HRS Heat Exchangers Biogas Dehumidification System

The Biogas Dehumidification System (BDS) from HRS Heat Exchangers removes water from biogas, protecting combined heat and power (CHP) engines from corrosion and cavitation. The system comes with a heat-recovery section, increasing the overall energy efficiency of an anaerobic digestion (AD) plant.

The BDS reduces biogas temperatures from around 40°C to approximately 5–7°C, 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 that is suitable 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.

Suitable for AD plants of all sizes, the BDS comes skid mounted for easy access and freedom of movement and features an automatic control panel for full process control.