Alkaline treatments on EFB fibre: the effect on mechanical-physical properties and fibre-cement hydration rate

The natural fibres commonly used to enhance the brittleness of the cement matrix but appropriate fibre should be used for a particular purpose depending upon the type of fibre and characteristics. The Oil Palm Empty Fruit Bunch (EFB) fibre is one of the major crops in Malaysia, which contribute large scale of waste that is durable and make it reasonable for utilization in cement-based product. However, the presence of hemicellulose, lignin and extractive (oil, sugar and starch) affect the performance of EFB fibre and causes an incompatibility of EFB fibre and cement. Hence, this research is been conducted to explore the suitable proportion of Sodium Hydroxide (NaOH) treatment for EFB fibre to increase the compatibility of cement with EFB fibre. The NaOH concentration of 0.2%, 0.4%, 0.6%, 0.8%, 1%, 2%, 3% and 4% were used in this study as a chemical pre-treatment of EFB fibre for surface morphology observation and hydration rate test. Meanwhile for only untreated fibre, fibre treated with 0.4% (low concentration), 1% (medium concentration) and 4% (high concentration) of alkali treatment were tested for tensile strength of single EFB fibre. The fibre treated with NaOH has shown a significant different on the hydration temperature for EFB fibre- cement mixed compared with the untreated fibre. The higher NaOH concentration, the greater hydration temperatures obtain. The Scanning Electron Microscopy (SEM) image show that the increment NaOH concentration applied, the rougher EFB fibre surface is observed with lesser silica body remain. The tensile properties of individual fibre treated with NaOH (0.4%, 1% and 4%) has shown significant increment as compare to the untreated fibre with the highest tensile properties mean value 422.90 N/mm2 at 4% NaOH concentration

Reduction of POME final discharge residual using activated bioadsorbent from oil palm kernel shell

A double insulated carbonisation-activation reactor was developed in order to produce activated carbon with high yield and surface area. This reactor was double insulated using low cement castable and covered around the internal space of the reactor with stainless steel plated and fibre glass jacketed heat insulation layer, which allow efficient heat transfer into the bed of material in the reactor. The carbonisation of oil palm kernel shell (OPKS) at 400 °C, followed by steam activation at 500–1000 °C continuously in the same reactor, with steam flow rate of 12.80–18.17 L/min had improved the activated carbon surface area from 305 ± 10.2 m2/g to 935 ± 36.7 m2/g and gave a high yield of 30% within 7 h retention time with a low gaseous emission. The activated carbon produced was successfully applied as bioadsorbent for the treatment of POME final discharge with the reduction of TSS, COD, colour and BOD up to 90%, 68%, 97% and 83%, respectively which met the standard set by Department of Environment Malaysia (DOE)

Exploration of a Chemo-Mechanical Technique for the Isolation of Nanofibrillated Cellulosic Fiber from Oil Palm Empty Fruit Bunch as a Reinforcing Agent in Composites Materials

The aim of the present study was to determine the influence of sulphuric acid hydrolysis and high-pressure homogenization as an effective chemo-mechanical process for the isolation of quality nanofibrillated cellulose (NFC). The cellulosic fiber was isolated from oil palm empty fruit bunch (OPEFB) using acid hydrolysis methods and, subsequently, homogenized using a high-pressure homogenizer to produce NFC. The structural analysis and the crystallinity of the raw fiber and extracted cellulose were carried out by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The morphology and thermal stability were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetric (TGA) analyses, respectively. The FTIR results showed that lignin and hemicellulose were removed effectively from the extracted cellulose nanofibrils. XRD analysis revealed that the percentage of crystallinity was increased from raw EFB to microfibrillated cellulose (MFC), but the decrease for NFC might due to a break down the hydrogen bond. The size of the NFC was determined within the 5 to 10 nm. The TGA analysis showed that the isolated NFC had high thermal stability. The finding of present study reveals that combination of sulphuric acid hydrolysis and high-pressure homogenization could be an effective chemo-mechanical process to isolate cellulose nanofibers from cellulosic plant fiber for reinforced composite materials

Properties of medium density fibreboard (MDF) from kenaf (Hibiscus cannabinus L.) core as function of refining conditions

