AB Volvo to Develop Third-Generation DME Engines for Heavy Vehicles
19 June 2006
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| Volvo DME truck. |
The Swedish Energy Agency (Energimyndigheten) has awarded AB Volvo a 62.2-million kroner (US$8.4-million) grant to support the technical development of a third-generation DME engine for heavy vehicles during the period 2006-2010.
The project’s goal is to deliver technology for a major field test with 30 third-generation DME-powered trucks planned for the years 2009 and 2010. The agency’s grant represents 50% of the project cost. AB Volvo is also investing in the project.
A small field test will be initiated in slightly less than a year with trucks based on Volvo’s second-generation DME technology, introduced in May 2005. (Earlier post.)
DME (dimethyl ether) is an LPG-like synthetic fuel that is produced through gasification of various renewable substances or fossil fuels. The synthetic gas is then catalyzed to produce DME. DME is particularly attractive for Sweden, as it is possible to use black liquor, a residual product from production of paper pulp, as the feedstock. (The energy balance of DME—and other synthetics derived from a gasification process—depends on the process and feedstock choice.)
DME is a gas that becomes a liquid under low pressure (i.e., like LPG). It has excellent characteristics as a compression ignition fuel; the primary work that needs to be done is on the fuel-injection system because of the different handling characteristics of the gas.
Volvo’s second-generation DME engine uses a low-pressure, common rail system, with an injection pressure less than 20% that of an equivalent diesel engine. A special fuel pump and sealing materials are designed to work with the DME gas.
For exhaust handling, the engine uses long route exhaust gas recirculation (EGR), with the gases introduced at the turbo inlet. This is possible because the gases have close to zero PM. Emissions from the engine are lower than the future Euro 5 standards, according to Volvo. Fuel consumption is, in energy equivalents, almost similar to a diesel truck, according to the company.
Earlier this year, AB Volvo acquired 40 million common shares, corresponding to 13%, in the Japanese truck manufacturer Nissan Diesel from Nissan Motor, with an option to acquire the remaining 6% of the shares from Nissan Motor within four years.
In addition to the other points of synergy between the two companies, each has developed its own compression-ignition engine trucks fueled by dimethyl ether. (Earlier post.)
DME is produced from methanol by chemical dehydration. In terms of its fuel and emissions properties, it is superior to mineral diesel.
One technical snag is that like LPG, it requires a pressurized tank for storage as a liquid. As a gas, it is slightly heavier than air and would settle near the ground if a leak were to occur in a enclosed parking structure. Ergo, both LPG and DME vehicles are denied entry.
Retrofitting a diesel-powered city bus is relatively inexpensive and substantially reduces its emissions. For commercial vehicles, the fuel only makes sense if there is a distribution network (vehicle range per unit of tank volume is reduced) and the cost is low enough. In that regard, Sweden and Finland are at a hug advantage as they each represent ~1/3 of the European paper pulp industry.
Note that there have recently been improvements in the pre-processing of wood pulp into sugars that are then turned into biomethanol. That may bring the cost of bio-DME closer to that of biodiesel, i.e. ~2x that of mineral diesel.
http://www.greencarcongress.com/2006/06/jgc_and_arkenol.html#more
Posted by: Rafael Seidl | 19 June 2006 at 02:29 PM
I understand DME has lower energy density than BTL diesel and the conversion is not particularly efficient. It all seems to be tied to the demand for paper and logically trucks in that industry should use it. However on a global scale the need for fuel will dwarf the demand for paper so that DME may not be the best route.
Posted by: Aussie | 19 June 2006 at 02:29 PM
Aussie -
the biochemical process for producing methanol and DME can use any lignocellulose as a feedstock, including e.g. straw. It's just that the paper mills have a lot of black liquor they need to recycle so that feedstock is available at relatively low cost.
No-one suggested that DME is the "best" route to meet global demand. No single biofuel will ever completely replace gasoline or diesel. Instead, until the industry shakes out, we'll see a proliferation of technological possibilities. Some may well remain limited to fleet users and/or certain countries. That in and of itself is no reason to dismiss them out of hand.
Posted by: Rafael Seidl | 19 June 2006 at 04:15 PM
DME also produced from natural gas. By building a DME plant at a natural gas rig will enable us to transport the energy without using high pressure tank or cryogenic tank.
The next thing is the cost of DME.
