Used Gas Processing for Sale

It's units that clean up a gas stream before compression, storage or a pipeline. Scrubbers and filters take out water, liquid hydrocarbons and solids, dryers remove water vapor, and sweeteners remove hydrogen sulfide (H2S). They protect downstream equipment and keep gas within spec.

Sources: Kimray — compressor stations · Kimray — filter separators · GATE Energy — H2S scavenging

Scrubber: knocks out free liquids, usually ahead of a compressor. Filter separator: traps solids and fine mist with filter elements and a mist extractor. Dryer: pulls water vapor down to a target dew point. Sweetener: removes H2S.

Sources: Kimray — compressor stations · Forum Energy Technologies — filter separators · CAGI — Air Drying Selection Guide · GATE Energy

Pipeline gas often arrives at about 7 lb of water per million cubic feet. Compressed to around 3,600 psi, that water condenses at about +52°F. Without a dryer, it can form hydrates and freeze-ups when gas expands, block fueling systems, and corrode storage vessels and piping.

Sources: CNG Center — how dry is CNG · ANGI Energy — dryers in CNG stations

The SAE J1616 guideline sets it relative to local weather. At maximum storage pressure, the gas dew point should be at least 10°F below the area's 99% winter design dry-bulb temperature. A dryer sized for a southern site may fall short up north, so check its rated dew point against where it will run.

Sources: CNG Center — summarizing SAE J1616 · ANGI Energy

A single tower dryer holds one desiccant bed that must be regenerated or recharged when saturated, which suits smaller or batch duty. A twin tower dryer runs one tower while the other regenerates, for continuous drying. Twin units are often fully automatic, though some use manual switching valves.

Sources: PSB Industries — CNG drying · ANGI Energy · Pneumatech — twin tower dryers

Start with the desiccant. Beds wear out and are replaced periodically, so plan to recharge an older or idle unit. Then check the switching valves, the regeneration heater and blower if fitted, the hygrometer or dew point meter, and the inlet and outlet filters. Ask for recent dew point readings so you know what it actually achieved.

Sources: CAGI — Air Drying Selection Guide · ANGI Energy · PSB Industries

Ask what gas it handled, at what inlet pressure and flow, its hours and history, and how it was stored after shutdown. Confirm the desiccant type and when it was last changed (CNG units commonly use a molecular sieve grade), whether the vessels are ASME code stamped, and their flange pressure class.

Sources: Lectrodryer — CNG dryer · PSB Industries

Gas counts as "sour" at about 4 ppm H2S or more, so start with the H2S level and gas volume the unit was built for. Solid metal-oxide beds aren't regenerated; the media is replaced when spent, which means confined-space work, so sites often run two trains. Amine units regenerate their solution and are used where large amounts of H2S must come out.

Source: GATE Energy — H2S scavenging