Simulation-assisted design of a catalytic hydrogenation reactor for plastic pyrolysis fuels

An enhancement of the properties pyrolysis liquids (PL) from municipal plastic waste (mainly low-density polyethylene) by catalytic hydrotreatment is required to obtain automotive quality fuels. In this context, we report design a pilot reactor using computational fluid dynamics (CFD). This modelling technique considered flows, gas diffusion, olefin hydrogenation reactions, and heat transfer. The built model allowed development different sensitive analysis evaluate influence spatial time, transfer (used as coolant) hydrogen/pyrolysis liquid ratio. Possible phase changes (from liquid) were analyzed thermodynamic approach. results showed that refrigerant oil allows alleviating possible temperature gradients arising exothermic reaction. It was also found system can be optimized in order minimize energy cost adjusting inlet reactive (H2) flow. Condensations chamber could avoided working at intermediate pressures (40–60 bar) and/or increasing feed H2. Additionally, obtained with CFD 3D together condensation optimize operational regime pilot-reactor terms dimensioning construction materials.