Category Archives: In Press

EFFECT OF EGR & NANOPARTICLES ON PERFORMANCE AND EMISSION CHARACTERISTICS OF A DIESEL ENGINE FUELLED WITH PALM BIODIESEL AND DIESEL BLENDS

This work examines the consequence of employing cerium oxide (CeO2) nanoparticles at a different proportion (30 ppm, 60 ppm and 90 ppm) to palm oil methyl ester and diesel blends (B20) in water-cooled single cylinder four stroke diesel engine. Adding nanoparticles is a strategy to improve the performance and reduce emissions of the biodiesel. Prepared samples are fuelled to diesel engine by admitting exhaust gas recirculation (EGR) of 10% and 20% by volume. The main intention of this study is to lessen the nitrogen oxide (NOX) emissions for diesel and biodiesel blends. Experimental results found a significant reduction NOX, carbon monoxide (CO), smoke and hydrocarbon (HC) emissions at 10% EGR rate. However, brake specific fuel consumption is increased with significant lower brake thermal efficiency by admitting EGR of 20% by volume. Thus, it can be inferred that EGR of 10% by volume is a optimal way on reducing harmful emissions without compromising much on performance aspects of biodiesel fuelled diesel engine.

LOW-TEMPERATURE DIRECTED INTERESTERIFICATION INCREASES TRIUNSATURATED AND TRISATURATED TRIACYLGLYCEROLS OF PALM OIL AND AFFECTS ITS THERMAL, POLYMORPHIC AND MICROSTRUCTURAL PROPERTIES

Directed interesterification (DIE) is an interesterification technique performed at a sufficiently low temperature to allow higher melting triacylglycerols (TAG) to crystallise out as they are formed during the reaction. Thus, DIE is an excellent tool for changing the TAG composition of oils and fats and consequently extends their applications. DIE converts liquid oils into plastic fats, reduces the formation of graininess and improves the plasticity of lard, and increases the unsaturation level of the olein fraction of fats. This study explored the possibility of using lipase-catalysed DIE (EDIE) as a ‘green’ technique to produce palm oil (PO) which is high in triunsaturated (U3) and trisaturated (S3) TAG, which in turn, when fractionated, produce an olein fraction which is high in unsaturated (especially, oleic acid) and a stearin fraction that is high in saturated (especially, palmitic acid) fatty acids. EDIE resulted in a significant (p<0.05) increase in U3 and S3 TAG of PO, from 4.3% and 5.2% before EDIE to 27.6% and 31.9% after EDIE, respectively. The increased content of U3 and S3 TAG subsequently altered the physical properties of PO. Higher U3 TAG content led to an increase in the proportion of the low melting fraction of PO. Meanwhile, the melting point, solid fat content at all temperatures and the proportion of high melting fraction of PO show to increase following the rise in S3 TAG after EDIE. A differential scanning calorimetry melting curve showed that the low and high melting fractions of EDIE PO were distinctively separated, indicating ease of fractionation. EDIE also increased the proportion of β crystals in PO. Thus, its microscopic structure showed dense crystal aggregates with a coarse plate-like and orderly packed structure.

ISOLATION OF AN OIL PALM CONSTITUTIVE PROMOTER DERIVED FROM UBIQUITIN EXTENSION PROTEIN (uep2) GENE

Constitutive promoters are essential component in genetic engineering. The promoters are usually derived from genes that are constitutively expressed or function as housekeeping genes. In this study, the ubiquitin extension protein (uep2) gene was identified as a constitutively expressed gene in oil palm. The 5’ region of the oil palm uep2 gene was isolated and the promoter truncation analysis was performed. The full length of uep2 (uep2a) and its truncation derivatives (uep2b and uep2c) were linked to β-glucuronidase (gus) reporter gene. The strength and the activity of the uep2 promoter were transiently evaluated in various oil palm tissues and tobacco leaves. Histochemical GUS analysis showed that the activity of truncated uep2b promoter was higher than the full length promoter and uep2c derivative in most tissues tested. Result also showed that uep2b was capable of directing the expression of GUS in all tissues with the high activity detected in oil palm embryoid, green leaves, and tobacco leaves. The full length of uep2 (uep2a) promoter also exhibited the ability to direct the expression of GUS in all tissues with the high activity detected in the plantlet stem. By contrast, although the uep2c showed high activity in young leaves and embryoid, a significant decrease of GUS expression was seen in green tissues. These results indicated that the region between position -1096 and -3237 is essential for constitutive transcriptional regulation as deletion of the region resulted in a significant decrease in the promoter activity. Though maize ubi1 and CaMV35S promoters showed a relatively higher activity than uep2, the uep2 has the ability to induce the constitutive GUS expression in all tissues tested. These results showed that 5’ flanking region of uep2 gene is active in oil palm and tobacco, suggesting that the promoter could be used as an alternative promoter for driving constitutive expression of transgenes in oil palm and other plants.

