The invention relates to a process for preparing propylene oxide, comprising (i) providing a stream comprising propene, propane, hydrogen peroxide or a source of hydrogen peroxide, water, and an organic solvent; (ii) passing the liquid feed stream provided in (i) into an epoxidation zone comprising an epoxidation catalyst comprising a titanium zeolite, and subjecting the liquid feed stream to epoxidation reaction conditions in the epoxidation zone, obtaining a reaction mixture comprising propene, propane, propylene oxide, water, and the organic solvent; (iii) removing an effluent stream from the epoxidation zone, the effluent stream comprising propene, propane, propylene oxide, water, and the organic solvent; (iv) separating propene and propane from the effluent stream by distillation, comprising subjecting the effluent stream to distillation conditions in a distillation unit, obtaining a gaseous stream (S1) which is enriched in propene and propane compared to the effluent stream subjected to distillation conditions, and a liquid bottoms stream (S2) which is enriched in propylene oxide, water and organic solvent compared to the effluent stream subjected to distillation conditions; (v) separating propane from the stream (S1) in a separation zone, comprising subjecting the stream (S1) to washing conditions in a scrubber, wherein a solvent mixture comprising organic solvent and water is added as entraining agent, obtaining a bottoms stream (S3), which comprises organic solvent, water and at least 70 weight-% of the propene comprised in (S1); and a gaseous top stream (S4), which comprises at least 5 weight-% of the propane comprised in stream (S1).

Disclosed in the present invention are a preparation method for an olefin epoxidation catalyst and applications thereof. The method comprises: loading an auxiliary metal salt onto a silica gel carrier, and carrying out a drying treatment to the silica gel carrier; loading a titanium salt (preferably TiCl.sub.4) onto the silica gel carrier by a chemical vapor deposition method; calcining to obtain a silica gel on which the auxiliary metal oxide and Ti species are loaded; obtaining an catalyst precursor (Ti-MeO—SiO.sub.2 composite oxide) by water vapor washing; loading alkyl silicate (preferably tetraethyl orthosilicate) onto the surface of the catalyst precursor by a chemical vapor deposition method and calcining the catalyst precursor to obtain a Ti-MeO—SiO.sub.2 composite oxide with the surface coated with a SiO.sub.2 layer; and carrying out a silylanization treatment to obtain the catalyst. The catalyst can be applied to a chemical process of propylene epoxidation to prepare propylene oxide, and has an average selectivity to PO up to 96.7%, the method of the present invention and the applications thereof have industrial application prospects.

Disclosed in the present invention are a preparation method for an olefin epoxidation catalyst and applications thereof. The method comprises: loading an auxiliary metal salt onto a silica gel carrier, and carrying out a drying treatment to the silica gel carrier; loading a titanium salt (preferably TiCl.sub.4) onto the silica gel carrier by a chemical vapor deposition method; calcining to obtain a silica gel on which the auxiliary metal oxide and Ti species are loaded; obtaining an catalyst precursor (Ti-MeO—SiO.sub.2 composite oxide) by water vapor washing; loading alkyl silicate (preferably tetraethyl orthosilicate) onto the surface of the catalyst precursor by a chemical vapor deposition method and calcining the catalyst precursor to obtain a Ti-MeO—SiO.sub.2 composite oxide with the surface coated with a SiO.sub.2 layer; and carrying out a silylanization treatment to obtain the catalyst. The catalyst can be applied to a chemical process of propylene epoxidation to prepare propylene oxide, and has an average selectivity to PO up to 96.7%, the method of the present invention and the applications thereof have industrial application prospects.

Method for treating production wastewater from the preparation of propylene oxide by co-oxidation. The wastewater includes a first portion of wastewater having a peroxide content of 2000 mg/L or more and a second portion of wastewater having a peroxide content of 50 mg/L or less.

Methods for preparing molybdenum-based catalyst for epoxidation reactions using MPG sourced from a propylene oxide/styrene monomer (POSM) production process are described. Streams exiting from the POSM reactor are combined and separated to isolate an aqueous-based, MPG-containing purge stream from other recoverable byproducts of the POSM process. This MPG-containing purge stream is then used as is in the catalyst preparation of molybdenum-based catalyst for epoxidation. Alternatively, the MPG-containing purge stream can undergo additional purification treatments before being utilized in the catalyst preparation.

A metal-organic framework (MOF) MIL-125 and a preparation method and a use thereof are provided. The MOF MIL-125 is a round cake-like crystal and has an external specific surface area (SSA) of 160 m.sup.2/g to 220 m.sup.2/g. The MOF MIL-125 provided in the present application has a large number of microporous structures, a large external SSA, and a high catalytic activity in oxidation.

A metal-organic framework (MOF) MIL-125 and a preparation method and a use thereof are provided. The MOF MIL-125 is a round cake-like crystal and has an external specific surface area (SSA) of 160 m.sup.2/g to 220 m.sup.2/g. The MOF MIL-125 provided in the present application has a large number of microporous structures, a large external SSA, and a high catalytic activity in oxidation.

An integrated process for making propylene oxide and propylene glycol involves reacting propene with an oxidant to provide propylene oxide, reacting a fraction of the propylene oxide with water to provide an aqueous glycol solution containing monopropylene glycol and dipropylene glycol, and separating monopropylene glycol and dipropylene glycol from the glycol solution by a multi-step distillation. The propylene oxide output can be increased without increasing capacity of the unit for reacting propene to propylene oxide, by reacting propene and hydrogen peroxide in the presence of a catalyst mixture, containing a phase transfer catalyst and a heteropolytungstate, in a liquid reaction mixture which contains an aqueous phase with a maximum apparent pH of 6 and an organic phase. The reaction mixture is separated into an organic phase, which is recycled to the reaction, and an aqueous phase containing monopropylene glycol and dipropylene glycol, which is passed to replace the glycol solution.

An integrated process for making propylene oxide and propylene glycol involves reacting propene with an oxidant to provide propylene oxide, reacting a fraction of the propylene oxide with water to provide an aqueous glycol solution containing monopropylene glycol and dipropylene glycol, and separating monopropylene glycol and dipropylene glycol from the glycol solution by a multi-step distillation. The propylene oxide output can be increased without increasing capacity of the unit for reacting propene to propylene oxide, by reacting propene and hydrogen peroxide in the presence of a catalyst mixture, containing a phase transfer catalyst and a heteropolytungstate, in a liquid reaction mixture which contains an aqueous phase with a maximum apparent pH of 6 and an organic phase. The reaction mixture is separated into an organic phase, which is recycled to the reaction, and an aqueous phase containing monopropylene glycol and dipropylene glycol, which is passed to replace the glycol solution.

The present invention relates to compound of formula (I), wherein R.sup.1 is chloro, bromo iodo or a brosylate group. The present invention also relates to methods of making this compound and its use in carrying out organic transformations.

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