The train was developed by Svensk Biogas, which converted an old Fiat locomotive by replacing the diesel engines with two Volvo gas engines. The train is equipped with eleven canisters containing enough gas to run for 600 kilometers (375 miles) before needing a refill, and can reach a maximum speed of 130 kilometers (80 miles) per hour.
Biogas refers to methane produced by the anaerobic digestion of biomass waste. (Aerobic decomposition, or composting, requires large amounts of oxygen and produces heat.)
Biogas produced in anaerobic digesters consists of methane (50%-80%), carbon dioxide (20%-50%), and trace levels of other gases such as hydrogen, carbon monoxide, nitrogen, oxygen, and hydrogen sulfide.
Sweden currently has 779 biogas buses and more than 4,500 cars that run on a mixture of petrol and either biogas or natural gas, according to the Swedish environment ministry.
The new train, which cost Svensk Biogas 10 million kronor (€1.07 million, US$1.3 million) to develop, will go into service in September, operated by SJ, the Swedish railway.