Our fuel road map
In addition to the refinement of drive systems, improved fossil fuels and high-quality alternative fuels are contributing to an optimal environmental performance of the entire drive system. They are therefore an important component of our road map toward sustainable mobility: Our route to the fuel of the future leads from clean conventional fuels via biofuels to hydrogen and electricity that are generated from renewable energy sources. We are trying out new types of fuel in our vehicles and working with partners from politics, research institutes, and business to ensure the use of more alternative fuels and fuels that produce less CO2. That’s why we need to forge ahead with the respective manufacturing technologies and the creation of an appropriate infrastructure.
1. Conventional fuels such as gasoline and diesel will continue to play a key 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.
2. Daimler believes that CNG (Compressed Natural Gas) is a promising option for certain applications, because it contains less carbon than gasoline or diesel, and its use therefore reduces CO2 emissions by around 20 percent, compared to gasoline.
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 and can, within certain limitations, be adapted to meet the requirements associated with internal combustion engines. The well-to-wheel CO2 emissions are comparable to those of fossil diesel fuel.
4. Fuel cell automobiles use hydrogen as fuel. In the fuel cell, the hydrogen reacts with oxygen to form water, while generating electricity in the process. Global hydrogen requirements have until now been largely met through steam reformation from natural gas. Because the creation of hydrogen by this means emits CO2, suitable economically viable processes need to be developed to produce hydrogen from renewable sources.
5. First-generation biofuels, such as bioethanol (made from grain or sugar beet) and biodiesel, are intelligent options for the short to medium term when blended with conventional fossil fuels in concentrations that are compatible with the operation of the vehicles. However, this is only the case if their manufacture does not negatively impact food production or the natural environment. Because biodiesel has quality shortcomings, the admixture of this fuel must, for technical reasons, be limited to a concentration of no more than seven percent.
6. Hydrotreated vegetable oils (HVO) are low in emissions and are already manufactured on an industrial scale. As is the case for first- and second-generation biofuels, the cultivation of biomass must be carried out in conformance with appropriate sustainability standards (such as the sustainability directive for biofuels) in order to ensure a positive ecological balance. HVOs will be suitable for use as an interim solution until it proves possible to introduce second-generation biofuels. They can be mixed with diesel fuel at higher levels of concentration without restriction. According to current estimates, around two million tonnes of HVO (Neste Oil process) will be available worldwide, beginning in 2011/2012.
7. Second-generation biofuels, such as BTL (biomass-to-liquid) fuel, will grow in importance, as soon as they can be produced on an industrial scale. Daimler is promoting the further development and use of largely CO2-neutral synthetic biofuels, which make optimal use of biomass and contain no sulfur or aromatic compounds. BTL fuels can be made from replacement and waste materials, which means that their production does not compete with the cultivation of food crops or animal feed. BTL fuel can also help to reduce emissions of particulates, CO, and HC. Depending on the biomass and production process used, BTL fuels can reduce well-to-wheel emissions of greenhouse gases by up to 90 percent.
BTL fuels and biogas (Compressed BioGas, CBG) from renewable raw materials achieve the highest energy yield per hectare. Vehicles running on natural gas can utilize biogas that has been processed until it has achieved the quality of natural gas without requiring any technical modifications. CBG is produced by fermenting biomass, slurry, and waste water under anaerobic conditions. Depending on the biomass and production process used, biogas can reduce well-to-wheel emissions of greenhouse gases by up to 80 percent.
8. Hydrogen produced using renewable resources and electricity are the fuels of the future. Used to power fuel cell or battery-driven vehicles, they guarantee emission-free and CO2-free mobility. Suitable production processes for hydrogen as a renewable resource involve electrolysis using electricity derived from renewable sources (hydroelectric, wind, solar, and geothermal power) or from the gasification of biomass.
High-quality biofuels reduce dependence on fossil energy sources and make a huge contribution to emission reduction. Bioethanol and biodiesel are first-generation biofuels that are especially suited for use as admixtures in conventional fuels.
Jatropha — A success story continues. High-quality biodiesel fuel can be manufactured from the seeds of the jatropha plant. Jatropha-based diesel fuel has a positive CO2 balance and offers clear environmental advantages compared to fossil-based diesel fuel, especially if the location-related advantages of the plant are taken into account. For example, jatropha can be cultivated on barren, eroded land where food plants cannot grow. Daimler launched a new jatropha project in southern India in early 2010. Farmers from the local villages are cultivating jatropha plants there and harvesting the nuts for the production of diesel fuel — and the project is extremely promising: The Indian government has declared that 20 percent of all fuels must consist of biofuels, relying primarily on those derived from the jatropha plant, by 2017.
Palm oil — An alternative with limitations. In a pilot project, Daimler is currently testing the use of the NExBTL diesel fuel in cooperation with Deutsche Post DHL, the energy company OMV, Stuttgarter Straßenbahnen AG, and the Finnish oil company Neste Oil. The aim of the field tests, which involve ten Mercedes-Benz trucks and four Mercedes-Benz Citaro urban buses, is to investigate to what degree this biofuel, which is made from hydrated vegetable oils (HVO), can be used in series- production vehicles and how great the resulting emissions reduction would be under the conditions of everyday use. It has already been determined that the combustion of NExBTL in the engines produces far fewer pollutant emissions. Compared with fossil fuels, the nitrogen emissions from the use of the biofuel are up to 15 percent lower, and the CO2 emissions are reduced by more than 60 percent throughout the entire process — from the cultivation of the raw material to the use of the fuel in the vehicle. However, in order to achieve these results the palm oil that is used as a raw material must be sustainably cultivated and harvested without cutting down rain forest area or turning land used for growing food into fields for growing energy plants. To ensure that this is the case, Neste Oil has specified strict rules for the production of the raw materials used for NExBTL. The oil company confirms that the suppliers are contractually obligated to use sustainable production methods and assures its customers that the fuel is produced 100 percent sustainably.
For Daimler, making progress on the road to having an effective, sustainable biofuel also means always taking the production of the base material into account. For example, the reduction of CO2 emissions does not justify the clearing of tropical rain forests for palm oil cultivation or expanding jatropha cultivation onto land used for growing food crops. In the longer term, therefore, synthetic fuels that are made from biogenic waste and are not in conflict with the production of food crops and animal feed are the better alternative.