Abstract: Acid gas is removed from a high pressure feed gas that contains significant quantities of CO2 and H2S. In especially preferred configurations and methods, feed gas is contacted in an absorber with a lean and an ultra-lean solvent that are formed by flashing rich solvent and stripping a portion of the lean solvent, respectively. Most preferably, the flash vapors and the stripping overhead vapors are recycled to the feed gas/absorber, and the treated feed gas has a CO2 concentration of less than 2 mol % and a H2S concentration of less than 10 ppmv, and more typically less than 4 ppmv.

Abstract: Solvent absorption processes for separating components of an impure feed gas are disclosed. The processes involve two stages of gas-liquid contacting, namely a first, absorption stage and a second, stripping stage. In the case of a carbon dioxide (CO2)-containing methane gas as an impure feed gas, contacting, in the stripping stage, the solvent effluent from the absorption stage with a recycled vapor fraction of the solvent effluent from the stripping stage can improve the recovery and purity of not only the methane (and/or other light hydrocarbons in the impure feed gas), but also that of the CO2 contaminant gas.

Abstract: Methods and apparatus for generating a vapor to be injected into a flue gas stream are described. Apparatus comprises a fluid vaporization and injection assembly further comprising: a stripper for producing first ammonia vapor and a first aqueous ammonia solution from a second aqueous ammonia solution; a reflux tank for producing a second ammonia vapor and the second aqueous ammonia solution from the first ammonia vapor and the first aqueous ammonia solution; and a first outlet for outputting the second ammonia vapor for introduction into the flue gas.

Abstract: An absorber (110) in a gas treatment plant (100) produces a rich solvent (116) that is flashed to produce flashed rich solvent (134D) and recycle gas (132D), wherein the recycle gas (132D) is not mixed with the absorber feed gas (112) as commonly practiced, but mixed with the rich solvent (116). Such configurations exhibit superior rich solvent loading, thereby reducing solvent circulation. Further contemplated gas treatment plants (100)may also include a regenerator (150) in which carbon dioxide from atmospheric flashed vapor (142) of the rich solvent (144) is employed as a stripping gas in a regenerator (150) to strip hydrogen sulfide from the rich solvent (144), and wherein sweet gas (114) is employed to strip the carbon dioxide from the rich solvent (144).

Abstract: A plant includes a vacuum stripper (118) that receives a lean hydrogen sulfide-containing physical solvent (32) and in which substantially hydrogen sulfide-free stripping gas (51,52) is provided by at least one of a high-pressure flash vessel (110) and a medium pressure flash vessel (112). Contemplated configurations advantageously extend the range of use for physical solvents to treat sour gas comprising carbon dioxide and hydrogen sulfide, and can be used to meet most pipeline specification of 4 ppm hydrogen sulfide.

Abstract: An improved method and structure for purification of an acid gas stream by using raw fuel gas as a stripper to remove the BTEX and VOCs from the liquid amine stream. The improved method is particularly useful for purification of acid gas streams with BTEX contaminant levels in excess of environmentally acceptable levels for standard processing. Raw fuel gas is utilized at moderate temperatures and pressures, the uptake of BTEX and VOCs reduces the level of these compounds in the waste amine stream to environmentally acceptable levels, and the remaining contaminants may then be dealt with by ordinary means. Levels of H2S and CO2. in the liquid amine stream are also reduced.

Abstract: A double-loop process for the removal of specified gas or gases from a process gas by absorption with a liquid absorbent for said specified gas or gases wherein the process gas is contacted counter-currently in a first absorption stage with semi-lean absorbent liquid and then in a second absorption stage with lean absorbent liquid to give a sweet process gas and the absorbed gases are stripped from the laden absorbent liquid in a first stage giving a semi-lean absorbent liquid. Part of the semi-lean absorbent is recycled to the first absorption stage while the remainder is subjected to further stripping by counter-current contact with an auxiliary gas that has a concentration of the specified gas or gases that is lower than the concentration of the specified gas or gases in the process gas to give the lean absorbent liquid which is recycled to the second absorption stage.

Abstract: A column to regenerate methanol from a methanol-water mixture includes a circular column having two contact beds with a plurality of gas inlets connected thereto to split the entering feed gas so that approximately equal portions are fed through each bed. An inlet near the top of the column allows a methanol-water mixture to be introduced to flow down through the two contact beds, countercurrent to the feed gas.

Abstract: An improved process for the glycol dehydration of water-containing natural gas comprises contacting the natural gas and glycol in a contacting zone to produce a dried natural gas and a water-rich glycol, and heating the water-rich glycol in a regeneration zone to produce a water-lean glycol for reintroduction into the contacting zone and a water-containing gaseous overhead. The gaseous overhead is partially condensed and the resulting gaseous components are returned to the contacting zone. In a preferred embodiment, the glycol is further purified by contact in a separate stripping column with dry stripping gas under a pressure lower than that of the regeneration zone.