Raw material pretreatment method of slurry bed hydrogenation process and design method and application thereof

Abstract

The invention provides a raw material pretreatment method of a slurry bed hydrogenation process and a design method and application thereof. The method comprises the steps that raw coal is pulverized and ground to obtain pulverized coal, heavy oil is heated, part of the heated heavy oil is mixed with the pulverized coal, and part of the heated heavy oil is mixed with a catalyst; or all the heavy oil is mixed with the pulverized coal and the catalyst, an obtained mixture is mixed and kneaded in a mixing and kneading machine and circularly stirred in at least one stage of swelling tank to obtain catalyst and coal-oil slurry, the catalyst and coal-oil slurry is conveyed to a hydrogenation reactor, and pretreatment effect indexes are monitored in real time, wherein the pretreatment effect indexes comprise the coal conversion rate, the total yield of light oil and the degree of wear of equipment, pipelines and pump valves which the catalyst and coal-oil slurry pass through; when one or more of the indexes are abnormal, the operation conditions of raw material pretreatment are adjusted till all the indexes return to normal ranges. By means of the raw material pretreatment method of the slurry bed hydrogenation process, the coal conversion rate and the total yield of the light oil are increased; meanwhile, wear of the raw materials to the equipment, pumps, the valves and the pipelines is reduced, operation is easy and convenient, and the method is accurate and practical.

Description

technical field [0001] The invention relates to a raw material pretreatment method of a slurry bed hydrogenation process, a design method and an application thereof, and belongs to the fields of petrochemical and coal chemical industries. Background technique [0002] my country is a country rich in coal and poor in oil. In dealing with the contradiction between oil supply and demand and implementing energy conservation and emission reduction policies, making full use of coal and heavy oil resources is an important choice to ensure energy security. Slurry bed hydrogenation technology is an important technology for converting coal and heavy oil into light oil and chemicals, including oil-coal mixing process, direct coal liquefaction process and heavy oil hydrogenation process. The slurry bed hydrogenation process can effectively utilize heavy oil resources and coal resources, and remove impurities such as sulfur, nitrogen and heavy metals in raw materials, which poses challen...

AI Technical Summary

Problems solved by technology

[0004] There are also several technical problems in the prior art. First, it is difficult to accurately control the concentration of the oil-coal slurry. Either the concentration of the oil-coal slurry is too thin, and the coal particles are easy to settle in the pipeline, causing blockage; or the concentration of the oil-coal slurry is too high. High, the viscosity is too high, the resistance to flow in the pipeline increases, and even cannot be transported

[0005] Second, the conversion rate of coal is low when oil and coal are jointly hydrocracked. Since coal is a complex substance composed of macromolecules, macromolecules are based on aromatic nuclei formed by polycyclic aromatic hydrocarbons, and bridges are used as links The formed cross-linked network structure is the stationary phase; small molecules are trapped in the macromolecular network structure and is the mobile phase

The main part of the polyaromatic ring in coal is the main part, and a small number of bridge bonds are the secondary part. Due to the stable structure of the aromatic ring, the adjacent atomic bonds are difficult to break. Therefore, compared with the hydrocracking of oil, the hydrogenation of coal Cracking is more difficult, the adaptability to oil-coal mixing is low, and the conversion rate of coal is also low

[0006] Third, the catalyst dispersion problem, because the catalyst is generally a heavy metal catalyst, the density is much higher than that of liquid oil, the density difference is large, the catalyst is difficult to disperse evenly in the raw material

According to related patents, in order to reduce the density difference between the catalyst and raw materials used in the oil-coal mixing process, the catalyst is attached to the coal powder and directly added to the reactor, but the large amount of coal powder attached will affect the equipment, pumps, valves, etc. Wear and tear of the pipeline, not easy to hydrocracking, easy to coke during the reaction process and reduce the contact area between the catalyst and the reactants, reduce the activity of the catalyst, the role of the catalyst cannot be exerted, and the conversion rate of light oil is low

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