Methods and systems for recovering sulfur dioxide from a Claus unit process emissions stream are provided. The method comprises the steps of generating a process emissions stream from a thermal oxidizer or other combustion device, introducing the emissions stream to an SO.sub.2 removal system, introducing the SO.sub.2 rich stream from the SO.sub.2 removal system to a CO.sub.2 removal system, and introducing an enriched SO.sub.2 stream back to the Claus unit. The SO.sub.2 removal system can include one or more SO.sub.2 selective membranes. The CO.sub.2 removal system can include one or more CO.sub.2 selective membranes.

A filtration method that includes a cleaning step using a chemical agent, wherein provided is the filtration method with excellent chemical resistance performance. The filtration method pertaining to the present invention comprises a filtration step in which a liquid to be filtered is filtered by being passed through a porous membrane formed of a resin, and a cleaning step in which the membrane interior of the porous membrane is cleaned after the filtration step, wherein a porous membrane for which the area ratio of a resin part having an area of 1 μm.sup.2 or less included in a cross section of the membrane interior is at least 70% of the total area of the entire resin part included in the cross section, and said cleaning step includes a step in which an aqueous solution of at least 1% sodium hydroxide is passed through the porous membrane.

A filtration method that includes a cleaning step using a chemical agent, wherein provided is the filtration method with excellent chemical resistance performance. The filtration method pertaining to the present invention comprises a filtration step in which a liquid to be filtered is filtered by being passed through a porous membrane formed of a resin, and a cleaning step in which the membrane interior of the porous membrane is cleaned after the filtration step, wherein a porous membrane for which the area ratio of a resin part having an area of 1 μm.sup.2 or less included in a cross section of the membrane interior is at least 70% of the total area of the entire resin part included in the cross section, and said cleaning step includes a step in which an aqueous solution of at least 1% sodium hydroxide is passed through the porous membrane.

The present invention relates to hyper-branched compounds, a method of synthesizing the hyper-branched compounds and applications of the hyper-branched compounds. The hyper-branched compounds of the present invention include hyper-branched fluorinated compounds, hyper-branched fluorinated graphene and hyper-branched amine functionalized graphene oxide.

The present invention relates to hyper-branched compounds, a method of synthesizing the hyper-branched compounds and applications of the hyper-branched compounds. The hyper-branched compounds of the present invention include hyper-branched fluorinated compounds, hyper-branched fluorinated graphene and hyper-branched amine functionalized graphene oxide.

A polymer film has a loofah-like structure. It has a fibrous framework structure formed by three-dimensional interwoven and interconnected polymer fibers and a three-dimensional interconnected network pore structure distributed in the fibrous framework structure. The polymer is an organic polymer and the fibrous framework structure is integrally formed by the polymer. The film has a volume porosity of from 50% to 95%. The film is obtained by means of a combination method for atomization pretreatment and non-solvent phase separation. The film can be used in the fields of gas filtration, liquid filtration, oil-water separation, adsorption materials, catalysis, pharmaceutical sustained release materials, anti-adhesion coatings, oil delivery and oil spill interception.

A polymer film has a loofah-like structure. It has a fibrous framework structure formed by three-dimensional interwoven and interconnected polymer fibers and a three-dimensional interconnected network pore structure distributed in the fibrous framework structure. The polymer is an organic polymer and the fibrous framework structure is integrally formed by the polymer. The film has a volume porosity of from 50% to 95%. The film is obtained by means of a combination method for atomization pretreatment and non-solvent phase separation. The film can be used in the fields of gas filtration, liquid filtration, oil-water separation, adsorption materials, catalysis, pharmaceutical sustained release materials, anti-adhesion coatings, oil delivery and oil spill interception.

Disclosed herein are systems and methods for purifying aqueous solutions. For example, disclosed herein are flexible membrane distillation systems comprising one or more stages stacked on top of each other, wherein each stage comprises: a feedwater layer; a membrane distillation layer; a distillate layer; and a thermally conductive layer. The systems further comprise substantially impermeable top surface, bottom surface, and perimeter. Each feedwater layer is independently receives a portion of a contaminated aqueous solution (a feed solution). Each feedwater layer further receives heat from a heat source to distill at least a portion of the feed solution through the membrane distillation layer, thereby producing a distillate in the distillate layer. Distilling said portion of the feed solution through the membrane distillation layer purifies said portion of the feed solution to produce a purified aqueous solution, which is condensed in the distillate layer to form a condensate.

Disclosed herein are systems and methods for purifying aqueous solutions. For example, disclosed herein are flexible membrane distillation systems comprising one or more stages stacked on top of each other, wherein each stage comprises: a feedwater layer; a membrane distillation layer; a distillate layer; and a thermally conductive layer. The systems further comprise substantially impermeable top surface, bottom surface, and perimeter. Each feedwater layer is independently receives a portion of a contaminated aqueous solution (a feed solution). Each feedwater layer further receives heat from a heat source to distill at least a portion of the feed solution through the membrane distillation layer, thereby producing a distillate in the distillate layer. Distilling said portion of the feed solution through the membrane distillation layer purifies said portion of the feed solution to produce a purified aqueous solution, which is condensed in the distillate layer to form a condensate.

A pervaporation membrane formed on a porous support containing a composition encompassing a polysiloxane, a crosslinker and a catalyst are disclosed and claimed. Also disclosed are the fabrication of membranes which exhibit unique separation properties, and their use in the separation of organic volatiles from biomass and/or organic waste, including butanol, ethanol, and the like.