NGV Global

The dual-fuel modified bus operates primarily on biomethane.

Emissions reduced by 50%

A consortium brought together by low carbon experts at the University of East Anglia (UEA) has launched what is claimed to be the first bus in the UK to run on clean, biomethane gas, which is reported to reduce pollutant emissions and greenhouse gas emissions by around a half. It is hoped the technology will be rolled out to bus fleets across the country and further afield.

The consortium is led by UEA’s Low Carbon Innovation Centre (LCIC) and includes independent bus operator Anglian Bus, bus manufacturer Optare plc, and engine conversion specialists Hardstaff Group of Nottingham.

The bus will make its first public showing at LCV 2009, UK exhibition of low carbon vehicle technology, on September 9 and 10.

The dual-fuel vehicle is a standard Optare Solo single-deck diesel midibus from the Anglian Bus fleet. Originally powered entirely by diesel, the Mercedes-Benz engine has been adapted to run for 60-80 per cent of the time on clean, low-carbon biomethane. The fuel tanks were installed at Optare’s Leeds plant and the engine conversion undertaken at Hardstaff’s Nottinghamshire headquarters. In addition, Hardstaff is supplying a gas refuelling station to Anglian Bus and will keep it supplied with biomethane.

Project leader Dr Bruce Tofield, of UEA’s Low Carbon Innovation Centre, said the cost of conversion of a diesel bus to dual-fuel use is a small fraction of the cost of a new natural gas bus and potentially a viable option for most if not all diesel buses in the UK and elsewhere.

Funding for the project came partly from an EU-sponsored Civitas programme in which UEA and Anglian Bus were partners with Norwich, Norfolk County Council and cities across Europe. The Civitas Initiative exists to promote cleaner and better transport in Europe’s cities.

LCIC scientists have been monitoring air pollution in Norwich since 2005 as part of the Civitas programme. In Norwich, as in many UK cities, emissions from buses are of particular concern. They noticed how the buses in Malmo in Sweden, a partner city in the Civitas programme, were powered by clean natural gas (methane), resulting in significantly lower levels of harmful emissions. Of special interest was the fact that Malmo was beginning to use biomethane rather than natural gas to reduce greenhouse gas emissions as well as pollutant emissions.

“This conversion shows just how important EU projects can be in helping us learn from what cities elsewhere have done,” said Dr Tofield. “Now we are going one step further and showing how existing bus fleets can be economically converted to low-carbon, low-emissions rung. The potential for reducing traffic pollution and greenhouse gas emissions from buses and other fleet vehicles in cities in Britain, Europe, and across the world is very exciting.

Replacing an entire bus fleet with new vehicles is extremely expensive but the LCIC staff realised that a lower-cost solution was already at hand in the UK. Hardstaff’s own fleet of heavy goods vehicles, converted to dual-fuel use, have now successfully covered in excess of 40 million kilometres and now run on biomethane.

Biomethane is chemically identical to the methane in natural gas but it is made by bacterial action on biowastes. Biomethane is extracted from landfill sites or from biogas produced in purpose-built anaerobic digestion facilities.of the time on clean, low-carbon biomethane.

Benefits of using biomethane as a fuel include:

• A reduction in particulate and NOx emissions levels of around half compared with diesel leading to cleaner air in towns and cities.
• Reduced operating costs on a cost per mile basis
• A reduction in greenhouse gas emissions of around half as a result of using methane from landfill sites, food and agricultural waste.

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