In February of this year the European Commission proposed to force automotive manufacturers to cut carbon dioxide (CO2) emissions from cars by 18percent, with new cars expected to meet this target by 2012. In addition, stricter standards have been proposed so that between 2011 and 2020 fuel suppliers in the EU will have to achieve a 10percent reduction in the greenhouse gas emissions their fuels produce when they are refined, transported and used. Improvements in fuel quality will cut emissions even further.

According to the Commission, road transport is second only to power generation in terms of greenhouse gas emissions, accounting for approximately one-fifth of the EU’s total CO2 emissions. Passenger cars are the source of around 12percent of the EU’s CO2 emissions. While automotive manufacturers have significantly improved fuel efficiency – which has a direct affect on CO2 emissions – this has been insufficient to counteract the trend towards larger cars, bigger engines and more traffic. Between 1990 and 2004, CO2 emissions from road transport rose by 26percent.

The European Commission has therefore decided that the average CO2 emissions from new passenger cars should not exceed 120g CO2 per km by 2012. This compares with 186g CO2 per km in 1995 and 163g CO2 per km in 2004. Note that 120g CO2 per km corresponds to a fuel consumption of 4.5 litres per 100km for diesel cars and 5 litres per 100km for petrol (gasoline) cars. It is expected that most of the CO2 reductions will be achieved by improving engine efficiency, with other contributions coming from technologies relating to tyres, air conditioning and other components that affect overall fuel consumption.

Another measure that the Commission sees as important is a greater use of biofuels, in which crops absorb CO2 as they grow, which balances out the CO2 produced when they are burnt as a fuel (though there are, of course, CO2 emissions that result from the fuel’s processing and transportation unless particular care is taken to make the end-to-end process

‘carbon-neutral’). An EU directive (2003/30/EC Directive on the promotion of the use of biofuels or other renewable fuels for transport) aims to raise the market share of biofuels in road transport fuels to 5.75percent by 2010. In addition, to reduce the fossil carbon content of transport fuels, the Commission has proposed to progressively reduce the carbon content of transport fuels from 2011 onwards. The CO2 savings delivered by this measure up to 2012 will be counted towards the 120g CO2 per km target.

E85 Bioethanol

The fuel that currently offers the best option for people wanting to buy a biofuel-powered car is E85 bioethanol. This is a mixture of 85percent bioethanol and 15percent petrol, though availability depends where in Europe you are based – Sweden is currently the best served. Bioethanol is made from crops such as sugar beet, wheat and barley; in France, bioethanol is produced from a by-product of winemaking.

However, the most efficient feedstock for producing ethanol is bio-mass in the form of straw, organic waste or sawdust and forestry residue. Here ethanol is produced from cellulose, instead of starch, so yields are higher and the process is less energy-intensive. An industrial process for producing ethanol from wood and forestry waste is currently under development at a research and development pilot plant run by Etek Etanolteknik at Örnsköldsvik, Sweden. In this process, 1tonne of sawdust or similar material is required to produce around 200–250litres of ethanol.

In fact there is nothing new about manufacturing bioethanol, as the Model T Ford (Fig.1) was designed to run on it and it has been used as an emergency back-up fuel to make for up wartime shortages of fossil-based fuels. Ethanol and methanol have also been used historically and contemporarily in preference to petrol for high-performance cars (see panel).

Although bioethanol cannot be used directly in conventional petrol or diesel cars, both Saab and Ford have launched models that are designed to use E85.

On sale initially in Nordic markets, the UK and Ireland, the Saab 9-5 2.3t Biopower will later be made available in other European countries. It is being offered alongside the current 2.0t Biopower model, which is now said to be Sweden’s best selling ‘environmentally-friendly’ vehicle. By using turbocharging to exploit the higher octane rating of E85 bioethanol fuel, the new 210BHP Biopower variant delivers 14percent more power and 11percent more torque when running on E85 compared to petrol.

Jan-Åke Jonsson, Saab Automobile’s managing director, said: “The launch of a 2.3 turbo model is a logical next step in the roll-out of our successful Biopower concept. It is being offered in response to customer demand for an eco-friendly vehicle that delivers even more performance. It is the first in a number of future Biopower initiatives that we have under development.”

