Methyl esters selectivity of transesterification reaction with homogenous alkaline catalyst to produce biodiesel in batch, plug flow, and continuous stirred tank reactors

Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60 C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations

Methyl esters selectivity of transesterification reaction with homogenous alkaline catalyst to produce biodiesel in batch, plug flow, and continuous stirred tank reactors

Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60 C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations

Training needs assessment in Malaysia: Exercise held at Kuala Lampur and Kota Bharu from 13th October 1989

Training / Irrigation / Evaluation / Malaysia

Rice yield classification using backpropagation network

Among factors that affect rice yield are diseases, pests and weeds. It is intractable to model the correlation between plant diseases, pests and weeds on the amount of rice yield statistically and mathematically. In this study, a backpropagation network (BPN) is developed to classify rice yield based on the aforementioned factors in MUDA irrigation area Malaysia. The result of this study shows that BPN is able to classify the rice yield to a deviation of 0.03

CO2 removal using amine-functionalized kenaf in pressure swing adsorption system

An agro-based adsorbent from kenaf (Hibiscus cannabinus L.) for CO2 removal was prepared by functionalizing it with amine. Amine functionalization improves the adsorbates–adsorbent interaction through the presence of basic active sites on the adsorbent surfaces. Several amines (MEA, DEA, MDEA, AMP, PEI, DETA, TETA, TEPA, DIPA, PEHA, TEA, and DGA) have been selected for the amine-screening process. The result revealed that adsorption capacity of raw kenaf is only 0.624 mmol/g, whereas TEPA attained the highest CO2 capture capacity (0.914 mmol/g). Further study on the effect of amine loadings was conducted using two types of amine (MEA and TEPA) and it was found that the highest CO2 adsorption capacity for is 2.070 mmol/g for MEA to kenaf ratio of 1:1 and 2.086 mmol/g for TEPA to kenaf ratio of 2:1. The regeneration study also showed that kenaf sorbent can be used for repeated cycle operations. Due to the presence of amine on kenaf, the regeneration values of MEA–kenaf (82.15%) and TEPA–kenaf (75.62%) were lower than the raw kenaf (99.07%)

CO2 Reforming of CH4 over Ni/SBA-15: Influence of Ni Loading on the Metalsupport Interaction and Catalytic Activity

The influence of Ni loading on the properties of Ni/SBA-15 and CO2 reforming of CH4 were studied. XRD, BET and TGA results indicated that the increasing Ni loading (3–10 wt%) decreased the crystallinity, surface area and physically adsorbed water content of the catalysts. FTIR, TEM and H2-TPR analysis confirmed the formation of Ni–O–Si by the substitution of surface silanol groups with Ni species and the maximum substitution of surface silanol groups with Ni were achieved at 5 wt%, while further increased in Ni loading stimulate the agglomeration of Ni particles. The activity of catalysts followed the order of 5Ni/SBA-15 > 3Ni/SBA-15 ≈ 10Ni/SBA-15 > SBA-15, with the conversion of CH4 and CO2 over 5Ni/SBA-15 was about 89% and 88% respectively, and CO2/CH4 ratio of 1.02. The superior catalytic performance of 5Ni/SBA-15 towards CO2 reforming of CH4 probably was related with the formation of metal-support interaction, Ni–O–Si, which enhanced the stabilization of the active Ni species on SBA-15 support and altered the properties of catalyst towards an excellent catalytic performance. The analysis of spent catalysts found that the presence of Ni–O–Si minimizes the growth of encapsulating graphite carbon and thus enhanced the stability of catalyst. This study provides new perspectives on the Ni-based catalyst, particularly on the influence of Ni on the metal-support interaction and catalytic performance of Ni/SBA-15 towards CO2 reforming of CH4

Analysis of Pressure Effects for Current Density and Electric Field Performance of Gas Insulations

Gas insulation had been used widely in high voltage industry as a dielectric component. According to the arrangement of gas particles that far apart from each other, lead to the movement of gas particles react fast with high temperature and pressure. Hence when breakdown occurred in a system, it will quickly protect the system by diminished the sparks to avoid flashover occurred. The intention of this research is to determine relationship between current density and electric field of gas insulations that have been used in the insulator. HV experimental test has been conducted, to obtain breakdown voltage of air to use as applied voltage in the simulation for breakdown purpose of three insulation gasses, which are Sulphur Hexafluoride (SF6), Octafluoropropane (C3F8), and Nitrogen (N2). Physical properties such as thermal conductivity, electrical conductivity, and temperature of each gasses are require to identify value of current density and electric field of each insulation gasses. Furthermore, two pressure spots were placed symmetrically between two electrodes in the insulator. Based on simulation’s results, C3F8 is the best gas insulation because in normal condition and when presence of pressures it had lowest current density compared to SF6 and N2. Thus, C3F8 had the highest value of electric field among the insulation gasses. Electrical insulator is an internal electrical charger that cannot move freely and its contrast with semiconductors and conductors that can conduct electrical current easily. When the insulating material was used to avoid electrical discharges, it’s called insulation. High voltage insulation has been used widely in industry at electrical equipment such as switchgear and circuit breaker. The importance of applied high voltage in the electrical equipment is to prevent it from damage when faulty or breakdown occurs. From the results that have been obtained, the best gas insulation can be applied in the insulator as a protective component in electrical industry

