An integrated simulation–optimisation approach for free fatty acid removal in palm oil deodorisation process

Abstract

AbstractDeodorisation is the key process to produce high‐quality refined, bleached and deodorised palm oil (RBDPO) in a palm oil refinery. In this work, an integrated simulation–optimisation approach was adopted for the analysis of a deodorisation process in an operating palm oil refinery. The process includes a deodoriser unit that removes free fatty acids (FFA) from bleached palm oil (BPO), and a vacuum scrubber utilising palm fatty acid distillate (PFAD) to reduce the FFA content entering the vacuum system. Being a proprietary technology, deodoriser is not found in the standard models of commercial simulation software. Approximation was made in simulation, with results compared to plant data. Detailed analyses showed that the reduction of FFA content relies on deodorisation temperature and pressure, stripping steam flowrate, as well as the temperature and flowrate of PFAD entering the vacuum scrubber. An optimisation model was solved to maximise profit from the deodorisation. Results showed that the FFA content entering the vacuum system is reduced significantly by 49.7%, leading to higher recovery of FFA in PFAD and lower loss into the condenser section. Applying the optimum values to the refinery has resulted in FFA levels greater than 91.2% in PFAD and RBDPO yield improvement of 0.5%.