Biogas is a useful form of natural gas that can be used in many different applications, including injecting back into the gas grid network and fueling natural gas powered vehicles. In this article we take a look at the time it takes to produce biogas and how biogas can be used.
Biogas is produced by anaerobic digestion, this is the process of breaking down organic material. When organic material is enclosed in an anaerobic digestion tank and oxygen is limited the natural bacteria begins to break down the waste material. As the organic material breaks down gas is released, this gas is called biogas. It is flammable and can be used for a number of uses such as in gas powered vehicles. It is important that the gas released is not allowed to enter the atmosphere in large volumes. The gas contains a high level of methane, this is the flammable part of the gas and is particularly damaging to the environment as it contributes to global warming. Some of the methane that is released into the atmosphere stops heat escaping and instead traps the sun's rays and directs them back towards Earth. This is the process of global warming that must be minimized to protect the Earth from extreme weather events.
The speed in which biogas is produced depends on the materials that are decomposing. Different waste products produce biogas at varying rates. The typical variation is between 10-30 days. One of the best waste materials used for biogas production is cow manure, cows naturally produce large amounts of methane and their manure breaks down quickly as part of biogas production. Variation also occurs based on the temperature and conditions that the waste material is being kept in. To speed up aerobic digestion the temperature should be kept at 35 degrees celsius or 95 degrees fahrenheit, this is the optimum temperature for the bacteria to develop and break down the organic matter to maximize biogas output. The organic waste should also be mixed on a regular basis to achieve a consistent temperature and mix of bacteria throughout the waste. Another way to speed up the process is to make sure the anaerobic digester is completely sealed, oxygen shouldn't be allowed to enter and the biogas needs to remain contained within the system.
In order to use the biogas to inject it back into the gas grid it must be upgraded. This is the process of removing contaminants including carbon dioxide, hydrogen sulfide and water from the biogas to improve its purity and make it fit for use. There are several ways which biogas can be upgraded, these include: Pressure Swing Adsorption, Amine Scrubbing, Water Washing and Membrane Separation. The aim of this process is to clean the biogas to leave behind biomethane. Biomethane has a high concentration of methane up to 90%, this gas has more uses than biogas and can be sold and added back into the gas network. Find out more in our article What is biogas upgrading?
Regardless of whether it has been converted into biomethane or not, biogas is a renewable fuel with many applications. The three most common uses of biogas are vehicle fuel, injecting back into the gas grid and burning biogas to produce electricity. Each of these uses can help businesses who have access to waste material to make money or reduce their business costs. It also helps to remove the issue many businesses have of disposing of waste products at a minimal cost. There are some initial costs associated with biogas upgrading but once in place the process is able to make money. Read more about the applications of biogas.
At QED we have a number of solutions that can help with biogas production. Our gas analyzers and gas detectors can help to improve the quality of the resulting biomethane gas. Gas detectors can also provide valuable information and details of any gas leaks that could be reducing biogas production output. Find out more about how we can help with biogas upgrading or anaerobic digestion projects.
