Hydroisomerization Of N-heptane Research Articles

Selectivity in the conversion of n-heptane on an Al-PILC modified with Ga

This work compares the catalytic activity for the hydroisomerization and hydrocracking of n-heptane for two pillared clay materials, one with polyoxycations of Al and the other with the same cation modified by the inclusion of Ga. The conversion rate for the clay pillared with mixed cations is lower than that for the material pillared only with aluminum throughout the temperature range, which is attributable to its smaller specific surface area. However, at high temperatures the conversion rate of the material with mixed pillars continues to rise steadily, indicating a greater thermal stability. The incorporation of Ga also increases the selectivity for isomerization.

Hydroisomerization and hydrocracking of n-heptane and n-hexadecane on solid superacids

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydroisomerization and hydrocracking of n-heptane and n-hexadecane on solid superacidsMichael Y. Wen, Irving Wender, and John W. TierneyCite this: Energy Fuels 1990, 4, 4, 372–379Publication Date (Print):July 1, 1990Publication History Published online1 May 2002Published inissue 1 July 1990https://doi.org/10.1021/ef00022a007RIGHTS & PERMISSIONSArticle Views588Altmetric-Citations73LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (906 KB) Get e-Alerts Get e-Alerts

Hydroisomerization and hydrocracking of n-heptane on Pth zeolites. Effect of the porosity and of the distribution of metallic and acid sites.

The catalytic properties of PtHY, PtHZSM5 and PtH mordenite catalysts are controlled by the number of their acid sites (n A, number of acid sites on which the adsorption heat of NH 3 is greater than 100 kJ mol −1) and their hydrogenating sites (n Pt). The activity of PtHY catalysts changes with n Pt/n A as can be expected from the classical bifunctional mechanism : it increases with n Pt/n A for the low values of this ratio, then reaches a plateau for n Pt/n A ⩾ 0.03. For low values of n Pt/n A, monobranched, multibranched isomers and cracking products are formed simultaneously but, for n Pt/n A ⩾ 0.17, n-heptane transforms successively into the three families of products. With PtHZSM5 catalysts, the same trend can be observed concerning the changes of the activity as a function of n Pt/n A. However the changes in the reaction scheme as a function of n Pt/n A are different : cracking remains the main reaction even at high values of n Pt/n A ; multibranched isomers are found in very low concentration. This can be attributed to a slower migration of the olefinic intermediates. Moreover, particular selectivities are found which are explained by a good matching between some intermediates and the space available near the acid sites. With PtH mordenite, the activity changes differently with n Pt/n A. In particular, it decreases for n Pt/n A > 0.015. This can be attributed to a partial pore blockage by platinum or by coke, leaving only a small part of the catalyst active. This is confirmed by the fact that the selectivities are the same as those of a PtHY zeolite with a n Pt/n A ratio 10–20 times lower.

Influence of tin on the stability of Sn/Pd Hy zeolites in the hydrocracking and hydroisomerization of n-heptane

The hydrocracking and hydroisomerization of n-heptane was carried out in a dynamic reactor under a total pressure of 6 MPa at temperatures in the range 503 – 563 K on Pd HY and Sn/Pd HY zeolite catalysts. The influence of tin on the behaviour of these catalysts was studied. To check their stability all the catalysts were deactivated by coking under severe conditions; a considerable increase in stability was observed in the tin-containing catalysts. The results obtained suggest that the main role of tin is to induce the production of highly active hydrogen species which diffuse by a spillover effect on the catalyst surface and lead to the hydrogenation of the coke precursor species adsorbed on the catalyst.