Advanced Extraction Technologies, Inc.

El Paso Hydrocarbons Company

Other

El Paso Products Company

Kinetic Technology International Corp.

Yuv R Mehra

Glenn C Wood

Wilfred K Lam

Robert H Stodghill

Don W Mullins

Dow W Mullins

Ralph E Clark

Freylon B Coffey

A retro fitted 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; and wherein the natural gas treatment process utilizes a solvent that is pre-saturated with lighter undesirable components present in the overhead stream from the NGL absorber.

Absorption process with solvent pre-saturation

A process for rejecting reactor byproduct from the polymerization reactor in an olefins polymerization process wherein reactor waste gas stream(s) comprising unreacted monomers, reactor byproduct and light components are treated in an absorption process to additionally recover the monomers. The absorption process comprises contacting the reactor waste gas stream(s) with an absorption solvent in an absorption zone to produce a gas stream comprising the light components, and a liquid stream comprising the absorption solvent, absorbed reactor byproduct and absorbed monomers. The liquid stream is fractionated in a distillation column to produce a distillation column bottoms stream that is the absorption solvent which is conveyed to the absorption zone, and an overhead stream comprising the monomers and reactor byproduct which is further fractionated in a splitter column to reject the reactor byproduct as a bottoms stream. The recovered monomers from the splitter overhead can be conveyed to the reactor. In a preferred embodiment, the absorption solvent consists essentially of components derived from the reactor waste gas stream(s) so that no external solvent is required.

Absorption process for rejection of reactor byproducts and recovery of

An absorption process for separating a feed gas stream having components with a spectrum of volatilities including volatile (light) components, intermediate volatility components, and least volatile (heavy) components. The disclosed process includes the steps of: (1) contacting the feed gas stream with an internally generated liquid lean solvent stream in an absorber to produce a light product gas stream that is composed of predominantly light components and a rich solvent stream containing most of the intermediate and heavy components; (2) flashing the rich solvent stream at reduced pressure in a flash zone to produce an intermediate product gas stream composed predominantly of intermediate components and a lean solvent stream; (3) conveying the lean solvent stream from the flashing zone to the absorber, wherein the lean solvent is composed predominantly of heavy components supplied from the feed; the process does not use an external lean solvent. The process is particularly useful for rejecting nitrogen from natural gas and for recovering hydrogen from refinery and petrochemical process offgases.

Absorption process without external solvent

An absorption process for recovering hydrogen, ethylene, methane and heavy hydrocarbons from refinery and petrochemical off-gas streams wherein the absorption solvent is comprised of heavy hydrocarbons derived from the off-gas feed stream; no external solvent is used. The process comprises the steps of absorbing ethylene out of the feed off-gas in an absorber stripper using the absorption solvent, and fractionating the rich absorption solvent in a distillation column to produce an ethylene product stream as the overhead stream and the heavy hydrocarbon absorption solvent as the bottoms stream.

Absorption process for recovering ethylene and hydrogen from refinery

A process for gas phase polymerization of olefins wherein reactor vent gas stream(s) comprising unreacted monomers and light components are treated in an absorption process to recover the monomers. The absorption process comprises contacting the reactor vent gas stream(s) with an absorption solvent in an absorption zone to produce a gas stream comprising the light components, and a liquid stream comprising the absorption solvent and absorbed monomers. The liquid stream is fractionated in a distillation column to produce a distillation column bottoms stream that is the absorption solvent which is conveyed to the absorption zone, and an overhead stream comprising the monomers which can be conveyed to the reactor. In a preferred embodiment, the absorption solvent consists essentially of components derived from the reactor vent gas stream(s) so that no external solvent is required.

Gas phase olefin polymerization process with recovery of monomers from

An absorption process for separating a feed gas stream having components with a spectrum of volatilities including volatile (light) components, intermediate volatility components, and least volatile (heavy) components. The disclosed process includes the steps of: (1) contacting the feed gas stream with a liquid lean solvent stream in an absorber to produce a light product gas stream that is composed of predominantly light components and a rich solvent stream containing most of the intermediate and heavy components; (2) flashing the rich solvent stream at reduced pressure in a flash zone to produce an intermediate product gas stream composed predominantly of intermediate components and a lean solvent stream; (3) conveying the lean solvent stream from the flashing zone to the absorber, wherein the lean solvent is composed predominantly of heavy components taken from the feed; the process does not use an external lean solvent. The process is particularly useful for rejecting nitrogen from natural gas and for recovering hydrogen from refinery and petrochemical process off-gases.

A continuous process is described for contacting an olefins-containing feed gas stream, which has been freed of CO.sub.2 and sulfur compounds, compressed, cooled, and dried, with a solvent in an intercooled and reboiled demethanizing absorber to produce a rich solvent bottom stream containing ethylene and heavier hydrocarbons and an absorber overhead stream which is fed to a methane absorber which recovers a hydrogen product stream as overhead and produces a rich solvent stream as bottoms. When recovering up to 50% of the incoming hydrogen, this rich solvent stream from the methane absorber is fed to the demethanizing absorber, but when recovering from 20% to 100% of the incoming hydrogen, this rich solvent stream is recycled in part to the demethanizing absorber and in part is fed to a methane stripper which sends its bottoms to the methane absorber and its overhead to an auto refrigerated recovery unit which removes H.sub.2, CH.sub.4, and CO as a fuel gas product and produces an ethylene and heavier stream. The rich solvent stream from the demethanizing absorber is separated in a solvent regenerator into an overhead stream of ethylene and heavier hydrocarbons and a bottom lean solvent stream for recycle to the methane absorber and then to the demethanizing absorber. The bottom stream of the recovery unit and the overhead stream of the solvent regenerator are combined to form an ethylene and heavier product stream.

