605results about "Preparation by ester-hydroxy reaction" patented technology

The invention discloses an efficient purification method of rBHET, and belongs to the technical field of waste polyester recycling. A reaction raw material obtained after premixing of waste PET polyester raw material particles and a catalyst and ethylene glycol are jointly and continuously introduced into a depolymerization reactor, the reaction raw material and ethylene glycol in the depolymerization reactor are mixed and pass through a plurality of rotating discs, and the materials form a flowing film on the rotating discs rotating at a high speed to promote depolymerization; depolymerization reaction liquid generated in the depolymerization reactor enters a temporary storage tank to be stored after being subjected to impurity removal, the depolymerization reaction liquid in the storage tank is introduced into a rectifying tower to be primarily concentrated and purified, obtained concentrated liquid enters an evaporator to be secondarily concentrated and purified, obtained secondary concentrated liquid enters a cooler to be cooled and then enters a product tank to be crystallized; and drying the crystallized solid to obtain a high-purity rBHET product. According to the method, the production efficiency is improved, and the purity of rBHET is effectively improved.

The recycled bis(4-hydroxybutyl) terephthalate according to one embodiment has a low amount of residual ethylene glycol derivatives and can therefore be used as a polymerization raw material for high crystallinity engineering polyester products or biodegradable polyesters, offering superior qualities, for example, color.

The invention provides a method for alcoholysis of polyethylene glycol terephthalate, and relates to the technical field of PET degradation. The PET alcoholysis method provided by the invention comprises the following steps: mixing PET, ethylene glycol, a cosolvent and a composite catalyst, and carrying out alcoholysis reaction to obtain bis (hydroxyethyl) terephthalate (BHET). According to the invention, dimethyl sulfoxide is taken as a cosolvent, zinc acetate and 1, 8-diazabicyclo [5.4. 0] undec-7-ene are taken as a composite catalyst, catalysis and solvent effect driving are combined, and ethylene glycol alcoholysis of PET is carried out under the synergistic effect of the composite catalyst and the cosolvent. According to the method, effective decomposition of PET can be achieved at the low temperature (140-155 DEG C) and within the short reaction time (60-100 min), and the yield of BHET is high (66% or above and can reach 80% or above). The method provided by the invention can realize high-efficiency alcoholysis of PET with ethylene glycol.

The invention discloses a method for efficiently depolymerizing polyethylene glycol terephthalate, which comprises the following steps: mixing a PET material, ethylene glycol and a core-shell type magnetic nano composite catalyst, and carrying out alcoholysis reaction at 160-200 DEG C for 30-180 minutes; after the reaction is finished, separating the catalyst from a reaction system through an external magnetic field to obtain a solution containing bis (2-hydroxyethyl) terephthalate; the core-shell type magnetic nano composite catalyst comprises a magnetic FeO core, a SiO shell layer and active metal sites, the FeO core is coated with the SiO shell layer, the SiO shell layer is an insulating inorganic layer and is of a porous structure, the active metal sites are fixed to the surface of the SiO shell layer through coordinate bonds, and active metal is selected from one or more of Co, Ni, Cu, Ce, La and Al. The problems that an existing PET alcoholysis catalyst is easy to dissolve out, difficult to separate, harsh in reaction condition and poor in cycling stability are solved.

The invention belongs to the technical field of copolymerization modification of degradable polyester, and relates to a depolymerization method and application of polybutylene terephthalate. During depolymerization, polybutylene terephthalate, dimethyl carbonate and dihydric alcohol are mixed and then subjected to a depolymerization reaction, and an intermediate ester is prepared; the dihydric alcohol is dihydric alcohol which does not form a ring with dimethyl carbonate in the depolymerization reaction process; the molar weight of the dimethyl carbonate is 10-30% of the molar weight of a repetitive unit of the polybutylene terephthalate; the sum of the molar weight of a 1, 4-butanediol unit in the polybutylene terephthalate and the molar weight of the added dihydric alcohol is a, the sum of the molar weight of a terephthalic acid unit in the polybutylene terephthalate and the molar weight of the added dimethyl carbonate is b, and the ratio of b to a is (1.2-1.5): 1; during application, the prepared intermediate ester is subjected to transesterification under the condition of negative pressure to obtain the copolyester. The depolymerization method is simple and easy to implement; the depolymerization product can be directly applied.

