Lotus Engineering has unveiled its latest development towards carbon neutral road transport at the 78th Geneva International Motor Show. The Lotus Exige 270E Tri-fuel is the most powerful road version yet of the Exige (0-60 mph / 96 kph in 3.88 seconds, a top speed of 158 mph (255 km/h), 270 hp (201 kW / 273 PS at 8000 rpm) and it runs on any mixture of gasoline, bioethanol and methanol. Emerging technologies will allow alcohol fuels such as methanol, already a proven internal combustion fuel, to be made synthetically from CO2 extracted from the atmosphere.

An alcohol-based fuel derived renewably from atmospheric CO2 would allow society to transfer relatively easily to sustainable, carbon-neutral internal combustion. Lotus Engineering is researching the use of sustainable synthetic alcohols as potential future fuels, with technology available from Lotus for introduction in four to five years. However, the supply infrastructure investment from governments and fuel companies could take 15 to 20 years.

The Exige 270E Tri-fuel is part of Lotus’ research to understand the complex combustion process involved in running on mixtures of alcohol fuels and gasoline, which will be important for a successful transition from today’s fuels to the sustainable, synthetic fuels of the future.

Methanol (CH3OH) can be produced synthetically from CO2 and hydrogen. Ultimately, emerging processes to recover atmospheric CO2 will provide the required carbon that can entirely balance the CO2 emissions at the tailpipe that result from the internal combustion of synthetic methanol. The result is that a car running on synthetic methanol, such as the Exige 270E Tri-fuel would be environmentally neutral.

As well as being green, the great benefit of synthetic methanol is that it would use similar engines and fuel systems to those in current cars; and synthetic methanol can be stored, transported and retailed in much the same way as today’s liquid fuels such as gasoline and diesel.

Synthetic methanol also possesses properties better suited to internal combustion than today’s liquid fuels, giving improved performance and thermal efficiencies. And it is ideal for pressure-charging (turbocharging and supercharging) already being introduced by manufacturers to downsize engines in a bid to improve fuel consumption.

Lotus Engineering’s Lotus Exige 270E Tri-fuel technology demonstrator illustrates how easy it is for synthetic methanol to be embraced over time as a future fuel for road transport. The Exige 270E Tri-fuel, with its supercharged 2ZZ-GE VVTL-i engine, could be the forefather of a new generation of conventionally driven cars that have the potential to be environmentally-neutral.

Techniques for the production of synthetic methanol through the extraction of atmospheric CO2 are well developed and understood but are not being employed on an industrial scale. An early solution would be the co-location of a nuclear or hydroelectric powerplant with a conventional power station – the hydrogen generated by hydrolysis of water would be combined with CO2 from either fossil or biomass sources to make liquid methanol. In the future, large volumes of CO2 could be extracted directly from the atmosphere.