Method for gasifying CO2 and recovering vented material in the production of dimethyl carbonate

Abstract

The invention provides a method for gasifying CO2 and recycling an emptied material in dimethyl carbonate production. The method comprises the following steps: firstly, pumping water in a water storage tank into a tube pass of a carbon dioxide vaporizer by virtue of a pump, feeding to a blowdown condenser, and returning to the water storage tank, so as to form a closed loop; carrying out heat exchange on water together with liquid carbon dioxide when penetrating through the carbon dioxide vaporizer, so as to reduce the temperature; gasifying the carbon dioxide in a manner of heat absorption, so that CO2 is transformed into a gas state from a liquid state, so as to meet the production requirements; feeding low-temperature water to the blowdown condenser, and carrying out heat exchange together with gas emptied from dimethyl carbonate production; and condensing the gas-phase material emptied dimethyl carbonate production in the blowdown condenser into liquid, heating the water and returning to the water storage tank to recycle. The method is relatively low in requirements on the properties of equipment and materials; the gas-phase material in the blowdown condenser is condensed into liquid; and the material is recycled, so that the pollution to the environment is reduced; energy sources are reduced, so that the method has good economic benefits and social benefits.

Description

Technical field: [0001] The invention relates to the technical field of producing dimethyl carbonate (DMC) by transesterification, in particular to a gasification of CO in the production of dimethyl carbonate. 2 and methods of recovering vented material. Background technique: [0002] At present, CO is used in the process of producing dimethyl carbonate (DMC) by transesterification at home and abroad. 2 as raw material. In the process of producing DMC, it is necessary to deal with the Cat (catalyst) process, the CO used 2 It is the gas phase, in order to meet the requirements of Cat treatment, the purchased liquid phase CO must be 2 converted to gaseous CO 2 . [0003] The traditional process is to pass the heat transfer oil heated by the organic heat carrier furnace into the CO 2 In the gasifier heating tube, liquid CO 2 According to a certain flow rate, it enters the gasifier and is heated into gaseous CO 2 , CO 2 Gasification absorbs the heat of the heat transfer...

AI Technical Summary

Problems solved by technology

The disadvantage of this process is that the heat transfer oil needs the oil furnace to continuously provide heat to him, and then it is combined with liquid CO 2 For heat exchange, coal needs to be consumed to provide a heat source, resulting in high energy consumption and high production costs; since the temperature of heat transfer oil in the production process is generally 250 ° C, while liquid CO 2 The temperature of the heat exchanger is about -17°C, and the heat transfer temperature difference is large, so the material performance of the heat exchanger is required to be good, and the investment cost is high. In addition, the heat transfer oil is flammable at high temperature, which poses a great safety hazard, and the oil furnace will also cause environmental pollution.

The traditional process uses a condenser for condensation recovery. The cooling medium used is circulating water. The general temperature of circulating water is 28°C-35°C. The cooling effect is poor and the recovery amount is small.

The first is to cause waste, which makes the production cost high, and the second is to cause environmental pollution due to the emptying of a large amount of materials (mainly methanol and dimethyl carbonate), and also bring great potential safety hazards

For decades, relevant experts in the technical field have done a lot of exploration and discussion, but no breakthrough has been made

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