A polymerization raw material obtained by the depolymerization of waste polyester is disclosed. The polymerization raw material contains recycled bis(2-hydroxyethyl) terephthalate in which the contents of acetate-based ester compounds and diethylene glycol ester compounds are adjusted to specific levels. The polymerization raw material is excellent in purity and quality, and free from the problem that thermal resistance characteristics deteriorate in the polymerization of a polymer from the recycled monomer.

The application belongs to the technical field of regenerated polyester, and particularly relates to a recycling method of waste polyester textiles, which comprises the following steps: decolorizing colored waste polyester textiles by using a decolorizing agent, wherein the decolorizing agent is one or more of dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate; depolymerizing the decolorized polyester textiles by using a depolymerizing agent to obtain terephthalate, wherein the depolymerization rate of the decolorized polyester textiles is 98.0-100%; converting the terephthalate into DMT first, and then performing a re-polymerization reaction on the DMT, ethylene glycol, a catalyst and a functional additive to obtain regenerated PET. The application adopts a process of decolorizing first and then depolymerizing, and the decolorizing and depolymerizing are coordinated, so that the process is simplified, the energy consumption and pollution are reduced, and the economy and sustainability of the recycling of waste polyester textiles are improved.

The present invention relates to a process for depolymerizing a polyester feedstock comprising opaque PET, which comprises: a) a conditioning step; b) a step of glycolysis, operated at between 180 and 400° C., a residence time of from 0.1 to 10 h in the presence of diol; c) a diol separation step, at a temperature of between 100 and 250° C., a pressure lower than that of step b) and producing a diol effluent and an effluent rich in monomers; d) a step of separating into a heavy impurities effluent and a prepurified monomers effluent, at a temperature of less than 250° C. and a pressure of less than 0.001 MPa and a residence time of less than 10 min; e) a step of decolourizing the prepurified monomers effluent, by adsorption of a mixture comprising between 20% and 90% by weight of the prepurified monomers effluent and a solvent, at a temperature of between 100 and 200° C., a pressure of between 0.1 and 1.0 MPa and in the presence of at least one adsorbent.

Provided are industrial processes for producing an organic acid alky ester from a feedstock containing organic acids and / or saponifiables, comprising: countercurrently contacting a feedstock with an organic alkylating reagent over two or more vessels or stages at temperature between 100° C. and 400° C. and pressure between 0.1 barg and 355 barg while simultaneously removing water and / or glycerin with unreacted alkylating reagent from the final vessel or stage to result in a first reaction method product containing organic acid alkyl esters, followed by a choice of using the alkyl esters as-is, purifying the organic acid alkyl esters from the first reaction product mixture or subjecting the first reaction product mixture to an additional transesterification reaction to convert saponifiables into additional organic acid alkyl esters, then purifying the organic acid alkyl esters from this second reaction method product.

The invention discloses a method for degrading and recycling waste plastics based on a deep eutectic solvent, and belongs to the technical field of waste plastic resource recycling. The method comprises the following steps: treating waste PET plastic by using a decolorizing agent, carrying out catalytic alcoholysis on the waste PET plastic and ethylene glycol at 180-200 DEG C under normal pressure by using a choline chloride / ethylene glycol / zinc acetate ternary eutectic solvent as a catalyst and a solvent to generate a bis (2-hydroxyethyl) terephthalate monomer, and synthesizing the waterborne polyurethane with isophorone diisocyanate. The preparation method comprises the following steps: mixing waterborne polyurethane with an acrylamide-acrylic acid copolymer and a ternary eutectic solvent, and carrying out UV photopolymerization to prepare the dual-network eutectic gel. The method has the characteristics that the ternary eutectic solvent and Zn < 2 + > synergistically catalyze the degradation of the waste PET to obtain the bis (2-hydroxyethyl) terephthalate monomer with the purity of more than or equal to 96.1% and the yield of more than or equal to 95.3%, and then the eutectic gel with the tensile strength of more than or equal to 1.5 MPa is prepared through photopolymerization, and the temperature is reduced by 60-80 DEG C compared with that of the traditional process. The method effectively solves the problems of high energy consumption, more waste acid and low yield of the traditional waste PET plastic recovery technology.