Design of planar dielectric resonator antenna array at 28 GHz

This article presents a planar array of rectangular Dielectric Resonator Antenna operating for 28 GHz applications. The proposed antenna is formed through two stages of designs which are a single element and planar array. It is made up from a ceramic material with a dielectric constant of 10 and mounted on RT/Duroid 5880 with a relative permittivity of 2.2 and a thickness of 0.254 mm. A prospective study using three different configurations of three by three planar array is done in order to obtain the best performance in terms of bandwidth, gain, and cost reduction. Besides that, this study is also conducted for a beam steering capability of each configuration. Finally, the best configuration is proposed for 5G application

Kesan penggunaan koswer multimedia animasi visual terhadap pencapaian pelajar dalam mata pelajaran matematik

Ramai pelajar yang bermasalah dalam topik Pelan dan Dongakan. Ini kerana pelajar sukar untuk membayangkan objek yang tersembunyi melalui proses pengajaran dan pembelajaran (P&P) secara konvensional. Penyelidik telah membangunkan satu koswer multimedia animasi visual dalam topik Pelan dan Dongakan dengan menerapkan kesemua elemen-elemen yang dapat membantu meningkatkan kemahiran visual iaitu elemen animasi, video, audio, grafik dan teks. Seterusnya, kajian kuasi eksperimental ini turut dijalankan bertujuan untuk mengetahui kesan penggunaan koswer multimedia animasi visual terhadap pencapaian pelajar bagi mata pelajaran Matematik di sekolah menengah. Ujian Pra dan Ujian Pos digunakan untuk melihat perbezaan pencapaian yang signifikan selepas menggunakan koswer multimedia animasi visual yang menggunakan teori Kognitif Visual Wiley. Responden yang terlibat dalam kajian ini ialah seramai 40 orang pelajar Tingkatan Lima yang dibahagikan kepada dua kumpulan iaitu kumpulan rawatan dan kumpulan kawalan yang dipilih daripada sebuah sekolah di daerah Batu Pahat, Johor. Hasil analisis menunjukkan peningkatan skor min markah bagi pelajar kumpulan rawatan. Hasil analisis ujian-t (paired-sample-t-test) membuktikan bahawa wujudnya perbezaan skor min markah yang signifikan di antara markah ujian pra dan markah ujian pos bagi kumpulan rawatan. Oleh itu, terdapat perbezaan yang signifikan di antara skor min markah ujian pra dan ujian pos bagi pelajar kumpulan rawatan selepas menggunakan koswer multimedia animasi visual. Manakala instrumen soal selidik yang digunakan untuk melihat tahap penerimaan pelajar selepas menggunakan koswer multimedia animasi visual berdasarkan tiga aspek iaitu aspek isi kandungan, aspek interaksi dan aspek persembahan telah memeperolehi skor min yang tinggi bagi ketiga-tiga aspek tersebut. Dapatan kajian ini menggambarkan penggunaan koswer multimedia animasi visual dapat membantu meningkatkan pencapaian Matematik di dalam bilik darjah terutama yang tidak melibatkan pengiraan

Hydrogen adsorption capacity using modified nickel-kenaf core at different concentrations

In this study, surface chemistry modification of kenaf adsorbent in adsorptive hydrogen storage system was computationally investigated using Brunauer-Emmett-Teller (BET) surface area, thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), and elemental dispersion X-ray (EDX) analysis, in which the suitability of the adsorbent was determined with detailed physicochemical characterisation analysis. The method used for surface modification was metal deposition method using Ni(NO3)2 with various concentrations at different levels of pressure (up to 6 bars). Based on this research, modified kenaf with 0.4 M Ni(NO3)2 and 2.559 m2 g-1 adsorbed up to 1.013 mmol g-1 of hydrogen compared to the raw kenaf with only 0.396 mmol g-1 of hydrogen adsorbed in 5 h. Two consecutive cycles of adsorption were carried out to show the delivery performance of hydrogen adsorptive storage. Thus, different adsorption ability between the modified kenaf and raw kenaf shows that Ni-metal on kenaf surface assists in hydrogen adsorption process