Acetylene hydrogenation slurry bed reaction as well as catalyst separation device and method

Abstract

The invention belongs to the field of preparing ethylene through acetylene hydrogenation, and relates to acetylene hydrogenation slurry bed reaction as well as a catalyst separation device and method.The method comprises the following steps of enabling acetylene and hydrogen gas to be subjected to hydrogenation reaction in a hydrogenation reactor which contains a catalyst and a working solution,discharging crude ethylene after reaction, separating a working slurry solution with a membrane separator to obtain a concentrated solution and a clear solution, conveying the concentrated solution directly to the hydrogenation reactor to be recycled, enabling the obtained clear solution to be subjected to gas-liquid separation, and then enabling gas and a fresh working solution to return into thehydrogenation reactor to be continuously used. The hydrogenation reactor is internally provided with an angle gear-shaped gas redistribution device, the gas volume fraction in the working solution can be improved, the radial distribution uniformity of the gas in the reactor is improved, the conversion rate of acetylene and ethylene yield are improved; an airtight membrane separator is adopted toperform solid-liquid separation on the working slurry liquid, the separation process can be guaranteed to be safe and stable, a by-product 'green oil' can be timely extracted, the activity of the catalyst is guaranteed, and the reaction can be promoted to be successfully performed.

Description

technical field [0001] The invention belongs to the field of hydrogenation of acetylene to produce ethylene, and relates to a slurry bed reaction and catalyst separation device and method for hydrogenation of acetylene. Background technique [0002] Ethylene is an important chemical raw material, mainly used in the field of PVC production. China is a big consumer of ethylene, and the annual ethylene consumption is increasing year by year. However, 70% of the world's ethylene is currently produced using crude oil as raw material. The development of this "oil-poor and coal-rich" region in China is extremely unfavorable; the production of acetylene from coal and hydrogenation of acetylene to ethylene are not only in line with China's basic national conditions, but also can solve the problem of excess acetylene in some areas. Good economic development model, but the acetylene hydrogenation process has the characteristics of large heat release and difficult control of the reactio...

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Problems solved by technology

[0002] Ethylene is an important chemical raw material, mainly used in the field of PVC production. China is a big consumer of ethylene, and the annual ethylene consumption is increasing year by year. However, 70% of the world's ethylene is currently produced using crude oil as raw material. The development of this "oil-poor and coal-rich" region in China is extremely unfavorable; the production of acetylene from coal and hydrogenation of acetylene to ethylene are not only in line with China's basic national conditions, but also can solve the problem of excess acetylene in some areas. Good economic development model, but the acetylene hydrogenation process has the characteristics of large heat release and difficult control of the reaction. The traditional fixed bed hydrogenation reactor is difficult to meet the existing process requirements, while the slurry bed reactor can Under certain conditions, the temperature in the reactor is kept uniform, and the solid catalyst is uniformly dispersed in the reactor, and the inner surface of the catalyst is utilized to a greater extent, thereby increasing the conversion rate of acetylene and the yield of ethylene. Therefore, the ethylene hydrogenation slurry bed production process It is widely used in the process of hydrogenation of acetylene to ethylene; however, in the industrialization process of hydrogenation of acetylene in a slurry bed to ethylene, there are often problems due to uneven gas distribution, which affects the conversion rate of acetylene and the yield of ethylene, or conventional plate and frame filtration Poor airtightness of operation, high risk index, low filtration precision, poor separation effect and other problems make the working fluid with by-product "green oil" unable to be removed safely and effectively in a timely manner, resulting in a decrease in catalyst activity; in order to optimize acetylene hydrogenation A lot of work has been done in the slurry bed reaction and separation process: Aiming at the problem of uneven gas-liquid distribution in the reactor, Chinese patent CN105056844A discloses a slurry bed distributor for hydrogenation of acetylene to ethylene. The distributor is composed of two groups of gas distribution tubes that intersect obliquely and are connected in the center. The plane where the two distribution tubes are located forms an acute angle with the horizontal plane. This distributor can increase the gas distribution area and improve the gas distribution effect, but such a distribution The gas distribution device can only achieve uniform gas distribution in a limited area close to the distributor. In the middle and upper part of the reactor far away from the distributor, it is impossible to avoid the bubble coalescence phenomenon, resulting in uneven gas in the reactor as a whole, which ultimately affects the reaction effect. ; Chinese patent CN106631674A discloses a device and method for hydrogenation of acetylene to ethylene. The invention uses vacuum filtration to separate the catalyst and the working fluid. Although this mode of operation can achieve solid-liquid separation to a certain extent effect, but the vacuum filtration accuracy is not high, and the vacuum filtration operation method is difficult to ensure the airtightness of the filtration system. There are certain safety hazards in the process of processing flammable and explosive gas working fluids such as acetylene, ethylene, and hydrogen.

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