The objective of this study was to evaluate the effect of fiber treatment on both morphological and single fiber tensile strength of empty fruit bunch (EFB). EFB fiber was treated with boiling water, 2% sodium hydroxide (NaOH) and combination both NaOH and boiling water. Fiber morphology was characterized by scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) was further used to measure the amount and rate of change in the weight (weight loss) of treated fiber as a function of temperature. Based on the results of this work it seems that alkali treatment improved most of the fiber properties. NaOH treatment was found to alter the characteristic of the fiber surface topography as seen by the SEM. The thermal stability of NaOH treated and water boiling treated EFB fiber was found to be significantly higher than untreated fiber. The best results were obtained for alkali treated fiber where the tensile strength and Young's modulus increased compared to untreated fibers. The overall results showed that alkali treatment on EFB fiber enhanced the tensile strength and thermal stability of the fiber samples.

Without appropriate treatment, lignocellulosic biomass is not suitable to be fed into existing combustion systems because of its high moisture content, low bulk energy density and difficulties in transport, handling and storage. The aim of this study was to investigate the effects of torrefaction treatment on the weight loss and energy properties of fast growing species in Malaysia (Acacia spp., and Macaranga spp.) as well as oil palm biomass (oil palm trunk and empty fruit bunch). The lignocellulosic biomass was torrefied at three different temperatures 200, 250 and 300 °C for 15, 30 and 45 min. Response surface methodology was used for optimization of torrefaction conditions, so that biofuel of high energy density, maximized energy properties and minimum weight loss could be manufactured. The analyses showed that increase in heating values was affected by treatment severity (cumulated effect of temperature and time). Our results clearly demonstrated an increased degradation of the material due to the combined effects of temperature and treatment time. While the reaction time had less impact on the energy density of torrefied biomass, the effect of reaction temperature was considerably stronger under the torrefaction conditions used in this study. It was demonstrated that each biomass type had its own unique set of operating conditions to achieve the same product quality. The optimized torrefaction conditions were verified empirically and applicability of the model was confirmed. The torrefied biomass occurred more suitable than raw biomass in terms of calorific value, physical and chemical properties. The results of this study could be used as a guide for the production of high energy density solid biofuel from lignocellulosic biomass available in Malaysia.

No abstract

No abstract

In the present study, agricultural biomass—palm kernel shell (PKS) and coconut shell (CS)—was used to produce high porosity bioadsorbent using two-stage continuous physical activation method with different gas carrier (air and N2) in each stage. The activation temperature was set constant at 600, 700, 800 or 900°C for both activation stages with the heating rate of 3°C min−1. Two parameters, the gas carrier and activation temperature, were determined as the significant factors on the adsorption properties of bioadsorbent. BET, SEM, FTIR, TGA, CHNS/O and ash content were used to elucidate the developed bioadsorbent prepared from PKS and CS and its capacity towards the adsorption of methylene blue and iodine. The novel process of two-stage continuous physical activation method was able to expose mesopores and micropores that were previously covered/clogged in nature, and simultaneously create new pores. The synthesized bioadsorbents showed that the surface area (PKS: 456.47 m2 g−1, CS: 479.17 m2 g−1), pore size (PKS: 0.63 nm, CS: 0.62 nm) and pore volume (PKS: 0.13 cm3 g−1, CS: 0.15 cm3 g−1) were significantly higher than that of non-treated bioadsorbent. The surface morphology of the raw materials and synthesized bioadsorbent were accessed by SEM. Furthermore, the novel process meets the recent industrial adsorbent requirements such as low activation temperature, high fixed carbon content, high yield, high adsorption properties and high surface area, which are the key factors for large-scale production of bioadsorbent and its usage.

Rubber forest plantation (RFP) in Malaysia was currently governed by small holders who provided lower diameter logs as they managed plantation using higher planting density, higher frequency tapping practice and young-tapping systems to enhance latex harvesting yield and fulfil demand for rubber timber. Nevertheless, these new planting systems will affect the growth of rubber tree and result in the production of smaller diameter (<20 cm) rubber logs compared to conventional planting systems. Hence, this raises the question of the small diameter log with respect to its impact on veneer quality. The aim of this study is to determine the properties of rubberwood veneers manufactured from outer to inner radial section of log at different veneer thicknesses. The rubber logs with diameter less than 20 cm were peeled up to 3 cm of peeler core to produce 1, 2 and 3 mm veneer thickness using spindleless lathe. Veneer properties such as thickness variation, lathe checks, surface roughness and contact angle were evaluated from outer to the inner radial section of log at three different veneer thicknesses. Results showed that rubber trees are suitable for peeling due to its consistent density ranging from 650 to 706 kg/m3. Better visual grades recovery can be obtained when peeling thinner rubberwood veneers. The thickness variation, lathe check depth, length and surface roughness of rubberwood veneers increased with increasing veneer thickness, whereas lathe check frequency decreased with increasing veneer thickness. In general, veneer thickness has more prominent effects on the properties of rubberwood veneer compared to the effect of log radial section.

Ethanolic fermentation using Saccharomyces cerevisiae was carried out on three types of hydrolysates produced from lignocelulosic biomass which are commonly found in Malaysia such as oil palm trunk, rubberwood and mixed hardwood. The effect of fermentation temperature and pH of hydrolysate was evaluated to optimize the fermentation efficiency which defined as maximum ethanol yield in minimum fermentation time. The fermentation process using different temperature of 25 degrees Celsius, 30 degrees Celsius and 40 degrees Celsius were performed on the prepared fermentation medium adjusted to pH 4, pH 6 and pH 7, respectively. Results showed that the fermentation time was significantly reduced with the increase of temperature but an adverse reduction in ethanol yield was observed using temperature of 40 degrees Celsius. As the pH of hydrolysate became more acidic, the ethanol yield increased. Optimum fermentation efficiency for ethanolic fermentation of lignocellulosic hydrolysates using S. cerevisiae can be obtained using 33.2 degrees Celsius and pH 5.3.

No abstract