The objective of this study was to evaluate physical and mechanical properties of medium density fibreboard (MDF) panels made from kenaf core as function of fibre geometry and refining conditions. Raw material was prepared by using pressure levels of 3, 5 and 7 bar at two heating times, namely 3 and 5 min. The length and width of the fibres were determined employing image analyser. Experimental samples with a target density of 700 kg m−3 were produced with 12% of urea formaldehyde as a binder. Physical properties such as swelling in thickness (TS) and water absorption (WA) of the panels in addition to their mechanical properties including modulus of rupture (MOR), modulus of elasticity (MOE) and internal bonding (IB) were evaluated based on MS 1787:2005. Based on the test results, low digestion pressure produced longer fibre length and panels made from these fibres had higher TS with MOR and MOE than those of the others panels. However, the IB properties of samples were low. Panels made from shorter fibre resulted in contradict properties found above. The ideal properties of the samples were found for the panels made having fibre length of 0.81 mm and aspect ratio of 23.4. Such sample had 14.6%, 63.2%, 30.3 MPa, 3619 MPa and 0.66 MPa for TS, WA, MOR, MOE and IB, respectively

Production of a bioadsorbent from oil palm kernel shell, and application for pollutants and colour removal in palm oil mill effluent final discharge

In an effort to mitigate the palm oil mill effluent (POME) final discharge to the river water, palm kernel shell activated carbon has been identified as a promising adsorption technique for enhanced removal of pollutants (Biological Oxygen Demand, Chemical Oxygen Demand, Total Suspended Solid) and colour from the wastewater treatment plant. The bioadsorbent was prepared by carbonize at 400°C using two-in-one carbonization and activation system and further steam activate at 900°C with a total process time of 7 hours. The adsorption capacity was evaluated at different bioadsorbent dosage, treatment time, and initial concentration of pollutants and colour. The bioadsorbent showed the maximum removal of pollutants with a bioadsorbent dosage of 40 g/L at treatment time of 12 hours. Scanning electron microscopy revealed that the treatment image of bioadsorbent was filled with impurities and elements of POME final discharge. This demonstrated that palm kernel shell activated carbon is a potential bioadsorbent for pollutants and colour removal in POME final discharge

Microwave-assisted pre-carbonisation of palm kernel shell produced charcoal with high heating value and low gaseous emission

Production of charcoal with a high higher heating value (HHV) while maintaining low gaseous emission requires high energy input and complicated methods. This paper presents a study of the production of charcoal with high HHV and low gaseous emission from palm kernel shell (PKS) within a microwave-assisted pre-carbonisation system. The maximum temperature was 300 °C, and three magnetrons were employed to assist with the pre-carbonisation process. The magnetrons were programmed to automatically shut down when the temperature reached 250 °C. Carbonisation took place when the PKS was combusted and the resulting heat was used to sustain the carbonisation. The gaseous emission was passed through a condensation unit and a scrubber system connected to the microwave reactor. Untreated PKS biomass with particle size of 6–15 mm was used in this study. A high HHV of 27.63 MJ/kg was obtained. The concentrations for the particulate matter with a size of 10 μm and below (PM10), CO, NO2, SO2 and HCl were below the standard limits set by the Malaysian Ambient Air Quality Standards (2014). Therefore, the microwave-assisted pre-carbonisation technology proposed in this study produced charcoal with high HHV and low gaseous emission which can be used as co-combustion for renewable energy generation

Optimization of phenol adsorption onto biochar from oil palm empty fruit bunch (EFB)

Malaysia, as one of the leading palm oil producers in the world faces problems in disposal of oil palm empty fruit bunch (EFB), which can be converted into various value-added products, including adsorbents. This study investigated the adsorption of phenol from its solution using biochar produced from EFB through carbonization. Response Surface Methodology (RSM) with Box-Behnken design was used to investigate the effects of three parameters (temperature, time and heating rate) during carbonization on phenol removal by the biochar produced. This was followed by process optimization based on statistical analysis. The results indicated that the optimized carbonization conditions were; 500 °C for temperature, 10 °C/min of heating rate and 80 min for reaction timwhich led to 7.57% of phenol removal. SEM revealed coarse and uneven surface of the biochar surface, with small degree of pore development. Comparison between FTIR spectrum of EFB and biochar revealed the loss water and hydroxyl compounds from EFB during carbonization. The lack of oxygenated groups (especially carbonyl groups) on the adsorbent surface as well as limited number of pores were the possible reasons leading to low phenol adsorption by biochar, therefore conversion of the biochar to activated carbon was necessary for higher adsorption performance

