Ultrafiltration Membrane for Degumming of Crude Palm Oil-Isopropanol Mixture

Abstract

Ultrafiltration (UF) is a membrane technology that has been applied for crude palm oil (CPO) degumming. It is considered as an alternative for the conventional CPO degumming technology because of its lower energy consumption, no need for the addition of chemicals, and almost no loss of natural oil. In this research, we separated a CPO-isopropanol mixture via laboratory-made flat-sheet polyethersulfone (PES) UF. Flux profiles confirmed that the increase in the CPO concentration resulted in lower fluxes. However, increasing the temperature from 30 °C to 45 °C initially raised the flux, but it was further decreased when the feed temperature was raised from 40 °C to 45 °C. Using UF of the CPO-isopropanol mixture at crude oil concentrations of 30 % and 40 %, we were able to reject more than 99 % phospholipids and nearly 93 % phospholipids, respectively. However, the separation of free fatty acids using this process was ineffective due to the small size of free fatty acids. Through the evaluation of the blocking mechanism in the Hermia model, it was proposed that the standard and intermediate blocking were the dominant mechanisms of filtration of CPO at a concentration of 30 and 40 %, and 50 and 60 %, respectively.

Recent development and challenges in extraction of phytonutrients from palm oil

“…Moreover, the dilution of palm oil plays a critical role in the rejection of phospholipid. In a past study, the rejection of phospholipids increased by more than twofold when the CPO concentration in isopropanol decreased from 50 to 30% (Aryanti & D.Hesti Wardhani, 2018). At 50% of CPO concentration, not all the phospholipids formed the isopropanol‐phospholipid micelles, resulting in the low rejection of phospholipids (37.52%) (Aryanti & D.Hesti Wardhani, 2018).…”

“…The formation of reverse micelles in membrane processing could also be improved by the use of 2‐propanol as a diluent (Aryanti & D. Hesti Wardhani, 2018). A polyethersulfone (PES) flat‐sheet membrane with the significantly larger pore size (25 kDa) successfully rejected 99% of phospholipids from a mixture of 2‐propanol and CPO (Aryanti & D.Hesti Wardhani, 2018). Additionally, the high permeability of membrane to 2‐propanol (63.58 Lm –2 hr –1 ) increased the permeate flux of CPO, thereby allowing a higher processing load or a shorter processing time (Aryanti & D.Hesti Wardhani, 2018).…”

“…Among the polymeric membrane, PES is one of the most common membranes applied for the removal of phospholipids from palm oil. The high degree of toughness and good thermal stability make PES suitable for the rejection of phospholipids from the palm oil under high‐pressure condition (Aryanti & D.Hesti Wardhani, 2018; Chiu et al., 2009; Ladewig & Al‐Shaeli, 2017; R. A. Majid et al., 2013; Ong et al., 1999). For instance, the rejection of ß‐carotene from the palm oil was successfully accomplished by NP10 membrane, which is a nanofiltration PES flat‐sheet membrane with MWCO of 200 Da (Chiu et al., 2009).…”

“…In a past study on removal of phospholipid, the permeate flux of PPFO increased by 13% when the feed temperature increased from 30 to 50 °C (R. A. Majid et al., 2013). In contrast, the removal of phospholipid from a mixture of CPO and 2‐propanol was impeded by a decrease in permeate flux, when the feed temperature increased from 40 to 45 °C (Aryanti & D.Hesti Wardhani, 2018). The decrement in permeate flux was highly related to the severity of membrane fouling, which was caused by the solid denaturation, gelatinization, or salt precipitation.…”

“…Hence, a diluent was introduced to CPO for promoting the formation of large-size reverse micelles. The formation of reverse micelles in membrane processing could also be improved by the use of 2-propanol as a diluent (Aryanti & D. Hesti Wardhani, 2018). A polyethersulfone (PES) flatsheet membrane with the significantly larger pore size (25 kDa) successfully rejected 99% of phospholipids from a mixture of 2-propanol and CPO (Aryanti (Ong et al, 1999) 3 Wardhani, 2018).…”