TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Plant: In the gas purification plant, a heat exchanger is provided prior to the scrubber or scrubber sequence; and the second flasher feeds all of its flashed gas stream as an additional infeed to the first compressor; and the first flasher feeds all of its flashed gas stream as an additional infeed inter-stage to the first compressor. The plant also comprises: a second compressor to receive the gas stream from the first compressor, where a heat exchanger is provided prior to the second compressor or a heat exchanger is provided prior to the scrubber or scrubber sequence. The first flasher feeds its entire flashed gas stream as an additional infeed to the second compressor. The additional infeed to the second compressor is provided before a heat exchanger. The second flasher feeds its entire flashed gas stream as an additional infeed to the first compressor. In the biogas processing plant, the first of the compressions stages is upstream of the second of the compression stages; the first flasher is downstream of the second flasher; and the pressure difference between the gas fed from the first flasher to the first compression stage and the feed supply gas is less than the pressure difference between the gas of the second flasher and the feed supply gas. Preferred System: In the system, a recycle gas output from the first flasher is fed back into the system at where the pressure of the feed supply gas is higher than at the inlet of the first compression stage; or a recycle gas from the first flasher is fed back into the system at a location downstream of the inlet of the first compression stage. The first compression stage comprises a first compression. The second compression stage comprises a second compressor. The first and second compressions stage occurs within a WFS type compression and the recycle gas output from the first flasher is fed back into the WFS compressor downstream of the inlet of the first compression stage of the WFS compressor. Preferred Apparatus: In the compressor, the additional intake is at a location downstream of the supply gas infeed.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The process (P1) has at least a two stage compression to provide a pressurized gas flow for scrubbing, where there is at least a two stage flashing after scrubbing of the pressurized gas stream to provide the purified gas output from the scrubber, and the flashing steps are to different pressures, with a flashed stream of gas of lower pressure being recycled to the inflow of the first, or an earlier, compression stage and with a flashed stream of gas of higher pressure being recycled to the inflow of the second, or a later, compression stage. The flashed stream of gas of lower pressure is from the second, or a later, flashing stage. The flashed stream of gas of higher pressure is from the first, or an earlier, flashing stage. There are only two flashing stages or at least two flashing stages. There are only two compression stages or at least two compression stages. The recycling on a normalized volume basis into the inflow of the first compression stage is 15-20% of the raw gas flow and on a normalized volume basis into the inflow of the second compression stage is 20-30% of the raw gas flow. There is a two stage flashing of recyclable gases from the liquid stream after scrubbing of the pressurized gas stream, and the flashed stream of gas of the later flashing stage is recycled to the inflow of the first compression stage and the flashed stream of gas of the first flashing stage is recycled to the inflow of the second compression stage. The flashed stream of gas of the second flashing stage is at a lower pressure than that from the first flashing stage. There are only two flashing stages. The process (P1) is a methane enrichment procedure involving gas compression and water scrubbing, where the use of two flashers in series post scrubbing to retrieve methane from the liquid stream from the scrubber and to return, at the respective flashed gas pressures, the flashed gas into the gas stream either side of the compressor or first compressor. The higher pressure flashed gas off the first flasher is fed inter-stage of the compressor. The lower pressure flash gas off the second flasher is fed to the inlet of the compressor. The higher pressure flashed gas off the first flasher is fed inter-stage of the compressor and the lower pressure flash gas off the second flasher is fed to the inlet of the compressor. There are least two compressors in series. The higher pressure flashed gas off the first flasher is fed to the inlet of the downstream more of the two compressors. The lower pressure flash gas off the second flasher is fed to inlet of the upstream more of the two compressors. The higher pressure flashed gas off the first flasher is fed to the inlet of the downstream more of the two compressors and the lower pressure flash gas off the second flasher is fed to inlet of the or an upstream more of the two compressors. The process (P1) is for treating a gas with a methane gas inclusion, involves: providing a feed supply of the gas to be treated, pressurizing the gas in a first compressor or first compressor stage (first compressor), optionally heat exchanging the pressurized gas stream from the first compressor stage, feeding the gas pressurized by the first compressor (optionally after heat exchange) into a second compressor or second compressor stage (second compressor) thus to provide gas at a higher pressure, optionally heat exchanging the higher pressure gas stream from the second compressor, subjecting the higher pressurized gas stream from the second compressor (optionally after heat exchange) to a scrubber or at least a series of scrubbers (a scrubber) thus to provide an outtake feed of a methane enriched gas and to provide a liquid outfeed that includes some entrained gas or gases (inclusive of methane), subjecting the liquid outtake from the scrubber to a first flashing stage (first flasher) thus to provide a liquid outtake from the first flasher and a gas recycle feed from the first flasher back to the second compressor as a component of its gaseous intake, subjecting the liquid outtake with some entrained gases from the first flasher to a second flashing stage (second flasher) thus to provide a gas recycle feed from the second flasher as an infeed component of the feed gases to the first compressor and to provide a liquid outtake of the second flasher. The compressor of each compressor stage is a liquid containing compressor able to commence a scrubbing of the gas encountered in that compressor. The liquid outtake from one or both compressors can be subjected to a methane recovery procedure. The process (P1) is a methane enrichment involving: feeding a gas stream comprising methane to be processed for methane enrichment to an upstream side of a compression stage and compressing the gas, supplying a water stream and the compressed gas stream to a water scrubbing stage, and contacting the compressed gas stream with the water stream, where the water scrubbing stage provides at least one downstream gas stream output and at least one downstream water stream output, and following the water scrubbing stage, directing the at least one water stream output to two flashers operating in series, where each of the flashers generating a flashed gas output stream, and returning the respective flashed gas output streams into the gas stream to be processed for methane enrichment, either upstream or downstream, or both, of the compression stage, and the flashed gas is returned into the gas stream at the respective flashed gas pressures of the respective flashers. In the methane enrichment process, the gas being processed is a biogas or other gas; or methane content; or carbon dioxide content; or methane and carbon dioxide content. The gas stream to be purified or processed comprises a methane inclusion or methane component. The scrubbing is with water. The compressor is a WFS compressor. The compression is by at least one WFS type compressor or at least two rotary vane compressors. In the method (M1), in the appropriate elevation at least one of the upstream flash vessels is below the downstream flash vessel; and there are two flash vessels and the upstream flash vessel is positioned lower than the downstream flash vessel; and the elevation is such that the fluid pressure entering the downstream flash vessel is less than the fluid pressure exiting the upstream flash vessel. EXAMPLE - No suitable example given.