Light hydrocarbon isomerization method

Abstract

The invention relates to a light hydrocarbon isomerization method comprising the following steps: light hydrocarbon materials are firstly separated by a de-isopentane tower, tower top streams are extracted as isomerization products, and tower bottom streams enter a front isomerization reactor to generate isomerization reaction; liquid phase streams obtained by the gas-liquid separation of outlet streams of the front reactor are separated in a de-isohexane tower, and tower top streams and tower bottom streams of the de-isohexane tower are extracted and then mixed with the tower top streams of the de-isopentane tower and are together taken as a gasoline-stripping stabilization system of the isomerization products; siding streams of the de-isohexane tower are extracted into a rear isomerization reactor; and liquid phase streams obtained by the gas-liquid separation of reaction streams of the rear isomerization reactor completely return and are mixed with the liquid phase streams of a gas-liquid separator of the front isomerization reaction system and together taken as feeding materials of the de-isohexane tower. The method has higher normal paraffin isomerization ratio, wherein the C6 normal paraffin realizes the complete isomerization basically, thereby greatly improving the octane number of the light hydrocarbon materials.

Description

technical field [0001] The invention relates to a method for isomerizing light hydrocarbons, more specifically, a method for generating branched isoparaffins from straight-chain alkanes with smaller carbon atoms through hydroisomerization to increase the octane content of light hydrocarbon raw materials. alkane number method. Background technique [0002] During the primary processing and secondary processing of crude oil, light hydrocarbon fractions mainly composed of C5 and C6 will be produced, which can be used as blending components of gasoline, raw materials for ethylene cracking or hydrogen production by steam reforming of light hydrocarbons raw material. Since the light hydrocarbons do not contain olefins and aromatics, it is a better gasoline blending component, but the normal paraffins in the light hydrocarbons have a lower octane number, which makes them blend in gasoline. The ratio is limited. Light hydrocarbon isomerization technology is to convert normal para...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that a part of the liquid phase stream of the gas-liquid separator of the rear isomerization reaction system is drawn as an isomerization product, and because the isomerization reaction is controlled by thermodynamic equilibrium, a certain amount of C6 n-alkane has a negative impact on improving the octane number of the isomerization reaction product, and if this stream is not provided, the accumulation of heavy components in the reaction system cannot be solved; in this method, the C5 n-alkane The isomerization rate is determined by the reaction conditions of the front isomerization reaction system, and cannot be further improved. When the proportion of C5 fraction in the light hydrocarbon feedstock is high, the octane number of the isomerization product will increase. subject to obvious restrictions

Therefore, the light hydrocarbon isomerization method proposed by ZL03102218.9 has not reached the ideal level for the isomerization conversion of C5 and C6 normal paraffins, and there is still room for further improvement

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