Using waste to treat waste: efficient alcoholysis of PET waste with a shrimp shell derived catalyst using the response surface method†

The recycling of post-consumer PET is a significant area of scientific research, with great importance for resource recycling and environmental protection. Here, we present our work on the glycolytic depolymerization of post-consumer PET, and we utilized kitchen waste shrimp shells as a raw material to prepare a derivative catalyst. To optimize the reaction in terms of PET conversion and BHET yield, the RSM based on the Box–Behnken design was applied for the process of the reaction. Based on the experimental results, regression models as a function of significant process parameters were obtained and evaluated by ANOVA to predict the depolymerization performance of X-700; the conversion of PET is 100% and the yield of BHET is 80.84% under the optimization conditions by the RSM. The yield of BHET still reached 76.30% after 3 cycles. The catalyst offers several advantages, including superior catalytic activity, low cost, environmental friendliness, a simple preparation method, and reusability. These advantages can provide valuable references for the preparation of biomass catalysts and their application in polymer waste.