Design of alternate solvent for recovery of residual palm oil: simultaneous optimization of process performance with environmental, health and safety aspects

In this work, a computer-aided molecular design (CAMD)-based approach has been developed to design alternative solvents for extracting palm oil from palm pressed fibre (PPF). PPF is a by-product from palm oil milling process produced during the extraction of crude palm oil from fresh fruit bunches. It is noted that the oil that found in PPF consists of high concentration of carotenoids; therefore, palm oil industries are trying to recover the residual oil in PPF. Hexane is conventionally used as a solvent to extract PPF. However, hexane has high boiling point which leads to significant degradation of carotene during solvent recovery. Besides, hexane is considered as a toxic chemical; thus, the extracted oil cannot be used in food applications. In order to overcome the limitations of hexane, this work presents a systematic approach to generate alternative solvents with desirable attributes for PPF oil extraction via CAMD with the integration of safety and health aspects. In this work, diffusivity is defined as a key parameter to evaluate the solvent functionality because the solvent must diffuse through the fibrous matrix to solubilize trapped oil. The safety and health aspects were assessed by implementing disjunctive programming to discretize the properties for allocation of subindex scores. The developed algorithm can trade-off the process and environmental, health and safety (EHS) performances and identify alternative solvents which improve EHS performance compare with hexane.