|Bio-DME: wood to wheel. Click to enlarge.|
In a joint project with the EU, the Swedish Energy Agency, fuel companies and the transport industry, Volvo Trucks is investigating the potential for large-scale investment in dimethyl ether (DME) fuel produced from biomass (Bio-DME).
Volvo Trucks is participating in the project by contributing 14 Volvo FH trucks that will be tested by selected customers at four locations in different parts of Sweden between 2010 and 2012. The first field-test truck was shown today in Piteå, where the production of Bio-DME will take place in Chemrec’s demonstration plant, which just broke ground. (Earlier post.) The Volvo Group, of which Volvo Trucks is a part, is one of the co-owners of Chemrec via its subsidiary, Volvo Technology Transfer. (Earlier post.)
|Volvo’s DME truck. Click to enlarge.|
Compared with a conventional engine, Bio-DME as a fuel in a diesel engine provides the same high efficiency rating along with a lower noise level. The combustion process produces very low emissions of particulates and nitrogen oxides. Therefore, a simpler system can be used for after-treatment of the exhaust gases. The engine can also provide higher torque at start-up and thus improve driveability. And, compared with petroleum-derived diesel, Bio-DME generates 95% lower CO2 emissions on a lifecycle basis. All this makes Bio-DME an ideal fuel for diesel engines, according to Volvo.
Volvo’s DME truck uses a 440 hp (328 kW), Euro 5 D13 engine which with some modifications to the tank system, injection system and engine management software.
DME is filled in liquid form and stored in pressurized tanks in a leak-proof system. The lower energy content of DME, just over half that of diesel oil, is compensated by fitting larger tanks.
A special fuel pump regulates the pressure in the common rail injection system; the pressure keeps the fuel in liquid form all the way to injection. Special DME injectors have been jointly developed by Volvo and Delphi.
The moving parts in the engine are identical to those in the diesel variant. The engine management software has been modified to suit the different energy content.
|Black liquor. Click to enlarge.|
From a facility beside the Smurfit Kappa Kraftliner pulp plant, the project will produce four tonnes of Bio-DME per day. The raw material used is black liquor, an energy-rich, highly viscous by-product of the pulp industry. The plant is based on Chemrec’s patented black liquor gasification technology and Haldor Topsøe’s unique DME synthesis process.
From the holistic viewpoint, Bio-DME is one of the most promising second-generation biofuels. Bio-DME provides both high energy efficiency and low emissions of greenhouse gases. We value these two properties particularly highly as we analyse various possible alternative fuels.—Lars Mårtensson, environmental affairs director at Volvo Trucks
The field test gets under way in 2010 and encompasses the entire technological chain from biomass to fuel in trucks—i.e., including distribution and filling stations. Fuel company Preem will build filling stations so the trucks can be used in regular regional and local operations. The other companies involved in the project are Chemrec, Delphi, ETC, Haldor Topsøe and Total who are contributing as partners.
Inspections and evaluations of the fuel, truck technology, customer perceptions and distribution system will provide answers as to whether Bio-DME may emerge as one of the fuels that can partially reduce dependence on diesel oil.
The project will continue for a specific period and its evaluation as well as the long-term decisions of the authorities will determine whether full-scale industrial production will become reality. The challenges facing new fuels lie primarily in taking a long-term view, producing sufficiently large quantities of biofuels, and handling distribution via a suitably large number of filling stations.
The field test will give us valuable new insight into the potential of Bio-DME as a future vehicle fuel. The project still requires many tests, larger-scale fuel production and an extended infrastructure. And, perhaps most of all, clear guidelines from the authorities on how they view the fuel.—Volvo Trucks’ President and CEO, Staffan Jufors
DME. DME is a gas but is transformed into liquid form at a pressure of just 5 bar. It is straightforward to handle in a process similar to that required for liquefied petroleum gas (LPG). The most common application today is as a propellant in spray cans. DME can be produced from natural gas and also from various types of biomass, in which case it is known as Bio-DME.
From an European perspective, Bio-DME has the potential for replacing just over 50% of the diesel oil in heavy road transport by 2030, according to analysis by EUCAR/CONCAWE/JRC 2005, the European Commission and Volvo. The biggest challenge lies in creating an infrastructure for distribution of the fuel.