Method of increasing melting temperature of Fischer-Tropsch wax by leaching

Abstract

The invention discloses a method of increasing the melting temperature of Fischer-Tropsch wax by leaching. The method comprises the following steps: step one. enabling the granular Fischer-Tropsch waxhaving the particle size of 0.01 to 5mm to contact with a solvent, wherein the weight ratio of the solvent to the granular Fischer-Tropsch wax is 20 to 0.1, the leaching temperature is 30 to 230 DEGC, and the leaching time is 10 to 300 minutes; step two. removing the solvent which is mixed in the granular Fischer-Tropsch wax after leaching, and recovering the solvent to obtain the Fischer-Tropsch wax with the high melting temperature; step three. recovering the solvent in raffinate, and meanwhile obtaining the Fischer-Tropsch wax with the low melting temperature; and step four. recycling thesolvent obtained in the step two and the step three. The method has the advantages that the energy consumption is low, high temperature and high vacuum degree are not required, the adverse impact ofhigh temperature on the performance of the Fischer-Tropsch wax is avoided, the melting temperature of the Fischer-Tropsch wax is increased, the melting range is relatively narrow, the cutting is relatively fine, and the method can meet the diversified needs of the market, the production operation is flexible, and the yield is easy to adjust.

Description

technical field [0001] The invention relates to a method for increasing the melting temperature of n-paraffin mixtures, more precisely a method for increasing the melting temperature of Fischer-Tropsch wax by leaching, and belongs to the field of fine chemical industry. Background technique [0002] Using coal, water vapor, air or oxygen as raw materials, reacting at a certain temperature, the coal can be converted into a mixture of carbon monoxide and hydrogen. After the mixture is purified, carbon monoxide and hydrogen are used as raw materials under the action of a catalyst. Chemical reaction can get methanol, acetic acid, vinyl acetate and other chemical products. [0003] Fischer-Tropsch synthesis belongs to the indirect liquefaction technology of coal. It uses carbon monoxide and hydrogen as raw materials, under the action of iron-based or cobalt-based catalysts, to carry out chemical reactions at a certain temperature and pressure to obtain n-alkanes mainly The mixtu...

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Problems solved by technology

[0004] The n-alkanes in Fischer-Tropsch wax have two characteristics. One is that the number of carbon atoms in n-alkanes is relatively large, which may be more than 120. The other feature is that the number of carbon atoms in n-alkanes is distributed in a wide range, from 18 carbon atoms to Up to 130, or even higher, thus resulting in a wide range of Fischer-Tropsch wax melting temperature, unable to meet the quality requirements of the market for high-end Fischer-Tropsch wax, so the development of Fischer-Tropsch wax with a narrow melting temperature range has become a problem that needs to be solved. CN106554822A discloses a method for deoiling using Fischer-Tropsch wax, using methyl isobutyl ketone as a solvent, deoiling by cooling crystallization, and adopting measures such as different dilution ratios to carry out multi-stage deoiling

[0005] Patent CN02814083.4 discloses a preparation method of Fischer-Tropsch wax, but its focus is how to control the process conditions of Fischer-Tropsch synthesis to obtain Fischer-Tropsch wax with narrow carbon atom distribution, so as to improve the purity of Fischer-Tropsch wax, patent CN103980940A Disclosed is the method that adopts high vacuum distillation to obtain high melting point Fischer-Tropsch wax, and patent CN104673383B discloses a kind of improved vacuum distillation method to obtain high melting point Fischer-Tropsch wax, and application number is that the patent of 2011102266326 discloses a kind of method its gist that will be obtained from After the crude wax component from the Fischer-Tropsch synthesis system is hydrogenated and refined, it is transported to the sweating tank by the raw material pump, and the lipids in the wax component are removed through sweating. Both of the first two patents involve the use of high temperature and high vacuum , because the normal alkanes in the Fischer-Tropsch wax have a large number of carbon atoms and low volatility, it is difficult to finely divide the normal alkanes in the Fischer-Tropsch wax, and the distillation effect is affected by the boiling point of the normal alkanes. It is very high, and there are safety hazards in the production under high temperature and high vacuum. The last method is also limited by the high melting point of normal alkanes in Fischer-Tropsch wax and the viscosity of low-melting components in Fischer-Tropsch wax. The sweating effect is not ideal.

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