Evaluation and optimal design of a high stability hydrothermal deoxygenation process for production of green diesel fuel via deoxygenation of waste cooking oil

Abstract

The environmental impacts of waste cooking oil (WCO) can be profoundly serious when it is not handled properly. Instead of discarding leftover cooking oil as waste, recent technological advancements have made it possible to use WCO as a sustainable feedstock for biofuels production, while also addressing the disposal issue. This work developed an efficient and high stability hydrothermal WCO transformation process into green diesel fuel. In the present work, a homemade environmentally benign activated carbon was prepared from a bio-sourced precursor and impregnated with a Pd precursor. A set of experiments were conducted at 300 °C–350 °C, 40 and 50 bar, and times up to 240 min to evaluate the performance of Pd/AC catalysts against deoxygenation (DO) and deactivation reactions. The results showed a substantial enhancement of the activity and stability of the coated Pd/AC catalyst versus the uncoated one. Also, the green diesel fuel possesses an outstanding higher heating value of 46 kJ/mol. Based on experiments, the best kinetic model for the DO process was developed. The optimum kinetic parameters were obtained by the optimization approach. For a wide variety of operating conditions, the projected product conversion demonstrated satisfactory agreement with the experimental results, with absolute average errors of less than 8%.