Simulation and Optimisation of Integrated Anaerobic-Aerobic Bioreactor (IAAB) for the Treatment of Palm Oil Mill Effluent

Abstract

This study highlights an innovative piece of hybrid technology, whereby the combination of anaerobic and aerobic processes into a single reactor, namely, the integrated anaerobic–aerobic bioreactor (IAAB) can surpass the limits of conventional methods treating palm oil mill effluent (POME). Optimisation of IAAB using SuperPro Designer V9 simulator for maximum biogas yield while addressing its economic and environmental trade-offs was conducted for the first time. Parameters such as hydraulic retention time (HRT) and organic loading rate (OLR) were optimised in the anaerobic compartment from 10 days and 6.2 g COD/L day to 9 days and 6.9 g COD/L day, respectively. Furthermore, sludge recycle ratio was optimised from 20% to 50% in the aerobic compartment. The optimisation was successful where the biogas yield increased from 0.24 to 0.29 L CH4/g CODremoved with excellent Chemical Oxygen Demand (COD), and Biological Oxygen Demand (BOD) removal efficiencies up to 99% with 5.8% lower net expenditure. This simulation results were comparable against the pre-commercialized IAAB with 11.4% increase in methane yield after optimisation. Economic analysis had proven the optimised process to be feasible, resulting in return on investment (ROI), payback time, and internal rate of return (IRR) of 24.5%, 4.1 years, and 17.9%, respectively.

Circular Economy Approaches in the Palm Oil Industry: Enhancing Profitability through Waste Reduction and Product Diversification

“…PKS, traditionally seen as waste, are now utilized for energy production and as raw materials for activated carbon, contributing to water and air purification processes [131,132]. POME, once a challenging waste stream due to its high organic content, is now harnessed for anaerobic digestion, generating biogas for electricity and heat generation [133]. This approach not only addresses waste disposal issues but also adds a renewable energy source to the industry's portfolio.…”

Life Cycle Assessment of an Integrated Membrane Treatment System of Anaerobic-Treated Palm Oil Mill Effluent (POME)

“…Regardless, these studies only concern themselves with the efficiency of the treatment and not the sustainability aspect of it to the environment. Taking into account the characteristics of POME, and in particular, the high concentrations of biodegradable organic compounds, a competitive technology for their neutralization may be anaerobic digestion [17]. Anaerobic treatment is a technologically sound and environmentally friendly method for the biodegradability of organic waste [18].…”