A method for transforming selected plant or plant-derived materials, and optionally selected waste plastics, into a plurality of phenolic reaction products having a lower sulphur content than the original feedstock, via supercritical water is disclosed. The method comprises: conveying the selected plant or plant-derived materials, and optionally waste plastic material, through an extruder, wherein the extruder is configured to continuously convey the selected feedstock to a supercritical fluid reaction zone; injecting hot compressed water into the supercritical fluid reaction zone, while the extruder is conveying the selected plant and/or plant-derived mixture and optionally waste plastic material into the supercritical fluid reaction zone so as to yield a water-containing mixture; retaining the mixture within the reaction zone for a period of time sufficient to yield the plurality of phenolic reaction products having a lower sulphur content than the original feedstock. The reaction zone may be characterized by a tubular reactor having an adjustably positionable inner tubular spear, wherein the tubular reactor and the inner tubular spear further define an annular space within the reaction zone, and wherein the mixture flows through the annular space and into a reaction products chamber for separation into three phases.

An embodiment of a method for producing a cyclic compound of the present invention includes a step of causing a decarboxylation reaction in a cyclic carboxylic acid compound by subjecting a starting material containing the cyclic carboxylic acid compound to a heat treatment of heating under a catalyst to obtain a cyclic compound, in which the catalyst includes zeolite formed of an aluminum/silicon-containing composite oxide, and in which the zeolite has an SiO.sub.2/Al.sub.2O.sub.3 ratio of 7 to 500. In addition, another embodiment of the method for producing a cyclic compound of the present invention includes a step of causing a decarboxylation reaction in a cyclic carboxylic acid compound by subjecting a starting material containing the cyclic carboxylic acid compound to a heat treatment of heating in the presence of a non-solid acid to obtain a cyclic compound.

There is disclosed a process for debromination of novel brominated flame retardants (NBFRs) through co-pyrolysis with zinc oxide (ZnO) and franklinite (ZnFe.sub.2O.sub.4) to effectively restrict brominated species emission from NBFRs during thermal degradation. The method addresses environmental concerns by converting tetrabromobisphenol A 2,3-dibromopropyl ether (TBBPA-DBPE) and tetrabromobisphenol A diallyl ether (TBBPA-DAE) into bromine-free hydrocarbons. Utilizing Zn-based metal oxides from electrical arc furnace dust (EAFD), this process transforms them into metal bromides, facilitating selective zinc extraction. Thermogravimetric analysis guides pyrolysis at up to 500 C., revealing ZnO's efficacy in capturing 92% of HBr gas and producing minimal brominated compounds (relative area, 0.83%). Phenol emerges as a significant condensable product, while inorganic gases and methane dominates the non-condensable fraction. The retained metal bromides in pyrochar and <8% HBr gas emissions underscore ZnO's debromination potential. This method also suggests ZnO's application for dehalogenating other polymers and using spinel ferrites in combating brominated polymers.

Provided is a bisphenol (I)-containing composition that can give an improved recovery rate of isopropenylphenol when the composition is subjected to an alkaline degradation and recombination process. A bisphenol (I)-containing composition includes: a bisphenol (I) comprising bisphenol A; and a compound (II) having a structure in which at least one hydroxyl group of a bisphenol is replaced with a carbonate ester group or a carbamoyloxy group, wherein the content of the bisphenol (I) in the bisphenol (I)-containing composition is 90% by mass or more; and the total number of moles of carbonyl bonds in the compound (II) relative to the mass of the bisphenol (I)-containing composition is 0.05 mol/g or more.

A method of recycling a plastic product comprising PET is provided. The method comprises combining a plastic product comprising PET, a heterogeneous metal oxide catalyst and a solvent to provide a reaction mixture and heating the mixture by microwave irradiation to provide reaction product.

The present disclosure relates to a production process and device for synthesizing bisphenol A by a resin method, including a condensation reaction unit for performing a catalytic condensation reaction between phenol and acetone to generate bisphenol A, a first-stage adduct crystallization unit for mixing a concentrated solution with adduct crystals recycled after melting and then performing adduct crystallization, a liquid-phase dephenolization unit for melting an adduct to yield a bisphenol A product, a secondary adduct crystallization unit for recycling phenol and bisphenol A from a mother solution, a solvent recycling unit for recycling unreacted phenol and unreacted acetone, and discharging phenol-containing process water for sewage treatment, and a cracking and rearrangement unit for recycling the phenol from the mother solution, and convert bisphenol A, 2,4-bisphenol A and the like therein in the mother solution into the bisphenol A.

The present disclosure relates to a monomer composition for synthesizing recycled plastic that can realize excellent color quality even though it is recovered through recycling by chemical decomposition of a polycarbonate-based resin, and allows improvement of efficiency in the recovery process, a preparation method thereof, and a recycled plastic and a molded product using the same.

A method for degrading polycarbonate includes: providing a de-polymerizing solvent; adding a metal hydroxide to the de-polymerizing solvent to form a mixed liquid; adding a polycarbonate material to the mixed liquid to form a reaction liquid, in which the polycarbonate material undergoes a de-polymerization reaction during the de-polymerization operation to form a bisphenol A product; passing the reaction liquid containing the bisphenol A product through an ion exchange column filled with an ion exchange resin to perform ion exchange, thereby forming a purified liquid, in which the metal ions are dissociated from the metal hydroxide; and crystallizing the purified liquid to precipitate bisphenol A crystalline solids from the purified liquid.