Fuels for the future: New fuels will replace fossil fuels
High-quality and alternative fuels represent a further component in the effort to achieve an optimal environmental balance for the overall drive system. Our path to the fuel of the future will take us from clean conventional fuels to second-generation synthetic biofuels and the use of hydrogen to power fuel cell drive systems.
Bioethanol and biodiesel as additives. The current practice of blending fossil fuels and crop-derived fuels such as ethanol and biodiesel is already helping to enhance the environmental balance sheet for road traffic. Daimler has committed itself to supporting activities that exploit the potential of biofuels more consistently than has previously been the case. More specifically, Daimler is committed to creating technologies which ensure that vehicles can run on fuels with up to 10 percent of biofuel admixtures. All of the gasoline engines in our current Mercedes-Benz and smart models are already suitable for operation with biogenic fuels containing up to 10 percent ethanol (E10). Plans call for such fuels to be introduced in Germany in mid-2008. By far the majority of all older Mercedes-Benz and smart models can also run on E10 fuel. Excluded here are vehicles with first-generation four-cylinder gasoline direct injection engines from the years 2002–2005. Also excluded are models produced ex works without a three-way catalytic converter, or with a carburetor. These vehicles are generally more than 23 years old.
Biomass-to-liquid (BTL) – the second, latest generation of biofuels. The testing of Mercedes-Benz diesel engines has shown that switching to synthetic fuels such as BTL would reduce particulate emissions by as much as 30 percent and cut emissions of carbon monoxide and hydrocarbons by up to 90 percent. BTL fuels are manufactured through the gasification of all types of biogenic waste materials, which means that their production does not compete with food crop cultivation. BTL fuels can also be used with all current and future diesel engines without any need for retrofitting.
Daimler and Volkswagen have been shareholders in CHOREN Industries GmbH in Freiberg, Germany, since October 2007. CHOREN is pursuing the market introduction of climate-friendly second-generation synthetic biofuels produced through gasification. CHOREN developed SunDiesel® fuel, which has a high cetane number and thus delivers much better ignition performance than conventional diesel. SunDiesel® is completely free of sulfur and aromatics and significantly reduces pollutant emissions. SunDiesel® can also be used without any adjustment of existing infrastructure or engine systems, and the fuel is largely CO2-neutral as well. The environmental “balance sheet” of SunDiesel shows that, compared to conventional fuels, as much as 90 percent of CO2 emissions can be prevented along the entire BTL value chain comprising cultivation, fuel production, and use. Mercedes-Benz intends to fill the tanks of all new diesel vehicles leaving its production plants with SunDiesel® as soon as an adequate supply of the fuel is available.
CHOREN commissioned the world’s first commercially operated BTL production facility in April 2008. When it reaches full capacity, the plant, which is located in the German state of Saxony, will produce 18 million liters of BTL fuel per year. That’s enough to fill the tanks of 15,000 passenger cars. A second facility with an annual capacity of 250 million liters is now being planned.
Hydrogen – the fuel of the future. Before the fuel cell drive can be brought to market, progress has to be made regarding the production of hydrogen from renewable sources and the establishment of a suitable hydrogen supply infrastructure. Both of these tasks call for extensive cooperation between governments, the oil industry, the energy sector, and other potential investors. In order to promote such an effort, Daimler is taking part in the Clean Energy Partnership (CEP) in Europe.
Daimler’s fuel road map
1. Conventional fuels such as gasoline and diesel will continue to be used in the years ahead, which is why they must be continually optimized. The goal here is the worldwide use of sulfur-free fuel that contains low levels of aromatic compounds.
2.Daimler believes that CNG (compressed natural gas) is a viable option for certain applications, because it contains less carbon than gasoline or diesel.
3. Beside BTL (biomass-to-liquid) fuels, GTL (gas-to-liquid) fuels are the cleanest and highest-quality fuels for diesel engines. This is because GTL diesel is free of sulfur and aromatic compounds – although not CO2-neutral – and can be adapted to meet many of the requirements associated with internal combustion engines.
4. Hydrogen will power the fuel cell vehicles of the future. In the fuel cell, the hydrogen reacts with oxygen to form water. Global hydrogen requirements have until now been largely met through steam reformation from natural gas. However, since this process still gives rise to CO2 emissions due to the carbon content of the gas, suitable economically viable processes for H2 production from renewable sources must be developed.
5. Bioethanol and biodiesel are intelligent options for the short to medium term when blended with conventional fossil fuels. However, such crop-derived fuels have a lower energy content, so their fuel economy is not as favorable as that of fossil fuels. In addition, the aggressiveness and viscosity of biodiesel, and a more pronounced clogging of the particulate filter, make its use in pure form prohibitive in modern diesel automobiles.
6. BTL fuels made from biomass will soon grow in importance, initially as an admixture blended with gasoline and diesel fuel. The Group is currently working on ways to further the development and use of largely CO2-neutral synthetic biofuels. These fuels represent the optimal use of biomass, contain no sulfur or aromatic compounds, and their production does not compete with the cultivation of food crops. In addition, they can be excellently matched to the requirements of internal combustion engines.
7. The fuel of the future is hydrogen from renewable sources, which in combination with the fuel cell will guarantee mobility free of emissions and CO2. Suitable production processes involve electrolysis using electricity derived from renewable sources (hydroelectric, wind, solar, and geothermic power) or from the gasification of biomass.
