Azil Bahari Alias

Investigation on thermochemical behaviour of low rank Malaysian coal, oil palm biomass and their blends during pyrolysis via thermogravimetric analysis (TGA)

This study aims to investigate the behaviour of Malaysian sub-bituminous coal (Mukah Balingian), oil palm biomass (empty fruit bunches (EFB), kernel shell (PKS) and mesocarp fibre (PMF)) and their respective blends during pyrolysis using thermogravimetric analysis (TGA). The coal/palm biomass blends were prepared at six different weight ratios and experiments were carried out under dynamic conditions using nitrogen as inert gas at various heating rates to ramp the temperature from 25 degrees C to 900 degrees C. The derivative thermogravimetric (DTG) results show that thermal decomposition of EFB, PMF and PKS exhibit one, two and three distinct evolution profiles, respectively. Apparently, the thermal profiles of the coal/oil palm biomass blends appear to correlate with the percentage of biomass added in the blends, thus, suggesting lack of interaction between the coal and palm biomass. First-order reaction model were used to determine the kinetics parameters for the pyrolysis of coal, palm biomass and their respective blends.

Co-combustion of agricultural residues with coal in a fluidised bed combustor

Power generation from biomass is an attractive technology that utilizes agricultural residual waste. In order to explain the behavior of biomass-fired fluidized bed incinerator, biomass sources from agricultural residues (rice husk and palm kernel) were co-fired with coal in a 0.15m diameter and 2.3m high fluidized bed combustor. The combustion efficiency and carbon monoxide emissions were studied and compared with those for pure coal combustion. Co-combustion of a mixture of biomass with coal in a fluidized bed combustor designed for coal combustion increased combustion efficiency up to 20% depending upon excess air levels. Observed carbon monoxide levels fluctuated between 200 and 900 ppm with the addition of coal. It is evident from this research that efficient co-firing of biomass with coal can be achieved with minimal modifications to existing coal-fired boilers.

Hazardous waste management: current status and future strategies in Malaysia

Although Malaysia is a model for economic success amongst Southeast Asian countries with its impressive development over the last 36 years, it has not been without its detrimental effects on the natural environment. The most apparent effect is the drastic increase in the generation of hazardous wastes. This paper highlights Malaysias current status in hazardous waste management and the potential major difficulties. The principles, objectives and the remedial plans for hazardous waste control are also explained in detail and have been stipulated in the environmental policies as issued by the Department of Natural Resources and Environmental Ministry, Malaysia.

Thermal behaviour study of senakin coal and Refuse Derived Fuel (RDF) blends during pyrolysis using thermogravimetric analysis

Preliminary Thermogravimetric (TG) studies of pyrolysed Refuse Derived Fuel (RDF) – Coal blends (20 to 80%) at various heating rates, 20, 40, 60oC·min–1 have been performed to develop an efficient locally sourced renewable solid fuel. The characteristics of the coal/RDF blends followed those of the parent fuels in additive manner. Among the tested blends, 50:50 blends showed the optimum blend ratio but no synergistic effect was observed between the coal and RDF during co-pyrolysis. However, the kinetic analysis using modified Arrhenius equation indicates the existence synergistic effect between the RDF and coal, which induces lower coal pyrolysis activation energy.

An overview of oil palm biomass torrefaction: Effects of temperature and residence time

Biomass is characterized as high moisture content, low bulk and energy density, possesses hygroscopic behaviour and poor grindability material as compared to the superior coal. A thermal treatment called torrefaction is a heating of biomass in a temperature range between 200°C to 300°C under inert atmosphere in order to upgrade biomass properties. Torrefied biomass has many similar characteristics to coal such as low moisture content, high bulk and energy density, hydrophobic and good grindability. This paper reviews the effects of oil palm biomass torrefaction in terms of temperature and residence time. This is because comprehensive studies on torrefaction parameters need to be carried out since different parameters might affect the chemical and physical characteristic of the torrefied product. Hence, this paper aims to discuss the effects of different torrefaction temperature and residence time towards physicochemical characteristic, mass and energy yield as well as calorific value of torrefied oil palm biomass.

Preparation and Characterization of Single and Mixed Activated Carbons Derived from Coconut Shell and Palm Kernel Shell through Chemical Activation Using Microwave Irradiation System

Single and mixed coconut shell (CS) and palm kernel shell (PKS) were successfully converted to activated carbon by using potassium hydroxide (KOH) as activating agent. Mixed activated carbon was produced from coconut shell: palm kernel shell at different KOH concentrations of 30%, 40% and 50%. Activation process was performed in a conventional microwave oven at fixed power and time of 600W and 20 minutes respectively. The results showed that activated carbon produced from single and mixed biomass at 40% concentration of KOH exhibited higher adsorption capacity for iodine number and percentage removal of MB with comparison to 30% and 50% of KOH concentrations. The highest BET surface area of 441.19 m2/g was obtained by CSAc-40. Further both CSAc-40 and PKSAc-40 produced an average pore size diameter of less than 2.0 nm which is in the range of micropore region. On contrary, the mixed CSPKSAc-40 produced an average pore size diameter of 6.0 nm which is in the region of mesopore. All the CSAc-40, PKSAc-40 and mixed CSPKSAc-40 showed similar adsorption trend for iodine number and percentage removal of MB. Interestingly, this finding showed that in the mixed activated carbon some chemical reactions might have occurred during the activation process producing mesoporous instead of microporous as obtained by the single biomass activated carbon.

