Wan Asma Ibrahim

Ethanol and lactic acid production using sap squeezed from old oil palm trunks felled for replanting.

Old oil palm trunks that had been felled for replanting were found to contain large quantities of high glucose content sap. Notably, the sap in the inner part of the trunk accounted for more than 80% of the whole trunk weight. The glucose concentration of the sap from the inner part was 85.2g/L and decreased towards the outer part. Other sugars found in relatively low concentrations were sucrose, fructose, galactose, xylose, and rhamnose. In addition, oil palm sap was found to be rich in various kinds of amino acids, organic acids, minerals and vitamins. Based on these findings, we fermented the sap to produce ethanol using the sake brewing yeast strain, Saccharomyces cerevisiae Kyokai no.7. Ethanol was produced from the sap without the addition of nutrients, at a comparable rate and yield to the reference fermentation on YPD medium with glucose as a carbon source. Likewise, we produced lactic acid, a promising material for bio-plastics, poly-lactate, from the sap using the homolactic acid bacterium Lactobacillus lactis ATCC19435. We confirmed that sugars contained in the sap were readily converted to lactic acid with almost the same efficiency as the reference fermentation on MSR medium with glucose as a substrate. These results indicate that oil palm trunks felled for replanting are a significant resource for the production of fuel ethanol and lactic acid in palm oil-producing countries such as Malaysia and Indonesia.

Efficient ethanol production from separated parenchyma and vascular bundle of oil palm trunk

For efficient utilization of both starchy and cellulosic materials, oil palm trunk was separated into parenchyma (PA) and vascular bundle (VB). High solid-state simultaneous saccharification and fermentation (HSS-SSF) using 30% (w/v) PA, containing 46.7% (w/w) starch, supplemented with amylases and Saccharomyces cerevisiae K3, produced 6.1% (w/v) ethanol. Subsequent alkali-pretreatment using sodium hydroxide was carried out with starch-free PA (sfPA) and VB. Enzymatic digestibility of 5% (w/v) pretreated sfPA and VB was 92% and 97%, respectively, using 18 FPU of commercial cellulase supplemented with 10 U of Novozyme-188 per gram of substrate. Likewise, HSS-SSF using 30% (w/v) alkali-pretreated sfPA and VB, with cellulases and yeast, resulted in high ethanol production (8.2% and 8.5% (w/v), respectively). These results show that HSS-SSF using separated PA and VB is a useful fermentation strategy, without loss of starchy and cellulosic materials, for oil palm trunk.

Oil extraction from Calophyllum inophyllum L. via Soxhlet extraction: Optimization using response surface methodology (RSM)

Biodiesel is an alternative biodegradable and nontoxic fuel, which is free of sulfur and aromatics. Several non-edible oils such as Madhuca indica, Jatropha curcas, Pongania pinnata and Calophyllum inophyllum L. has been investigated experimentally, are found to be suitable for biodiesel production. In this study, Response Surface Method (RSM) based on Central Composite Design (CCD) was applied to determine the optimum condition of oil extraction from Calophyllum inophyllum L. oil via Soxhlet extraction. Three variables studied were solvent to seed ratio (ml), extraction time (hr), and drying time (hr) with total of 15 individual experiments conducted for optimizing the combination effects of those variables. The mathematical model developed was found to be adequate and statistically accurate to predict the optimum yield of Calophyllum inophyllum L. oil. From the analysis of variance (ANOVA), the significance of various factors and their influences were identified. The optimum condition identified was solvent to seed ratio of 56.82 ml/g, extraction time of 2.55 hours, and drying time for the kernel of 6.82 hours. With high percentage of oil yield from Calophyllum inophyllum L. kernel, it serves as a very promising feedstock for biodiesel production.

Utilization of felled oil palm trunk: Trunk sections storage on oil palm sap production

Oil palm trunk (OPT) is one of the biomass produce during replanting of palm tree and this is generated every twenty five years in a given plantation. The core of the OPT when mechanically squeezed produce sap, which can be used to produce bio-ethanol. In this study, four OPT was used and each OPT was chopped into four sections which were upper, middle 1, middle 2 and bottom. The sections were stored for 1, 15, 30 and 45 days before being mechanically pretreated to produce palm sap. The mass balance during the production was recorded which resulted in the decrease of the sap volume during trunk storage time from 304.98L to 85.74L.

Microwave-Alkali Activation on the Morphology and Structure of Bamboo Activated Carbon

A study was conducted for production of activated carbon (AC) from industrial bamboo waste using carbonization and Microwave-alkali (Mw-A) activation techniques. The aim of the study is to produce activated carbon with higher surface area via Mw-A activation techniques. The study was focused on the effect of activation (KOH soaking and Mw-A) and carbonization temperature (400oC and 500oC) on the physical and chemical structure of AC. The analysis was conducted using proximate analysis, BET surface area, FESEM and FTIR analysis. The morphology and characteristic study on activated carbon shown that Mw-A activation techniques gave higher BET surface area and well develop pore structure. The results indicated that Mw-A activation of activated carbon gave BET surface area of 950m2g-1, whereas by using steam activation only 719 m2g-1 of BET surface area was recorded. Higher carbonization temperature for Mw-A treated bamboo produced higher surface area of AC. At 500oC, 1578m2g-1 BET surface area of AC was achieved. This work highlighted, Mw-A activation can be applied and further enhanced to obtain higher surface area of activated carbon derived from industrial bamboo waste.