Key Engineering Materials Vol. 797

Abstract: Carica papaya leaf (CPL) and Garcinia mangostana pericarp (GMP) are potential anti-dengue nutraceutical drink. Here, its production plant was modelled and optimised using Superpro Designer® simulation software to achieve an economically viable production scheme. Three production schemes were presented. Scheme 1 yielded low ROI (18.07%) and lengthy payback period (5.54 years). Despite doubling the output in scheme 2, the new ROI (27.09%) and payback period (3.69 years) remained unattractive. Staggered configuration of the bottlenecking process (fermentation) yielded Scheme 3; which turned out the most economically viable as indicated by its ROI (49.96%) and payback period (2.26 years).

Abstract: Owing to the annually increasing market value of pure agarwood oil, the extracted agarwood oil from Aquilaria malaccensis was emulsified in an aqueous solution using non-ionic surfactant (Tween 80). The surfactant concentration of 0.0167% was determined as the critical micelle concentration (CMC) with an interfacial tension value of 0.014 mNm^-1. The adsorption of surfactant at the oil/water interface at the CMC value, however, reduced the zeta potential of the emulsified oil from –45 to –43 mV, and increased its size from 85 to 89 nm. Outside of the CMC value, the emulsified oil droplets tended to coalesce, owing to insufficient coverage of the surfactant at oil/water interface and Ostwald ripening. The droplet size distribution and zeta potential value of the emulsified oil droplets produced at the CMC were the most stable over a month of storage. No significant changes in the emulsified droplet size occurred when the pH conditions varied from pH 3 to 10. The emulsified droplets images obtained from transmission electron microscopy analysis showed a reduction in the layer thickness of the surfactant from 30 to 10 nm in acidic condition and 30 to 19 nm in alkaline condition. The agarwood oil emulsification at CMC value enhance the stability of chemically unstable compounds from degradation.

Abstract: Drying also known as dehydration is commonly used as a unit operation in herbs manufacturing industry to preserve the food product by removing the moisture content in the herbs. Unfortunately, most drying process degraded the product quality because the feedstock is exposed to a very high temperature within a long period of time by using conventional oven Therefore this research has focused on the alternatives technique in overcoming the degradation of nutrients by applying the irradiation concepts. The objectives of this research were to investigate the effect of drying onto the physical properties of Aquilaria Malaccensis leaves by using fabricated far-infrared dryer. The experiments were conducted at various temperature ranging from 40, 50 and 60°C. The color difference and the moisture content of the leaves before and after drying were examined. The color measurements data shows that at 60°C, the brightness and the chroma were the highest. On the other hand, the hue angles were the highest for 60°C when the time was reached 100 minutes.

Abstract: Gaharu oleoresin is a mixture of wood resin and essential oil substances that naturally accumulates in the gaharu plants species. The aim of this study was to determine the appropriate solvent types and the contents of oleoresin and oil as well as the chemical compounds present in the gaharu extracts. Gaharu oleoresin can be extracted from gaharu powder using polar solvents and the essential oil can be separated using non-polar solvents. The extraction was done by Soxhlet method using methanol and ethanol for oleoresin extraction, and n-hexane and toluene for oil extraction from which the most appropriate solvents, extraction yields and the extracts quality were determined. The percentage of oleoresin extraction yield was found highest in methanol (6.97 %) followed by ethanol (6.85 % w/w). Meanwhile, the gaharu oil was found higher in toluene extract (1.06 %) compared to n-hexane (0.38 % w/w). The GC-MS results showed the extracts from ethanol and n-hexane solvents are the best quality due to the present of key compounds of 4-phenyl-2-butanone, β-guaiene, agarospirol, α–bisabolene, alloaromadendrene oxide, γ-Gurjunen and aromadenderene oxide. Different chemical component in gaharu oil determines the characteristic or quality of the gaharu. Meanwhile, the sesquiterpene compounds in gaharu produce its specialty aroma characteristics. Therefore, ethanol and n-hexane solvents are suitable to be used for oleoresin and oil extraction beside less expensive and more environmental-friendly.

Abstract: Lignocellulosic biomass containing cellulose, hemicelluloses and lignin is significantly analyzed via methods from infrared to microscopy. These methods help researchers to explore the organic or inorganic functional groups and physical surface impacts microscopically on the particles of the pretreated biomass. Some concerns arise in understanding the data results. An investigation with the presence of ionic liquids on Leucaena Leucocephala (Petai Belalang), Acacia Auriculiformis and Melastoma Malabathricum (Senduduk) are reported via the results of Fourier Transform Infrared Spectrum (FTIR) and Scanning Electron Microscopy (SEM). The model ionic liquids as green solvents used are 1-Ethyl-3-methylimidazolium Acetate (EMIMAc) and 1-Ethyl-3-methylimidazolium Chloride (EMIMCl). This work is very essential to sustain preliminary reliable understanding on the chemical and physical effects on lignocellulosic biomass during pretreatment with solvents.

Abstract: Empty fruit bunch (EFB) is a potential chemical feedstock particularly cellulose and lignin. However, the complete extraction of lignocellulosic structure in EFB is complex and difficult to achieve. Steam explosion is a pre-treatment process which has the ability to loosen the polymeric bond between the EFB structures. In this paper, the effect of steam explosion process towards the lignin removal was investigated. The raw EFB and exploded EFB were further extracted through the alkaline-hydrolysis process to obtain the yield of the insoluble lignin. In addition, the samples were also characterized using FTIR and TGA analysis. The yield obtained showed that the amount of lignin was reducing after the steam explosion process. Similar data were also recorded from the FTIR and TGA analyses. This work concludes that other than reducing the polymeric strength of the EFB’s lignocellulosic structure, the steam explosion also helps the delignification process.

