A cumulative study on pyrolysis of waste motor oil exploring the design and development of a fixed-bed laboratory scale setup with emphasis on process parameter optimization, COMSOL simulation and preliminary risk assessment

A designed flexible bench-scale pyrolysis setup has been explored for optimizing the pyrolysis yield by the varying reactor temperature (T R , degrees C), heating rate ( beta, degrees C/min), nitrogen flowrate (nu, LPM) and holding time (t, min). However, with the increase in nu and t, there is an increase in operational costs. T R = 500 degrees C, beta = 10 degrees C/min, n = 0.6 LPM, and t = 20 min were selected as the optimum process parameters. This study demonstrated a 90.5% conversion of waste motor oil (WMO) by weight into pyro-oil possessing diesel -like fuel characteristics. Further, the performance of the reactor design was investigated using the COMSOL Multiphysics utilizing Reaction Engineering, Heat transfer, and Fluid flow modules that helped to understand the temperature distribution and concentration profile inside the reactor and its co-relation with the product yield. Furthermore, a preliminary risk assessment (PRA) was also conducted to identify even minor issues that might affect the safety and operability of the WMO pyrolysis process if scaled up. Hence, this research article better explains the WMO pyrolysis process design. Lastly, the current study's findings lay a foundation for the industrial manufacture of automotive quality fuels from WMO.