The preparation of activated carbon using palm kernel shells as the precursor (PKSAC) was successfully accomplished after the parametric optimization of the carbonization temperature, carbonization holding time, and the ratio of the activator (H3PO4) to the precursor. Optimization at 500 °C for 2 h of carbonization with 20% H3PO4 resulted in the highest surface area of the activated carbon (C20) of 1169 m2 g−1 and, with an average pore size of 27 Å. Subsequently, the preparation of shape-stabilized phase change material (SSPCM-C20) was done by the encapsulation of n-octadecane into the pores of the PKSAC, C20. The field emission scanning electron microscope images and the nitrogen gas adsorption-desorption isotherms show that n-octadecane was successfully encapsulated into the pores of C20. The resulting SSPCM-C20 nano-composite shows good thermal reliability which is chemically and thermally stable and can stand up to 500 melting and freezing cycles. This research work provided a new strategy for the preparation of SSPCM material for thermal energy storage application generated from oil palm waste.

The effect of the surface area of palm kernel shell activated carbon (PKSAC) on the properties of n-octadecane-encapsulated shape stabilized phase change material (SSPCM) for thermal energy storage (TES) application were studied. Various surface areas of the PKSAC were prepared using different amounts of H3PO4 treatment given to palm kernel shells from 0, 5, 10, 30 and 40% before the activation. The impregnation of n-octadecane into the different surface areas of PKSACs produced SSPCMs with different physico-chemical characteristics. The DSC analysis indicates that the higher the surface area of the PKSAC resulted in the higher freezing temperature due to the higher PCM loading that was encapsulated into the PKSAC pores. The results obtained from XRD, FESEM, Raman spectroscopy, TGA/DTG and leakage study indicate that the PKSAC is a good framework material for the development of n-octadecane-encapsulated SSPCM. It was also found that the surface area and porosity of the frameworks, activated carbon play an important role on the PCM loading percentage and their ability to be used as a thermal energy storage material.

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Background: Oil palm fronds (OPF) when pretreated with white rot fungi (WRF) shows increased rumen degradability but with significant biomass loss. Thus, effects of pre-treated OPF with enzyme extracts from WRF on rumen degradability were studied in vitro. The enzyme extracts were prepared by inoculating OPF with three WRF, i.e Ceriporiopsis subvermispora, Lentinula edodes and Ganoderma lucidum, for 15, 30 and 45 days with either ammonium sulphate, (NH4)2SO4 and sodium nitrate, NaNO3 added to the culture media for each inoculation period. After preparation of enzyme extracts, the enzyme activities were determined. OPF was then pre-treated with enzyme extracts in a citrate buffer (pH 5.0) in a forced air oven at 40 oC during 5 days. Further, the in vitro rumen degradation of OPF pre-treated with enzyme extracts, with respect to the short chain fatty acid (SCFA) production, was determined after 24 h incubation. Activity of lignolytic (laccase and MnP), cellulolytic (CMCase and avicelase) and hemicellulolytic (xylanase) enzymes were measured in all of the extracts irrespective on the inoculation period. Results: Treatment of OPF with enzyme extracts from G. lucidum after 45 days of inoculation showed a numerical increase (13%) in total SCFA and apparently rumen degradable carbohydrates (ARDC) after 24 h in vitro incubation, without any loss of biomass. However, this increase was not clearly correlated to results of the enzyme assays. Conclusion: This study indicates pre-treatment of OPF with enzyme extracts from specific WRF to be promising to enhance the ruminal degradability of OPF without simultaneous loss of biomass.

This study aims to increase the in vitro ruminal degradability of oil palm fronds (OPFs) through enzymatic pretreatment. The isolated fungi were selected based on their lignocellulosic degrading enzyme activities. Eleven fungi were successfully isolated, and their enzyme activities were evaluated. Three fungi, F1, F2 and F4 were selected, and they were identified as Trichoderma harzianum MK027305, Trichoderma harzianum MK027306 and Fusarium solani MK027309, respectively. The highest total gas and methane production was produced when OPFs were pretreated with an enzyme extract from 15 and 30 days of solid-state fermentation of T. harzianum MK027305 and T. harzianum MK027306, respectively. Meanwhile, OPFs pretreated with an enzyme extract from F. solani MK027309 after 45 days of solid-state fermentation produced the highest amount of volatile fatty acids. The pretreatment using the enzymes extracted from 45 days of solid-state fermentation of F. solani MK027309 increases the apparent rumen degradable carbohydrate (ARDC) by 35.29% compared to unpretreated OPF. This study showed that pretreatment of the OPFs using selected fungi’s enzymes increases the volatile fatty acid production and in vitro ruminal degradability of OPF, hence improving livestock production via increased utilization of agricultural by-products with minimal impact on the production cost.