Built-in instant dehydration micro-interface reinforced DMC preparation system and method

Abstract

The invention provides a built-in instant dehydration micro-interface reinforced DMC preparation system and method, wherein the system comprises a reaction tower; the middle part of the reaction tower is provided with a sealing plate; a first reaction section is arranged above the sealing plate, and a second reaction section is arranged below the sealing plate; the side wall of the first reaction section is connected with a methanol pipeline and a mixed gas pipeline from top to bottom; a first micro-interface generator is arranged in the first reaction section, a second micro-interface generator is arranged above the first micro-interface generator, and the first micro-interface generator and the second micro-interface generator are both connected with the mixed gas pipeline so as to disperse and crush mixed gas into micron-level microbubbles; a microbubble outlet is formed above the first micro-interface generator and clings to the first micro-interface generator; and a bottom outlet of the second micro-interface generator is connected with a micro-bubble pipeline. The preparation system disclosed by the invention is low in required reaction temperature and pressure, few in side reaction, high in methanol conversion rate and worthy of wide popularization and application.

Description

technical field [0001] The invention relates to the field of methanol carbonylation reaction preparation, in particular to a built-in instant dehydration micro-interface enhanced DMC preparation system and method. Background technique [0002] The methanol liquid-phase oxidative carbonylation method is a CH-based 3 OH, O 2 And the method for synthesizing DMC (dimethyl carbonate) with CO under catalyst action. [0003] The existing production process is generally carried out in two sets of reaction devices. Each reaction device consists of two parallel reactors and a gas-liquid separation tank. The reaction temperature is 115-120° C., and the reaction pressure is 2.2-2.5 MPaG. The normal operating liquid level of the gas-liquid separation tank is about 50%. The catalyst is a cuprous chloride-based catalyst, the particle size of the catalyst particle is 200 mesh (74 μm), it is in a quasi-homogeneous state in the slurry, and the content is 1.5%-3% (wt). [0004] The liqui...

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Problems solved by technology

Since the sparger openings are at the millimeter level (φ5mm), the diameter of the generated bubbles is relatively large (8-15mm), the gas-liquid interface area is relatively small, and the initially distributed bubbles are easy to coalesce during the rising process, and the bubbles in the reactor The distribution is uneven, and the liquid circulation adopts the density difference circulation method, and the flow velocity is slow (<0.1m / s), which makes the gas-liquid mass transfer rate low, resulting in a macroscopic reaction rate that is seriously lower than the design expected value;

[0008] (2)O 2 The consumption is high, but the actual effective utilization rate is very low;

[0009] (3) The single-pass conversion rate of CO is about 2-8%, and the amount of CO feed is too much, so the power consumption of the fresh CO compressor and the circulating CO compressor is too large;

[0010] (4) Because the product DMC stays in the system for too long, it undergoes a hydrolysis reaction with water to generate CO 2 , while CO and O 2 Side reactions are prone to occur, and these factors greatly reduce the conversion rate of raw materials

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