The invention provides a photocuring composition and application thereof. The composition comprises the following components: (a) at least one benzoyl formate compound; (b) at least one ethylenically unsaturated photopolymerizable compound; the benzoyl formate compound is obtained by reacting a compound shown in a general formula (I) with a compound shown in a general formula (II) or a general formula (III), or is obtained by further reacting the compounds shown in the general formula (I), the general formula (II) and the general formula (III) with a compound with an end-capped substituent group for end capping. The sensitivity of the obtained product is not reduced compared with that of existing small molecules, and the hardness of the product is improved under LED curing.

The invention discloses a zinc oxide modified silicon dioxide catalyst, a preparation method and application of the zinc oxide modified silicon dioxide catalyst in catalytic alcoholysis of waste PET (polyethylene terephthalate), zinc acetate and silicon dioxide are added into a mixed solution of water and ethanol and uniformly mixed, and a mixed reaction solution is obtained; adding a sodium hydroxide aqueous solution into the mixed reaction solution, carrying out a first reaction, and standing to obtain a suspension; and adding an L-ascorbic acid aqueous solution into the suspension, carrying out a second reaction, carrying out solid-liquid separation, and calcining the solid part in an air atmosphere to obtain the product. The prepared zinc oxide modified silicon dioxide nano material can be used as a catalyst to be applied to alcoholysis recovery of waste polyester, the product yield reaches up to 92% or above, the product selectivity is high, metal residues are avoided, the catalyst is easy to recover and can be recycled, and the application prospect is wide.

The invention relates to the field of functional materials, in particular to chemical recycling of a series of polyesters represented by PET (Polyethylene Terephthalate) by using a novel and efficient magnesium-based catalyst technology, which is of great significance for treating plastic pollution and realizing green circular economy.

The invention provides an ester exchange reaction separation coupling device and method, and belongs to the technical field of chemical engineering, the ester exchange reaction separation coupling device comprises a reaction kettle, a circulation pipeline and a catalyst preparation tank; the top of the reaction kettle is provided with a feed port, and the bottom is provided with a discharge port; the circulating pipeline is located on the outer side of the reaction kettle, and the two ends of the circulating pipeline are communicated with the feeding port and the discharging port respectively; the circulating pipeline is sequentially connected with a membrane filtering unit, a micro-interface strengthening mixer and a pre-reactor from the discharging opening to the feeding opening, and the circulating pipeline is further connected with a circulating pump; the catalyst preparation tank is connected to the position, between the membrane filtration unit and the micro-interface strengthening mixer, of the circulation pipeline through a feeding pipe; the circulating pipeline is provided with a waste catalyst discharging pipe at the upstream of the feeding pipe, and when part of the waste catalyst in the circulating pipeline is regularly discharged, a new catalyst is supplemented to the circulating pipeline at the same time; according to the arrangement, after mixed feed liquid is introduced into the reaction kettle, the influence of discharge of a waste catalyst on the transesterification reaction in the reaction kettle can be reduced.

The present invention relates to a method for alcoholysis of a plastic, in which the plastic is subjected to an alcoholysis reaction using a specific binuclear metal complex catalyst in the presence of an alcoholysis agent to obtain a monomer, and the plastic is one or more selected from the group consisting of polyester, polycarbonate, polyamide and polyurethane. According to the alcoholysis method of the plastic, catalytic alcoholysis can be efficiently carried out, the purity of a monomer product is high, post-treatment is simple, and various plastics can be treated.

