Hydrogen receives a lot of airtime as the annointed energy carrier of the future, but there are other possibilities that could go into our future energy mix—one of them being Dimethyl Ether (DME).
DME is a clean burning (completely sootless) synthetic fuel that can substitute for conventional diesel, liquified petroleum gas (LPG) or be reformed into hydrogen for fuel cells. As a diesel fuel replacement it reduces NOx emissions 90%, meeting the 2007 diesel emission standards, and features high cetane. A cetane number marks the ignition quality of a diesel fuel by measuring the delay between the start of injection and combustion. A high cetane number has a shorter delay period and is more desirable.
Part of the interest in DME stems from the ability economically to produce it from a number of feedstocks: coal, natural gas, biomass.
Asian countries, especially China, India, Japan and Korea, are extremely interested in DME, given their increasing energy needs and current consumption of diesel, LPG and LNG (liquefied natural gas). China, in particular, because of its enormous coal reserves, is interested in the Coal to DME process.
Oil and gas companies are focusing on DME as a way to productize their natural gas resources. (Bringing stranded natural gas -- i.e., natural gas produced by wells that are far from distribution pipelines -- is driving the interest in LNG (earlier post). Another option is for the oil and gas companies to convert the gas to product (liquid, fuel, chemical) close to the well site and tranport that instead.)
On the biomass side, a European consortium including Volvo recently published research on generating DME from black liquor—liquid waste from the paper pulp process—at a cost competitive with gasoline.
At FISITA this week, there were three technical sessions related to DME: two exploring use of DME as a fuel for HCCI engines (see earlier post on HCCI) and one on DME in a truck.
Lets keep track of this as we move along.