Abstract: A retrofitted unit to an existing simple refrigerated natural gas plant that substantially increases the amounts of propane, butanes and natural gasoline, or ethane, propane, butanes and natural gasoline recovered from the natural gas in the existing gas treatment plant, wherein in one embodiment the existing natural gas treatment plant includes a refrigerated feed cooler, a separator and a stabilizer and the retrofitted unit comprises an NGL absorber, a refrigerated lean solvent cooler and a lean solvent regenerator; and wherein in a second embodiment the existing simple refrigerated gas treatment plant additionally includes an NGL fractionation train that separates the recovered NGL into saleable fractions and wherein the NGL fractionation train includes a debutanizer that produces all or part of the lean solvent utilized in the retrofitted unit which comprises an NGL absorber and a refrigerated solvent cooler.

Abstract: A hydrogen-containing inlet gas stream is countercurrently extracted with lean solvent to produce an overhead stream of at least 90% purity hydrogen and a bottoms stream of rich solvent which is flashed in one to a plurality of stages. The flashed gas from at least the first stage, after compression, is recycled to the extracting step. The flashed gases from the remaining stages are recovered as fuel gas. When a hydrogen purity of more than 95% is needed, a minor portion of the stripped solvent from the last flashing stage is regenerated in a distillation column to form very lean solvent which is fed to the top of the extractor column while the major portion of the stripped solvent is fed to its middle.