Anwar Johari

Isolation, characterization, and application of nanocellulose from oil palm empty fruit bunch fiber as nanocomposites

Nanocomposites, consisting of a polymeric matrix and nanosized elements as reinforcement, have attracted significant scientific attention because of their high mechanical performance. A large variety of nanocomposites have been prepared using bio-based materials as a matrix and nanoreinforcement, so that it can reduce the dependence on nondegradable products and move to a sustainable materials basis. The objective of this study was to isolate nanocellulose from empty fruit bunch (EFB) fiber and their reinforcing effect on polyvinyl alcohol (PVA)/starch blend films. A series of PVA/starch films with different content of nanocellulose were prepared by solution casting method. Nanocellulose fiber with diameters ranging from 4 to 15nm has been successfully prepared. On the other hand, PVA/starch films reinforced with nanocellulose fiber possess significantly improved properties compared to unreinforced film. From the results, PVA/starch films with the addition of 5% (v/v) of nanocellulose exhibited best combination of properties. This nanocomposite was found to have tensile strength at about 5.694 MPa and elongation at break was 481.85%. In addition to good mechanical properties, this nanocomposite has good water resistance and biodegradability.

Variation of the crystal growth of mesoporous silica nanoparticles and the evaluation to ibuprofen loading and release.

Mesoporous silica nanoparticles (MSNs) were synthesized with variable microwave power in the range of 100-450 W, and the resulting enhancement of MSN crystal growth was evaluated for the adsorption and release of ibuprofen. X-ray diffraction (XRD) revealed that the MSN prepared under the highest microwave power (MSN450) produced the most crystallized and prominent mesoporous structure. Enhancement of the crystal growth improved the hexagonal order and range of silica, which led to greater surface area, pore width and pore volume. MSN450 exhibited higher ibuprofen adsorption (98.3 mg/g), followed by MSN300(81.3 mg/g) and MSN100(74.1 mg/g), confirming that more crystallized MSN demonstrated higher adsorptivity toward ibuprofen. Significantly, MSN450 also contained more hydroxyl groups that provided more adsorption sites. In addition, MSN450 exhibited comparable ibuprofen adsorption with conventionally synthesized MSN, indicating the potential of microwave treatment in the synthesis of related porous materials. In vitro drug release was also investigated with simulated biological fluids and the kinetics was studied under different pH conditions. MSN450 showed the slowest release rate of ibuprofen, followed by MSN300 and MSN100. This was due to the wide pore diameter and longer range of silica order of the MSN450. Ibuprofen release from MSN450 at pH 5 and 7 was found to obey a zero-order kinetic model, while release at pH 2 followed the Kosmeyer-Peppas model.

Hydrogen production from acetic acid steam reforming over bimetallic Ni-Co on La2O3 catalyst- Effect of the catalyst dilution

Catalytic steam reforming of acetic acid using bimetallic catalysts of 5 wt.% nickel and 5 wt.% cobalt supported on Lanthanum (III) oxide (La2O3) for hydrogen production was investigated in a micro fixed bed reactor. The reactor was of quartz tube with a 10 mm inside diameter. The effect of catalyst dilution on the reaction was studied. Silicon carbide was used as the dilution material. The experiments were conducted at atmospheric pressure and temperatures ranging from 500 to 700°C. The complete conversion of acetic acid to product gases has been observed at 550°C and 700°C for diluted and non-diluted catalysts respectively. It shows that catalyst dilution had a profound effect on the conversion of acetic acid at low temperature (550°C) whilst high temperature of 700°C was required for the non-diluted catalyst. The product gas distributions are similar when using both diluted and non-diluted catalysts.

Non-isothermal kinetic analysis of oil palm empty fruit bunch pellets by thermogravimetric analysis

The pyrolysis kinetics of oil palm empty fruit bunch (OPEFB) pellets was examined under non-isothermal conditions in a thermogravimetric (TG) analyser. Thermal analysis was carried out from 30 °C to 1,000 °C using three different heating rates 5, 10, 20 °C min -1 under nitrogen gas (N2). The TG-DTG curves showed that the pyrolysis process occurred in three steps; drying, active pyrolysis and passive pyrolysis signifying the removal of moisture, holocellulose and lignin. The pyrolysis kinetic parameters; activation energy, Ea, and frequency factor A, were deduced from the Flynn-Wall-Ozawa (FWO) model. The average Ea and A values from α = 0.10 0.60 were 160.20 kJ/mol and 1.38 x 10 24 min -1 . The highest Ea (231.42 kJ/mol) and A (8.27 x 10 24 min -1 ) occurred at α = 0.30 indicating this is the slowest or rate determining step (RDS) during thermal degradation of OPEFB pellets. The average Ea for OPEFB pellets was comparably lower than cornstalk (206.40 kJ/mol), sawdust (232.60 kJ/mol) and oak (236.20 kJ/mol). The kinetic compensation or isokinetic effect was also observed during thermal decomposition of the OPEFB pellets. Hence, the results indicate OPEFB pellets can be utilized as a potential feedstock for pyrolysis.

