Perspective of dimethyl ether as fuel: Part I. Catalysis

Abstract

Dimethyl ether (DME) is heralded as the cleanest high-efficiency compression ignition fuel as a substitute for diesel. DME's autoignition property and high octane number are favorable to use it as a substitute for diesel and also LPG as a cooking fuel. DME can be synthesized from different routes such as coal, petroleum and biomass including various greenhouse gases. Huge amounts of greenhouse gases (CO and CO2) are generated in coal or petroleum operated thermal power plants and released in the atmosphere. Roughly 5–10% of total CO2 emission can be utilized for fuel and chemical production. CO2 capture and sequestering (CCS) plants only can be sustainable if supported by DME synthesis plant with a capacity of 3000–7500 TPD. DME can be produced from CO2 using innovative catalysts, reactors and separators. Part I of this review is a representation of the innovative strategies which have been reported for the production of DME from different sources of raw materials, catalysts and influence of operational parameters on DME selectivity and yield. The critical gaps are identified and further, research potentials are given in Part I. However, the industrial processes using a variety of reactor configurations affect the overall capex and opex. The production of syngas, irrespective of the source, is the first step in DME synthesis, which is then followed by conversion into DME using a battery of reactors and separators. A critical analysis is presented and future scope is outlined in Part II.