Abstract: This research was focused on the utilizing one of palm oil biomass; the palm pressed fibre (PPF) for producing CMC through etherification of cellulose with monochloroacetic acid. The gained CMC fibre based was tested for its potential as anti-redeposition agent. The main objective was to synthesize cellulose and carboxymethyl cellulose value added product from oil palm biomass PPF using established standard method of ASTM (American Standard Test Method) and to run quality control studies for all sample such as viscosity of CMC, purity of CMC, Fourier Transform Infrared Spectroscopy (FT-IR) and Thermal Gravimetric Analyzer (TGA) Analysis. The effect of the CMC as anti-redeposition agent in laundry detergent making was focused as the main potential. The produced CMC was excellent in quality and has imitated the standard CMC with degree of substitution of 0.7 rather than 0.9. By using the TGA analysis, the moisture, volatile, carbon and ash content of the CMC was valued as 14.79%, 40.29%, 8.32% and 17.93%, respectively. 1% CMC added into three (3) different types of detergents against number of wash cycle to avoid soil redeposited back to our laundry load with Yr/Yo represents the whiteness retention in fabric swatches. Five wash cycles with duration of 10 minutes for each cycle was chosen since there was possibility that within minimum cycle of 1-2 detergent performance is still at its best. Detergent A + 1% (w/v) CMC has proved to give significant brightness of 59% better than Detergent A without CMC. CMC produced and reported in this paper has been proved to own such a potential and is expected to achieve interesting quality with better research exposure or maybe through a great pilot plant scale of CMC-antiredeposition-detergent with real dirty clothing-real washing machine test. Keywords. Palm Pressed Fibre; CMC (Carboxymethyl Cellulose); anti-redeposition

Abstract: The inhibition efficiency of Musa sapientum (banana) peel extracts at different concentrations and temperatures on mild steel corrosion in acidic solution of 1 M hydrochloric acid (HCl) were investigated by using weight loss method. The banana peel extract concentrations were tested from 300 to 500 ppm at temperature range between 25°C to 60°C. The performance of banana peel extract as an inhibitor was found compatible in the tested solution. The corrosion rates, which were calculated from the weight loss data, showed that the inhibition efficiency of the extract increased from 86.9% to 89.0% as the concentration of banana peel extract increased from 300 ppm to 500 ppm. It was also observed that the inhibition efficiency decreased as the temperature was increased from 25°C to 60°C. Characterization of the peel extract by using gas chromatography-mass spectrometry (GC-MS) has detected the presence of bioactive compounds which are responsible for the corrosion inhibition and adsorption properties on mild steel surface. Eleven major compounds have been identified as having corrosion inhibition properties. FTIR analysis confirmed the presence of functional groups of alcohols, alkanes, carbonyls, aromatics, ethers, and esters that can prevent corrosion by adsorption on steel surface.

Abstract: The characterization and properties of sand from beaches in Malaysia that has potential to be used as proppant in hydraulic fracturing was investigated through impingement tests. Eight sand samples were obtained from eight different locations in Malaysia; three samples from West Coastal beaches (Selangor) and five from East Coastal beaches (Kelantan). These impingement tests were conducted by varying several parameters i.e. size ranges of sand, type of targeted metal and distance of nozzle standoff from target. In these tests, air was fed through an acrylic pipe with inner diameter of 8 mm and 4 m length at gas velocity of 100 m/s and flow rate of 200 l/min. 250 g of sand samples were fed in compressed air stream and the samples were projected toward targeted metal i.e. mild steel and aluminium with a 90° of impingement angle. These tests were conducted at different separation distance of 0.5, 2.5 and 5.0 inches of nozzle and target. The results were analysed by measuring the mass loss of the metals after impingement and the images of the impinged metals were captured using camera. The highest metal loss was obtained when the targeted metal was impacted with the largest size range of sand samples. The mass loss of mild steel ranged from 0.03 to 0.16 g and 0.10 to 0.22 g for aluminium, at a variable distance between the nozzle and metal target due to higher hardness of mild steel than aluminium. The mass loss reduced when the distance between nozzle and metal target increased due to energy loss because of the inter particle collision.

Abstract: Rubber industry is one of major raw material for many industries around the world. Therefore, supplying quality raw material is major concern among the market player. The objectives of this paper is to formulate natural rubber latex (NRL) by addition of bio fillers and to determine the impact of bio fillers (rice husk ash and tacca starch) towards the tear strength and tensile strength of the film samples. Normally, filler compounded in NRL named carbon black filler is chemical based, expensive and difficult to handle. Blending method was applied whereby named as compounding process. The vulcanized NRL was blended with the bio fillers before manual dipping process applied to obtain the film. The bio filler loaded was 10 phr and 30 phr. The optimum concentration was found to be 10 phr of tacca starch, producing tensile stress at maximum load was 18 Mpa while elongation at break was 650%. In addition, tensile stress at 300 mm elongation was 2 Mpa and tear strength is 15 N/mm.