A process for producing biomethane by scrubbing a biogas feed stream includes introducing the feed gas stream into a pretreatment unit wherein a CO.sub.2-depleted gas stream is partially separated from a CO.sub.2 stream and an oxygen stream and is compressed to a pressure P1 above 25 bar abs. Subjecting the CO.sub.2-depleted gas stream to cryogenic separation in a distillation column to separate a nitrogen stream and produce a CH.sub.4-enriched stream, the distillation column comprising n plates, n being an integer between 8 and 100. Recovering a pressurized CH.sub.4-enriched stream by pumping the CO.sub.2-depleted gas stream to a pressure P2 above 25 bar absolute.

A process for producing biomethane by scrubbing a biogas feed stream, including introducing a feed gas stream into a pretreatment unit thereby partially separating a CO.sub.2 stream and an oxygen stream and producing a CO.sub.2-depleted gas stream which is then compressed to a pressure P1 above 25 bar abs; introducing the CO.sub.2-depleted gas stream to cryogenic separation in a distillation column to separate a nitrogen stream, the distillation column having n plates, n being an integer between 8 and 100; recovering a pressurized CH.sub.4-enriched stream by pumping the CO.sub.2-depleted gas stream) at a pressure P2 above 25 bar, wherein, when the molar concentration of nitrogen of the CO.sub.2-depleted gas stream is less than a predetermined threshold, nitrogen is injected prior to introduction into the distillation column, in order that the stream introduced into said column has a molar concentration of nitrogen at least equal to said predetermined threshold.

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 (72) from the regeneration unit is combined with the regenerated lean hybrid solvent (55) prior to reuse in the purification unit and none of the condensed water is recycled into the regeneration unit.

Disclosed is a desulfurizer of a fuel cell. The desulfurizer includes a pipe extended long and having one side that is open and the other side that is closed; a cap coupled to one side of the pipe and closing the pipe; a plurality of baffles installed in an inner space of the pipe and sequentially partitioning the inner space in a direction crossing a length direction of the pipe; an inflow pipe penetrating through the cap and the plurality of baffles and communicating from the outside of the pipe to the inner space of the pipe; and an outflow pipe installed in the cap and communicating the outside of the pipe and the inner space of the pipe.

A method, scrubbing solution and apparatus for removing a H.sub.2S scavenger, for example dithiazine, from a gas stream uses an acidic solution to convert the H.sub.2S scavenger to a salt. The acidic solution may be a phosphoric acid solution.

Disclosed is a desulfurizer of a fuel cell. The desulfurizer includes a pipe extended long and having one side that is open and the other side that is closed; a cap coupled to one side of the pipe and closing the pipe; a plurality of baffles installed in an inner space of the pipe and sequentially partitioning the inner space in a direction crossing a length direction of the pipe; an inflow pipe penetrating through the cap and the plurality of baffles and communicating from the outside of the pipe to the inner space of the pipe; and an outflow pipe installed in the cap and communicating the outside of the pipe and the inner space of the pipe.

Various embodiments disclosed relate to extraction of target materials using a CZTS sorbent. A method of extracting a target material from a medium includes contacting a copper zinc tin sulfur (CZTS) sorbent with the target material in the medium including the target material to form a used CZTS sorbent that includes the target material.

A manufacturing method for an acidic gas separation membrane sheet includes: a step of preparing a hydrophilic resin composition liquid for forming a hydrophilic resin composition layer; a step of removing bubbles contained in the hydrophilic resin composition liquid; a step of applying the hydrophilic resin composition liquid onto a first porous layer to form an applied layer on the first porous layer; and a step of laminating a second porous layer on the applied layer to form a laminated body. The step of removing bubbles includes: a step of applying a shear to the hydrophilic resin composition liquid; and a step of leaving the hydrophilic resin composition liquid.

The invention relates to a method for purifying a gaseous, liquid or aerosol composition, containing at least one pollutant consisting of a volatile inorganic compound (VIC), a siloxane and/or a functional volatile organic compound (Pollution Trap Concept or P.T.C. System).

A method for preparing nickel/manganese/lithium/cobalt sulfate and tricobalt tetraoxide from battery wastes adopts the following process: dissolving battery wastes with acid, removing iron and aluminum, removing calcium, magnesium and copper, carrying extraction separation, and carrying out evaporative crystallization to prepare nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate or/and tricobalt tetraoxide. By using the method, multiple metal elements, such as nickel, manganese, lithium and cobalt, can be simultaneously recovered from the battery wastes, the recovered products are high in purity and can reach battery grade, battery-grade tricobalt tetraoxide can also be directly produced. The method is simple in process, low in energy consumption and free in exhaust gas pollution, and can realize zero release of wastewater.