Two frost-free household refrigerator-freezers, one with 492 liter capacity and one with 460 liter capacity were tested in the laboratory to determine the sensitivity of several variables those influence consumption refrigerator-freezers energy consumption greatly. The effects of single variables such as room temperature, thermostat setting positions, and door openings on the energy consumption were investigated. Using Response Surface Methodology (RSM), a mathematical model has been developed to investigate the combined effect of room temperature, thermostat setting positions, and door opening on the energy consumption of refrigerator-freezers. From the mathematical model, it has been observed that room-temperature has the highest effect on the energy consumption followed by the thermostat setting position. The door opening has lowest on the energy consumption. More detailed tests were performed under different room temperature, thermostat setting positions, and door opening conditions and presented in this paper.
Optimization of transesterification process for Ceiba pentandra oil: A comparative study between kernel-based extreme le...Published: 01 September 2017 by Elsevier BV in Energy
A comparative study of ultrasound and infrared transesteriﬁcation of Sterculia foetida oil for biodiesel productionPublished: 14 June 2017 by Informa UK Limited in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects
Optimization of extraction of lipid from Isochrysis galbana microalgae species for biodiesel synthesisPublished: 28 April 2017 by Informa UK Limited in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects
Microalgae are promising alternative plant sources for biodiesel production because of the signiﬁcant increase in lipid yield through heterotrophic cultivation and genetic engineering approaches. This study aims to evaluate the extraction and conversion of lipids from Isochrysis galbana. Response surface methodology (RSM) was used to optimize lipid extraction and thereby obtain high yields from the four microalgae species. The optimal lipid yields for Isochrysis galbana is 8.41 wt%. Moreover, the dominant lipid composition found from Isochrysis galbana extractions was palmitic acid (C16:0) at 22.3%. The high saturated acid of Isochrysis galbana contributed to the improved biodiesel properties because biodiesel quality is influenced by the lipid composition of microalgae species. The study employed the two-step esteriﬁcation–transesteriﬁcation process to convert the microalgae oil into biodiesel, glycerol, and water. The FAME content is 99.7% under the methanol to oil molar mass of 12:1, 1 wt%, 65°C, and 800 rpm. Furthermore, the main biodiesel properties, such as viscosity, higher heating value, and iodine value, were measured according to ASTM D6751 and EN 14124. Results show that microalgae oil can potentially be used as biofuel in future applications.
Synthesis and optimization of Hevea brasiliensis and Ricinus communis as feedstock for biodiesel production: A comparati...Published: 01 July 2016 by Elsevier BV in Industrial Crops and Products
Highlights•H. brasiliensis and R. communis are the potential feedstock for biodiesel.•The optimum yields of rubber and castor biodiesel are 99.32% and 99.07%.•The properties of biodiesel produced fulfilled ASTM D6751. AbstractBiodiesel from non-edible seeds has attracted the attention of the authors to investigate Hevea brasiliensis (HB) and Ricinus communis (RC) as potential feedstocks. Biodiesel production was carried out using esterification-neutralization-transesterification (ENT) process. The transesterification process was carried out under variation methanol to oil molar ratio, catalyst concentration, reaction temperature, reaction time and speed agitation. On top of that, optimization was evaluated using Response Surface Methodology (RSM) and a quadratic polynomial model for ENT method. The optimization results show that production biodiesel from HBME and RCME with ENT method were 99.32% and 99.07% respectively. All the properties measured for produced methyl ester met in ASTMD 6751. Moreover, the presence of ricinoleic (α-elaeostearic) in RCME can improve the cold point, pour point and cold filter plugging point, which resulted in −40.4 °C, −27.8 °C and −35.0 °C respectively. The results of the cold flow properties are better due to higher unsaturated fatty acid concentration. It is indicates that RCME has good performance during cold weather engine operation. It short, biodiesel production using ENT method can produce high methyl ester yield and good biodiesel properties. Graphical abstract
Pilot-scale production and the physicochemical properties of palm and Calophyllum inophyllum biodiesels and their blendsPublished: 01 July 2016 by Elsevier BV in Journal of Cleaner Production
Biodiesel production has grown rapidly in response to the escalating price of fossil fuels in the last 20 years. Biodiesels appear to be one of the solutions to fulfil the increasing energy demands of the transportation sector since it can be used as substitutes of diesel in diesel engines without the need to modify the engines. The aim of this study is to evaluate the properties of biodiesels produced from crude palm and Calophyllum inophyllum oils using a pilot plant. A 50 L stainless steel jacketed reactor pilot plant is built to convert crude palm oil into palm methyl ester using transesterification process whereas crude C. inophyllum oil is processed using acid-catalysed esterification followed by alkaline-catalysed transesterification. The properties of the palm and C. inophyllum methyl esters are characterized according to the American society for testing and materials (ASTM) D6751 and European standard (EN) 14214 standards. In a latter section of this study, the palm and C. inophyllum methyl esters are blended with diesel fuel using different volume ratios. The oxidation stability of these blends is evaluated for two storage conditions for 90 days: (1) vacuum chamber and (2) room temperature. The oxidation stability of these blends is maintained for more than 12 h for 90 days when the fuels are stored in the vacuum chamber, which fulfils the biodiesel standards. Based on the results, both crude palm and C. inophyllum oils are potential feedstocks for industrial-scale biodiesel production and the biodiesels can likely replace diesel fuel in the future.
