Process system engineering in biodiesel production: a review

Biodiesel is fast becoming a popular alternative to fossil fuels, as it is natural, renewable and has low toxic emissions. Strategies that have been adopted to ensure continued growth of the biodiesel industry are policy development, reduction of biodiesel tax, offset funding for incremental fuel cost from CO2 emission fuel and support for research and development of potential biodiesel feedstocks. Recent innovations of biodiesel processes are focused on the development of more efficient catalysts and in the utilization of novel reaction media such as supercritical fluids as well as on a variety of oil feedstocks such as virgin and waste oils. Biodiesel production involves complex processes which require systematic process design and optimization. The main aim of designing biodiesel plants is to maxime conversion of ethyl or methyl esters at the lowest capital cost of the plant. The design should also consider safety and environmental concerns. Process system engineering (PSE) is a systematic approach to design and analyze complex processes by using a variety of PSE tools for the optimization of biodiesel production. This paper reviews the latest PSE tools used in development of novel biodiesel processes. It describes the main PSE elements such as process model development and product design, simulation of biodiesel processes, optimization of biodiesel synthesis, and integration of reactor and separation systems. This review also highlights the sustainability of biodiesel production

Process system engineering in biodiesel production: a review

Biodiesel is fast becoming a popular alternative to fossil fuels, as it is natural, renewable and has low toxic emissions. Strategies that have been adopted to ensure continued growth of the biodiesel industry are policy development, reduction of biodiesel tax, offset funding for incremental fuel cost from CO2 emission fuel and support for research and development of potential biodiesel feedstocks. Recent innovations of biodiesel processes are focused on the development of more efficient catalysts and in the utilization of novel reaction media such as supercritical fluids as well as on a variety of oil feedstocks such as virgin and waste oils. Biodiesel production involves complex processes which require systematic process design and optimization. The main aim of designing biodiesel plants is to maxime conversion of ethyl or methyl esters at the lowest capital cost of the plant. The design should also consider safety and environmental concerns. Process system engineering (PSE) is a systematic approach to design and analyze complex processes by using a variety of PSE tools for the optimization of biodiesel production. This paper reviews the latest PSE tools used in development of novel biodiesel processes. It describes the main PSE elements such as process model development and product design, simulation of biodiesel processes, optimization of biodiesel synthesis, and integration of reactor and separation systems. This review also highlights the sustainability of biodiesel production

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

Effect of repeated heating on thermal behavior of crude palm oil

Thermal behavior of crude palm oil (CPO) is important to determine the optimal fractionation process and product yield. In this study, the effects of repeated heating on thermal behavior of CPO were examined by differential scanning calorimetry. CPO was heated at 80°C for 5 min, and heating was repeated five times to simulate the common conditions experienced by an oil before reaching the refinery. The result revealed that the thermal behavior of CPO changed after heating. The change, however, occurred only in the behavior of the high-melting stearin peak but not in the low-melting olein peak. Overheating split the stearin peak at 17.30°C to two peaks at 18.88 and 17.30°C and formed a new peak at 11.28°C. Apparently, a new substance has been synthesized

Structural, electronic and optical studies of Sr<inf>2</inf>NiTeO<inf>6</inf> double perovskite by first-principle DFT–LDA + U calculation

The structural, electronic and optical properties of monoclinic Sr2NiTeO6 double perovskite have been studied using corrected density functional theory–local density approximation with applying of Hubbard U corrected energy (DFT–LDA + U) method in plane-wave pseudopotential basis. The influence of on-site Coulomb interaction on structural, electronic and optical properties of Sr2NiTeO6 double perovskite compound, which consists of strongly localized Ni 3d electrons, were investigated. The highly Coulomb repulsion between electrons was corrected using Hubbard U parameter, varying from 0 to 8 eV for Ni 3d orbitals. The calculated results demonstrated that Sr2NiTeO6 double perovskite was sensitive to the change in U values. The optimized structural properties give a good agreement with experiment and other calculation data with lattice parameters a = 5.673 Å, b = 5.565 Å, c = 7.847 Å, α = 89.999°, β = 90.257° and γ = 90.000°. The DFT–LDA + U predicted the calculated electronic band structure of Sr2NiTeO6 was showed metallic behaviour (0 and 2 eV) and insulator behaviour (4, 6 and 8 eV). The density of state (DOS) shows that there was a significant effect on hybridization of Ni 3d and O 2p states at the conduction and valence band, respectively. Moreover, the results of optical studies such as dielectric function, absorption and reflectivity were found significant to the variation of U values applied indicates that the U values give a better description on the electronic localization of Ni 3d states

