Biogas most commonly known as biomethane is a renewable fuel constructed through the breakdown of organic matter (such as animal manure, municipal rubbish/ waste, plant material, food waste or sewage) by bacteria in an oxygen-free environment through a process called anaerobic digestion. Biogas systems use anaerobic digestion to repurpose these organic materials, converting them into biogas, of which consists of both energy (gas), and valuable soil products (liquids and solids). It can be used for many different functions; these include vehicle fuel and for heating and electricity generation.
What industries is Biogas used in?
Biogas can be produced through the combustion process to produce heat only. When burned, one cubic metre of biogas produces around 2.0/2.5 kWh of thermal energy, providing the nearby buildings with the heat generated. The unused heat is dismissed, and unless it is heated and converted into hot water through a local pipe network into local houses, it is wasted. This concept of heating water and transferring to homes as part of central heating is popular in some Scandinavian countries.
Biogas is eligible for support under the Renewable Transport Fuel Obligation due to the combustion of biomethane from vehicles being more environmentally friendly than those who use transport fuels such as modern petrol and diesel, thereby helping reduce greenhouse emissions. Examples of renewable transport fuels in vehicles that are formed out of biogas are compressed natural gas (CNG) or liquefied natural gas (LNG).
Electricity can be generated from the combustion of biogas. Electricity is easier to transport and measure than heat and gas supply, however, requires the right infrastructure in order for it to feed into the grid, that is expensive and complex. Although, generating green electricity can benefit the generators (households and communities) by using the Feed-in Tariffs (FiTs) or for bigger players can maximise the Renewable Obligation Certificates (ROCs) for industrial scale production, thereby leading to a reduction in cost as well as being better for the environment.
Other industries include hospitality, manufacturing, retail and wholesale.
Which gases does Biogas contain?
Biogas consists mainly of methane and carbon dioxide. The most common ratio is 60% CH4 (methane) and 40% CO2 (carbon dioxide), However, the respective quantities of these will vary depending on the type of waste involved in the production of the resulting biogas, therefore the most common ratio will be 45 to 75% methane and carbon dioxide from 55 to 25%. Biogas also contains small amounts of hydrogen sulphide, siloxanes and some moisture.
What are the key benefits?
There are several reasons why biogas technology is useful as an alternate form of technology: Primarily, the raw material used is very cheap, and to farmers it is practically free with the biogas having the ability to be used for a range of household and farming applications. The burning of biogas does not produce harmful gases; therefore, it is environmentally clean. One of the most convenient benefits of biogas is that the technology required for its production is relatively simple and can be reproduced in large or small scale without the need for a large initial capital investment. As this type of energy is a renewable, clean source of energy that relies on a carbon-neutral process, therefore no new amounts of carbon are released into the atmosphere when using biogas. As well as it helping to divert food waste from landfills, positively impacting the environment and economics. Biogas also helps to reduce soil and water contamination from animal and human waste, allowing for the maintenance of a healthy and safe environment for many communities worldwide. With methane being a contributor to climate change, biogas contributes to its reduction that is emitted into the atmosphere, helping to counteract its impact on climate change, thereby helping to possibly help with its immediate impact on the environment.
However, biogas as a source of energy does have its disadvantages, one is that Biogas production is dependent on a biological process that doesn’t have the ability to be controlled fully. Additionally, biogas works better in warmer climates, this consequently means biogas doesn’t have the capacity to be accessible equally worldwide.
Is Biogas Good or Bad?
Biogas is an outstanding source of clean energy, due to it possessing a lower impact on the environment than fossil fuels. Although biogas doesn’t have a zero impact on the ecosystems, it is carbon neutral. This is because biogas is produced from plant matter, of which has previously fixed carbon from carbon dioxide in the atmosphere. A balance between the carbon being let out as a result of producing biogas and the amount absorbed from the atmosphere is maintained.