The present disclosure relates to the recovery of an alkoxide catalyst used in a process depolymerizing a polyester to form a diacid or diester and a diol. The present disclosure also relates to the recovery of an alkoxide catalyst used in a process depolymerizing polyethylene terephthalate to form dimethyl terephthalate and mono ethylene glycol.

The present disclosure relates to the recovery of an alkoxide catalyst used in a process depolymerizing a polyester to form a diacid or diester and a diol. The present disclosure also relates to the recovery of an alkoxide catalyst used in a process depolymerizing polyethylene terephthalate to form dimethyl terephthalate and mono ethylene glycol.

A silica membrane filter 10 includes an ultrafiltration membrane 15, which is disposed on a support body 14 and which contains an element 14 as a primary component, and a silica membrane 18 which is disposed on the ultrafiltration membrane 15 and which has an aryl group. The ultrafiltration membrane 15 has a structure infiltrated by Si of the silica membrane 18, the atomic ratio A (=Si/M) of Si to the element M in a membrane-side region 16, which is a region corresponding to 25% of the ultrafiltration membrane 15 from the silica membrane 18, satisfies 0.01≦A≦0.5, and the ratio A/B of the atomic ratio A to the atomic ratio B (=Si/M) in a base-material-side region 17, which is a region corresponding to 25% from the support body 14, is within the range of 1.1 or more.

A silica membrane filter 10 includes an ultrafiltration membrane 15, which is disposed on a support body 14 and which contains an element 14 as a primary component, and a silica membrane 18 which is disposed on the ultrafiltration membrane 15 and which has an aryl group. The ultrafiltration membrane 15 has a structure infiltrated by Si of the silica membrane 18, the atomic ratio A (=Si/M) of Si to the element M in a membrane-side region 16, which is a region corresponding to 25% of the ultrafiltration membrane 15 from the silica membrane 18, satisfies 0.01≦A≦0.5, and the ratio A/B of the atomic ratio A to the atomic ratio B (=Si/M) in a base-material-side region 17, which is a region corresponding to 25% from the support body 14, is within the range of 1.1 or more.

Method for lowering aldehyde content in a mixture comprising (i) diethylene glycol (DEG) and/or triethylene glycol (TEG) and (ii) aldehyde are disclosed. An ion exchange resin is soaked in monoethylene glycol. The mixture comprising 5 to 200 ppm aldehyde is then flowed to make contact with the soaked ion exchange resin to produce a product comprising DEG and/or TEG and less than 15 ppm aldehyde.

Method for lowering aldehyde content in a mixture comprising (i) diethylene glycol (DEG) and/or triethylene glycol (TEG) and (ii) aldehyde are disclosed. An ion exchange resin is soaked in monoethylene glycol. The mixture comprising 5 to 200 ppm aldehyde is then flowed to make contact with the soaked ion exchange resin to produce a product comprising DEG and/or TEG and less than 15 ppm aldehyde.

Method for lowering aldehyde content in a mixture comprising (i) diethylene glycol (DEG) and/or triethylene glycol (TEG) and (ii) aldehyde are disclosed. An ion exchange resin is soaked in monoethylene glycol. The mixture comprising 5 to 200 ppm aldehyde is then flowed to make contact with the soaked ion exchange resin to produce a product comprising DEG and/or TEG and less than 15 ppm aldehyde.

Disclosed herein is a polycrystalline metal-organic framework membrane comprising a substrate material having a surface and a polycrystalline metal-organic framework attached to the surface of the substrate material, wherein the polycrystalline metal-organic framework is formed from a secondary building unit having the formula Ia or IIb and a ligand as defined in the application.

Disclosed herein is a polycrystalline metal-organic framework membrane comprising a substrate material having a surface and a polycrystalline metal-organic framework attached to the surface of the substrate material, wherein the polycrystalline metal-organic framework is formed from a secondary building unit having the formula Ia or IIb and a ligand as defined in the application.

A gas separation method includes supplying a mixed gas to a zeolite membrane complex and permeating a high permeability gas through the zeolite membrane complex to separate the high permeability gas from other gases. The mixed gas includes a high permeability gas and a trace gas that is lower in concentration than the high permeability gas. The molar concentration of a first gas included in the trace gas in the mixed gas is higher than the molar concentration of a second gas included in the trace gas in the mixed gas. The adsorption equilibrium constant of the first gas on the zeolite membrane is less than 60 times that of the high permeability gas. The adsorption equilibrium constant of the second gas on the zeolite membrane is 400 times or more that of the high permeability gas.