The recycling of polyhydroxybutyrate (PHB) via depolymerization-polymerization is here proposed and assessed for the first time. Effective depolymerization of PHB to crotonic acid through a thermolytic distillation at mild conditions (170 °C and 150 mbar), and without the need of any catalyst, gives a crotonic acid-enriched condensate (94% yield and 98% selectivity towards trans-crotonic acid) that was used without any further purification as a substrate for producing renewed PHB with a culture of Cupriavidus necator. The yield of PHB (0.6 g PHB per g of crotonic acid), final PHB content (63%), and PHB-molecular weight (1.5 MDa) confirmed the technical feasibility of this tandem approach, with a 55% overall yield. A preliminary evaluation of the energy consumption of various depolymerization approaches indicated that the thermolytic distillation consumes 20–25% less energy than previously reported methods; the energy requirement for producing crotonic acid from PHB_waste with 50% moisture has a still acceptable energy demand (4 MJ/kg_{crotonic acid}), comparable to the energy required for obtaining fermentable sugars (4.4 MJ/kg_sugar) to be used for feeding bacteria that accumulate PHB.

这里首次提出并评估了通过解聚-聚合回收聚羟基丁酸酯 (PHB) 。在温和条件（170 °C 和 150 mbar）下通过热解蒸馏将 PHB 有效解聚为巴豆酸，无需任何催化剂，得到富含巴豆酸的缩合物（94% 的产率和 98% 的反式巴豆酸选择性）酸），无需任何进一步纯化即可用作底物，用于生产带有钩虫培养物的更新 PHB 。PHB 的产量（每克巴豆酸 0.6 g PHB）、最终 PHB 含量 (63%) 和 PHB 分子量 (1.5 MDa) 证实了这种串联方法的技术可行性，总产量为 55%。对各种解聚方法能耗的初步评估表明，热解蒸馏比以前报道的方法消耗的能源少 20-25%；从含 50% 水分的PHB_废物中生产巴豆酸的能量需求仍然可以接受（4 MJ/kg_巴豆酸），与获得用于饲养的可发酵糖（4.4 MJ/kg_糖）所需的能量相当积累PHB的细菌。