PHB material alcoholysis recovery method

The invention relates to a method for chemically depolymerizing PHB materials to generate 3-hydroxy butyric acid alkyl ester to achieve chemical recycling of the PHB materials. The PHB material alcoholysis recovery method is characterized in that 1-methyl-3-(3-sulfonic acid propyl) imidazole hydrogen sulfate salt plasma liquid, N-methyl-N-(3-sulfo propyl) morpholine hydrogen sulfate salt plasma liquid, N-(3-sulfonic acid propyl) pyridine hydrogen sulfate salt plasma liquid, N-(3-sulfonic acid propyl) pyridine p-toluene sulfonate plasma liquid and N-(3-sulfonic acid propyl) triethylamine hydrogen sulfate salt plasma liquid are adopted as catalysts, alcoholysis reactions are carried out under the temperature ranging from 110DEG C to 150DEG C, and after the reactions come to an end, the 3-hydroxy butyric acid alkyl ester is obtained through operation like filtering and distillation, and the recycled plasma liquid can be directly used without being processed, wherein the 1-methyl-3-(3-sulfonic acid propyl) imidazole hydrogen sulfate salt plasma liquid, N-methyl-N-(3-sulfo propyl) morpholine hydrogen sulfate salt plasma liquid, N-(3-sulfonic acid propyl) pyridine hydrogen sulfate salt plasma liquid, N-(3-sulfonic acid propyl) pyridine p-toluene sulfonate plasma liquid and N-(3-sulfonic acid propyl) triethylamine hydrogen sulfate salt plasma liquid can be easily recycled. Compared with the traditional method, the method has the advantages that traditional strong acid in the background art is not needed, and therefore equipment erosion and waste water discharge are obviously improved; because the plasma liquid serves as the catalysts and can be recycled, reaction conditions are improved, and the problem that catalysts in the background art can not be recycled is solved.