Abstract: The disclosure provides a chemical recycling method for polyester fabrics, which includes the following steps. The polyester fabric is extracted using a composite solvent and filtered to obtain a decolored polyester fabric. The composite solvent contains alcohol ether and phenyl ether, and the decolored polyester fabric contains the composite solvent. Ethylene glycol is then added to the decolored polyester fabric to depolymerize into ethylene terephthalate monomers.

Abstract: A method for improving a recovery rate of recycled bis(2-hydroxyethyl) terephthalate (BHET) is provided, which includes: providing a recycled polyester fabric; using a chemical de-polymerization liquid to chemically depolymerize the recycled polyester fabric, so as to form a de-polymerization product containing BHET; dissolving the BHET in water to form a aqueous phase liquid; cooling the aqueous phase liquid from a dissolution temperature to a first crystallization temperature, so as to crystallize at least a part of the BHET; and cooling the aqueous phase liquid from the first crystallization temperature to a second crystallization temperature, so as to crystallize at least another part of the BHET.

Abstract: A method for improving the hue of recycled BHET is provided. The method includes: providing a recycled polyester fabric; using a chemical de-polymerization liquid to chemically depolymerize the recycled polyester fabric to form a de-polymerization product; distilling out the chemical de-polymerization liquid from the de-polymerization product by evaporation; dissolving the BHET in water to form a aqueous phase liquid; adding an activated carbon material to the aqueous phase liquid to adsorb impurities; and cooling the aqueous phase liquid to crystallize the BHET from the aqueous phase liquid to obtain a recycled BHET.

Abstract: A gas-liquid mixing control system includes a liquid supply unit, a liquid pressure regulating valve, a gas supply unit, a gas pressure regulating valve, a mixing tank, an output pipe, and a non-electric control flow regulator. The mixing tank communicates with said regulating valves; liquid and gas are mixed in the mixing tank to form mixed fluid. The first end and second end of output pipe communicate with the mixing tank and the machine respectively, making mixed fluid output from mixing tank to machine through the output pipe. The mixed fluid in first end and second end have third flow and fourth flow respectively. Said flow regulator communicates with the output pipe; the mixed fluid passing through said flow regulator has fifth flow. The first flow is not lower than at least one of the fourth and the fifth flow. Additionally, a control method for gas-liquid mixing is disclosed.

Abstract: A method for crystallizing succinic acid includes agitating a succinic acid reaction solution with a jet-flow agitator that is rotated at low speed and has a low volume power density; compared with the conventional agitators, the jet-flow agitator helps increase the uniformity of succinic acid particles, shorten the time required for crystallizing succinic acid, and raise the yield of the crystallized succinic acid as well as purity of crystallized succinic acid having a purity of 99.8-99.9%.

Abstract: A method for crystallizing succinic acid includes agitating a succinic acid reaction solution with a jet-flow agitator that is rotated at low speed and has a low volume power density; compared with the conventional agitators, the jet-flow agitator helps increase the uniformity of succinic acid particles, shorten the time required for crystallizing succinic acid, and raise the yield of the crystallized succinic acid as well as purity of crystallized succinic acid having a purity of 99.8-99.9%.