Mohd Johari Kamaruddin

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.

A REVIEW OF MIXED REVERSE MICELLE SYSTEM FOR ANTIBIOTIC RECOVERY

This article discusses the application of mixed reverse micelles in downstream processing of antibiotics. Purification and recovery processes for antibiotics in downstream processing are major expenses, about 70% of the total cost of production, giving them a significant impact on manufacturing cost. Moreover, there are a number of challenges and difficulties in the separation process requirements for antibiotics, since the mixture is quite complex, with broth, hazardous solvents, by-products, intermediate material, and impurities; in addition, antibiotics are easy to denature. Therefore, the development of effective separation techniques is required to produce high-purity of biomaterials. The use of reverse micelles is thought to be among the most promising due to the processs high selectivity and efficiency. Most studies on reverse micelle extraction technology have been performed by using anionic surfactant sodium bis (2-ethyl-1-hexyl) sulfosuccinate (AOT). However, the activities of antibiotics hosted in this type of surfactant have a significant effect due to the strong electrostatic and hydrophobic interaction between antibiotic and surfactant molecules. Due to these problems many alternatives have been developed recently, and reverse micelles have high potential in the purification of biomolecules. Therefore, this review discusses the ability of mixed ionic-nonionic reverse micelles to provide a safe microenvironment for antibiotics by maintaining the strength of attraction between the reverse micelle molecule and the antibiotic while avoiding the denaturation of the antibiotic. The article highlights the potential of mixed ionic-nonionic reverse micelle technology as a tool of antibiotic recovery from various mediums.

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

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

Dielectric properties of materials play a significant role in design of microwave assisted processing system. This paper is focused on the dielectric properties of ε-caprolactone (ε-cap) which is the monomer for the biodegradable polymer, Poly (ε-caprolactone) (PCL). The dielectric properties of ε-cap were measured across a wide range of frequencies (0.1 GHz5.0 GHz) and temperatures (20-150oC). Then the measured dielectric properties data was modelled using Debye model in order to relate quantitatively the dielectric properties to microwave heating mechanisms. The analysis carried out gives a clear picture of interaction of ε-cap with microwave energy and its heating mechanism in microwave assisted polymerisation process. This study concluded that microwave heating mechanism of the ε-cap in the measured range may be dominated by the dipole reorientation.

Methodology on scaling-down of membrane separation process into microfluidic platform

The use of membrane separation techniques in microfluidic devices has been gaining interest in many research field particularly in analytical chemistry where such a device is utilised to selectively remove impurities and/or unwanted components for a better detection of analyte of interest. Many different strategies have been reported to combine membranes and microfluidics. In this paper, details on how to fabricate such a micro scale filtration device are discussed. Topics covered include size and operation mode, materials and fabrication methods, strategy to integrate membrane on chip, fluidics (and electrical) interconnects, online measurement and process automation. Each design parameters were reviewed and discussed in accordance to the steps (or methodology) needed to fabricate a microfluidic membrane filtration unit. A low cost fabrication solution using polymers as materials for fabrication and the use of Arduino board for process automation have been suggested to realise a fully automated microfluidic membrane filtration unit.

Dielectric properties of sodium hydroxide-impregnated and activated cempedak peel samples at microwave frequencies

This study was aimed to evaluate the dielectric properties of sodium hydroxide-impregnated samples and activated carbons derived from jackfruit peel (Artocarpus chempeden, Artocarpus integer). The dielectric properties were examined by using open-ended coaxial probe method at microwave frequencies. The results show that the dielectric properties of cempedak peel samples are influenced by frequency, concentration of activator, moisture content and carbon content. The impregnated sample with NaOH ratio of 1.5 (CN1.5) showed a better microwave absorber due to sufficient moisture content (8.55 %), consequently higher tan δ. Sodium hydroxide can function as microwave absorber to enhance the efficiency of microwave heating for low loss material like cempedak peel. Moisture content and carbon content have to be taken into consideration as these parameters can influence the dielectric properties of the modified cempedak peel samples.

