Method and device for producing good-quality diesel oil through combined hydrogenation of low-temperature Fischer-Tropsch synthesis oil and inferior crude oil

Abstract

The invention discloses a method and device for producing good-quality diesel oil through combined hydrogenation of low-temperature Fischer-Tropsch synthesis oil and inferior crude oil. The method includes the following steps that firstly, Fischer-Tropsch synthesis oil is subjected to hydrogen mixing treatment, and hydrofining is conducted in a liquid-phase circulating hydrogenation mode after saturation hydrogen dissolving; secondly, the hydrofining reactant obtained in the first step is mixed with inferior crude oil and Fischer-Tropsch wax oil to obtain mixed oil, and then hydrofining is conducted on the mixed oil in a gas-liquid countercurrent hydrogenation mode; thirdly, the hydrofining reactant obtained in the second step is subjected to hydrocracking and isomerization reaction in a gas-liquid countercurrent hydrogenation mode; fourthly, liquid-phase production oil obtained in the third step is fractionated to obtain the good-quality diesel oil. The invention provides a technical method for processing and producing the good-quality diesel oil from Fischer-Tropsch synthesis oil and inferior diesel oil through liquid-phase hydrogenation and gas-liquid countercurrent hydrogenation. The diesel oil with qualified density and high cetane number is obtained.

Description

technical field [0001] The invention relates to diesel production technology, in particular to a method and equipment for producing high-quality diesel through joint hydrogenation of low-temperature Fischer-Tropsch synthetic oil and inferior raw material oil. Background technique [0002] With the shortage of petroleum resources and the increasingly stringent environmental regulations around the world, the development of clean alternative energy technologies has gradually attracted attention, among which Fischer-Tropsch synthesis technology has attracted much attention because it can use coal, natural gas, biomass and other raw materials to produce high-clean fuels. focus on. Fischer-Tropsch synthesis technology can be divided into high-temperature Fischer-Tropsch synthesis technology and low-temperature Fischer-Tropsch synthesis technology according to the reaction temperature. The composition of the Fischer-Tropsch synthesis product is quite different from that of petrole...

AI Technical Summary

Problems solved by technology

However, the low-temperature Fischer-Tropsch synthesis product has the characteristics of high linear alkanes, high freezing point, and low density, which makes the hydrogenated diesel fraction have a high freezing point and low density, and cannot be directly sold as commercial diesel.

At the same time, in the process of refinery processing, inferior secondary processed diesel oil contains a large amount of aromatics and has a high density, but its cetane number is very low. The content of impurities such as sulfur, nitrogen and aromatics, and the H generated during the hydrogenation process 2 S, NH 3 Other gaseous impurities compete for adsorption on the active center on the surface of the catalyst, which has a greater inhibitory effect on hydrocracking and isomerization. The reaction temperature required for hydrocracking will be high, which in turn will affect the service life of the catalyst and energy consumption. and operating costs

[0003] There are some reports about how to utilize low-temperature Fischer-Tropsch synthesis products to produce diesel oil in the prior art, such as: Chinese patent CN10313468A discloses a kind of low-temperature Fischer-Tropsch synthetic oil hydrofinishing and / or hydroisomerization cracking process, the method is Hydrofining or hydrocracking unit adopts liquid phase hydrogenation and lower feed method, the disadvantage of this method is that the obtained diesel oil density is low, only 0.7586g / cm 3 Disclosed in the U.S. Patent No. 6,858,127 is a method for producing middle distillate oil, the method is to carry out hydrocracking of at least part of the synthetic oil, then separate out the kerosene diesel fraction wherein, tail oil is carried out hydrocracking again, and then separate the product kerosene diesel fraction, wherein the density of diesel fraction is 0.78g / cm 3 , The freezing point is -28 ~ 0 ℃, the disadvantage of this method is that the density of the diesel fraction is low, which cannot reach the diesel oil index for vehicles

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