BioDME (dimethylether) / Biomethanol
Dimethyl ether (typically abbreviated as DME), also known as methoxymethane, wood ether, dimethyl oxide or methyl ether, is the simplest ether. It is a colourless, slightly narcotic, non-toxic, highly flammable gas at ambient conditions, but can be handled as a liquid when lightly pressurized.
DME demand in Europe is around 80 kton per year, the production capacity is 140 kton. DME is used in non-transport applications with demonstration projects in transport. In Europe the main application is as aerosol spray can propellant replacing. BioDME can be produced using Biomethanol of Syngas produced from biomass. A commercial Biomethanol plant with a 440 kton capacity is in the Netherlands. DME production technology is mature and there are many commercial scale plants globally. World production of DME today stands at approximately 5 million tons per annum, and is primarily by means of methanol dehydration. The majority of global DME production is currently in China. Japan, Korea and Brazil have signi cant new production facilities, and major new capacity additions are planned or under construction in Egypt, India, Indonesia, Iran and Uzbekistan. China’s National Development and Reform Commission is calling for 20 million tons of DME production capacity by 2020. South Korea is studying all aspects of commercializing DME as a potential alternative energy source for the 21st century. In Sweden, Chemrec uses black liquor gasi cation, a waste stream from the pulping process, to produce BioDME.
DME and BioDME have a number of uses in products and are most commonly used as a replacement for propane in liquid petroleum gas (LPG) especially in Asia, but can also be used as a replacement for diesel fuel in transportation. Diesel fuel contains more energy per gallon than the gasoline that we use in most passenger cars, and where pure methanol would not be able to power a diesel engine as effectively, DME can. Today, DME is primarily produced by converting hydrocarbons via gasification to synthesis gas (syngas). Synthesis gas is then converted into methanol in the presence of catalyst (usually copper-based), with subsequent methanol dehydration in the presence of a different catalyst (for example, silica-alumina) resulting in the production of DME. Besides being able to be produced from a number of renewable and sustainable resources, DME also holds advantage over traditional diesel fuel because of its high cetane number – which measures the combustion quality of diesel fuel during compression ignition. By combusting more thoroughly, an engine tailored to run on DME can achieve higher efficiencies, better mileage and emissions reductions.
The FLEDGED project will deliver a process for bio-based dimethyl ether (DME - ethanol) production from biomass by combining the processes of flexible sorption enhanced gasification (SEG) and a novel sorption enhanced DME synthesis (SEDMES). The primary aim of FLEDGED is to develop a highly intensified and flexible process for DME production from biomass and validate it in the industrial environment (technology readiness level 5). Duration: 2016 - 2020.
The initial BioDME project to demonstrate production of BioDME from lignocellulosic biomass at industrial scale, involved a consortium of Chemrec, Haldor Topsøe, Volvo, Preem, Total, Delphi and ETC. The project was supported by the Swedish Energy Agency and the EU's Seventh Framework Programme. Dimethylether (DME) was produced from black liquor through the production of clean synthesis gas and a final fuel synthesis step. In order to check technical standards, commercial possibilities and engine compatibilities the BioDME has been tested in a fleet of Volvo trucks.
Due to its good ignition quality, with a high cetane number, DME can be used in diesel engines as a substitute for conventional diesel fuel. However, compared to diesel fuel DME has a lower viscosity (insufficient), and poor lubricity. Like LPG for gasoline engines, DME is stored in the liquid state under relatively low pressure of 0.5 MPa. This helps to limit the number of modifications required to the engine. Still, some slight engine modifications are necessary, primarily relating to the injection pump and the installation of a pressure tank, similar to that for LPG. The fuel line must also be adapted with specific elastomers. DME in diesel engine burns very cleanly with no soot.
The infrastructure of LPG can be used for DME. As part of the FP7 project BioDME, under the leadership of the Volvo Group, DME production is being optimized, especially for use as a transport fuel.
For more information on DME: International DME Organsiation (www.aboutdme.org)