Abstract: A continuous process for selective countercurrent extraction of C.sub.2 + hydrocarbons from a gas stream with a lean oil as solvent is rejuvenated by substitution of a preferential physical solvent for the lean oil solvent to produce a residue gas stream meeting specifications for methane content and a hydrocarbon product having a composition which can be adjusted to a selected minimum degree for ethane that is as low as 2% ethane and produce at the maximum propane content that is available from the equipment, whereby profitability of the extraction operation can be maximized at all times. The preferential physical solvent has a minimum relative volatility of methane over ethane of at least 6.0 and a solubility of at least 1.0 standard cubic foot of gaseous hydrocarbons per gallon of the solvent (thereby defining its hydrocarbon loading capacity) or, alternatively, a preferential factor of at least 6.0. Preferred solvents include polyalkylene ethers of dialkylene glycol and alkyl-substituted monocyclic C.sub.

Abstract: A continuous process is described for contacting a raw hydrocarbon gas which is lean and/or at a pressure above about 400 psia with a preferential physical solvent within an extractive-stripping (ES) column to produce a residue gas, containing selected amounts of an undesired hydrocarbon component and lighter hydrocarbons, and a rich solvent, containing the remaining desired hydrocarbons, which is sent to a distilling step in which the product is produced as overhead and the lean solvent is produced as bottoms. To avoid undesirably high bottoms temperatures in the ES column, a portion of the product is recycled to and admixed with the inlet raw gas to the extractive-stripping step to enrich the raw gas. This recycled stream may be: (1) a broad-spectrum recycle stream of gas products, after compression and before cooling thereof, (2) a broad-spectrum recycle stream of liquid products, after compression, cooling, and complete condensation thereof, (3) a relatively narrow-spectrum recycle vapor stream of C.sub.

Abstract: A process is disclosed in which a preferential physical solvent selectively extracts and strips desirable C.sub.2 + hydrocarbons from a raw hydrocarbon gas stream which is fed into the midsection of an Extractor-Stripper (ES) column, the rich solvent produced from the bottoms thereof being regenerated in a distillation column which produces a hydrocarbon gas liquid stream as product and a lean physical solvent for recycling to the top of the ES column. When certain operating conditions and product specifications necessitate operating the ES column bottoms at a temperature high enough to become relatively energy inefficient, a single-stage intermediate flashing vessel is provided for effectively removing undesirable hydrocarbons at a pressure consistent with the operating pressure of the distillation column. The separated overhead vapor stream from the flashing vessel contains all of the undesirable components along with some desirable hydrocarbons.

Abstract: A natural gas stream containing more than 3 mol percent of inert gases is extractively stripped with a preferential physical solvent to separate the inert gas from the C.sub.1 + hydrocarbons and to separate selected amounts of C.sub.2 +, C.sub.3 +, C.sub.4 +, or C.sub.5 + hydrocarbon product from a C.sub.1 gas product which may additionally contain one or more of unselected C.sub.2 -C.sub.4 hydrocarbons. The extraction and stripping are performed within at least one Extractive Stripping (ES) column which has a reboiler at its bottom, receives a stream of lean solvent at its top, and receives feed near its middle. When two ES columns are utilized, inert gas and methane may be recovered within the first ES column as overhead, and rich solvent may be withdrawn as its bottoms. The overhead may be separated in the second ES column into inert gas and methane. The rich solvent is regenerated by distilling in a product recovery column.