A gas pressurized separation system strips a product gas from a stream yielding a high pressure gaseous effluent containing the product gas such as may be used to capture CO.sub.2 from coal fired post combustion flue gas capture and to purify natural gas, syngas and EOR recycle gas. The system comprises a gas pressurized stripping column allowing flow of one or more raw streams in a first direction and allowing flow of one or more high pressure gas streams in a second direction, to strip the product gas into the high pressure gas stream and yield a high pressure gaseous effluent that contains the product gas. The process can further comprise a final separation process to further purify the product gas from the GPS column. For CO.sub.2 product, a preferred energy efficient final separation process, compound compression and refrigeration process, is also introduced.

A composition for scavenging hydrogen sulphide and/or mercaptans in hydrocarbon streams includes a H2S scavenger selected from oxazolidine compounds, triazine and metal-based carboxylate compounds, and a synergistic additive allowing boosting the effect of the H2S scavenger compound.

Disclosed is an apparatus and method of preparing synthetic fuel using natural gas extracted from a stranded gas field on land or at sea as a raw material through a compact GTL process or a GTL-FPSO process. A parallel-type gas purification unit for controlling a molar ratio of synthetic gas and a concentration of carbon dioxide in the synthetic gas, in which a CO.sub.2 separation device and a bypass unit are disposed in parallel, is provided and, thus, the gas purification unit may prepare the synthetic gas by a steam carbon dioxide reforming (SCR) reaction using natural gas having different CO.sub.2 contents of various stranded gas fields and then supply the synthetic gas having an optimum composition suitable for a Fischer-Tropsch synthesis.

There is an absorbent mixture usable for the removal of sour gases from gas mixtures. The mixture has at least one organic base having a pK.sub.b (in water) less than or equal to 3.2; at least one alcoholic solvent of general formula R(OH).sub.n having a boiling temperature above or equal to 100° C. at ambient pressure, wherein R is a linear or branched saturated alkyl group having a number of carbon atoms between 2 and 20 and n is a whole number varying between 1 and 20; an aprotic polar solvent having a dielectric constant E at 25° C. greater than or equal to 30, a viscosity μ at 25° C. less than or equal to 14 cP, preferably less than or equal to 12 cP; and a boiling temperature at normal pressure equal to or above 130° C. There is also a process for the removal of sour gases using the absorbent mixture.

The present disclosure provides a method of dehydrating a feed stream processed in a distillation tower. The method may include (a) introducing a feed stream comprising a first contaminant stream into a distillation tower; (b) forming a solid from the feed stream in a controlled freeze zone section of the distillation tower; (c) feeding a second contaminant stream into the feed stream outside the distillation tower; and (d) removing water from the feed stream with a second contaminant stream by feeding the second contaminant stream.

Disclosed is a process for regenerating a hybrid solvent used to remove contaminants from a fluid stream and to provide an improved yield of purified fluid. Said process comprises at least one purification unit (12) and at least one regeneration unit (40) wherein condensed water 62 from the regeneration unit is recycled back into the purification unit and none of the condensed water is reintroduced into the regeneration unit.

Treatment of hydrocarbon streams, and in one non-limiting embodiment refinery distillates, with high pH aqueous reducing agents, such as borohydride, results in reduction of the sulfur compounds such as disulfides, mercaptans and thioethers that are present to give easily removed sulfides. The treatment converts the original sulfur compounds into hydrogen sulfide or low molecular weight mercaptans that can be extracted from the distillate with caustic solutions, hydrogen sulfide or mercaptan scavengers, solid absorbents such as clay or activated carbon or liquid absorbents such as amine-aldehyde condensates and/or aqueous aldehydes.

A process and an apparatus are disclosed for a compact processing assembly to fractionate lighter components from mixed hydrocarbon streams. The hydrocarbon stream is supplied to the processing assembly between an absorbing means and a mass transfer means. A distillation vapor stream is collected from the upper region of the absorbing means and cooled in a first heat and mass transfer means inside the processing assembly to partially condense it, forming a volatile stream and a condensed stream. The condensed stream is supplied to the absorbing means as its top feed. A distillation liquid stream is collected from the lower region of the mass transfer means and heated in a second heat and mass transfer means inside the processing assembly to strip out its volatile components, forming a relatively less volatile stream and a vaporized stream. The vaporized stream is supplied to the mass transfer means as its bottom feed.

The invention relates to a method of selectively removing hydrogen sulfide H.sub.2S from a gaseous effluent comprising at least H.sub.2S and CO.sub.2, wherein a stage of selective absorption of hydrogen sulfide over CO.sub.2 is carried out by contacting said effluent with a solution comprising (a) water and (b) at least the following diamine: 1,2-bis(2-dimethylaminoethoxy)ethane ##STR00001##
and wherein the absorption selectivity is controlled by adding (c) a viscosifying compound to the absorbent solution.

A degradant concentration measurement device 14 according to the invention has an electric conductivity measurement instrument 71A measuring the electric conductivity of a lean solution 16 that is an acidic gas-absorbing solution and detection means 72 obtaining the concentration of a degradant contained in a lean solution 16 from the measured electric conductivity of the lean solution 16 based on the relationship between the previously-obtained electric conductivity of the lean solution 16 and the concentration of the degradant contained in the lean solution 16.