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The aim of this research was to investigate the effect of temperature, medium initial pH and rotation rate on the production of bioethanol from OPF juice without nutrient and nitrogen source supplementation using Saccharomyces cerevisiae Kyokai No. 7 (ATCC 26622). A five-level-three-factor central composite design (CCD) was employed in this study and the central point of each process variable was chosen based on the best condition obtained from the one-factor-at-time (OFAT) method. The parameters ranges were set as follows; medium initial pH (5-9), temperature (27.5-37.5°C) and rotation rate (80-120 rpm). Bioethanol and residual sugars concentration were determine using High Performance Liquid Chromatography (HPLC). The optimum conditions for bioethanol production from OPF juice were achieved at medium initial pH (6.62), rotation rate (96.51 rpm) and temperature (33.03°C). Based on the validation experiment, the optimum bioethanol yield was 0.50 ±0.02 g/g sugars and this value was in close agreement with the model prediction where the difference was only 4.17%. Under the optimal conditions, the bioethanol yield obtained was 47.06% higher compared with non-optimized condition. The promising yield obtained in this study suggests that OPF juice can be used as a renewable and complete fermentation feedstock for bioethanol production.

Supported liquid membrane (SLM) is the most effective technique to extract and recover the desired product from the biomass products in a single step. The study of the operation parameters in SLM system is very important to improve the yield of extraction and recovery of the product. In this study, different types of stripping agents such as sodium hydroxide (NaOH), sodium carbonate, hydrochloric acid, trimethylamine, and water were tested in the SLM system to extract levulinic acid (LA). By using 0.3 M trioctylamine in 2-ethyl-1-hexanol as liquid membrane phase, it was found that NaOH was the best stripping agent to extract LA. The concentration of the NaOH stripping agent was varied from 0.25 M to 1 M. The best stripping agent concentration was 0.5 M, which gave an LA extraction of 86% from a 10 g/L LA aqueous solution. The flow rate of the feed and stripping phase was investigated from 25 mL/min to 125 mL/min. SLM operated at 75 L/min was found to be adequate in reducing the boundary layer thickness at both sides of the SLM phases without any leakage of the liquid membrane and breakage of the matrix support. At the best stripping condition, 89% of the LA was extracted using 0.5 M NaOH that operated at flow rate of 75 mL/min.

High free fatty acid (FFA) content results in low palm oil yield in refinery and 5 wt% are the limit for crude palm oil acceptance. Common method of the FFA quantification in the mills is titration. The intent of this study was to determine the FFA content in extracted palm oil by using Fourier transform infrared (FTIR) spectroscopy coupled with AOCS titration method for verification. The oil extractions took place on days 1, 5, 8, 12 and 15. The fruitlets were initially washed and autoclaved. By separating the kernel, the mesocarp was heated and pressed. After centrifugation, the oil from the top layer of extract was further analyzed. In this study, % transmittance of FFA had been measured at carboxyl band, C=O between 1730 and 1700 cm−1. The stretch of carboxyl band denotes that the FFA had proportionally increased with time. The FFA content of the samples increased in sigmoidal pattern with critical rise after day 8, reaching 15 wt% equilibrium states after 15 days. A calibration model was developed via linear regression and R2 of 0.979 indicating the results were significant.