Biogas Dehumidification System (BDS) reduces biogas temperatures from around 40ºC to approximately 5-7ºC, condensing more than 90% of the water volume. It works via a chiller system which supplies a coolant that is transferred to heat exchangers. Biogas flows on the product side of the exchanger, while the coolant flows on the service side.
More than half of the heat transfer duty is used to condense the water contained in the biogas, while the remainder is used to reduce the gas temperature. As it cools, the water separates from the gas, leaving a clean biogas ideal for use in CHP engines.
A heat recovery option is available, whereby the resulting cold biogas is then used to pre-cool any incoming biogas. This reduces the load on the final cooling heat exchanger, recovering as much as 20% of the energy needed for the process. Any extra investment required is soon recouped in energy cost savings.