Extracting agent for wax material in methanol to olefin reaction and application of aromatics solvent oil

Abstract

The invention belongs to the technical field of methanol to olefin technologies, and specifically relates to an extracting agent for a wax material in methanol to olefin reaction and application of aromatics solvent oil. The extracting agent comprises not less than 20% VOL of aromatics solvent oil. The extracting agent has the same extracting efficiency as pure xylene, and the toxicity and the corrosion are less than those of the pure xylene used as the extracting agent; the melting point, the boiling point and the flash point are higher than those of xylene; the safety is superior to that ofxylene; the price is less than that of xylene; the washing cost can be effectively saved.

Description

technical field [0001] The invention belongs to the technical field of methanol-to-olefins process, and in particular relates to an extractant for waxes in the reaction of methanol to olefins, and the application of aromatic solvent oil as the extractant for waxes in the reaction of methanol to olefins. Background technique [0002] With economic development and increasing demand for ethylene and propylene, resources such as naphtha and light diesel oil, which are raw materials for olefin production, are facing increasingly severe shortages. The chemical route of producing olefins from non-petroleum resources has begun to receive widespread attention. The methanol-to-olefins (MTO) process is a chemical technology that uses coal-based or natural gas-based synthetic methanol as a raw material to produce low-carbon olefins. The improvement of its process technology is of great significance to ensure the stable supply of low-carbon olefins. [0003] On August 8, 2010, the world...

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Problems solved by technology

[0004] However, after several years of operation, some problems have gradually been exposed, which have become bottlenecks restricting the long-term smooth operation of the project

For example, the oil substances produced during the reaction process of methanol to olefins cause frequent blockage of the water washing tower, heat exchanger and air cooler of the olefin separation device downstream of the system, resulting in poor oxide removal effect in the product gas of methanol to olefins, and alkali washing A series of problems such as a large amount of tower butter and blockage of the tower tray seriously affect the long-term operation of the device

[0005] The cleaning of heat exchangers and air coolers has to be carried out continuously, at least three times a week, and the cleaning cost of each heat exchanger is about 20,000 yuan, and the annual cleaning cost is about 3 million yuan; due to the main water washing The tower tray was clogged, and the pressure difference was extremely high after three months of operation of the device, up to 40KPa, seriously affecting the long-term operation of the device. In February 2012, due to the high pressure difference of the main water washing tower, the device had to be partially shut down for cleaning. Tower treatment, the product gas is torched during the tower washing period, and a total of about 2,700 tons of methanol is consumed. Calculated at the factory cost price, the cost is also more than 3 million

[0006] At present, this set of equipment uses xylene as the extraction agent to clean the waxy and oily substances in the equipment, and the cleaning effect is relatively ideal, but xylene is highly toxic and has great potential safety hazards, so it is urgent to find a New less toxic and less costly extractant than xylene to address deficiencies in prior art

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