Production process and device for preparing ethylene through dehydration of ethanol

Abstract

The invention provides a production process and device for preparing ethylene through dehydration of ethanol. According to the invention, an ethanol dehydration reaction system, a quenching compression system, an alkaline tower system, a molecular sieve regeneration system, an ethylene purification system, a propylene refrigeration circulation system and the device are arranged. The production process comprises the following steps: feeding ethanol to the ethanol dehydration system, and carrying out a dehydration reaction to obtain reaction gas; cooling and separating the reaction gas in the quenching compression system, and returning the recovered ethanol to the ethanol dehydration reaction system; feeding crude ethylene, carbon dioxide, water and the like to the alkali washing and molecular sieve system, and removing carbon dioxide and water to obtain crude ethylene; feeding the crude ethylene to the ethylene purification system to obtain an ethylene product; and providing cooling quantity for the ethylene purification system via the propylene refrigeration circulation system. According to the process, gradient utilization of heat of high-temperature reaction product gas is designed; a propylene circulation compression refrigeration system is adopted to provide a low-temperature refrigerant, so energy consumption in the process is effectively reduced; and external water replenishing is canceled while sewage discharge of the system is reduced, so water resource consumption is reduced.

Description

technical field [0001] The invention relates to a process for producing ethylene, in particular to a process and device for preparing ethylene by dehydration of ethanol. Background technique [0002] The chemical formula of ethylene is C 2 h 4 , is the simplest alkene. Ethylene is a colorless gas with a sweet smell at room temperature, and its density is 0.5678g / cm at -104°C 3 , Insoluble in water, slightly soluble in acetone and benzene, soluble in ethanol and ether. Ethylene is flammable and explosive, and can form explosive mixtures with air, with an explosion limit of 2.7% to 36% (V). Ethylene is active in nature and prone to reactions such as polymerization, oxidation, alkylation, halogenation and carbonylation. [0003] Ethylene can be used to prepare a variety of organic raw materials. At present, about 75% of petrochemical products are produced from ethylene, including acetaldehyde, acetic acid, ethylene oxide, ethylene glycol, ethylbenzene, chloroethanol, vinyl...

AI Technical Summary

Problems solved by technology

[0011] The main inventions and optimizations are all based on the local design on the original basis, lack of overall understanding of the ethanol to ethylene process, and have not fundamentally solved the existing problems of the existing original process, such as small reaction unit scale, poor selectivity, and catalyst accumulation. Serious carbon, unreasonable energy utilization in the low-temperature refining process, high energy consumption in operation, high process waste emissions, and high failure rate of production process equipment have not been resolved.

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