Saab BioHybrid Concept
From Press Release:
Sweden has a long cultural and political tradition of environmental respect and this is reflected in Saab's own achievements, from the pioneering introduction of asbestos-free brake linings to the removal of CFCs from air conditioning systems. Now Saab BioPower offers the prospect of countering one of the main threats to the global environment, the build-up of 'greenhouse' gases such as carbon dioxide (CO2). BioPower's widespread adoption can also help overcome our historic dependency on fossil fuels.
In demonstrating the benefits of bioethanol as a fuel - it delivers more engine power as well as zero fossil CO2 emissions - Saab is supporting initiatives by the EU and the Swedish government to encourage the growth of bio-fuels. The outstanding success of Saab's current Saab 9-5 BioPower models, for example, shows how environmental benefits can be delivered with an even sportier level of performance.
"We have reached a turning point where action must be taken if we are to avoid a crisis in meeting our future energy needs for transport," says Jan Åke Jonsson, Saab Automobile's Managing Director. "Bioethanol provides an effective first step. It is a bridge that can lead us from obsolete fossil fuels towards new, sustainable technologies."
The use of bioethanol as a renewable fuel is a response to two global issues that must be addressed if the great mobility offered by road transport is to be sustained. First, there is an urgent need to begin to combat global warming brought about by the so-called 'greenhouse effect'. Second, alternatives must be found to overcome our dependence on oil. Global resources will soon no longer be able to keep pace with rising demand and it is only a matter of time before supplies eventually run out completely.
A long-standing natural balance in global CO2 levels began to change more than a century ago, with the advent of industrialization built on the use of fossil energy. A UN body, the Inter-governmental Panel on Climate Change (IPCC), estimates that this process is largely responsible for generating a 35 per cent increase in the global level of atmospheric CO2.
While industrial processes in the developed world have improved, emissions of fossil CO2 from road transport continue to rise and are now widely recognized as a major cause of the 'greenhouse effect'. Unless action is taken, future prospects are bleak. The World Business Council for Sustainable Development estimates that in the next 25 years the world's vehicle population will double, largely due to huge growth in China and other developing economies.
The use of bioethanol as a fuel can help reverse this environmental trend because its consumption does not raise atmospheric levels of CO2. It is already produced commercially from agricultural crops; in Brazil from sugar cane and in the United States from corn. And in Sweden research is underway to produce it from cellulose in wood and forestry by-products.
Unlike gasoline or diesel, the consumption of bioethanol does not add more CO2 to the atmosphere because emissions during driving are balanced by the amount of CO2 that is removed through the process of photosynthesis when crops for conversion are grown. In this way, the CO2 already present in the atmosphere is simply recycled, whereas the use of a fossil fuel, such as gasoline, releases new amounts of CO2 which have been locked away underground for millions of years.
Bioethanol is already added in very small quantities (5 to 10 per cent) to most of the gasoline blends we use today. Its main attraction as an alternative fuel is the fact it is available here and now; there is no expensive investment required in new technologies and, as it is a liquid fuel just like gasoline and diesel, it can be conveniently distributed through existing supply infrastructures.
Its other great benefit is that it can be introduced in parallel with existing fuels. And 'flex-fuel' vehicles, such as the Saab 9-5 BioPower, can run without adjustment from the driver, on bioethanol (E85) or gasoline in any proportions. So a Saab BioPower driver can put gasoline in the tank at any time should E85 not be available.
BioPower is part of a three-pronged approach in General Motors' propulsion strategy for the future. In the near-term, the use of renewable fuels, such as bioethanol, and improvements to gasoline and diesel powertrains will provide a first step. Energy efficient hybrid vehicles, using electric power, will be the next development and fuel cells powered by hydrogen offer the ultimate environmental answer. These technologies are not mutually exclusive and can be used in parallel to allow convenient periods of transition.
By combining bioethanol with turbocharging, Saab BioPower fully exploits the high octane performance of this fuel, as well as its environmental benefits. The technology is already well-proven by the outstanding sales success of the Saab 9-5 2.0t BioPower in Sweden.
Running on E85 (85% bioethanol/15% gasoline) fuel, which has an octane rating of 104 RON, compared to 95 RON for gasoline, it produces 20 per cent more maximum power and 16 per cent more maximum torque. This gives improved acceleration, with zero to 100 kph accomplished in 8.5 seconds, compared to 9.8 seconds for the 9-5 Sedan running on regular gasoline.
Turbocharging with bioethanol allows the use of a higher compression ratio - giving more engine power - and more advanced ignition timing than would be possible with gasoline, due to the risk of harmful 'knocking' or pre-detonation. The only hardware modifications necessary for the Saab 9-5 BioPower engine are the fitment of more durable valves and valve seats, together with bioethanol-compatible materials in the fuel system, including the tank, pump, lines and connectors.
E85 fuel is currently adopted to overcome cold starting problems that may occur in freezing temperatures but Saab is already developing engines that can run in all conditions on pure E100, completely eliminating fossil fuel emissions. This technology, introduced on the BioPower 2.8V6 turbo engine in the Aero X Concept car at the 2006 Geneva Motor Show, involves the use of spark ignited direct injection (SIDI), which gives BioPower engines the same starting performance as their gasoline counterparts.