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The ideal gasoline must have a high pump octane number, in the 86 to 94 range, and a low environmental impact. Alkanes, as a family, have much lower photochemical reactivities than aromatics or olefins, but only the highly branched alkanes have adequate octane numbers. The purpose of this work is to examine the possibilities of extending the technological alternative of paraffin isomerization to heavier feedstocks (i.e., n-heptane) using non-conventional catalytic systems which have been previously proposed in the literature: a Pt/sulfated zirconia catalyst and a molybdenum sub-oxide catalyst. Under the experimental conditions at which these catalysts have been evaluated, the molybdenum sub-oxide catalyst maintains a good activity and selectivity to isomerization after 24 h, while the Pt/sulfated zirconia catalyst shows a higher dimethylpentanes/methylhexanes ratio, probably due to a lower operating temperature, but also a high formation of cracking products, and presents signs of deactivation after 8 h. Though much remains to be done, the performance of these catalysts indicates that there are good perspectives for their industrial application in the isomerization of n-heptane and heavier alkanes.

A challenge for the oil refinement industry is the production of high-octane gasoline with a low benzene content. This work reports the calculation of the atmospheric benzene emissions generated from gasoline storage, transfer, and transport operations in Mexico, estimating 1.48 KBPD of environmental release. The aim was to estimate the minimum benzene emissions through operative improvements in refineries, initially by performing simulations of the Naphtha Catalytic Reforming (NCR) process using ASPEN HYSYS® ver. 8.8 (34.0.08909) and then by optimizing the operative conditions to improve the reformate quality while reducing the benzene content. The operative ranges comprised hydrogen/hydrocarbon (H2/HC) feedstock molar ratios from 2.0 to 6.0 and reaction temperatures from 450 to 525 °C, which were used as independent variables to assess the benzene content and the Research Octane Number (RON) of the produced gasoline. The Surface Response Method (SRM) and multi-objective optimization analysis were applied. The improved operative conditions were 491 °C and a H2/HC ratio of 2.0, which allowed us to obtain a RON value of 89.87, an aromatics value of 37.39% (v/v), and a benzene value of 1.48% (v/v), with an estimated 16.44% drop in atmospheric benzene emissions, meaning a reduction in greenhouse gas emissions and climate change, thus favorably impacting public health by improving refinery operations. The simulation outcomes were compared with industrial-scale data and the experimental results, with significant similitudes being observed.

The ideal gasoline must have a high pump octane number, in the 86 to 94 range, and a low environmental impact. Alkanes, as a family, have much lower photochemical reactivities than aromatics or olefins, but only the highly branched alkanes have adequate octane numbers. The purpose of this work is to examine the possibilities of extending the technological alternative of paraffin isomerization to heavier feedstocks (i.e., n-heptane) using non-conventional catalytic systems which have been previously proposed in the literature: a Pt/sulfated zirconia catalyst and a molybdenum sub-oxide catalyst. Under the experimental conditions at which these catalysts have been evaluated, the molybdenum sub-oxide catalyst maintains a good activity and selectivity to isomerization after 24 h, while the Pt/sulfated zirconia catalyst shows a higher dimethylpentanes/methylhexanes ratio, probably due to a lower operating temperature, but also a high formation of cracking products, and presents signs of deactivation after 8 h. Though much remains to be done, the performance of these catalysts indicates that there are good perspectives for their industrial application in the isomerization of n-heptane and heavier alkanes.