Isopropanol urea dewaxing method

Abstract

The invention relates to a dewaxing method for an isopropanol urea aqueous solution. According to the method, liquefied gas is employed to replace water to serve as a cooling medium, and the liquefied gas and a reaction mixture undergo direct contact heat transfer in a tower reactor. When the liquefied gas changes from liquid into gaseous hydrocarbon, the heat of the reaction mixture is absorbed, and the gaseous hydrocarbon has a stirring effect on the reactant during rise in the reactor, thus facilitating contact of urea and n-alkanes in raw oil and uniform distribution of a formed complex in the reaction mixture. The material attachment phenomenon appearing when water is adopted as the cooling medium can be avoided, the heat transfer can be more uniform, the complexation reaction can be more complete, the use of a large amount of low temperature water can be avoided, and promotion the application of the technology in areas with relative lack of water resources can be realized.

Description

technical field [0001] The invention relates to a dewaxing method, in particular to an isopropanol urea aqueous solution complexation reaction dewaxing method. Background technique [0002] The urea dewaxing technology uses the basic principle of contacting urea molecules with n-alkane to form helical hexagonal crystals around n-alkane to form a complex that is immiscible with oil, thereby separating n-alkane from oil. The pore size of the helical hexagonal crystal is 0.525nm, which can also be regarded as an organic molecular sieve with a single pore size. [0003] Isopropanol urea dewaxing is to mix urea with a certain proportion of water and isopropanol, and heat the mixture until the urea is completely dissolved to form a uniform solution. After the contact of alkanes, the temperature of the reaction mixture is gradually reduced, and the urea and n-alkanes react to form an oil-insoluble complex, so that the n-alkanes (wax) are released from the oil. As the reaction tem...

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Problems solved by technology

[0005] Due to the isopropanol aqueous solution urea dewaxing technology, when water is used as the refrigerant, the reaction system needs a large amount of cooling water, and the water temperature requirement is also low, and the heat exchange method is indirect heat exchange, which will cause the reactor directly in contact with the cooling medium water The wall temperature is lower than the temperature inside the reactor, the urea and the normal alkanes in the raw oil will react on the wall to form a complex, and attach to the tube wall to form a wall phenomenon, which reduces the heat transfer effect. It is easy to block the pipeline for a long time and affect the normal production

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