Kinetic and Economical Evaluation of the Ultrasonicated and Un-ultrasonicated Anaerobic Digestion Plants Fed with Palm Oil Mill Effluent (POME)

Over the last thirty years, the palm oil industry in Malaysia has grown to become an important sector of agriculture-based industry. A total of 108.52 billion MYR was generated in export earnings for Malaysia in 2021. However, the disposal of palm oil mill effluent (POME) is causing a major issue that must be appropriately addressed for sustainable development. In this study, economic evaluation was performed based on a comparison of biogas production from anaerobic treatment of POME with and without ultrasonication pre-treatment it is important to evaluate the potential energy produced and cost in the current treatment system of POME, and further improvement was required to polish it. The Gompertz Model and Logistic Model were applied for kinetic study. The results showed that the Gompertz Model has a better correlation for this study. The energy content in the biogas was the main consideration in the economic evaluation. With the implementation of ultrasonication pre-treatment, it is possible to produce an additional 1.719 × 109 m3 of methane gases from 2015 to 2019, which means that a total of 6.68 × 1013 kJ of energy content from methane was available to utilize as heat energy for the generation of electrical energy as well. Hence, POME treatment using ultrasonicated anaerobic digestion system is a feasible method. Due to the high capital and operating cost of the anaerobic digestion system in tanks and ultrasonication pre-treatment, it caused an extra expenditure, which reduced the attraction of implementation of the treatment. Hence, further improvement regarding the efficiency of POME treatment is required to reduce the overall operating cost of the treatment system.