Largest-Yet DME-Powered Diesel Cuts Emissions
20 December 2005
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| The DME-fueled generator |
JFE Engineering Corp., Daihatsu Diesel Mfg. and Iwatani International Corp. announced the development of a low-pollution generator system powered by a diesel engine that runs on dimethyl ether (DME)—the largest such engine to date powered by the synthetic fuel. (Topic.)
DME is to diesel what LPG is to gasoline. It is gaseous at ambient conditions but can be liquefied at moderate pressure. As a fuel for compressed ignition engines it has very attractive characteristics, burning very cleanly and producing virtually no particulates (a dedicated DME vehicle would probably not require a particulate filter but would need a purpose-designed fuel handling and injection system).
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| WTW energy requirement and GHG emissions for synthetic diesel fuel pathways and 2010 vehicles. |
DME is produced through gasification of various renewable substances or fossil fuels. The synthetic gas is then catalyzed to produce DME. DME can be produced at lower energy use and GHG (greenhouse gas) emissions—especially when biomass is used as a feedstock—than other GTL or BTL fuels.
The generator system, built at the Tsurumi plant of JFE Engineering, has an output of 1,250 kW. Daihatsu Diesel provided the engine and Iwatni the provision of the DME fuel.
Through engineering such as adding an exhaust gas recirculation device, the companies were able to maintain the same thermal efficiency as in conventional generators while reducing nitrogen oxide emissions to 30 parts per million. The new generator produces one-thirtieth as much air pollution as diesel engines that use conventional fuel and clears even Yokohama’s emissions standards, which are the strictest in the country.
The three companies expect to sell the generator system as a power source for factories in urban areas with strict emissions regulations.
DME is being considered as an alternative transportation fuel is several regions of the world, notably Asia. Shanghai Automotive in China recently displayed new DME-fueled city buses. (Earlier post.) Last fall Japan began a series of DME road trials evaluating the durability and practicability of DME trucks when they run long distances on public roads. (Earlier post.)
Earlier this year, the Volvo Group unveiled its first truck equipped with a DME (dimethyl ether) engine. This represents Volvo’s second-generation heavy-duty DME vehicle. Volvo Truck Corporation and Volvo Bus Corporation built an earlier (1996–1998) prototype DME bus for testing and demonstration of the low-emissions and high-efficiency capabilities of the fuel. (Earlier post.)
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DME doesn't appear to have the flex fuel option like blends of ethanol and petrol. The ability to phase in a fuel gradually could be a key to its success. I hope the vapour is not as trippy as the old diethyl ether (DEE) we used to spray inside carburettors on frosty mornings.
Posted by: Aussie | 20 December 2005 at 05:47 PM
The claims I've seen for DME state that it is non-toxic.
DME can be made catalytically from methanol (forms DME and water), so a DME engine could presumably take pure methanol fuel. Carbureting methanol into the intake air (high octane) and igniting with DME (high cetane) might allow some very innovative fuel systems and control strategies.
Posted by: Engineer-Poet | 20 December 2005 at 08:18 PM
Only problem I can see is that breathing it is addictive and it's fairly easy to overdose. It will probably kill quite a few kids before it's outlawed.
Posted by: Lucas | 21 December 2005 at 10:22 AM
If it doesn't exist except between a vehicle's on-board reactor and the fuel injectors, I don't see what kids could get into.
Posted by: Engineer-Poet | 21 December 2005 at 11:15 AM
EP, you don't know kids, then.
Posted by: jcwinnie | 21 December 2005 at 02:02 PM
When the DME unit is part of a heavy truck, any kids hanging around it are going to be chased off muy pronto.
Posted by: Engineer-Poet | 21 December 2005 at 07:04 PM