Biogas Technology in Europe
In Europe and USA anaerobic digestion was seen as being mainly used for processing
sewage. Traditionally the gas generated was used in static engines to power processes
on the sewage plant site and even for powering vehicles. In 1990, the Non-Fossil
Fuel Obligation scheme in the UK encouraged investment in new engines in sewage plants
to generate electricity to sell to the grid. It also inspired the collection of gas
from landfill sites to run electric generating units.
More recent interest by the Green Movement in mainland Europe has encouraged the
development of plants to process wastes more directly. High rate anaerobic digestion
projects, such as DRANCO, Valorga and Kompogas, were developed in the 1990s, but
were not seen as economically attractive for widespread investment.
The introduction of financially attractive electricity feed-in tariffs in Germany
in 2000 encouraged the development of large tank digesters to process agricultural
wastes and energy crops such as forage maize. The tariffs tended to emphasize the
use of energy crops in Germany, a policy that suddenly became less attractive when
crop prices increased in 2007. Plants using agricultural and domestic wastes were
seen as better investments in Denmark and Sweden. Some of these plants provide gas
to power public transport.
A German design of plant was built in the UK by Farmatic Biotech Energy at Holsworthy
in 1998, but a combination of a lack of government support and regulations caused
the operation to go bankrupt twice. The plant is now being run by Andigestion Ltd
who seem to be more successful. The main feed is organic commercial wastes.
Greenfinch Ltd has been developing a digester for domestic food waste, which has
culminated in a pilot commercial plant in Ludlow in early 2006. After some initial
problems, mainly caused by the feeding of the wrong sort of waste materials, the
plant is now running very effectively. They have recently joined up with Biogen to
offer AD expertise for the UK.
