Whajah Bernard, da Silva Moura Natalia, Blanchard Justin, Wicker Scott, Gandar Karleigh, Dorman James A, Dooley Kerry M
Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States.
Department of Chemistry, Rhodes College, Memphis, Tennessee 38112, United States.
Ind Eng Chem Res. 2021 Oct 27;60(42):15141-15150. doi: 10.1021/acs.iecr.1c02674. Epub 2021 Oct 14.
Low- and high-density polyethylene (LDPE/HDPE) have been selectively depolymerized, without added H, to C2-C20 + alkanes/alkenes via energy-efficient radio frequency induction heating, coupled with dual-functional heterogeneous FeO and Ni- or Pt-based catalysts. FeO was used to locally generate heat when exposed to magnetic fields. Initial results indicate that zeolite-based Ni catalysts are more selective to light olefins, while Ni supported on ceria catalysts are more selective to C7-C14 alkanes/alkenes. LDPE conversions up to 94% were obtained with minimal aromatic, coke, or methane formation which are typically observed with thermal heating. Two depolymerization mechanisms, a reverse Cossee-Arlman mechanism or a random cleavage process, were proposed to account for the different selectivities. The depolymerization process was also tested on commercial LDPE (grocery bags), polystyrene, and virgin HDPE using the Ni on FeO catalyst, with the LDPE resulting in similar product conversion (∼48%) and selectivity as for virgin LDPE.
通过节能射频感应加热，并结合双功能多相FeO和镍基或铂基催化剂，低密度和高密度聚乙烯（LDPE/HDPE）在不添加氢气的情况下被选择性解聚为C2 - C20 + 烷烃/烯烃。FeO在暴露于磁场时用于局部产生热量。初步结果表明，基于沸石的镍催化剂对轻质烯烃的选择性更高，而负载在氧化铈催化剂上的镍对C7 - C14烷烃/烯烃的选择性更高。在热加热过程中通常会观察到的芳烃、焦炭或甲烷生成量极少的情况下，LDPE的转化率高达94%。提出了两种解聚机制，即反向科塞-阿尔曼机制或随机裂解过程，以解释不同的选择性。还使用FeO上的镍催化剂对商业LDPE（购物袋）、聚苯乙烯和原始HDPE进行了解聚过程测试，LDPE的产物转化率（约48%）和选择性与原始LDPE相似。
