Degradation of LDPE/VGO mixtures to fuels using a FCC equilibrium catalyst in a sand fluidized bed reactor

Plastic degradation for recovery of useful products or raw materials is a very interesting alternative for reducing the plastic accumulation. This paper explores the possibility of using refinery facilities to carry out the plastic cracking as well as to take the most of the products obtained. In the present work, LDPE/VGO blends with different percentages of polymer are degraded in presence of a FCC equilibrium catalyst. The reactor used in this study is a laboratory scale sand fluidized bed reactor at 500 °C, and a 7:1 catalyst:LDPE/VGO blend ratio in order to simulate the operating conditions in a large scale industrial reactor. Polyethylene blends evaluated show relative proportions of LDPE of 0, 6, 25, 75 and 100% (w/w). Gas and liquid compounds were collected and quantified. The results obtained are compared with those generated in a thermal cracking.In all cases, the FCC equilibrium catalyst showed a high selectivity to the production of isobutane and isopentane in the volatile compounds as well as to aromatics in the liquid products.Results shown in this paper evidences the viability of introducing plastics into FCC unit, producing potential valuable products from low value materials.

An interesting alternative of plastic recycling is shown in the present paper. Blends of low-density polyethylene (LDPE) and vacuum gas oil (VGO) are pyrolyzed under catalytic conditions. A wide range of LDPE percentages is evaluated. The reactor used is a laboratory scale sand fluidized bed reactor at 500 °C and the catalyst is a FCC equilibrium catalyst with a catalyst:blend ratio of 7:1. All these conditions are typical in an industrial scale fluid catalytic cracking, and the process simulates the polymers addition into a refinery stream and the degradation of the blend in the petrochemical installations.The results obtained indicate that it is possible to produce valuable products by pyrolyzing LDPE/VGO blends. Figure optionsDownload as PowerPoint slide