The present invention discloses a method for recycling urea in the process of separating and purifying unsaturated substances through a urea adduction method. The method comprises the following steps: liposoluble substances containing target unsaturated components are used as raw materials, and subjected to urea adduction, crystallization and filtration to produce a filtrate, from which the specific unsaturated components are obtained; the urea adduct is dissolved in a polar solvent, and after the adducted adducts are layered and released, adding a certain solvent to the urea solution to adjust the polarity, then cooling for crystallization, and recycling the urea. The method can realize complete release of the adducted components and recycling and reuse of urea, and the process is simple, the recovery rate is high, and the adduction effect is not influenced when recycling urea for reuse, and the production cost of the urea adduct is reduced, thus alleviating the adverse impact of urea discharges on the environment.

The present invention relates to Form IV of fenofibrate and its preparation methods thereof. Its X-ray powder diffraction pattern expressed as 2θ angle has characteristic peaks at 14.15±0.2°, 15.94±0.2°, 16.49±0.2°, 17.45±0.2°, 20.21±0.2°, and 22.87±0.2°. The present invention also provides preparation methods of Form IV. The preparation methods are simple, easy to operate, short, and have good repeatability. The methods are also non-toxic and non-polluting by using water as a medium and using a pharmaceutically accepted excipient, such as polyvinylpyrrolidone or polyvinyl alcohol as an inducer. The results of stability experiments (light exposure, high humidity and grinding) and solubility tests show that Form IV is stable and has a higher solubility than the prior art crystal form.

The present invention relates to Form IV of fenofibrate and its preparation methods thereof. Its X-ray powder diffraction pattern expressed as 2θ angle has characteristic peaks at 14.15±0.2°, 15.94±0.2°, 16.49±0.2°, 17.45±0.2°, 20.21±0.2°, and 22.87±0.2°. The present invention also provides preparation methods of Form IV. The preparation methods are simple, easy to operate, short, and have good repeatability. The methods are also non-toxic and non-polluting by using water as a medium and using a pharmaceutically accepted excipient, such as polyvinylpyrrolidone or polyvinyl alcohol as an inducer. The results of stability experiments (light exposure, high humidity and grinding) and solubility tests show that Form IV is stable and has a higher solubility than the prior art crystal form.

The present invention relates to Form IV of fenofibrate and its preparation methods thereof. Its X-ray powder diffraction pattern expressed as 2θ angle has characteristic peaks at 14.15±0.2°, 15.94±0.2°, 16.49±0.2°, 17.45±0.2°, 20.21±0.2°, and 22.87±0.2°. The present invention also provides preparation methods of Form IV. The preparation methods are simple, easy to operate, short, and have good repeatability. The methods are also non-toxic and non-polluting by using water as a medium and using a pharmaceutically accepted excipient, such as polyvinylpyrrolidone or polyvinyl alcohol as an inducer. The results of stability experiments (light exposure, high humidity and grinding) and solubility tests show that Form IV is stable and has a higher solubility than the prior art crystal form.

The invention relates to a solid composition comprising at least 90.0 wt. % bis(2-hydroxyethyl) terephthalate (BHET), as based on dry weight and having a pore volume in the range of 0.20 to 1.0 cm3/g. The porosity is above 25% or even above 35%. The solid composition is made by crystallisation, followed by granulation and fluid bed drying.

The invention relates to a solid composition comprising at least 90.0 wt. % bis(2-hydroxyethyl) terephthalate (BHET), as based on dry weight and having a pore volume in the range of 0.20 to 1.0 cm3/g. The porosity is above 25% or even above 35%. The solid composition is made by crystallisation, followed by granulation and fluid bed drying.

The invention relates to a solid composition comprising at least 90.0 wt. % bis(2-hydroxyethyl) terephthalate (BHET), as based on dry weight and having a pore volume in the range of 0.20 to 1.0 cm3/g. The porosity is above 25% or even above 35%. The solid composition is made by crystallisation, followed by granulation and fluid bed drying.

The present invention provides a process for producing a compound represented by formula (I), comprising the steps of (a) reacting a compound represented by formula (II) with dimethyl sulfate in the presence of an alkali carbonate in a aqueous ketone solvent to obtain the compound represented by formula (I) as a crystalline material, and (b) washing the crystalline material with heated water at 30 to 100° C. and then further washing with an organic solvent at 30 to 80° C.

A method of processing one or more streams in a phthalate-containing polymer recycling system, the method comprising receiving an extract stream and a raffinat4e stream from a liquid chromatography unit, which is part of the polymer recycling system, wherein the extract stream comprises a bis(hydroxyalkyl) phthalate monomer, C.sub.2-5 alkylene diol, and solvent, and wherein the raffinate stream comprises first impurities, C.sub.2-5 alkylene diol, and solvent; vacuum distilling the extract stream to produce a first solvent stream and a monomer and diol stream comprising the bis(hydroxyalkyl) phthalate monomer and C.sub.2-5 alkylene diol; subjecting the monomer and diol stream to steam separation to produce a monomer stream comprising the bis(hydroxyalkyl) phthalate monomer and water, and a diol stream comprising C.sub.2-5 alkylene diol and water; and vacuum distilling the raffinate stream to produce a second solvent stream and a first impurities stream comprising first impurities and C.sub.2-5 alkylene diol.

A method of processing one or more streams in a phthalate-containing polymer recycling system, the method comprising receiving an extract stream and a raffinat4e stream from a liquid chromatography unit, which is part of the polymer recycling system, wherein the extract stream comprises a bis(hydroxyalkyl) phthalate monomer, C.sub.2-5 alkylene diol, and solvent, and wherein the raffinate stream comprises first impurities, C.sub.2-5 alkylene diol, and solvent; vacuum distilling the extract stream to produce a first solvent stream and a monomer and diol stream comprising the bis(hydroxyalkyl) phthalate monomer and C.sub.2-5 alkylene diol; subjecting the monomer and diol stream to steam separation to produce a monomer stream comprising the bis(hydroxyalkyl) phthalate monomer and water, and a diol stream comprising C.sub.2-5 alkylene diol and water; and vacuum distilling the raffinate stream to produce a second solvent stream and a first impurities stream comprising first impurities and C.sub.2-5 alkylene diol.