Production and characterisation of single and mixed activated carbons from coconut shell and rubber seed pericarp using microwave-induced chemical activating agent

Activated carbon from biomass namely coconut shell (CS-AC), rubber seed pericarp(RSP-AC) and their mixed blend (50:50 w/w) coconut shell-rubber seed pericarp activated carbon(CSRSP-AC) were successfully produced by using ZnCl2 as chemical activating agent viamicrowave irradiation heating system. Activation process was performed in commercial microwaveoven at power of 600W for 20 min by using 30%, 40% and 50% of ZnCl2 concentrations. Theactivated carbon was characterized according to BET surface morphology, iodine number andpercentage of MB removal. The results showed that the mixed CSRSP-AC produced the highestsurface area of 584.68 mg2/g with comparison to single CS-AC and RSP-AC at 445.9 mg2/g and462.5 mg2/g respectively. Although CSRSP-AC has the highest surface area and pore volumedevelopment, RSP-AC was found to have the highest iodine number, with the opposite trend beingobserved with MB removal indicating that RSP-AC has the highest adsorptive capacity among thethree activated carbons. The iodine number value and percentages of MB removal increased as theZnCl2 concentration increase from 30% to 50%. These findings revealed that activated carbonproduced from mixed blend of coconut shell and rubber seed pericarp has almost similarcharacteristics to their respective activated carbon derived from single individual biomass.

Biochar dan Pemangkin berasaskan tempurung kelapa sawit untuk penghasilan biodiesel

A promising catalyst based on a biomass pyrolysis by-product, biochar, has been developed to produce biodiesel. A carbon-based solid acid catalysts were prepared by sulfonating pyrolysis char with concentrated sulfuric acids. The catalysts were characterized using thermogravimetric analyses (TGA), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and surface area analyzer. Prepared catalysts were studied for their ability to catalyze transesterification of vegetable oils. The catalyst sulfonated with the concentrated sulfuric acid demonstrated considerable conversion in free fatty acid esterification. Further investigation of the catalyst was conducted to determine the effect of sulfonation time (1 and 3 hours) and surface area on the transesterification reactions. The surface area of the biochar was increased by chemical treatment using 10M potassium hydroxide through porosity development. Results showed the catalyst with the highest surface area and acid density to have the highest catalytic activity to produce biodiesel from canola oil in the presence of methanol as the reagent. The effects of alcohol to oil (A:O) molar ratio, reaction time and catalyst loading on the esterification reaction catalyzed by the sulfonated biochar were also investigated. Results revealed that more than 90% biodiesel yield was achieved at 15 wt% of catalyst amount, methanol to oil molar ratio was 9:1 and the agitation rate was 700 rpm. As a conclusion, the prepared biochar-based catalyst has a tremendous potential to be used in a process converting a high Free Fatty Acids (FFA) feedstock to biodiesel.

Effect of Washing Pre-treatment of Empty Fruit Bunch Hydrogel Biochar Composite Properties as Potential Adsorbent

Hydrogel biochar composite (HBC) showed a great potential as effective organic contaminant removal in various wastewater and gas treatment. The effectiveness is depending upon quality of biochar used during the preparation of the HBC. In this work, pre-treatment of the biochar samples (EFB in this case) through washing was investigated. The raw EFB biochar was prepared using microwave assisted pyrolysis under 1,000 W for 30 min under N2 flow with 150 mL/min. The prepared biochar is chemically treated using either acid solution (HCl) or oxidising agent (H2O2) to enlarge the pores and remove impurities. The biochar is then polymerised by using acrylamide (AAm) as monomer, N,N’-methylenebisacrylamide (MBA) as crosslinker and ammonium persulfate (APS) as initiator to form the treated hydrogel biochar composite (EFB-HBC). The H2O2 treated biochar [EFB-HBC (P100)] shows better porosity compared to HCl treated biochar [EFB-HBC (H100)] where EFB-HBC (P100) has higher surface area (1.5997 m2/g) compared to EFB-HBC (H100) (1.2562 m2/g). The HBC is porous and carbonaceous material with 21 % and 31 % of carbon content in EFB-HBC (P100) and EFB-HBC (H100) which have potential as an adsorbent in wastewater and gas treatment.

Characterization of upgraded hydrogel biochar from blended rice husk with coal fly ash

Rice husk biochar (RB) blended with coal fly ash (CFA) is used as a material to develop hydrogel for heavy metal removal. This combination, namely hydrogel rice husk biochar-coal fly ash (HRB-CFA) composite is synthesized by embedding the biochar into acrylamide (AAM) as monomer, with N,N’-Methylenebisacrylamide (MBA) as crosslinker and ammonium persulfate (APS) as initiator. While activated carbon (AC) remains an expensive material, HRB-CFA is attracting great interest for its use in the absorption of organic contaminants due to its low material cost and importance as renewable source for securing future energy supply in the environmental system. Although the CFA does not have the surface area as high as AC, certain metallic components that are naturally present in the CFA can play the catalytic role in the removal of heavy metal from wastewater. The percentage of heavy metal removal is depends on the parameters that influence the sorption process; the effect of pH solution, dosage of adsorbent, initial ...