Dimethyl Ether Production in China

Donish Khan
December 13, 2012

Submitted as coursework for PH240, Stanford University, Fall 2012

Fig. 1: A DME production flowchart. (Source: Wikimedia Commons)

Introduction

Dimethyl Ether (DME) is a clean alternative fuel that is coal based. China plans to lead the world in the clean energy race by creating the largest dimethyl ether project in order to reduce oil consumption. The country's high population faces oil shortages and is developing methods for substitution. [1] In comparison to liquefied petroleum gas (LPG) and diesel, DME is both economical and better for the environment because of its lower smoke emission rates. China's goal is to fulfill the country's growing demand of alternative fuel and rely less on oil imports by using this organic chemical. [1]

Attractiveness of DME

The biodegradable fuel, which is both non-carcinogenic and non-corrosive, is ideal for everyday applications. Although China is focusing on using the coal-based product as a fuel substitute for LPG, dimethyl ether also serves as an aerosol spray propellant and may be applied to domestic use for heating and cooking. DME's purity rate of 99.9% makes it the better environmental choice. Unlike the majority of fossil fuels that harm the environment, dimethyl ether has no impact on climate because it does not emit sulfur when burned. [2] Chlorofluorocarbons (CFCs) which causes depletion of the ozone layer may also be replaced by this coal-based alternative because DMEs do not damage the ozone layer. [2,3] DME's low carbon footprint and high energy efficiency are most appealing to a country like China where energy usage is increasing. China Energy Limited is the biggest Chinese producer of dimethyl ether. The company uses liquid phase dehydration technology to produce DME. [4] The company sells its product to LPG distributors who blend the DME in the gas and the output is a product with improved combustion. This company also produces methanol, which is used entirely as a feedstock for the production of DME. [1] However, China's use of methanol is controversial because methanol production increases CO2 emissions. [4]

Conclusion

Currently, China plans to increase DME capacity by adding more DME plants, such as the China Energy Limited company, throughout the region. By promoting the benefits of dimethyl ether, China has built an industry where DME serves as a readily available substitute for conventional diesel and petroleum based fuel. [4]

© Donish Khan. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.

References

[1] Y. Niu et al., "Dimethyl Ether - Clean Fuel in the 21st Century," J. Nat. Gas Chem. 9, 59 (2000).

[2] T. A. Semelsberger, R. L. Borup, H. L. Greene, "Dimethyl Ether (DME) as an Alternative Fuel," J. Power Sources 156, 497 (2006).

[3] G. Brasseur and C. Granier, "Mount Pinatubo Aerosols, Chlorofluorocarbons, and Ozone Depletion," Science 257, 1239 (1992).

[4] C.-J. Yang and R. B. Jackson, "China's Growing Methanol Economy and Its Implications for Energy and the Environment," Energy Policy 41, 878 (2012).