Biogas

Biogas is produced by methane fermentation of biomass. It is a flammable gas.
The active factor in the fermentation process are anaerobic microorganisms, whose metabolism involves the decomposition of organic matter to simple substances.

Biogas usually includes:

Methane	CH4	45 – 85 %
Carbon dioxide	CO2	10 – 55 %
Nitrogen	N2	0 – 10 %
Oxygen	O2	0 – 5 %

Biogas produced in sewage treatment plants, landfills, in agriculture and as a by-product in biomass processing is an excellent fuel for production of cheap electricity and heat for your companies needs and for sale. However, before use, biogas must be cleaned of hydrogen sulfide, dust and siloxanes.

Below is a graph of the calorific value of biogas calculated based on the ZN-G-4002 standard.

BIOGAS IMPURITIES:

• Hydrogen sulfide (H₂S) - the most common biogas contaminant, which has an extremely corrosive effect on biogas-powered devices (engines, boilers, turbines). Hydrogen sulfide also has a negative impact on fixed beds and membranes used in the processes of biogas further treatment and enrichment. Thus its deep removal at the early stage of biogas treatment is very important. BIOSULFEX^® allows for deep desulfurization of biogas, which has a significant impact on further purification of biogas.

• Siloxanes – organic silicon compounds, components of biogas that adversely affect its combustion process, especially in case of gas piston engines. Silica (SiO₂, commonly known as sand) produced during biogas combustion forms deposits that have an erosive/abrasive effect on the sliding surfaces of engines, leading to a rapid deterioration of the lubricating parameters of engine oil and, consequently, destruction of the engine. To remove siloxanes effectively, it is important that prior desulfurization of biogas is most efficient.

• Water - the humidity level of biogas produced in biological processes is almost 100%. High biogas humidity results in water mist and condensate in the biogas stream whenever the biogas temperature drops. However, biogas desulfurization using the BIOSULFEX^® method is not sensitive to high moisture content, and the additional heterogeneous moisture removal module makes the biogas purification by the Innovative Group PROMIS.

• Dust - fine solid particles suspended in the biogas stream. Depending on the chemical composition and physical parameters, they may have a negative impact on fittings and biogas receivers.

Purifying biogas from the above pollutants is key to ensuring failure-free operation of engines, gas turbines and boilers. Hydrogen sulfide in combustion processes produces a highly acidic environment, which favors the erosion of metallic alloys and the decomposition of lubricating oils. Crystalline silica, which forms during the combustion of siloxanes, acts as an abrasive material on sliding surfaces in engines. It may also stick to turbine blades or surface of boilers, which results in many failures. However, excessive moisture in biogas enhances the above processes, facilitating chemical erosion of devices and fittings. Thus biogas purification is extremely important to ensure failure-free operation of devices.