Method for preparing fuel oil through catalytic hydrogenation of shale oil

Abstract

The invention relates to a method for preparing fuel oil through catalytic hydrogenation of shale oil. The method comprises the following steps: (a) removing impurities of which the particle size is greater than 20 mu m from the shale oil, mixing the shale oil with a sulfur-containing assistant and then mixing the shale oil with hydrogen, thus obtaining hydrogen mixed raw oil; (b) enabling the hydrogen mixed raw oil to react in a hydrogenation protective reactor and a hydrorefining reactor in sequence, carrying out gas-liquid separation on a reaction output object, mixing a liquid separation object of a low-pressure separator with desalted water containing an ammonia catcher, and entering a hydro-upgrading reactor for reacting; (c) carrying out primary separation on the reaction output object through a second high-pressure separator, and carrying out secondary separation on a separation object at the lower part of the second high-pressure separator through a second low-pressure separator; (d) separating materials in the second low-pressure separator, recycling a gas separation object at the top part, and feeding the liquid separation object at the bottom part to a fractionating tower; (e) fractionating in the fractionating tower, thus obtaining a final product. By using the method disclosed by the invention, the problem of coking can be effectively solved, poisoning cannot be easily caused by a catalyst, and the production cost is low.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a method for preparing fuel oil by catalytic hydrogenation of shale oil. Background technique [0002] Shale oil is a liquid product obtained by pyrolysis of kerogen shale. Compared with natural oil, it has the characteristics of high olefin content and high heterocyclic aromatic hydrocarbon content. The high heterocyclic aromatic hydrocarbons in shale oil hinder its direct utilization as transportation fuel oil; in addition, most of the nitrogen in shale oil exists in the form of aromatic compounds, and the presence of nitrogen in shale oil reduces the stability of the fuel, leading to To storage problems, also lead to increased NOx emissions during combustion. In addition, there is a high content of sulfur in shale oil. When the oil is burned, both nitrogen and sulfur are undesirable components because sulfur is released in the form of SOx. Therefore, to produce fuel oil from...

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Problems solved by technology

[0005] In the above two methods, the shale oil enters the hydrogenation reactor directly at high temperature. In this case, the unsaturated components in the shale oil will react sharply to form colloid, and then coke at high temperature to block the catalyst channel or catalyst bed. , leading to an increase in the system pressure difference, a decrease in the stability of the device, and even forced shutdown

In addition, because shale oil itself is not as stable as crude oil, it is easy to produce metastable substances at high temperature, and these metastable substances are prone to polymerization in the high-temperature, high-pressure hydrogen atmosphere in the reactor, which further aggravates the coking phenomenon

[0006] In addition, due to the high nitrogen content in shale oil, which can reach 5000-18000 μg / g, in this case the NH in the reactor 3 The relative content will be quite high, which will easily destroy the acidic center of the hydrogenation catalyst, so that the hydrogenation catalyst will be deactivated rapidly, and the life will be shortened. It is necessary to continuously interrupt production to replace the catalyst, resulting in high production costs.

[0007] The advantage of the one-stage hydrogenation method is that the process is simple and conventional catalysts can be used. The disadvantages are poor system stability, serious coking, and short catalyst life; the advantages of the two-stage hydrogenation method are good system stability, coking problems, and short catalyst life. The problem is relatively good, but its disadvantage is that it needs to use a special catalyst, the cost is high, and if the quality of shale oil is poor (high colloid content, high nitrogen content), the problem of catalyst poisoning and coking has not been solved well

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