Process of producing dimethyl ether liquefied gas by methanol

Abstract

The invention relates to a method of producing dimethyl ether liquefied gas by methanol, directly inputting methanol steam to a reaction kettle with compound liquid catalyst, controlling producing temperature at 120-250 deg.C and pressure at 0.2-3.8 MPa, making it pass through a buffer, a condensing tower, a gas-liquid separator, and then input it to liquid gas storage tanks by a compressor, and obtaining the products. It can use 72%-99.9% methanol as raw material, the producing temperature is easy to control, the heat conduction is fast, and the reactor is uniformly used; it uses liquid catalyst, the catalyst is inactivated slowly and easy to make and able to repeatedly use, the corrosion to the device is low, and it can implement continuous production, and make the dimethyl ether products with purity 90-99%.

Description

Technical field [0001] The invention relates to a method for producing dimethyl ether liquefied gas from methanol. Background technique [0002] The molecular formula of dimethyl ether (DME) is CH 3 OCH 3 , colorless, non-toxic, has similar physical properties to liquefied petroleum gas (LPG), has no damage to the atmospheric ozone layer, and is easily degraded in the atmospheric troposphere; since dimethyl ether does not contain sulfur, it has non-corrosive liquefied gas tanks, The superior characteristics of liquefied gas cylinders. DME has a high octane number, good power performance, and less pollution. It can be developed and widely used as vehicle fuel, achieving the dual effects of environmental protection and independent energy. At present, the preparation method of dimethyl ether requires large equipment investment, complex production equipment, high heating temperature and high production pressure. Some of them use solid catalysts. , It is easy to cause catalys...

AI Technical Summary

Problems solved by technology

At present, the preparation method of dimethyl ether requires large equipment investment, complex production equipment, high heating temperature and high production pressure. Some of them use solid catalysts. , it is easy to cause catalyst poisoning, so that the expensive catalyst is discarded, which seriously affects the production

Chinese patent application CN 1368493A discloses a "method for preparing dimethyl ether by catalytic dehydration of methanol", which is in the presence of SO 4 2- Dehydration is carried out in the presence of a solid acid catalyst, and the solid acid catalyst contains alkali metal oxides, which is unfavorable to the dehydration reaction. Therefore, the content of alkali metals needs to be controlled, and the catalyst must be prepared through a series of processes. The process is complicated and the catalyst is easy to lose It must be replaced after deactivation, otherwise the catalytic reaction cannot proceed, and the catalyst cannot be reused

In addition, some preparation methods use liquid catalysts and use liquid methanol (99.9% refined methanol) as a raw material. Once the amount of feed increases, the temperature will drop sharply, and the methanol in the reactor cannot react immediately, and the methanol will fill the reactor. Stop production to process unreactable methanol, so continuous production cannot be guaranteed