To systematically study the conversion process of paraffin,cycloalkane,and aromatic on ZSM-5 molecular sieve in naphtha hydrocracking,a series of related experiments were carried out based on the prepared hydrocrackin...To systematically study the conversion process of paraffin,cycloalkane,and aromatic on ZSM-5 molecular sieve in naphtha hydrocracking,a series of related experiments were carried out based on the prepared hydrocracking catalyst,Catalyst-HC.Ni and ZSM-5 molecular sieve were selected as the hydrogenation active component and the cracking component of Catalyst-HC,respectively.The results obtained through this work indicate that on ZSM-5 molecular sieve,the paraffin and cycloalkane in naphtha are mainly convertible hydrocarbons.The higher the content of convertible hydrocarbons in naphtha,the easier it is for the conversion reaction to occur.As C_(5+)conversion rate rises,the yields of paraffin and cycloalkane decline,and the yields of aromatic and aromaticcarbon in product-naphtha remain almost unchanged.The aromatic-average carbon-number(CN)in productnaphtha changes very little,decreasing from 8.3 to 8.2.This means that almost no aromatic undergoes the saturation reaction or conversion reaction on Catalyst-HC.Due to the small pore size of ZSM-5,C_(5+)i-paraffin has a lower conversion rate and a higher average CN compared to C_(5+)n-paraffin.Meanwhile,as C_(5+)conversion rate gradually rises from 0 to 23%,the average CN drop-values of C_(5+)n-paraffin and C_(5+)i-paraffin are 1.3 and 0.14,respectively.C_(5)-ring cycloalkane-ring-carbon(C_(5)-ring CRC)is more likely undergoing ring-opening(RO)reaction than that of C6-ring cycloalkane-ring-carbon(C6-ring CRC).The conversion rate of C_(5)-C_(7)cycloalkane is higher than that of C8+cycloalkane,and the former bears a higher jump-value compared to the latter with the increase of C_(5+)conversion rate.Unlike paraffin and aromatic,the average CN of cycloalkane gradually rises with the increase of C_(5+)conversion rate.展开更多
A series of related experiments were carried out based on prepared hydrocracking catalyst, Catalyst-HC. Ni & W and USY molecular sieve were selected as the hydrogenation active component and the cracking component...A series of related experiments were carried out based on prepared hydrocracking catalyst, Catalyst-HC. Ni & W and USY molecular sieve were selected as the hydrogenation active component and the cracking component of Catalyst-HC, respectively. Meanwhile, a kinetic model for paraffin conversion was constructed based on paraffin conversion law. Results obtained through this work indicate that the impact of H_(2)-pressure is relatively complex. As the H_(2)-pressure changes, the degree of hydrocracking reaction may be influenced by both hydrogen supply capacity and hydrogen proton concentration. Obtained conversion priority for three types of hydrocarbons on USY molecular sieve is as follows, aromatic ≫ cycloalkane > paraffin. Aromatic content in SRGO can affect its paraffin-retention in Hydro-D. Compared with the hydrotreating of SRGO with low aromatic content, when SRGO with relatively higher aromatic content is hydrotreated, its paraffin-retention is higher and its paraffin loss is also relatively smaller. Base on constructed model, the calculated values of SRGO-BJ conversion rate and paraffin-retention in Hydro-D are within ±10 % and ±5 % error lines, respectively. Thus, model schematic diagram is reasonable and can provide modeling reference for relevant model research.展开更多
基金supported by SINOPEC Research Programs(Grant KL20009 and 121028-2).
文摘To systematically study the conversion process of paraffin,cycloalkane,and aromatic on ZSM-5 molecular sieve in naphtha hydrocracking,a series of related experiments were carried out based on the prepared hydrocracking catalyst,Catalyst-HC.Ni and ZSM-5 molecular sieve were selected as the hydrogenation active component and the cracking component of Catalyst-HC,respectively.The results obtained through this work indicate that on ZSM-5 molecular sieve,the paraffin and cycloalkane in naphtha are mainly convertible hydrocarbons.The higher the content of convertible hydrocarbons in naphtha,the easier it is for the conversion reaction to occur.As C_(5+)conversion rate rises,the yields of paraffin and cycloalkane decline,and the yields of aromatic and aromaticcarbon in product-naphtha remain almost unchanged.The aromatic-average carbon-number(CN)in productnaphtha changes very little,decreasing from 8.3 to 8.2.This means that almost no aromatic undergoes the saturation reaction or conversion reaction on Catalyst-HC.Due to the small pore size of ZSM-5,C_(5+)i-paraffin has a lower conversion rate and a higher average CN compared to C_(5+)n-paraffin.Meanwhile,as C_(5+)conversion rate gradually rises from 0 to 23%,the average CN drop-values of C_(5+)n-paraffin and C_(5+)i-paraffin are 1.3 and 0.14,respectively.C_(5)-ring cycloalkane-ring-carbon(C_(5)-ring CRC)is more likely undergoing ring-opening(RO)reaction than that of C6-ring cycloalkane-ring-carbon(C6-ring CRC).The conversion rate of C_(5)-C_(7)cycloalkane is higher than that of C8+cycloalkane,and the former bears a higher jump-value compared to the latter with the increase of C_(5+)conversion rate.Unlike paraffin and aromatic,the average CN of cycloalkane gradually rises with the increase of C_(5+)conversion rate.
基金supported by National Key R&D Program of China(No.2021YFA1501204)SINOPEC Research Program(Grant 118022-2).
文摘A series of related experiments were carried out based on prepared hydrocracking catalyst, Catalyst-HC. Ni & W and USY molecular sieve were selected as the hydrogenation active component and the cracking component of Catalyst-HC, respectively. Meanwhile, a kinetic model for paraffin conversion was constructed based on paraffin conversion law. Results obtained through this work indicate that the impact of H_(2)-pressure is relatively complex. As the H_(2)-pressure changes, the degree of hydrocracking reaction may be influenced by both hydrogen supply capacity and hydrogen proton concentration. Obtained conversion priority for three types of hydrocarbons on USY molecular sieve is as follows, aromatic ≫ cycloalkane > paraffin. Aromatic content in SRGO can affect its paraffin-retention in Hydro-D. Compared with the hydrotreating of SRGO with low aromatic content, when SRGO with relatively higher aromatic content is hydrotreated, its paraffin-retention is higher and its paraffin loss is also relatively smaller. Base on constructed model, the calculated values of SRGO-BJ conversion rate and paraffin-retention in Hydro-D are within ±10 % and ±5 % error lines, respectively. Thus, model schematic diagram is reasonable and can provide modeling reference for relevant model research.
