Abstract Waste plastics packaging (WPP) was converted into valuable products by two-step microwave cracking. The wax (38.47–72.53 wt%), gas (20.18–43.85 wt%) and solid (2.00–24.18 wt%) were produced in the first step, and the liquid (60.55–79.94 wt%), gas (18.44–38.45 wt%) and solid (1.00–5.56 wt%) were produced in the second step. Different heating strategies including the selection of absorbers and catalyst, the adjustment of heating power, the mass ratio of absorber to feedstock have been proposed to optimize the products in each step. Commercial spherical activated carbon, columnar activated carbon and molecular sieves type 4A have been used as absorbers and catalysts. The gas products (mainly H2, CH4, C2H4 and C3H6) can be used as combustion gas. The solid products (mainly CaO, TiO2 and SiO2) in the first step are suitable for absorbers because of their fast temperature rise (30–115 °C/min) in microwave field. The liquid products are distributed between C7 and C26, which are suitable for gasoline and diesel fractions. Absorbers have been used many times to reduce costs. Two-step method can effectively remove plastic additives, and other attachments in the first step, and the separation of ‘dirty’ process and ‘clean’ process can reduce the possibility of catalyst deactivation due to impurity coverage.

中文翻译：

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通过不同加热策略的两步微波裂解将废塑料包装回收为增值产品

摘要 废塑料包装（WPP）通过两步微波裂解转化为有价值的产品。第一步生产蜡（38.47–72.53 wt%）、气体（20.18–43.85 wt%）和固体（2.00–24.18 wt%），液体（60.55–79.94 wt%）、气体（18.44–38.45 wt%） wt%) 和固体 (1.00–5.56 wt%) 在第二步中产生。提出了不同的加热策略，包括吸收剂和催化剂的选择、加热功率的调整、吸收剂与原料的质量比，以优化每一步的产品。商业球形活性炭、柱状活性炭和 4A 型分子筛已被用作吸收剂和催化剂。气体产品（主要是 H2、CH4、C2H4 和 C3H6）可用作燃烧气体。固体产物（主要是 CaO、第一步中的 TiO2 和 SiO2）适用于吸收剂，因为它们在微波场中升温速度快（30-115 °C/min）。液体产品分布在C7和C26之间，适用于汽柴油馏分。吸收器已被多次使用以降低成本。两步法可以有效去除第一步中的塑料添加剂和其他附着物，“脏”过程和“清洁”过程的分离可以减少由于杂质覆盖而导致催化剂失活的可能性。