Delayed coking and reduced pressure distillation combined processing method

Abstract

The invention discloses a delayed coking and reduced pressure distillation combined processing method. The method comprises the following steps that: high-temperature gases produced by the delayed coking device are delivered into a coking fractional distillation column for distillation and a dry point of the wax oil is controlled to ensure the quality of the wax oil; and coking tail oil and normal-pressure residual oil are delivered into a reduced pressure distillation device together to further and deep extract residual coking wax, the residual coking wax and straight run wax oil are discharged out from the device at the same time, and reduced pressure residual oil containing a small amount of coke powder is used as delayed coking feed. The method improves the yield of coking wax oil and ensures the quality of the coking wax oil. With the increase of the extraction amount of the coking waxy oil, the amount of coking circulation oil is greatly reduced and the processing capacity of the coking device is improved, so the economic benefits are increased.

Description

technical field [0001] The invention belongs to the combined process of thermal processing technology and distillation device, in particular, it is a method for maximum production of distillate oil in the process of delayed coking and vacuum distillation. Background technique [0002] According to statistics, by 2005, the processing capacity of delayed coking units in the world will reach 226.48Mt / a. It can be seen that the coking process is still one of the important means to deal with residual oil. In terms of how to improve the yield of delayed coking liquid, major companies in the world have researched and developed many technical methods, such as: US5925236, US4784744, US5006223, US7067053, CN1448466A, CN1552799A, CN1487056A, CN1246514A, CN1465658A mainly reveal the improvement of delayed coking process , which increases the liquid yield. However, due to the poor separation precision of the coking fractionation tower, the output of the wax oil cannot be guaranteed whil...

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Problems solved by technology

Due to the limitation of the coking fractionation tower process, this technology still cannot achieve satisfactory results in the end

[0003] The coking fractionation tower mainly relies on the heat generated by coking to generate oil and gas to complete the separation of products under normal pressure conditions. Therefore, the separation accuracy of wax oil with a higher boiling point is poor, so that the temperature difference between the 90% point of coking wax oil and the dry point is very large. If If the output of coking wax oil is increased, its quality will become worse, and downstream processing devices will be difficult to process, which will seriously affect the total liquid yield of coking and cause a waste of resources

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