Method for preparing narrow fraction nontoxic high-purity isohexane

Abstract

The invention relates to a method for preparing narrow fraction nontoxic high-purity isohexane, which is characterized in that: active metal nickel is used as a benzene catalytic hydrogenation catalyst; catalytic reforming raffinate oil, which has a distilling range of less than or equal to 140 DEG C, aromatic hydrocarbon content of less than or equal to 1.3 percent and sulfur content of less than or equal to 1ppm, and industrial hydrogen are pumped into a hydrogenation reactor to undergo all-component catalytic hydrogenation under conditions of a hydrogen to oil ratio of 5.5-7.5:100, a liquid benzene space velocity of 0.01 to 1 hour, a temperature of 160 to 175 DEG C, a pressure of 0.3 to 1.5MPa and in the presence of the catalyst for dearomatization and desulfuration; the product of the dearomatization and desulfuration is introduced to a dehydrogenation tower, the temperature of the tower is controlled to be 63 to 102 DEG C and light components with a distilling range less than or equal to 60 DEG C are removed; the residual fraction obtained after dehydrogenation is introduced into a heavy component removing tower, and the heavy components of which the distilling range is more than or equal to 75 DEG C are removed; and the fraction (of which the distilling range is 60 to 75 DEG C) left after the removal of the heavy components is introduced into an isohexane tower for fine fractionation, and a fraction obtained at 60 to 64.5 DEG C is the required product. The preparation method has the advantages of relatively mild catalyst operation conditions, obvious dearomatization and desulfuration effects, simple and practical process, stable and reliable product quality and high economic efficiency.

Description

Technical field: [0001] The invention relates to a preparation method of narrow-fraction non-toxic high-purity isohexane, which belongs to the technical field of petrochemical design. Background technique: [0002] Whether it is refined No. 6 solvent oil or high-purity hexane oil, its main component contains hexane. However, as early as 1990, the United States Clean Air Act officially listed n-hexane as one of the 189 air pollutants, affirming that human exposure to n-hexane vapor would damage the central nervous system and motor nerve cells. In 2001, the U.S. Environmental Protection Agency officially announced the standards for the emission of hexane into the atmosphere by oil refineries. Since then, people have paid more attention to the research and development of the oil leaching solvent hexane replacement technology. The oil industry has discussed more than 60 organic solvents, and found that isohexane, isopropanol, ethanol, ethyl acetate and their azeotropic solvents...

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Problems solved by technology

[0003] Chinese patent 200410027004.5 - the manufacture method of isohexane solvent, has introduced the method that is 60~90 ℃ of solvent oil distillation preparations isohexane by distillation, but its product isohexane content≤95%, and distillation range is relatively wide ( 58~63℃); there is still a gap with the performance requirements of high-purity narrow-fraction isohexane (isohexane content > 95%, distillation range 60-64℃), and it still cannot meet the safety production of plant extract oil and the non-toxic narrow-fraction solvent Environmental requirements for oil

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