Bath Bus Company, which operates a service that shuttles people between Bristol Airport and Bath City Centre, has put into operation the first bus in the UK to run entirely off biomethane generated through the breakdown of human waste and food waste.
When anaerobic digestion occurs, oxygen starved bacteria begins to break down biodegradable material in order to produce a biogas that is full of methane. If this gas is then treated in order to remove carbon dioxide and to add propane, it can be used as a biofuel. Bath Bus Company has utilised this to the full in order to operate the "Bio-Bus", with the biomethane gas being generated at Bristol sewage treatment works in Avonmouth.
The Bio-Bus can travel 186 miles on one tank of gas, which can be made out of the annual waste of only five people. That roughly means that the annual food and human waste deposits created by a single passenger can fuel the bus for 37 miles. However, it is not just a great way of using the gas produced during the treatment of human and food waste, it is also good for the environment, as the Bio-Bus will emit 30% less carbon dioxide when compared to conventional diesel engines.
Bath Bus Company's Collin Field said, "With so much attention being directed towards improving air quality generally, the public reaction to the appearance of this bus on a service between a world heritage city and an airport will further focus on the potential for this particular fuel."
As Mr Field also explained, the bus has been put into operation at a very appropriate time, considering Bristol will be the European Green Capital next year.
