The present invention relates to an improved process for the preparation of (2S)-2-[(4R)-2-oxo-4-propyltetrahydro-1H-pyrrol-1-yl] butanamide compound of formula-1, its intermediates, novel salt compounds of intermediates of the compound of formula-1. Further the use of novel salts in the preparation of the compound of formula-1. The present invention also relates to the novel process for the preparation of the compound of formula-1.

A method for manufacturing and a method for decolorizing dioctyl terephthalate are provided. The decolorizing dioctyl terephthalate includes: providing an unpurified dioctyl terephthalate; mixing the unpurified dioctyl terephthalate with a reducing agent and an adsorption medium to obtain a first decolorizing product; and mixing the first decolorizing product with a decolorizing adsorbent material to obtain a second decolorizing product. The method for manufacturing dioctyl terephthalate includes: a transesterification step, an alkaline washing and neutralization step, a redox step, a decolorization step and a stripping step; the decolorizing adsorbent material has an acid value between 0.1 and 2 mg KOH/g, a relative humidity between 2 and 10%, and a fineness between 80 and 100 cm.sup.2 /g.

Particles of a transition metal are used as a catalyst for depolymerisation of condensation polymers in alcohol. In the method of catalysed depolymerisation of a condensation polymer in a solid form into monomers and/or oligomers, transition metal particles; are mixed with the condensation polymer in alcohol to obtain a reaction mixture. This reaction mixture is processed to disperse the condensation polymer into the alcohol and decompose it, wherein the transition metal particles act as a catalyst and the alcohol is a reagent. The catalyst is particularly supplied as a catalyst composition of transition metal particles in an alcoholic liquid. The transition metal particles are typically non-porous and may have an oxide surface.

Particles of a transition metal are used as a catalyst for depolymerisation of condensation polymers in alcohol. In the method of catalysed depolymerisation of a condensation polymer in a solid form into monomers and/or oligomers, transition metal particles; are mixed with the condensation polymer in alcohol to obtain a reaction mixture. This reaction mixture is processed to disperse the condensation polymer into the alcohol and decompose it, wherein the transition metal particles act as a catalyst and the alcohol is a reagent. The catalyst is particularly supplied as a catalyst composition of transition metal particles in an alcoholic liquid. The transition metal particles are typically non-porous and may have an oxide surface.

Process for purification of unreacted vinyl acetate monomers comprising the steps of preliminarily loading an adsorbent agent bed with a mixture comprising an inert gas and fresh vinyl acetate; and feeding said adsorbent agent bed with unreacted vinyl acetate monomers to remove acetic acid.

Process for purification of unreacted vinyl acetate monomers comprising the steps of preliminarily loading an adsorbent agent bed with a mixture comprising an inert gas and fresh vinyl acetate; and feeding said adsorbent agent bed with unreacted vinyl acetate monomers to remove acetic acid.

The disclosure provides a decolorization and purification method of BHET material, which includes the following steps. A first dose of activated carbon is added to preliminarily treat the BHET material. After the preliminary treatment, a first cooling crystallization process and filtration are performed to obtain BHET crystals. Afterwards, an oxidant is used to chemically react with the BHET crystals to destroy a dye or impurities, and then a second dose of activated carbon is added to adsorb a chemically reacted oxide. Next, a second cooling crystallization process, filtration, and drying are performed to obtain a finished product of BHET.

The disclosure provides a decolorization and purification method of BHET material, which includes the following steps. A first dose of activated carbon is added to preliminarily treat the BHET material. After the preliminary treatment, a first cooling crystallization process and filtration are performed to obtain BHET crystals. Afterwards, an oxidant is used to chemically react with the BHET crystals to destroy a dye or impurities, and then a second dose of activated carbon is added to adsorb a chemically reacted oxide. Next, a second cooling crystallization process, filtration, and drying are performed to obtain a finished product of BHET.

The present invention relates to oil compositions that are enriched in polyunsaturated fatty acids; compositions containing the oil compositions; and methods of making and using the oil compositions. The oil is preferably a microbial or marine oil.

The present invention relates to oil compositions that are enriched in polyunsaturated fatty acids; compositions containing the oil compositions; and methods of making and using the oil compositions. The oil is preferably a microbial or marine oil.