ABSTRACT

This research involves developing and thermo-economic evaluation of a small-scale waste plastic pyrolysis plant for recovery from petroleum oil. The plant was developed using locally sourced materials to provide an alternative method of reducing waste plastics from the environment. The design of the reactor, catalytic-cracker, diffuser and air-condenser components of the plant was made subject to energy and exergoeconomic analysis to identify thermal and cost-related improvements in the system. During the plant's pilot batch, the plant's feed rate was designed to be 2kg/h of waste plastics and 1.0kg of the iron catalyst with reactor pyrolysis temperatures in the range of 310 -500^oC to produce diesel and aviation kerosene. Performance analysis was made, and several key parameters were investigated on the thermal and economic performance of the plant. The experimental results showed that the volumetric flow rate and the maximum product yield of diesel (AGO) oil are one lit/h and 87.3%, respectively. The oil samples were characterized, and the results from the laboratory revealed that liquid oil with a reactor inlet temperature of 310, 360, 400, and 460^oC have the same results as standard diesel oil. Additionally, it was shown that the diesel oil (Olefins) with a reactor inlet temperature of 360^oC had the best impact and can be approximated to the regular conventional diesel oil. The liquid oil with a reactor inlet temperature of 500^oC fell within the range of standard aviation kerosene (Naphthenes) according to the ASTM standard. Subsequently, the various petroleum products yield were 84.24, 87.3, 84.25,82, and 82%, at corresponding inlet reactor temperatures of 310, 360, 400,460 and 500^oC, respectively. The data from different pilot-batches were fitted on the thermal and exergoeconomic equation models for the performance of the plant. The reactor, catalytic cracker, diffuser and air-condenser energy efficiencies were 85.75, 82.17, 80.4 and 70.19 %, respectively. Furthermore, the exergoeconomic analysis indicates thermal improvement of the condenser due to its low exergoeconomic factor of 0.00261 and high total cost rate of 1.895 $/h. Finally, the diffuser component in the plant regulate the fluid flow rate and enhance the production of petroleum products.