The invention discloses a method for recovering monohydroxyethyl terephthalate from a polyester textile, which comprises the following steps: carrying out multi-stage decolorizing treatment on the polyester textile to be recovered by using ethylene glycol as a decolorizing agent to obtain the decolorized polyester textile; mixing a depolymerization catalyst, a sodium phosphate buffer solution and the decolored polyester textile, and carrying out a depolymerization reaction to obtain a depolymerization solution; adding ethyl acetate into the depolymerization liquid for extraction, rotary evaporation concentration and sublimation treatment to obtain monohydroxyethyl terephthalate. According to the method for recycling the monohydroxyethyl terephthalate from the polyester textile, the decolorization rate of the polyester textile can reach 90% or above, the purity of the recycled monohydroxyethyl terephthalate is larger than 98%, and the whiteness of the recycled monohydroxyethyl terephthalate is larger than 97%. The method for recycling the monohydroxyethyl terephthalate from the polyester textile, provided by the invention, is an efficient, economical and green new method for recycling the polyester, and the recycling of the polyester textile is realized.

Provided are a preparation method of an ion catalyst material for PET chemical recycling and a PET chemical recycling method. The preparation method of an ion catalyst material for PET chemical recycling includes the following. A metal chloride is added to an alkylimidazole-chloride ionic liquid to form a bisalkylimidazole-metal tetrachloride ionic liquid that is grafted on a porous carrier.

The invention discloses a method for synthesizing dialkyl terephthalate through waste PET plastic alcoholysis based on a VTa-coated NC / C catalyst, the conversion rate of PET plastic is 100%, the yield of dimethyl terephthalate and ethylene glycol is as high as 99%, no obvious inactivation phenomenon exists after the catalyst is used for 10 times, and the method is suitable for industrial production. The catalytic system is also effective to n-butyl alcohol, 2-ethylhexanol, isononyl alcohol, isodecyl alcohol and ethylene glycol, a series of plastic additives and ethylene glycol can be obtained, and the product yield is 89% or above.

The invention relates to the technical field of high-valued utilization of solid wastes, and discloses a transition metal doped iron-containing solid waste catalytic material, a preparation method thereof and an application of the transition metal doped iron-containing solid waste catalytic material in degradation of PET (Polyethylene Terephthalate). The method comprises the following steps: carrying out physical screening or disc (ball) milling treatment on the iron-containing solid waste, then dissolving the iron-containing solid waste in organic acid, and heating and stirring to obtain turbid liquid; carrying out solid-liquid separation on the turbid liquid to obtain a solid; dissolving transition metal salt in water, adding the transition metal salt and the solid into a reaction container, adding oxalic acid, adjusting the pH value, and uniformly stirring and mixing; carrying out heating reaction on the mixed solution, and drying an obtained reaction product to obtain a precursor; and roasting the precursor to obtain the transition metal doped ferrite catalyst. The method for preparing the PET alcoholysis efficient catalyst from the iron-containing solid waste has the advantages of being low in raw material cost, high in catalytic efficiency, low in equipment requirement, easy to separate and recycle and the like, a brand new thought is provided for PET alcoholysis, the method has a large application prospect, and the catalytic material is suitable for industrialization.

The invention relates to the technical field of high polymer material recovery, in particular to a composite catalyst for preparing DMT through PET alcoholysis and a preparation method and application of the composite catalyst. The composite catalyst comprises a solid acid material which is obtained by carrying out proton transfer reaction on silica gel of which the surface is grafted with aluminum alkyl and perfluoroalkyl sulfonic acid of which the general formula is Rf-SO3H, wherein Rf is a perfluoroalkyl group with the carbon atom number of 1-10. Through the synergistic effect of the components, the composite catalyst shows excellent performance in the process of degrading PET (Polyethylene Terephthalate) by monohydric alcohol. When methanol is used as an alcoholysis agent, the yield of the main product dimethyl terephthalate (DMT) can reach 95% or above, the catalytic efficiency is high, the stability is good, an efficient catalyst is provided for industrialization of chemical recovery of PET, and the method has important economic and environmental values.

