System and method for continuously producing dihydric alcohol ether

Abstract

The invention provides a system and a method for continuously producing dihydric alcohol ether. The system comprises a microchannel reaction unit and a separation and refinement unit which are connected with each other, wherein the microchannel reaction unit comprises microchannel reactors and a light component removal tank which are connected with each other; the microchannel reaction unit comprises at least one microchannel reactor. The invention also provides the production method. The system, provided by the invention, for continuously producing the dihydric alcohol ether has the advantages of being small in backmixing, high in heat exchange efficiency, and the like; after the system and the method are adopted, a reaction feed alcohol ratio is reduced, by-products are reduced, the technological process is simplified, the epoxide conversion rate is increased and can reach 99.9% or above, the selectivity of the dihydric alcohol ether is improved and can reach about 96%, the production efficiency is increased, the production energy consumption is reduced, and the economic benefit is improved.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and relates to a system and a method for continuously producing glycol ethers. Background technique [0002] Alcohol ether is a traditional good organic chemical solvent, which is widely used in fuel antifreeze, cleaning agent, extraction agent, flexo printing ink, screen printing ink, non-ferrous metal mineral processing agent, etc., among which ethylene glycol monobutyl ether, Propylene glycol monomethyl ether is two types of bulk solvent products commonly used in industry. Propylene glycol monomethyl ether (PM) is a green, environmentally friendly, non-toxic, excellent performance, and widely used chemical solvent. Its demand is second only to alcohol ether products of ethylene glycol monomethyl ether. With the increasingly stringent control requirements for environmental protection, it is also the most promising solvent product to replace the toxic medium glycol ether, and its deve...

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Problems solved by technology

CN101337864B discloses a method for preparing ethylene glycol mono-n-butyl ether by continuous pipeline reaction, the alcohol ratio adopts (5-6): 1, and the reaction time needs 1-3h, but its high feed alcohol ratio leads to the separation of light components The process is complicated and the separation energy consumption is high, and the reaction time is too long, which leads to many by-products of polyether.

CN102617299A discloses a method for continuous production of electronic-grade glycol ethers, using epoxides and alcohols as raw materials, adopting a two-stage series fixed-bed reaction process based on a composite solid alkali catalyst, and after the reaction, dealcoholization and deionization Electronic grade glycol ether products can be obtained through two processes. This process belongs to the fixed bed reaction method. The etherification reaction is carried out on a fixed bed reactor. The feed ratio is generally controlled above 4:1, and the temperature control generally reaches 160 °C, there are disadvantages such as large alcohol ratio, high reaction temperature and many side reactions

CN100556881A discloses a kind of preparation method of ethylene glycol monoethyl ether, this method first prepares catalyst, and then catalyst is placed in the tubular membrane in continuous membrane reactor, nitrogen blows outside membrane, is 3-4:1 with molar ratio Ethanol and ethylene oxide are used as raw materials. After the ethanol is preheated and vaporized at 90-100°C, the gas-phase ethoxylation reaction is carried out at normal pressure and 100-140°C. The space velocity of the reaction gas is (1-3) ×10 3 mL·g -1 h -1 , to produce ethylene glycol monoethyl ether. Membrane reactor is a relatively new reaction form. It reacts in the membrane after vaporizing the reaction raw materials, but there are generally few catalyst active sites, and the selectivity and yield of alcohol ether are relatively low. Low, not conducive to large-scale production

[0006] Compared with the traditional batch-type stirred tank production method, although the production method of alcohol ether disclosed in the above-mentioned documents has been improved, the problems of complex process, large alcohol ratio and low efficiency still generally exist.

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