Fuels of the future: New fuels will replace fossil fuels
Improved fossil fuels and high-quality alternative fuels represent a further component in the effort to achieve an optimal environmental balance sheet for the overall drive system. Our path to the fuel of the future will take us from clean conventional fuels and first- and second-generation biofuels to the use of hydrogen for fuel cell drive systems.
Bioethanol, biodiesel, and hydrotreated vegetable oils as admixtures. The current practice of blending fossil fuels with bioethanol and biodiesel is already helping to enhance the environmental balance sheet for road traffic. Daimler has committed itself to supporting activities that consistently exploit the potential of biofuels. Daimler is initially creating the technologies which ensure that Mercedes-Benz passenger 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 can already operate with biogenic fuels containing up to 10 percent ethanol (E10). Most older Mercedes-Benz and smart models equipped with gasoline engines can also run on E10 fuel.
To also enable diesel vehicles to reduce the CO2 emissions from their fuel even more, the admixture of biodiesel (fatty acid methyl ester, or FAME) will be increased in Germany from 5 to 7 percent (B7) starting in January 2009. Extensive fleet tests of new and older vehicles from Mercedes-Benz Cars have demonstrated that B7 is suited for use while at the same time meeting the German quality standard DIN 51628. The admixture of biofuel above 7 percent would be possible through the use of high-quality hydrotreated vegetable oils (HVO). These HVOs are low in emissions and can be easily used as admixtures.
Biomass-to-liquid (BTL) — the second 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 can also be used with all current and future diesel engines without any need for retrofitting. BTL fuels are manufactured through the gasification of all types of biogenic replacement and waste materials, which means that their production does not compete with food and animal feed crop cultivation.
Daimler and Volkswagen have been shareholders in CHOREN Industries GmbH in Freiberg, Germany, since October 2007. The company is pursuing the market introduction of climate-friendly second-generation synthetic biofuels. CHOREN developed SunDiesel® fuel, which has a high cetane number and thus delivers much better ignition performance than conventional diesel. The biofuel is completely free of sulfur and aromatics. It can also be used without adjusting existing infrastructure and drive systems, while 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 during its cultivation, 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 the German federal state of Saxony in April 2008. The plant is currently being ramped up and will commence production during the course of 2009. The annual production capacity is 18 million l (4.8 million USgal) of BTL fuel, which is enough to operate around 15,000 passenger cars.
CHOREN plans to build further plants, each of which will be able to produce 250 million l (66 million USgal) of fuel per year. The first large-scale industrial facility could be operating as early as 2013.
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 cooperation between political decision-makers, the oil industry, the energy sector, and other potential investors. In order to promote such an effort, Daimler is taking part in cooperative projects such as the Clean Energy Partnership (CEP) in Europe.
Daimler’s fuel road map
- Conventional fuels such as gasoline and diesel will continue to play a dominant role 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.
- CNG (compressed natural gas) is, from Daimler’s viewpoint, a promising option for certain applications, because it contains less carbon than gasoline and diesel.
- GTL (gas-to-liquid) fuels are — beside BTL (biomass-to-liquid) fuels — the cleanest and highest-quality fuels for diesel engines. This is because GTL diesel is free of sulfur and aromatic compounds — although it is not CO2-neutral — and can be adapted to meet the requirements associated with internal combustion engines.
- Hydrogen is the energy carrier for fuel cell vehicles. In the fuel cell, 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 natural gas, suitable economically viable processes for H2 production from renewable sources must be developed.
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First-generation biofuels, such as bioethanol and biodiesel represent an intelligent option for the short to medium term, insofar as negative effects on food production can be avoided and they can be blended with conventional fossil fuels in concentrations that are compatible with the operation of the vehicles. Because biodiesel has quality short-comings that can only be improved by means of suitable standardization, the admixture of this fuel must, for technical reasons, be limited to a concentration of no more than 7 percent.
Hydrotreated vegetable oils (HVO) are low in emissions and are manufactured on an industrial scale. They are suited for use as an interim solution until second-generation biofuels are introduced. HVOs can be mixed with fossil fuels at any level of concentration without restriction.
- BTL (biomass-to-liquid) fuels made from biomass will grow in importance as soon as they can be produced on an industrial scale. 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 directly compete with the cultivation of food or feed crops. In addition, they can be excellently matched to the requirements of internal combustion engines.
- Hydrogen from renewable sources is the fuel of the future. In combination with the fuel cell it will guarantee mobility that is free of emissions and CO2. Suitable production processes include electrolysis using electricity derived from renewable sources (hydroelectric, wind, solar, and geothermal power) or from the gasification of biomass.