The invention relates to a reaction process for recovering BHET by depolymerizing PET, belonging to the technical field of high polymer material recovery. The process comprises the following steps: mixing a raw material containing waste PET particles and ethylene glycol with a sylvite catalyst, placing the mixture in a closed container, carrying out a depolymerization reaction in an inactive atmosphere to obtain a depolymerization solution, mixing the depolymerization solution with methanol and BHET seed crystals, carrying out an ester exchange reaction to obtain a reaction solution, cooling the reaction solution to 25 DEG C at a speed of 10 DEG C / min, crystallizing for 3-6 hours, carrying out acid pickling, and drying to obtain the PET / BHET composite material. A BHET crystal is obtained; pressure oscillation is intermittently carried out in the depolymerization reaction process. The low-temperature depolymerization rate is increased by adopting the potassium salt catalyst, and meanwhile, directional migration of impurities is induced through periodic pressure change, so that full-continuous operation is realized.

The invention discloses a surface zinc-loaded molecular sieve catalyst for PET (polyethylene terephthalate) depolymerization and a preparation method of the surface zinc-loaded molecular sieve catalyst. According to the catalyst, a molecular sieve with a framework silica-alumina ratio of 25-400 is adopted as a carrier, and zinc species are strongly loaded on the outer surface of the molecular sieve through chemical bonding. The preparation method comprises the following steps: dissolving a zinc source in water, and adjusting to a specific pH value by using inorganic acid to obtain a zinc-containing solution; dipping a molecular sieve carrier in the solution under a heating condition; and finally, filtering, washing, drying and roasting to obtain a finished product. The catalyst successfully solves the problem that reaction activity and separability of a traditional solid catalyst in PET glycol alcoholysis are difficult to consider at the same time by accurately regulating and controlling active site distribution, shows high activity and excellent cycling stability close to those of a homogeneous catalyst, and has remarkable industrial application potential.

This invention discloses a method for preparing high-quality bio-based 1,9-nonanediol, comprising the following steps: transesterification, precipitation, fatty acid methyl ester refining, ozone oxidation pyrolysis, solvent recovery, esterification, dimethyl azelaate refining, and hydrogenation to obtain high-quality bio-based 1,9-nonanediol. This invention achieves gradient and full-component utilization of vegetable oil raw materials: the oil-based portion of triglycerides is used to produce high-quality bio-based 1,9-nonanediol, while simultaneously producing byproducts such as methyl palmitate, methyl stearate, propionic acid, hexanoic acid, and nonanoic acid; the glycerol-based portion of triglycerides is used as a byproduct of glycerol production. This invention utilizes esterification to reconstruct the products of ozone oxidation pyrolysis, converting the high-boiling-point monomethyl azelaate into the low-boiling-point dimethyl azelaate, achieving efficient separation from saturated fatty acid methyl esters. The dimethyl azelaate, as a raw material, is then hydrogenated to obtain high-quality nonanediol, significantly reducing production costs.

The present disclosure relates to a process for the depolymerization of polyethylene terephthalate (PET). The process of the present disclosure is performed without using any catalyst or ionic liquids. Further, the reagents used in the process can be recovered and reused.

The invention relates to an electrochemical process for the preparation of 1,2,3,4-butanetetracarboxylic acid tetraalkyl esters containing alkyl groups having 1 to 6 carbon atoms. The process comprises the electrohydrodimerization of dialkyl maleates containing alkyl groups having 1 to 6 carbon atoms in a reactant solution containing an alcohol and a conductive salt.