Both of Saab’s Biopower models combine the benefits of ‘going green’, through cutting CO2 emissions, with the enjoyment of sporty performance. A further practical advantage of the Biopower formula allows customers to run on gasoline and/or E85 fuel in any proportions without the need to make adjustments.

Running on E85, the 2.3t Biopower engine delivers a maximum power of 210BHP and 310Nm of torque, which compares with 185BHP and 280Nm when using petrol. As an example of what the increased performance enables, the saloon with manual transmission accelerates from zero to 100kph in 7.9seconds on E85 and 8.5seconds on petrol.

The adaptability of Saab’s Trionic engine management system has facilitated re-programming to accommodate the different ignition timing and fuel/air mixture requirements of E85 fuel. The Trionic system monitors fuel quality after each visit to the filling station and automatically makes any adjustments necessary for running on E85 and/or petrol in any combination.

E85 has a much higher octane rating (104RON) than petrol (95RON), and turbocharging allows the use of a higher boost pressure and more advanced ignition timing – giving more engine power – than is possible on petrol, without any risk of harmful ‘knocking’

(pre-detonation). The only hardware modifications necessary are more durable valves and valve seats, and the use of bioethanol-compatible materials in the fuel system, including the tank, pump, lines and connectors.

Kjell ac Bergström, executive director of Saab Automobile Powertrain, explains: “The engine management system automatically adjusts for the blend of fuel so, if there is no E85 available, the customer can simply run on gasoline at any time.”

More power, less CO2

Saab has already developed engines that can run on 100percent pure bioethanol (E100), eliminating fossil fuel emissions altogether, as seen in its AeroX and Saab Biopower Hybrid concept cars. Shown in 2006 at the Stockholm, London and Paris motor shows, the Saab Biopower Hybrid Concept demonstrates how pure bioethanol and electric power can be combined to yield fuel and energy savings, as well as greater performance. It is claimed to be the world’s first hybrid vehicle capable of delivering zero fossil fuel emissions at all times.

However, the ultimate example of Saab Biopower is the exciting Aero X concept car. Running on E100, its twin-turbo 2.8-litre V6 engine delivers maximum power and torque of 400BHP and 500Nm, respectively. Computer simulations for this high-performance,

all-wheel-drive coupé suggest zero to 100kph acceleration in just 4.9seconds.

Continuing on the theme that being environmentally friendly does not mean that life has to be dull, Ford unveiled a bioethanol-powered Ford Focus

Coupé-Cabriolet concept at its stand at the British International Motor Show in 2006 (Fig.2). This flexible fuel vehicle (FFV) concept was shown alongside the

new FordC-MaxFFV and the existing five-door and estate versions of the Ford Focus FFV that was launched in 2005 (Fig.3).

Ford’s 1.8-litre FFV technology in the three cars is said to achieve a CO2 emission figure of 99.6gperkm, and there is no difference in purchase price between the standard models and the FFV variants.

With the European Commission and some of the automotive giants backing bioethanol, the pressure is mounting on governments to play their part.

Anna Petre, Saab’s government relations manager, has been hosting fact-finding visits to Sweden for civil servants and politicians from various European member states.  She says: “Momentum behind E85 is starting to build. There is a great deal of international interest in what is happening here in Sweden. This has been stimulated by the EU taxation and energy directives and the availability of flex-fuel vehicles such as our Saab9-5Biopower model.

“The real attraction of E85 is the fact that it can be supplied in parallel with the existing gasoline infrastructure. For the short and medium term, it provides a practical ‘here and now’ solution, ahead of the arrival of fuel-cell vehicles using hydrogen-based technology, which are currently under development within the industry.

“In Europe as a whole, I believe we are approaching a critical mass situation, when suitable products and fuel both start to become available. To facilitate this process, it is essential for governments and the automotive industry to work together. I can foresee a time in the not-too-distant future when the majority of car manufacturers will be offering flex-fuel vehicles.”