Biogas
Biogas is a gaseous renewable energy source[1] produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste, wastewater, and food waste. Biogas is produced by anaerobic digestion with anaerobic organisms or methanogens inside an anaerobic digester, biodigester or a bioreactor.[2] The gas composition is primarily methane (CH
4) and carbon dioxide (CO
2) and may have small amounts of hydrogen sulfide (H
2S), moisture and siloxanes. The methane can be combusted or oxidized with oxygen. This energy release allows biogas to be used as a fuel; it can be used in fuel cells and for heating purpose, such as in cooking. It can also be used in a gas engine to convert the energy in the gas into electricity and heat.[3]
After removal of carbon dioxide and hydrogen sulfide it can be compressed in the same way as natural gas and used to power motor vehicles. In the United Kingdom, for example, biogas is estimated to have the potential to replace around 17% of vehicle fuel.[4] It qualifies for renewable energy subsidies in some parts of the world. Biogas can be cleaned and upgraded to natural gas standards, when it becomes bio-methane. Biogas is considered to be a renewable resource because its production-and-use cycle is continuous, and it generates no net carbon dioxide. From a carbon perspective, as much carbon dioxide is absorbed from the atmosphere in the growth of the primary bio-resource as is released, when the material is ultimately converted to energy.
Peterborough (/ˈpiːtərbərə, -ˌbʌrə/ (About this soundlisten)) is a cathedral city in Cambridgeshire, England, with a population of 202,110 in 2017.[5] Historically part of Northamptonshire, it is 76 miles (122 km) north of London, on the River Nene which flows into the North Sea 30 miles (48 km) to the north-east. The railway station is an important stop on the East Coast Main Line between London and Edinburgh. Peterborough is also the largest city and borough in Cambridgeshire and the East Anglia area of England.
The local topography is flat, and in some places the land lies below sea level, for example in parts of the Fens to the east of Peterborough. Human settlement in the area began before the Bronze Age, as can be seen at the Flag Fen archaeological site to the east of the current city centre, also with evidence of Roman occupation. The Anglo-Saxon period saw the establishment of a monastery, Medeshamstede, which later became Peterborough Cathedral.
The population grew rapidly after the railways arrived in the 19th century, and Peterborough became an industrial centre, particularly known for its brick manufacture. After the Second World War, growth was limited until designation as a New Town in the 1960s. Housing and population are expanding and a £1 billion regeneration of the city centre and immediately surrounding area is under way. Industrial employment has fallen since then, a significant proportion of new jobs being in financial services and distribution.