Technology for preparing dimethyl ether by performing gas-phase catalytic dehydration on methanol

Abstract

The invention discloses a technology for preparing dimethyl ether by performing gas-phase catalytic dehydration on methanol. The technology is implemented by the following steps: pressurizing and metering methanol serving as a raw material in a circular methanol storage tank by using a methanol feed pump, exchanging heat with reaction gas in a methanol heat exchanger, introducing into a methanol vaporization tower, heating a vaporization tower reboiler with heat conducting oil, exchanging heat of vaporized vapor-phase methanol with reaction gas through a gas heat exchanger, and introducing the heat-exchanged vapor-phase methanol into a reactor at two segments; indirectly cooling a crude methyl ether condenser with cooling water; introducing a material discharged from the crude methyl ether condenser into a crude methyl ether storage tank for undergoing gas-liquid separation to form crude methyl ether serving as a liquid phase and hydrogen serving as a gas phase, introducing the gas-phase material into a washing tower, absorbing DME (Dimethyl Ether) in the gas-phase material by using a methanol aqueous solution from a rectifying tower kettle, pressuring and metering the crude methyl ether discharged from the crude methyl ether storage tank by using a rectifying tower feed pump, and introducing into a rectifying tower. A DEM product is obtained by rectifying and separating from the upper part of the tower, is placed into product storage tanks after being metered in product metering tanks, and is sold by being pumped into a tank car.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a technology for producing dimethyl ether through catalytic dehydration of methanol in gas phase. Background technique [0002] In recent years, my country's dependence on oil has increased rapidly, and the development of oil substitutes and clean energy has become an important choice for energy strategy. As an alternative energy source, dimethyl ether has gradually shown its advantages and has been widely valued by countries all over the world. [0003] Dimethyl ether is an internationally recognized green renewable new energy, which is environmentally friendly, does not pollute the environment, and has a low and stable price. It has been listed as one of the key promotion projects of the National Science and Technology Commission. As civil fuel gas, its storage and transportation, combustion safety, premixed gas calorific value and theoretical combustion temperature ...

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Problems solved by technology

[0005] (1) Sulfuric acid method: The main features of this process are mild reaction conditions, high conversion rate of methanol per pass, and intermittent or continuous production, but the equipment is seriously corroded, the residual liquid and waste water are serious environmental pollution, the operating conditions are harsh, and the post-treatment of products is comparatively difficulty

[0006] (2) Direct synthesis of dimethyl ether from synthesis gas: This process actually combines the two-step reactions of methanol synthesis and methanol dehydration into one reactor. Large-scale industrial installations, the technology is not yet mature

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