PREPARATION OF CELLULOSE FROM OIL PALM EMPTY FRUIT BUNCHES VIA ETHANOL DIGESTION: EFFECT OF ACID AND ALKALI CATALYSTS

ABSTRACT ABSTRACT ABSTRACT ABSTRACT ABSTRACT Ethanol digestion of oil palm empty fruit bunches (OPEFB) fibres at a temperature between 165ºC -180ºC for 2 hr and at a solid-to-liquid ratio of 10:1, ethanol-to-water ratio of 1:1, and with or without 10% 1 N HCl and 1.25 M NaOH as catalysts was studied in order to prepare cellulose via ethanol pulping. The pulp produced was studied for yield, moisture content, solubility in cold/hot water and 1% NaOH, lignin, holocellulose and α-cellulose content. The highest yield of pulp (57%, oven dried weight basis) was from OPEFB fibres digested at 170ºC for 2 hr without addition of catalyst, whereas OPEFB fibres digested at 175ºC for 2 hr with acid catalyst gave the lowest yield of 45% (oven dried weight basis) pulp. Higher cooking temperature gave lower yield of pulp since the reaction hydrolyzed out the hemicellulose, lignin and part of the cellulose. The reactions at 165ºC, 170ºC and 175ºC with acid catalyst produced 56%, 50% and 45% of pulp yield, respectively. It was found that a temperature of 180ºC with or without catalyst was too high for pulping because it totally digested the fibre into a viscous soluble pulp. On the effect of catalysts, acid catalyst was found to enhance the pulping of OPEFB fibres. Without the acid catalyst, at temperature of 165ºC, the fibres could not be fully cooked and would still be in the fibrous form. Reactions at 170ºC and 175ºC without catalyst gave 57% and 55% yield of pulp, respectively whereas with acid catalyst gave 50% and 45% yield of pulp respectively. The base catalyst could only fully pulp the OPEFB fibres at a temperature of 175ºC, but the fibres dissolved at temperature 180ºC. Pulp produced at 175ºC for 2 hr with 10% 1.25 M NaOH gave the best quality pulp, which contained lowest lignin and highest holocellulose at 8.2% and 91.8% (based on the dry weight of pulp), respectively. The maximum yield of α-cellulose (isolated from the pulp) also was obtained from OPEFB digested with alkali catalyst at 175ºC for 2 hr (64.3% based from dry weight of pulp; 34.1% based on dry weight of OPEFB)

Preparation and characterisation of activated carbon from palm kernel shell by physical activation with steam

Granular activated carbon was produced from palm kernel shell using commercial scale carbonisation and activation systems. Carbonisation was carried out using kiln earth system while activation took place in a commercial scale rotary kiln. Steam was used as oxidising agent during activation process with temperature range from 900oC to 1000oC. Palm kernel shell activated carbon was characterised based on proximate and ultimate analyses, thermal stability, chemical functional groups, and surface area. Scanning electron microscope was used to determine the surface morphology of the carbon products. It was found that palm kernel shell is a suitable material to produce activated charcoal owing to its low ash content (2.3 wt %) but high in carbon and volatile content, 23 wt % and 61.7%, respectively. The maximum thermal stability was observed up to 700oC for palm kernel shell activated carbon and raw palm kernel shell but 600oC for palm kernel shell charcoal. The Brunauer-Emmett-Teller (BET) surface area of palm kernel shell activated carbon produced in this study is 607.76 m2 g-1 with 541.76 m2 g-1 micropore area; this is comparable to commercial activated carbon with BET surface area of 690.92 m2 g-1 with 469.08 m2 g-1 micropore area. From the adsorption experiment, palm kernel shell activated carbon could remove up to 80.7% of chemical oxygen demand with 8.83 mg g-1 adsorption capacity; this is comparable to the performance of commercial activated carbon available in the market. The results of this study proved that good quality activated carbon can be produced from palm kernel shell

Phytoremediation Potential of Vetiver System Technology for Improving the Quality of Palm Oil Mill Effluent

Palm oil mill effluent (POME), a pollutant produced by the palm oil industry, was treated by the Vetiver system technology (VST). This technology was applied for the first time to treat POME in order to decrease biochemical oxygen demand (BOD) and chemical oxygen demand (COD). In this study, two different concentrations of POME (low and high) were treated with Vetiver plants for 2 weeks. The results showed that Vetiver was able to reduce the BOD up to 90% in low concentration POME and 60% in high concentration POME, while control sets (without plant) only was able to reduce 15% of BOD. The COD reduction was 94% in low concentration POME and 39% in high concentration POME, while control just shows reduction of 12%. Morphologically, maximum root and shoot lengths were 70 cm, the number of tillers and leaves was 344 and 86, and biomass production was 4.1 kg m−2. These results showed that VST was effective in reducing BOD and COD in POME. The treatment in low concentration was superior to the high concentration. Furthermore, biomass of plant can be considered as a promising raw material for biofuel production while high amount of biomass was generated in low concentration of POME