Removal of Reactive Dye Using New Modified Chitosan-pandan Sorbent

This research aims to synthesise the modified Chitosan-Pandan by performing impregnated approach at which the extracted polyphenols of pandan oil was served as stabiliser. The extractions of pandan leaves were carried out using maceration process whereby ethanol (95 vol%) was used as solvent. The characterisations of the modified Chitosan-Pandan were examined using Fourier transform infrared spectroscopy (FTIR). A batch adsorption of Reactive Black 5 (RB5) from aqueous solution using the modified Chitosan-Pandan were conducted under different range of retention time (0 - 40 min), initial mass concentration dyes (0.1 - 1.0 g/L), pH solution (5 - 11), temperature (25 - 80 ± 1 ?C) and dosage of sorbent (0.1 - 1.0 g). The optimum adsorption was achieved up to 99.9 % within 30 min, 0.2 g/L initial dye concentration, 0.1 g dosage of sorbent, pH 7 and at room temperature. Compared to raw chitosan, the modified Chitosan-Pandan was proven to have better percentage removal of RB5.The results obtained shows that the modified Chitosan-Pandan has great potential to be used as a powerful novel sorbent.

Fourier Transforms Infrared Spectroscopy and X-ray Diffraction Investigation of Recycled Polypropylene/polyaniline Blends

The main objective in this paper is to characterise rPP/PANI blends chemical composition, structure and crystalline phases. This study investigates the synthesis and characterisation of recycled polypropylene/polyaniline (rPP/PANI) blends, prepared by single screw extrusion. Blends with 0 to 10 wt% PANI loading were prepared. The rPP/PANI blends were characterised by Fourier transforms infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The FTIR spectra show the PANI nanofiber in emeraldine salt form and show the grafting and strong interaction between PANI and rPP in the blends. The FTIR results for pure PANI and the blends with varying contents of PANI are consistently related to the structure of the pure PANI and blends discussed in the XRD analysis. XRD results confirmed the formation of PANI nanofiber in the blends and the presence of PANI nanofiber changes in crystallinity of rPP matrix.

Contribution of permit to work to process safety accident in the chemical process industry

Permit to Work (PTW) is the Technical Measurement Document required to control work such as maintenance, inspection, modification and non-routine high risk activities to prevent a major accident. It is one of the elements of the Process Safety Management (PSM). The current issue of the chemical process industry (CPI) is that the accident rate has not decreased even though PSM has been widely implemented in the developed country. Statistics on the accident cases published by Chemical Safety and Hazard Investigation Board (US), European Major Accident Reporting System and Failure Knowledge Database (Japan) has revealed that PTW has significance contribution to the occurrence of accidents and is worthwhile to be studied in details. Failure in complying with PTW system has caused major accidents cases, such as Motiva Enterprise LLC (2001), Phillips Pasadena (1989) and Piper Alpha Platform (1988). Another reason for studying PTW, being that the trend of its percentage of contribution to process accident rate is not decreasing over the past two decades even though there are shared information and feedback available. In the chemical process industry, there are various types of PTW namely Hot Work, Confined Space Entry, Line breaking & vessel opening and others. Each has its own function and the percentage contribution of each PTW type is determined using data mining approach. This study is focusing on the identification of main factors of PTW- related accidents which are classified under organisation, human factors, communication, competency, procedure, supervision, tools and equipment and etc. The percentage contribution of each main factor is determined and the results are presented for sharing and learning purposes.

Dielectric properties for extraction of orthosiphon stamineus (Java Tea) leaves

A dielectric properties study was performed at ISM frequencies and a range of temperatures (25 – 45 °C) on the extraction of Orthosiphon Stamineus (Java Tea) leaves system in order to relate their dielectric properties to microwave heating mechanisms and design of microwave applicator quantitatively. The main results concluded that the heating mechanism of the extraction mixture in an electromagnetic field was controlled by the dielectric properties of solvent (water), where the solvent was the major component (> 90 % v/v) as well as the component with highest dissipation factor (tan d). The penetration depths of extraction mixture at ambient temperature (25 °C) are 3.8 cm, 3.2 cm and 1.4 cm at ISM frequencies of 0.433 GHz, 0.915 GHz and2.45 GHz. These tiny penetration depths limit the potential to achieve the successful scale up of a microwave- assisted extraction of Orthosiphon Stamineus leaves in batch mode at ISM frequencies. This will lead to inhomogeneous bulk temperature distribution within the extraction mixture and irreproducible extraction yield without sufficient stirring and stirrer compatible with microwave system. A fast heating rate based on a high value of tan d of the extraction mixture revealed that the microwave heating technique has a great potential in reducing the processing time especially at heating up stage compared to conventional thermal heating technique in extraction of Orthosiphon Stamineus leaves. The dielectric properties of extraction mixture are worth to be considered to certify the consistency and reproducibility of the microwave-assisted extraction at large scale production.