A low-rank coal hydrogenation-pyrolysis-gasification coupled integrated polygeneration process method

Abstract

A low-rank coal hydrogenation-pyrolysis-gasification coupled integrated polygeneration process. Pulverized coal is obtained from low-rank coal through a pulverizing unit; part of the pulverized coal is mixed with external heavy oil, pyrolysis sludge, heavy fraction tar and catalyst to carry out a hydrogenation unit; the liquid phase product separated from the hydrogenation reaction product is hydrogenated and upgraded to obtain fuel oil , the solid oil residue is mixed with coal and enters the pyrolysis unit; the pyrolysis produced pyrolysis sludge and heavy fraction tar and heavy oil are mixed into the hydrogenation unit, the light fraction tar is separated from crude phenol and then enters the upgrading unit, and semi-coke enters the gasification unit , the part that generates synthesis gas provides hydrogen for the whole process, and the rest is used as raw material for other chemical equipment, and the ash is directly removed from the device. The invention couples the hydrogenation, pyrolysis and gasification processes of coal, utilizes the characteristics of the by-products of coal processing alone, uses low-rank coal and heavy oil as raw materials, and high-quality gasoline, aviation kerosene, diesel oil, coarse powder and synthesis gas as products , realize the large-scale, clean and efficient utilization of coal, and improve the overall operating economy of the device.

Description

Technical field [0001] The present invention belongs to the field of petrochemical and coal chemicals, and in particular, the present invention relates to a low-order coal hydrotion-pyrolysis-gasification coupling integrated multi-teleconcurrent process. Background technique [0002] my country's oil and gas resources is serious, and the crude oil is nearly 60% of the external dependency, and the resource endowment based on coal is determined that my country's energy consumption structure does not have a fundamental change. Coal consumption accounts for about 70% of my country's total resource consumption, causing serious environmental pollution with coal-dominated energy consumption structure, causing high attention to the government, and the policy of environmental protection will also be more strict. Therefore, coal clean transformation and efficient use are an important way to protect my country's energy strategy, industrial safety and mitigation coal extensive application ca...

AI Technical Summary

Problems solved by technology

However, in addition to the traditional oil and gas products, the two process routes also have 10-30% liquefaction by-product residues, which are composed of heavy oil (16.22%), asphaltenes (25.49%), pre-asphaltenes (14.02%) and organic insolubles. (44.27%), but it is a kind of solid waste, which is difficult to effectively use; at the same time, both of the two process routes belong to the hydrogenation reaction process of coal, and a large amount of hydrogen is needed as a raw material for hydrogenation during the operation of the device, and the construction cost of the device is high. In addition, the kerosene co-refining process requires a large amount of heavy oil raw materials with suitable properties, and the source of raw materials has always been one of the main reasons for the rapid development of this technology

However, at present, the yield of tar produced by coal pyrolysis in my country is generally lower than 8%, and the obtained coal tar has high oxygen content, high ash content, high content of polycyclic aromatic hydrocarbons, high colloid, and high asphaltene content. There are problems such as coking deposition in the reaction system and short service life of the catalyst during the catalyst and process; the pulverized coal is prone to dust, flammable, and explosive, and the pulverization during the pyrolysis process causes the pipeline to be easily blocked and coked, and the pyrolysis tar has a large dust content , resulting in difficult-to-handle oil sludge, difficulty in utilizing fine powder semi-coke, and serious excess production capacity, which greatly reduces the economical technology of pulverized coal pyrolysis

[0005] Because the operating temperature of traditional fluidized bed gasifier is lower than the ash melting point of coal, the coal with poor gasification reaction activity has a low carbon conversion rate in the fluidized bed gasifier, and the material cannot be fully utilized and converted.

Moreover, traditional fluidized bed gasifiers generally use dry slagging

At present, it is difficult to operate the dry slagging device under high pressure, resulting in low operating pressure of the gasifier, which limits the production capacity of the gasifier, and has stricter requirements on the melting point of the ash.

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