Harmonic reduction of a single-phase multilevel inverter using genetic algorithm and particle swarm optimization

Inverter play important role in power system especially with it capability on reducing system size and increase efficient. Recent research trend of power electronics system are focusing on multilevel inverter topic in optimization on voltage output, reduce total harmonics distortion, modulation technique and switching configuration. Standalone application multilevel inverter is high focused due to the rise of renewable energy policy all around the world. Hence, this research emphasis on identify best topology of multilevel inverter and optimize it among the diode-clamped, capacitor clamped and cascaded H-bridge multilevel inverter to be used for standalone application in term of total harmonics distortion and voltage boosting capability. The first part of research that is identify best topology multilevel inverter is applying sinusoidal pulse width modulation technique. The result shown cascade H-bridge give the best output in both total harmonics distortion (9.27%) and fundamental component voltage (240 Vrms). The research proceed with optimization with fundamental switching frequency method that is optimized harmonic stepped waveform modulation method. The selective harmonics elimination calculation have adapt with genetic algorithm and particle swarm optimization in order to speed up the calculation. Both bio-inspired algorithm is compared in term of total harmonic distortion and selected harmonics elimination for both equal and unequal sources. In overall result shown both algorithm have high accuracy in solving the non-linear equation. However, genetic algorithm shown better output quality in term of selected harmonics elimination where overall no exceeding 0.4%. Particle swarm optimization shows strength in finding best total harmonics distortion where in 7-level cascaded H-bridge multilevel inverter (m=0.8) show 6.8% only as compared to genetic algorithm. Simulation for 3-level, 5-level and 7-level for each multilevel inverter at different circumferences had been done in this research. The result draw out a conclusion where the possibility of having a filterless high efficient invert can be achieve

Gunung Tahan Trail: a historical review

There are still a lot of information on the history of Gunung Tahan Trail which remain unknown to the Malaysian public; some were buried with the demise of the elderly living around this mountain. This paper attempts to reveal the history of this famous trail which is located in Taman Negara in relation to the origin of its name, local belief and folklore of the mountain, colonial proposal for the establishment of grand hill station and early attempts to explore the mountain. Most of the data and information for this review were gathered from field notes and expedition reports published in various journals between 1880 and 1940. These information would be useful to Taman Negara Park Management in enriching recreational and nature tourism experiences among users of Gunung Tahan Trail

Novel Anode Catalyst for Direct Methanol Fuel Cells

PtRu catalyst is a promising anodic catalyst for direct methanol fuel cells (DMFCs) but the slow reaction kinetics reduce the performance of DMFCs. Therefore, this study attempts to improve the performance of PtRu catalysts by adding nickel (Ni) and iron (Fe). Multiwalled carbon nanotubes (MWCNTs) are used to increase the active area of the catalyst and to improve the catalyst performance. Electrochemical analysis techniques, such as energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS), are used to characterize the kinetic parameters of the hybrid catalyst. Cyclic voltammetry (CV) is used to investigate the effects of adding Fe and Ni to the catalyst on the reaction kinetics. Additionally, chronoamperometry (CA) tests were conducted to study the long-term performance of the catalyst for catalyzing the methanol oxidation reaction (MOR). The binding energies of the reactants and products are compared to determine the kinetics and potential surface energy for methanol oxidation. The FESEM analysis results indicate that well-dispersed nanoscale (2–5 nm) PtRu particles are formed on the MWCNTs. Finally, PtRuFeNi/MWCNT improves the reaction kinetics of anode catalysts for DMFCs and obtains a mass current of 31 A g−1 catalyst

Evaluation On Compression Properties Of Different Shape And Perforated rHDPE In Concrete Structures

The purpose of this study was to develop a concrete structure by incorporating waste HDPE plastic as the main reinforcement material and cement as the matrix via standard casting technique. There are eight different shapes of rHDPE reinforcing structure were used to investigate the compression properties of produced concrete composites. Experimental result shown that the highest shape in compressive strength of rHDPE reinforcing structure were the concrete with the addition of X-perforated beam (18.22 MPa), followed by X-beam (17.7 MPa), square perforated tube (17.54 MPa), round tube (17.42 MPa) and round perforated tube (16.69 MPa). In terms of their compressive behavior, the average concrete containing rHDPE reinforcement was successfully improved by 6 % of the mechanical characteristic compared to control concrete. It is shown that the addition of waste plastic as reinforcement structure can provide better compressive strength based on their shape and pattern respectively