Biofuel breakthrough

A static diesel engine that runs on 100 per cent biofuel could help provide electricity to the remotest communities in the developing world, according to its UK developer, Lister Petter.

The engine, which the company claims is the first to be able to run on pure biodiesel — known as B100 — with no additives, can also run on a variety of vegetable oils which have not been converted to conventional biofuels.

Diesel engines were originally invented to run on a variety of fuels; the very first ran on peanut oil, But Lister Petter's group engineering director, Bob Bell, said the increasing complexity of the engines, designed to improve performance, made them less fuel-tolerant. The new engines, the Alpha-Bio range, have been developed to military-specification — designed to burn a wider range of fuels.

While conventional diesel engines are capable of running on 100 per cent biofuels, Bell said they might encounter problems. 'You might not get them to start when it's cold,' he said. 'Then, the majority of diesel fuel injection systems will clog with biofuels. You normally have to use additives to make them flow better, or mix them with mineral diesel. You've also go to ensure they are emissions-compliant.'

The Alpha-Bio range was a result of the company's decision in 2004 to develop its fuel-tolerant engines for civil applications. This, said Bell, involved redesigning the shape of the combustion chamber to maximise fuel efficiency. 'Then, we looked at what we had to do to make it burn biofuels, and that turned out to involve changing the valves and the valve seats,' he said.

Bell refused to be drawn on the design of the new valves, but he said that biodiesel tends to be somewhat abrasive and that a new design was needed to ensure components weren't damaged by wear.

He is adamant the Alpha-Bio represents a first for B100 engines, despite recent developments such as John Deere's announcement that many of its engines will run on B100 with a proprietary additive, and Virgin Air's Boeing 747 flight from London to Amsterdam on B100 earlier this year. 'Our engine requires no additives, and no changes at all — you can fill it with ordinary diesel, then switch to biofuels, or even just fill it with rapeseed oil, and it'll run and meet European emissions standards without any adjustment to the injectors or the timing,' he claimed.

The most likely application for the engine is in the developing world, particularly Africa, where the company has made its first Alpha-Bio sale. 'African communities often don't have diesel, and if they can get it, there's a risk it will be stolen. We also make a bioreactor that converts vegetable oils to biodiesel. This allows people to grow an oil crop, make biodiesel to run the engine, with which they can pump water for irrigation and generate electricity. With that comes lighting, which means schools and hospitals, gives people the opportunity for sustainable development.'

Stuart Nathan