The present application discloses a chiral dienyl-substituted carboxylate compound and an asymmetric preparation method thereof, wherein the chiral dienyl-substituted carboxylate compound is an optically active compound with the structure shown in the following formula I, including stereoisomers with the same chemical formula: in the formula, * represents a chiral carbon atom; the substituent R is selected from hydrogen, C 1‑10 alkyl or aryl; Ar is an aromatic ring or a substituted aromatic ring; R 1 , R 2 , R 3 , R 4 , R 5 are independently selected from hydrogen, halogen, C 1‑10 alkyl or alkoxy; R 6 is independently selected from C 1‑10 alkyl or aryl; R 7 is independently selected from C 1‑10 alkyl or aryl. The present application applies a chiral isothiourea catalytic electrochemical synthesis system to precisely and quickly synthesize the chiral dienyl-substituted carboxylate compound in a high yield and high stereoselectivity and in a gram-scale. The preparation method of the present application is simple, and has biomedical practicability and industrial application prospect.

Through a transesterification reaction in which a predetermined amount of bis(2-hydroxyethyl)terephthalate relative to glycol is fed in a divided or continuous manner, bis(glycol)terephthalate with a low residual amount of an ethylene glycol derivative is prepared, and polyester engineering products or biodegradable polyester products with high crystallinity can be produced therefrom.

This invention discloses a method for preparing ethylhexyl palmitate, relating to the technical field of ethylhexyl palmitate. First, isooctanol is vaporized and passed into a methyl palmitate solution to prepare ethylhexyl palmitate via transesterification. The gaseous feed increases the instantaneous concentration of alcohol in the liquid phase, promoting the reaction in the forward direction and increasing the reaction rate. Simultaneously, methanol generated by the transesterification process is also vaporized and carried out of the system, further promoting the forward reaction and making it more complete. Second, a catalyst is synthesized using a chromium salt as a metal source precursor and a 2-sulfonyl-4,4'-biphenyldicarboxylic acid ligand. The biphenyl groups in the ligand provide rigid and hydrophobic large pores, providing a locally high-concentration reaction environment. Gaseous isooctanol can easily diffuse into the catalyst pores, contacting the enriched methyl palmitate. Furthermore, the uniformly distributed sulfonic acid groups in the ligand, acting as a solid superacid, provide strong acidic sites, improving production efficiency.

The invention discloses a polyol gradient synergetic depolymerization-esterification coupling reaction device for PETG chemical recovery, and belongs to the technical field of depolymerization-esterification coupling reaction devices, the polyol gradient synergetic depolymerization-esterification coupling reaction device comprises a main reaction kettle, the main reaction kettle is of a vertical cylindrical structure, the top of the main reaction kettle is fixedly connected with a sealing cover, the sealing cover is connected with a plurality of feeding ports, and the feeding ports are communicated with the main reaction kettle. A liquid collecting cavity is connected below the main reaction kettle, a return pipe is connected to the bottom of the liquid collecting cavity, a one-way valve is arranged on the return pipe, a multi-stage alcohol feeding system is arranged on one side of the main reaction kettle, a gradient temperature control jacket assembly is arranged on the other side of the main reaction kettle, and an in-situ esterification module is arranged on the inner side of the main reaction kettle. According to the method, multiple alcohol reagents are introduced according to the gradient synergistic effect, the breaking requirements of different types of ester bonds in PETG molecules are accurately matched, the depolymerization and esterification processes are coupled in situ, efficient, low-consumption and high-valued closed-loop recovery is achieved, and the defects that depolymerization is not thorough, products are complex, the technology is tedious and the like when PETG is treated in the prior art are effectively overcome.

The application discloses a method for alcoholysis of waste PET polyester, which comprises the following steps: dissolving waste PET polyester in ethylene glycol, contacting with a catalyst, and reacting to obtain bis(hydroxyethyl) terephthalate; the waste PET polyester is at least one selected from waste PET packaging bottles, waste PET films and PET fiber waste; the catalyst is composed of a metal oxide carrier and active metal oxides loaded on the surface of the metal oxide carrier; the metal oxide carrier is at least one selected from ZnO, gamma-Al2O3, Fe3O4, SiO2, TiO2, CeO2 and MgO; the active metal oxides are at least one selected from MnO2, Co2O3, CeO2, PbO, CuO, NiO and SnO2; the mass of the active metal oxides is 5-60 wt% of the mass of the catalyst, wherein the mass of the active metal oxides is the mass of metal elements contained therein.