Continuous Reforming-C5/C6 Isomerization Combined Process Technology

With the increasingly stringent environmental protection requirements, the upgrading of gasoline standards for vehicles has accelerated. On January 1, 2017, the national V gas oil standard was implemented nationwide. On January 1, 2019, the national VI (a) gasoline standard is planned to be implemented nationwide, stipulating:

① The volume fraction of aromatics is not more than 35%;

② The volume fraction of olefins is not more than 18%;

③The volume fraction of benzene is not more than 0.8%.

At the same time, the National VI gasoline standard lowers the control index of gasoline distillation range (50% distillation temperature) from 120°C of National V gasoline to 110°C, which means that more gasoline such as C5/C6 isomerized gasoline can be added High-octane premium light gasoline blending component.For the first time in China, Tahe Refining & Chemical used feedstock pre-treatment to remove the reaction precursors of benzene generated in reforming raw materials (referred to as benzene precursors),controlling C6 alkanes and cycloalkanes (methylcyclopentane, cyclohexane) in the reforming feedstock.The technical plan to make the benzene content of the reformed product meet the gasoline standard, cooperating with the C5/C6 isomerization unit to form a C7+ continuous reforming-C5/C6 isomerization combined process, and producing National V or National VI motor gasoline.Specifically: by optimizing the design of the pre-fractionation tower of the pre-hydrogenation-continuous reforming unit, controlling the cut temperature of the overhead fraction of the pre-fractionation tower, the benzene precursor components (C6 alkanes, methylcyclohydrocarbons) in the reforming feedstock pentane and cyclohexane) are distilled from the top of the tower as the feedstock for the C5/C6 isomerization unit; the C7+ fraction at the bottom of the pre-fractionator is used as the continuous reforming feedstock.The continuous reforming-C5/C6 isomerization unit has been in operation since July 2014.