Saturday, May 9, 2015
Victoria's Green Matters - 7th May 2015
Natural gas is a fossil fuel, formed from dead organic matter many millions of years ago and burns with emissions that result in climate warming. Biomethane is produced by anaerobic digestion – micro-organisms in the absence of oxygen break down human sewage and food waste to produce gas. This gas is then cleansed of impurities and carbon dioxide and, as a result, produces less greenhouse gas emissions – 80% less nitrogen oxide and 20-30% less carbon dioxide – and is almost free of particulates when used as a fuel.
The ‘BioBus’ is fuelled from the Bristol Sewage Treatment Works, situated seven miles from the city centre, where methane has been added to the national gas grid at the rate of 2,000 cubic metres per hour which is sufficient to power 8,300 homes. The one great drawback is that the bus must make the journey to the sewage works to refuel, miles from its route and the bus company cannot run any more ‘Bio-Buses’ until it can work out a more efficient way to refuel them.
This form of biofuel may well provide a solution the recent concerns over air pollution.