Absorption process for hydrogen and ethylene recovery

A subquality nitrogen-rich natural gas stream containing more than 0.1 mol % helium is countercurrently extracted with a lean physical solvent to produce a rich solvent bottoms stream which is flashed twice to produce a methane-rich gas product and a nitrogen-helium product which is fed to at least one membrane unit. A reject nitrogen stream and a crude helium stream are discharged from this unit. The crude helium stream is either compressed to a pressure within the range of 200 to 3,000 psia for sale or is compressed to no more than 1,000 psia and fed to a PSA unit which produces a reject nitrogen stream and a highly purified (99.99+ mol %) helium stream which is compressed to a pressure within the range of 200 to 3,000 psia for sale.

Process for recovering helium from a gas stream

A continuous process is described for contacting an olefins-containing feed gas stream, freed of CO.sub.2 and sulfur compounds, in a front-end heat-pumped depropanizer to remove the C.sub.4+ compounds, selectively hydrogenating the overhead stream to significantly reduce the acetylene and diolefins content, dehydrating the reactor effluent to remove traces of moisture, feeding the dehydrated stream to an intercooled and reboiled demethanizing absorber to produce a rich solvent containing ethylene and heavier hydrocarbons, feeding the absorber overhead stream to an auto refrigerated recovery unit to remove hydrogen, methane, and CO as overhead to a fuel gas system, separating the rich solvent in a solvent regenerator into an overhead stream of ethylene and heavier hydrocarbons and a bottom lean solvent stream for recycle to the demethanizing absorber, combining the overhead of the solvent regenerator with the bottoms of the demethanizer in the auto refrigerated recovery unit, and feeding the combined stream to a deethanizer which produces an overhead stream that is split into ethylene as product and ethane for recycling to the cracker.

Front-end hydrogenation and absorption process for ethylene recovery

A continuous process is disclosed for separating components of a hydrocarbon gas stream which are selected from the group consisting of methane, ethane, higher saturated hydrocarbons, and mixtures thereof by countercurrently contacting the hydrocarbon gas stream with a physical solvent selected from the group consisting of:

Processing hydrocarbon gases with selected physical solvents

A process is described for processing an inert-rich natural gas stream with a lean oil physical solvent to obtain a specification-grade inert gas product, and a specification-grade hydrocarbon gas product, preferably in combination with an existing absorber plant. The process is an adaptation of the extractive flashing and extractive stripping versions of the Mehra Process.

Processing nitrogen-rich gases with physical solvents

A continuous process is disclosed for separating components of a hydrocarbon gas stream which are selected from the group consisting of hydrogen, nitrogen, methane, ethylene, ethane, higher saturated and unsaturated hydrocarbons, and mixtures thereof by countercurrently contacting the hydrocarbon gas stream with a physical solvent selected from the group consisting of: (1) paraffinic solvents having molecular weights ranging from 75 to 140 and UOP characterization factors ranging from 12.0 to 13.5, these factors being independent of the aromatic content of the paraffinic solvents, (2) naphthenic solvents having molecular weights ranging from 75 to 130 and UOP characterization factors ranging from 10.5 to 12.0, these factors being independent of the aromatic content of the naphthenic solvents, and (3) benzene and toluene, to produce an overhead stream which is at least rich in at least one of the components and a rich solvent bottoms stream; and by recovering the lean physical solvent from the rich solvent bottoms stream and recycling the recovered stream to the contacting of Step A.

Processing nitrogen-rich, hydrogen-rich, and olefin-rich gases with

A gas-liquid extractive stripping process is disclosed which uses at least one preferential physical solvent in at least one solvent loop, each loop passing through at least two unit operations: extractive-stripping and distillation. At least the first extractive-stripping operation may additionally comprise a rectification section on top of the extraction section. Three products are made from streams of thermally cracked gases or refinery gases: a hydrogen-rich gas stream, a methane-rich gas stream, and a C.sub.2 =+ hydrocarbons stream which is the feed stream for the conventional fractionation train of an olefins manufacturing facility. Ethylene can be economically produced from the C.sub.2 =+ hydrocarbons product stream at a recovery of at least 99.5% and a purity of at least 99.9%.

Selective processing of gases containing olefins by the mehra process

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.8 -C.sub.10 aromatic hydrocarbons, preferably including mesitylene, reformates, crackates, and mixed xylenes.

Conversion of lean oil absorption process to extraction process for

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. This stream is compressed to a pressure level consistent with the operating pressure of the ES column, and the compressed vapors are recycled to the ES column for additional recovery of desirable hydrocarbons. Suitable preferential physical solvents are C.sub.8 -C.sub.10 aromatic compounds having methyl, ethyl, or propyl aliphatic groups, including mesitylene, n-propyl benzene, n-butyl benzene, o-xylene, m-xylene, p-xylene, and mixtures thereof, and certain reformate streams rich in mixed xylenes and other C.sub.8 -C.sub.10 aromatics.

Growing community of inventors

Odessa, TX, United States of America

Yuv R Mehra