Posted by: rexis | 19 June 2006 at 06:49 PM
Its also made from coal.
Posted by: wintermane | 19 June 2006 at 08:14 PM
According to the article, DME is produced from gasification of renewable biomass or fossil fuel and then the synthetic gas is catalyzed to produce DME. Sounds like a pretty efficient processing of renewable biomass next best in term of efficiency to the direct utilization of resultant methane and hydrogen produced from gasification. Biodiesel is a lot more complex molecule structure and cannot be produced from any type of biomass, but must be produced from oil-rich biomass such as soy, rapeseed, animal fat, etc, thus greatly limit biodiesel's availability. In contrast, DME can be produced from gasification of any type of biomass, be it wood, straw, paper waste, etc... Furthermore, DME is also burns a lot cleaner and almost free of particulate matter (PM) and equivalent in energy to biodiesel.
What is there not like about DME? Thus, in the renewable fuel future, hydrogen and methane for cars, xTL fuel for those who so chooses (leery about the safety of hydrogen and methane), and DME for diesel trucks and diesel cars, and, well, of course, limited quantity of biodiesel and mineral diesel for those who must have (are addicted to) the pungent classical diesel exhaust. (It doesn't feel right going to a men's club without the smell of cigarette smoke, either)
Posted by: Roger Pham | 19 June 2006 at 11:01 PM
DME has energy density of about 19MJ/L (from http://www.greencarcongress.com/dme/index.html) while BTL diesel is alleged to have double this (from http://www.biorefineryworkshop.com/presentations/Blades.pdf). I don't have comparative energy losses from similar feedstocks but I believe in both cases the manufacturing thermal efficiency is well under 60%. DME apparently beats BTL diesel on nox and soot. However BTL diesel requires no engine modifications or special tanks, is always greenhouse neutral and can be blended with ethanol and petrodiesel. That's why I think it may be the fuel of the future.
Posted by: Aussie | 20 June 2006 at 12:28 AM
P.S. by BTL diesel I mean Fischer-Tropsch diesel from biomass, not biodiesel from transesterified fats and oils. That too is great, but limited.
Posted by: Aussie | 20 June 2006 at 12:33 AM
DME [and fischer tropsch reactions to make alcohols, paraffins, esters] can be made from any carbaceous material including carbon dioxide. In fact, any organic molecule can be made from any carbaceous material. The gasification step that produces CO and H is the one where the distinction lies. Some use steam reforming; others use partial oxidation; while you can also use carbon dixide reforming; autothermal reforming; or even feed CO2 and H into a reactor. Some of these may be technically feasible but economically might not fly.
There is a single phase DME reaction that combines methanol production and dehydration via the use of one slurry bubble column containing two catalysts - the methanol CuO/ ZnO and Aluminum dehydration catalyst. If the reaction goes longer the DME could tun into gasoline - the MTG process.
Posted by: alan njeru | 21 June 2006 at 09:20 AM
Find out more about the DME buzz at www.altfueltechnology.com
Posted by: Alternative Fuel Technology | 30 November 2006 at 01:06 PM
There are DME developments in China today:
China is already most advanced in commercial use of DME as a mixture with LPG. China is mainly interested in DME production from their own coal resources as national policy. South Korea is also interested in DME. As KOGAS is predominant in handling gas in South Korea , MOU for market study in South Korea has been signed between TOTAL and KOGAS quite recently. Their interest of DME is for LPG market as well as fuel for diesel trucks.
If you would like to know more on the latest DME developments, join us at upcoming North Asia DME / Methanol conference in Beijing, 27-28 June 2007, St Regis Hotel. The conference covers key areas which include:
DME productivity can be much higher especially if
country energy policies makes an effort comparable to
that invested in increasing supply.
By:
National Development Reform Commission NDRC
Ministry of Energy for Mongolia
Production of DME/ Methanol through biomass
gasification could potentially be commercialized
By:
Shandong University completed Pilot plant in Jinan and
will be sharing their experience.
Advances in conversion technologies are readily
available and offer exciting potential of DME as a
chemical feedstock
By: Kogas, Lurgi and Haldor Topsoe
Available project finance supports the investments
that DME/ Methanol can play a large energy supply role
By: International Finance Corporation
For more information: www.iceorganiser.com
Posted by: Cheryl Ho | 23 May 2007 at 08:16 PM