Di-metil eter

 

Application: To produce dimethyl ether (DME) from methanol using Toyo Engineering Corp.’s (TEC’s) DME synthesis technology based on methanol dehydration process. Feedstock can be crude methanol as well as refined methanol.

Description: If feed is crude methanol, water is separated out in the methanol column (1). The treated feed methanol is sent to a DME Reactor (2) after vaporization in (3). The synthesis pressure is 1.0 – 2.0 MPaG. The inlet temperature is 220 – 250°C, and the outlet is 300 – 350°C. Methanol one-pass conversion to DME is 70 – 85% in the reactor. The reactor effluents — DME with byproduct water and unconverted methanol — are fed to a DME column (4) after heat recovery and cooling.

In the DME column (4), DME is separated from the top and condensed. The DME is cooled in a chilling unit (5) and stored in a DME tank (6) as a product. Water and methanol are discharged from the bottom and fed to a methanol column (1) for methanol recovery. The purified methanol from this column is recycled to the reactor after mixing with feedstock methanol.

Economics: The methanol consumption for DME production is approximately 1.4 ton-methanol per ton-DME.

Commercial plants: A 10,000-tpy unit was commissioned in August 2003 in China and is the first fuel DME facility. A second 110,000-tpy facility is scheduled to start up in the third quarter of 2005 in China and will be the largest DME plant.

Reference: Mii, T., “Commercial DME plant for fuel use,” First International DME Conference, Paris, France, Oct. 12 –14, 2004

Licensor: Toyo Engineering Corp. (TEC).