INFLUENCE OF SOIL COMPACTION ON OIL PALM YIELD

The threat of soil compaction is greater today because of the marked increase in the size and weight of machinery used in oil palm plantations. Concern has grown on their direct effects on soil physical properties and indirect effects on crop yield. Therefore, the objective of this study was to determine the influence of soil compaction on yield of oil palm planted on a clay-textured Bernam soil series (Typic Endoaquepts). Compaction treatments were imposed for six consecutive years with combination treatments of trailer weights and transportation frequencies. Although soil compaction was expected to reduce the oil palm yield, the results showed that an increase in soil bulk density (BD) and reduction in total porosity (TP) were beneficial to the oil palm. The fresh fruit bunch (FFB) yield, bunch number, and bunch weight were significantly increased by about 8%-11%, 7%-9%, and 2%-3% respectively, in the compacted plots as compared to control. The three rounds (3R) per month transportation frequency resulted in higher FFB yield and bunch numbers for all compaction treatments. Thus, compaction may not be a problem to oil palm planted on Bernam soil series, but further study needs to be carried out on other soil series.

PERFORMANCE AND EMISSION ANALYSIS OF DIESEL ENGINE USING THERMAL BARRIER COATING AND ADDITION OF CERIUM OXIDE NANOPARTICLES TO PALM BIODIESEL

This work investigates the effect of thermal barrier coating and addition of cerium oxide nanoparticles to the palm biodiesel fuelled diesel engine. The combustion chamber parts of cylinder liner and piston were coated 200 and 100 micron thickness respectively using equal percentages of Yittria Stabilised Zirconia (YSZ) and alumina powder in plasma spraying technique. The 30 ppm and 60 ppm of cerium oxide (IV) nanoparicles were added to the palm biodiesel fuel separately. The performance and pollution parameters were analysed initially using a thermal barrier coated (TBC) engine with neat palm biodiesel. Cerium oxide (IV) nanoparticles were then added to the palm biodiesel and their effects were compared with the base engine. The final performance results showed reduction in the specific fuel consumption on an average of 11.86%, 16.92% and 20.57%, while brake thermal efficiency was increased by 3.21%, 4.28% and 4.82% in neat palm biodiesel fuel, 30 ppm and 60 ppm CeO2 mixed palm biodiesel fuel used thermal barrier coated engine respectively. Carbon monoxide and unburned hydrocarbon emission were reduced by 2.2% and 3.7% and nitrogen oxide emission was increased by 1.7% for thermal barrier coated engine. However, the use of oxygen denoting catalyst of cerium oxide nanoparticles caused a 2.4% reduction in nitrogen oxide emission.

AN RFLP MARKER, CB75A, PREDICTS FOR PALMITIC ACID CONTENT ACROSS SELECTED OIL PALM GERMPLASM AND INTERSPECIFIC-HYBRIDS

Development of markers followed by construction of genetic linkage maps and quantitative trait locus (QTL) identification is a widely applied strategy towards marker assisted selection (MAS). In MPOB, researchers have reported that a restriction fragment length polymorphism (RFLP) marker, CB75A, generated from a OxG genetic linkage map showed significant correlation with QTL for iodine value (IV) and fatty acid composition (FAC) in oil palm. This indicated a potential use of the marker to assist breeding to develop genotypes with more liquid oil. The objective of this study is to validate the CB75A marker across various independent populations to gauge its utility for oil palm breeding. Palms were selected based on their palmitic acid composition, and classified as low, intermediate and high. Validation was carried out using RFLP technique on 18 Madagascar germplasm samples from Trial 0.240 at MPOB Kluang, 20 hybrids from Trial 0.236 at MPOB UKM and 60 backcross 1 (BC1) from Trial 0.336 at MPOB Kluang. Three bands were observed and assigned as A, B and C. The assay showed that the AA genotype is associated with low palmitic acid. In addition, significant segregation can only be observed in interspecific hybrid backcross samples. This inferred that although CB75A can predict FAC content to some extent, additional markers are required for a more precise prediction.

EFFECT OF FLOW RATE AND CONCENTRATION OF CARBAMIDE ON THE REDUCING NOx EMISSIONS IN PALM BIODIESEL FUELED RESEARCH ENGINE

This study examines the consequences of concentration and flow rate of carbamide (urea) to reduce NOx emissions from a diesel engine propelled with biodiesel. Taguchi-Grey relational-based multi-response optimisation method was employed for test-plan. Results revealed that carbamide flow rate and its concentration have a positive impact on NOx emissions reduction in unmodified diesel engine. The obtained results are also justified with results attained from ANOVA. It is also confirmed that the results obtained in the experimentations are in line with the calculated values obtained Taguchi technique. Hence, the usage of carbamide in tailpipe is an effective way in reducing NOx emissions from diesel engine.