Gasification of Empty Fruit Bunch Briquettes in a Fixed Bed Tubular Reactor for Hydrogen Production

The gasification of EFB briquette was investigated in a fixed bed tubular reactor to examine the effects of temperature on gas composition, heating value and cold conversion efficiency.The resultsrevealedthat H2 gas composition increased from 17.17 mol. % to 29.67 mol. % with increasing temperature from 600°C to 700°C at an equivalence ratio (ER) of 0.4. The heating value (HHV) of the producer gas increased from 6.18 MJ/Nm3 to 7.64 MJ/Nm3 and cold gas efficiency increased from 35.19% to 43.50% with increasing temperature during gasification. However, carbon conversion efficiency increased only marginally from 31.85% to 32.84% while a significant quantity of char (~ 21%) was produced per unit mass of EFB briquette. The results indicate that higher temperatures are required to increase the overall efficiency of EFB briquette gasification in a fixed bed tubular reactor.

Renewable energy and carbon reduction potentials of municipal solid waste in MALAYSIA

Release of green house gases (GHGs) from landfills as a result of ineffective management of those landfills is a serious environmental problem especially in developing countries. The landfill gas (LFG) thus released is a potential resource that can be converted to renewable energy. LFG is made up majorly of methane and carbon dioxide and produced by anaerobic biodegradation processes of municipal solid waste in landfills. This study estimates the amount of this methane emitted from landfills and its potential economic benefits. Using the Intergovernmental Panel on Climate Change (IPCC) methodology, in 2002, methane emission of 251,000 tonnes per year was estimated for Peninsular Malaysia based on 16,988 tonnes per day of municipal solid waste generated. This can generate 1.5 billion kWh of electricity per year worth over RM 450 million (US

Influence of Hydrophilic Polymer on Pure Water Permeation, Permeability Coefficient, and Porosity of Polysulfone Blend Membranes

141 million). In addition, this leads to carbon dioxide reduction of 5,271,000 tonnes per year equivalent to carbon credit of RM 222 million (US

Major Hazards of Process Equipment Failures in the Chemical Process Industry

69 million). Therefore, the exploration of this resource, besides the economic benefits helps in reducing the dependence on depleting fossil fuel and hence mitigating global warming.

A Linear Programing Approach for Landfill Gas Utilization for Renewable Energy Production

It is well known that membrane with hydrophobic property is a fouling membrane. Polysulfone (PSf) membrane has hydrophobic characteristic was blended with a hydrophilic polymer, cellulose acetate phthalate (CAP) in order to increase hydrophilicity property of pure PSf membrane. In this study, membrane casting solutions containing 17 wt% of polymer was prepared via wet phase inversion process. The pure PSf membrane was coded as PC-0. PSf/CAP blend membranes with blend composition of 95/5, 90/10, 85/15 and 80/20 wt% of total polymer concentration in the membrane casting solutions were marked as PC-5, PC-10, PC-15 and PC-20 respectively. All of the membranes were characterized in terms of pure water flux and permeability coefficient in order to study their hydrophilicity properties. The investigated results shows that increased of CAP composition in PSf blend membranes has increased pure water flux, permeability coefficient and porosity of the blend membrane which in turn formed membrane with anti-fouling property.

Dielectric relaxation process and microwave heating mechanism in ε- Caprolactone as a function of frequency and temperature

Process equipment failures play significant roles in most accidents that occur and recur in the chemical process industry resulting in fire, explosion, and toxic release. In this study, 50 equipment-related accident investigation reports were used to analyze type and severity of incidents. The comprehensive accident report data were retrieved from U.S. Chemical Safety and Hazard Investigation Board (CSB) and U.S. National Transportation Safety Board (NTSB) accident databases with a mean year of 2005. Among the identified process equipment failures were piping systems (32%), storage tanks (20%), process vessels (16%), separation equipment (10%), reactors (8%), heat transfer equipment (8%), and others (6%). The analysis shows that 32% of the cases led to fire and explosion, followed by toxic release (26%), and explosion (22%) incidents. A total of 126 fatalities, 590 injuries, 260 exposures, four shelter-in-place, and 13 evacuations were reported. In most accident cases, fire, explosion, and/or toxic release incidents occur simultaneously. The synergy between major hazards results in catastrophic accidents with severe consequences in numbers of fatalities, injuries, exposures, shelter-in-place, and evacuations. To minimize the losses, plant and equipment should be designed and prepared for the worst-case scenario, not just adapting to any ‘applicable’ standards or guidance.