Two-stage hydrocracking method for high-nitrogen raw material

Abstract

The invention relates to a two-stage hydrocracking method for a high-nitrogen raw material. According to the method, high-nitrogen heavy distillate oil is used as a raw material, and two-stage process flow is employed; under hydrorefining conditions, the raw material heavy distillate oil and hydrogen are mixed and enter into a first-stage reaction zone which uses a hydrorefining catalyst, and an effluent of the first-stage reaction zone enters into a separation system; a separated liquid phase of the effluent of the first-stage reaction zone enters into a second-stage reaction zone with hydrogen, the hydrorefining catalyst and a hydrocracking catalyst are successively utilized along a flow direction of reaction materials in the second-stage reaction zone, and an effluent of the second-stage reaction zone enters into the separation system so as to obtain a hydrocracking reaction product. Compared with conventional two-stage hydrocracking technology, the method provided by the invention has the following advantages: process flow is more flexible, and more inferior raw materials can be processed. Compared with conventional one-stage tandem hydrocracking technology, the method can substantially improve processing capability of an apparatus. Moreover, the method can be carried out at mild conditions, which is favorable for increasing a running period of a hydrogenation apparatus.

Description

technical field [0001] The invention discloses a hydrocracking method, in particular to a two-stage hydrocracking method for processing high-nitrogen raw materials. Background technique [0002] With the rapid development of my country's economy, the oil processing capacity has grown rapidly. At the same time, domestic hydrocracking technology has also obtained large-scale industrial applications. By the end of 2009, there were more than 30 sets of hydrocracking units in operation in my country, with a total processing capacity of more than 40.0Mt / a, ranking first in the world. second. In addition, due to the year-by-year deterioration of the quality of domestic crude oil, the substantial increase in the processing volume of imported high-sulfur crude oil, the increasingly stringent requirements for environmental protection on the refining process and the quality of petroleum products, and the increasing market demand for clean fuel oil and chemical raw materials, especially...

AI Technical Summary

Problems solved by technology

[0005] In view of the deterioration of crude oil quality, the increase of impurity content, and the development of crude oil vacuum deep pressure and other unconventional energy sources, the impurity content of hydrocracking raw materials is getting higher and higher, especially the nitrogen content of some hydrocracking raw materials is relatively high. However, when the existing hydrocracking method deals with the hydrocracking feedstock with high nitrogen content, higher reaction temperature or lower operating space velocity is required, the processing capacity of the unit will decrease, energy consumption will increase, and the operation cycle will be shortened

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