed desorption(NH3-TPD),hydrogen-temperature-programmed reduction(H_(2)-TPR),and X-ray photoelectron spectroscopy(XPS)).The results indicated that Ni and Mo carbides were the major species in the carbonized NiMo/Hβcatalyst and were considered to be active sites for the activation of CH_(4)and H_(2).After loading the metal components,the catalyst displayed prominent weak acidic sites,which may be suitable locations for cracking,alkylation,and other related reactions.Therefore,the carbonized NiMo/Hβcatalyst displayed multiple functions during the hydrocracking of polycyclic aromatic hydrocarbons in a CH_(4)and H_(2)environment.These results could be used to develop a new way to efficiently utilize polycyclic aromatic hydrocarbons and natural gas resources.展开更多
采用Hβ沸石为载体,以Ni为主剂,分别以P、Mg、La为助剂合成了FCC汽油加氢改质双功能催化剂。考察了采用不同热处理方式脱模板剂对Naβ沸石载体的影响,以及助剂种类和助剂含量对双功能催化剂性能的影响。结果表明,采用阶段焙烧法脱模板...采用Hβ沸石为载体,以Ni为主剂,分别以P、Mg、La为助剂合成了FCC汽油加氢改质双功能催化剂。考察了采用不同热处理方式脱模板剂对Naβ沸石载体的影响,以及助剂种类和助剂含量对双功能催化剂性能的影响。结果表明,采用阶段焙烧法脱模板剂可以有效的抑制分子筛脱铝,更好的保持分子筛原始结晶态和比表面积;在FCC汽油加氢改质反应中,加入0.25%磷改性后的Ni P β催化剂,有效的降低了汽油中的烯烃含量,使烯烃转化率达到65%,并保证汽油的辛烷值基本不降低。展开更多
基金the financial support from the Graduate Student Innovation and Practical Ability Training Program of Xi’an Shiyou University (No. YCS21212111)Open Fund Project of the State Key Laboratory of Heavy Oil, China (SKLHOP201703)+3 种基金National Natural Science Foundation of China (No. 52274039)Natural Science Foundation of Shaanxi Provincial Department of Education (Grant 2023-JC-YB-414)Natural Science Foundation of Shaanxi Province in China (No. 2022JZ-28)the Open Fund Project of the National Oil Shale Exploitation Research and Development Center, China (No. 33550022-ZC0613-0255)
文摘To obtain high yields of monocyclic aromatic hydrocarbons with methyl side chains,such as toluene and xylene,methane(CH_(4))can be introduced into the hydrocracking of polycyclic aromatic hydrocarbons.CH_(4)can participate in the reaction,supply methyl side chains to the product,and improve product distribution.In this study,the hydrogenation reaction of polycyclic aromatic hydrocarbons over a carbonized NiMo/Hβcatalyst in a CH_(4)and hydrogen(H_(2))environment was investigated to study the promotional effect of CH_(4)on the hydrocracking of polycyclic aromatics.Under conditions of 3.5 MPa,380℃,volume air velocity of 4 h^(-1),gas-oil volume ratio of 800,and H_(2):CH_(4)molar ratio of 1:1,the conversion rate of naphthalene was 99.97%,the liquid phase yield was 93.62%,and the selectivity of BTX were 17.76%,25.17%,and 20.47%,respectively.In comparison to the use of a H_(2)atmosphere,the selectivity of benzene was significantly decreased,whereas the selectivity of toluene and xylene were increased.It was shown that CH_(4)can participate in the hydrocracking of naphthalene and improve the selectivity of toluene and xylene in the liquid product.The carbonized NiMo/Hβcatalyst was characterized by a range of analytical methods(such as X-ray diffraction(XRD),ammonia-temperature-programmed desorption(NH3-TPD),hydrogen-temperature-programmed reduction(H_(2)-TPR),and X-ray photoelectron spectroscopy(XPS)).The results indicated that Ni and Mo carbides were the major species in the carbonized NiMo/Hβcatalyst and were considered to be active sites for the activation of CH_(4)and H_(2).After loading the metal components,the catalyst displayed prominent weak acidic sites,which may be suitable locations for cracking,alkylation,and other related reactions.Therefore,the carbonized NiMo/Hβcatalyst displayed multiple functions during the hydrocracking of polycyclic aromatic hydrocarbons in a CH_(4)and H_(2)environment.These results could be used to develop a new way to efficiently utilize polycyclic aromatic hydrocarbons and natural gas resources.
文摘采用Hβ沸石为载体,以Ni为主剂,分别以P、Mg、La为助剂合成了FCC汽油加氢改质双功能催化剂。考察了采用不同热处理方式脱模板剂对Naβ沸石载体的影响,以及助剂种类和助剂含量对双功能催化剂性能的影响。结果表明,采用阶段焙烧法脱模板剂可以有效的抑制分子筛脱铝,更好的保持分子筛原始结晶态和比表面积;在FCC汽油加氢改质反应中,加入0.25%磷改性后的Ni P β催化剂,有效的降低了汽油中的烯烃含量,使烯烃转化率达到65%,并保证汽油的辛烷值基本不降低。
