Biogas consists mainly of methane and carbon dioxide. Methane can be used in energy production in a similar manner as natural gas. Biogas is a valuable fuel that can be used for several purposes such as heat and combined heat and power (CHP). Processed biogas can be used as traffic fuel or it can be distributed with natural gas pipeline networks.
Heat
One of the simplest and the most inexpensive option is to burn biogas in gas boilers and use the generated energy as heat. In heat production, there are hardly requirements for purity. It is recommended to dry biogas, as it also eliminates majority of hydrogen sulfide, decreasing corrosion risk.
CHP, Combined Heat and Power
There are several technical solutions available for the CHP production from biogas. One of the most common solution is to burn biogas in petrol engines or diesel engines suitable for biogas. Engines spin generator connected to transmission network. CHP can produce twice as much heat than electricity.
Traffic fules
Purified biogas (biomethane) is similar to natural gas. Natural gas is, however, of fossil origin whereas biomethane is a renewable energy source. The burning of biomethane does not increase the net carbon dioxide content in the atmosphere. Biogas utilization in vehicles and appliances requires emission of moisture, carbon dioxide and impurities and compressing. There are several commercial solutions available for biogas purification, such as activated carbon adsorption and purification using water.
Biogas injection to natural gas grid
Biogas injected to natural gas grid needs to be, according to the current regulations, similar to natural gas when it comes to odor and heat of combustion. In Finland, Russian natural gas is used. Therefore, biogas should have similar methane content and hydrogen sulfide, carbon dioxide and moisture should be removed.