Biogas Compression

Our engineers have leveraged over 50 years of company experience in gas separation and compression to become experts in the Biogas and Landfill gas markets. Our specialty is providing custom-engineered Blower, Gas Compressor, and Dehydration packages that are designed to fit the specific needs of our clients.


GAS can provide both centrifugal and positive displacement blower systems for RNG systems. The feed blower skid system is one of the first pieces of equipment in the renewable natural gas processing system and is responsible for increasing the pressure of the gas in preparation for pretreatment/ treatment and compression. The gas is pressurized (typically between five-to-15 psig), then is usually chilled by a glycol-cooled heat exchanger. The cold gas is sent to the appropriate moisture separating equipment, then reheated to be transported to the subsequent process (usually H2S removal). The second system that utilizes centrifugal or positive displacement blowers is the vacuum blower, which creates suction on the negative pressure side of the CO2/methane membrane to recycle the permeate back to the feed blower for further refining. Our vacuum blower skid systems are capable of handling any desired recycle gas flow rates. For positive displacement blowers, optional inlet and outlet silencers can be installed for sound dampening in noise-sensitive environments. Because the vacuum blower is usually used in conjunction with the feed blower, the two systems can be integrated into a single skid system for compact installation.


The feed gas compressor skid raises the pressure of the gas on the positive-pressure side of the CO2/methane membrane separation system. The two types of machines typically used for this step are rotary screw compressors or vane compressors. For this process, our compressors can achieve pressure increases from zero-to-15 psig, to over 100 psig, and up to 350 psig. We can also provide larger custom compressors/motors to handle more extreme compression ratios for applications with higher pressures and flows. Feed gas compressor skids may also utilize an inlet knockout/moisture separator to protect the compressor and downstream equipment. Additional moisture removal and gas polishing can be integrated after the compressor to further prepare the feed gas for the membrane system.


Clean and dry purified “sales” gas is compressed to be transported via the preexisting utility pipeline network systems. At this stage, the pipeline gas quality is approximately 95-to-99% methane content. Similar to the feed gas compressor, reciprocating or screw mechanisms (reciprocating being the most popular) are used to compress the gas. Depending on the pipeline pressure requirements, gases can be compressed to between 200 and 1200 psig, or higher. GAS RNG Systems can custom-design single or two-stage compression systems, based on inlet/outlet pressures, to handle a vast range of sales gas inlet pressures ranging from 2 psig to over 200 psig. Because gas compression generates heat, a skid mounted cooler is integrated with the sales gas compressor to maintain safe operating temperatures. Aftercooler systems are used for single stage compressors, while intercooler and aftercooler systems are provided for two-stage compression.