Optimization of biodiesel production process for mixed Jatropha curcas–Ceiba pentandra biodiesel using response surface ...Published: 01 May 2016 by Elsevier BV in Energy Conversion and Management
Highlights•Jatropha curcas and Ceiba pentandra are potential feedstock for biodiesel.•Optimization of biodiesel production by response surface methodology.•Jatropha curcas–Ceiba pentandra mixed biodiesel yield was 93.33%.•The properties of mixed biodiesel fulfill ASTM D6751 standard. AbstractExploring and improvement of biodiesel production from non-edible vegetable oil is one of the effective ways to solve limited amount of traditional raw materials and their high prices. The main objective of this study is to optimize the biodiesel production process parameters (methanol-to-oil ratio, agitation speed and concentration of the potassium hydroxide catalyst) of a biodiesel derived from non-edible feedstocks, namely Jatropha curcas and Ceiba pentandra, using response surface methodology based on Box–Behnken experimental design. Based on the results, the optimum operating parameters for transesterification of the J50C50 oil mixture at 60 °C over a period of 2 h are as follows: methanol-to-oil ratio: 30%, agitation speed: 1300 rpm and catalyst concentration: 0.5 wt.%. These optimum operating parameters gives the highest yield for the J50C50 biodiesel with a value of 93.33%. The results show that there is a significant improvement in the physicochemical properties of the J50C50 biodiesel after optimization, whereby the kinematic viscosity at 40 °C, density at 15 °C, calorific value, acid value and oxidation stability is 3.950 mm2/s, 831.2 kg/m3, 40.929 MJ/kg, 0.025 mg KOH/g and 10.01 h, respectively. The physicochemical properties of the optimized J50C50 biodiesel fulfill the requirements given in the ASTM D6751 and EN14214 standards. Graphical abstract
ChemInform Abstract: A Perspective on Bioethanol Production from Biomass as Alternative Fuel for Spark Ignition EnginePublished: 10 March 2016 by Wiley in ChemInform
The increasing fuel consumption of fossil fuels has led to the development of alternative fuels for the future. The increasing consumption of fossil fuels has led to the development of alternative fuels for the future. Domestic biofuel production and the utilization of alternative fuels can decrease dependency on petroleum oil, reduce trade deficits, reduce air pollution and reduce carbon dioxide emission. Bioethanol is a renewable fuel produced by the fermentation of sugar which is derived from plants such as sugarcane or beet, maize, or cassava etc. However, bioethanol consumption in an engine is approximately 51% higher than gasoline since the energy per unit volume of ethanol is 34% lower than for gasoline. Bioethanol is an oxygenated fuel that contains 35% oxygen, which can reduce particulate matter and NO x emissions caused by combustion of the fuel. Therefore, bioethanol–gasoline blends can significantly reduce petroleum use and GHG emission. In addition, utilization of lignocellulosic materials in bioethanol production is the most viable pathway from an environmental point of view. This paper reviews the current status and technologies involved in bioethanol production and the properties and engine performance from various biomass feedstocks which are the recommended sustainable alternative fuel in the future.
Rice straw supply chain for electricity generation in Malaysia: Economical and environmental assessmentPublished: 01 December 2014 by Elsevier BV in Applied Energy
Engine performance and emissions using Jatropha curcas, Ceiba pentandra and Calophyllum inophyllum biodiesel in a CI die...Published: 01 May 2014 by Elsevier BV in Energy
Optimization of biodiesel production and engine performance from high free fatty acid Calophyllum inophyllum oil in CI d...Published: 01 May 2014 by Elsevier BV in Energy Conversion and Management
Biodiesel Conversion from High FFA Crude Jatropha Curcas, Calophyllum Inophyllum and Ceiba Pentandra OilPublished: 01 January 2014 by Elsevier BV in Energy Procedia
Experimental study on performance and exhaust emissions of a diesel engine fuelled with Ceiba pentandra biodiesel blendsPublished: 01 December 2013 by Elsevier BV in Energy Conversion and Management
Modeling and simulation to determine the potential energy savings by implementing cold thermal energy storage system in ...Published: 01 November 2013 by Elsevier BV in Energy Conversion and Management
Fuel Properties ofCroton megalocarpus,Calophyllum inophyllum, andCocos nucifera(coconut) Methyl Esters and their Perform...Published: 23 October 2013 by Wiley in Energy Technology
Biodiesel has been considered recently as a viable alternative to fossil diesel fuels. This study aims to evaluate the potential of biodiesel production from Croton megalocarpus oil and compared it with coconut (Cocos nucifera) and Calophyllum inophyllum methyl esters. The study presents the physical and chemical properties of Croton megalocarpus, Calophyllum inophyllum and coconut methyl esters (CMME, CIME, and COME) together with their 10 and 20 % blends by volume (B10 and B20). This is followed by evaluating their blends in a multicylinder Mitsubishi Pajero diesel engine. It has been found that the properties of all biodiesel and their blends are comparable with ASTM D6751 and ASTM D7467 standards, respectively. Over the entire range of speed, it was found that the B10 and B20 blends of CMME, CIME, and COME result in average reduction in torque and brake power (BP) along with increased brake‐specific fuel consumption (BSFC) compared to pure diesel fuel. With respect to engine emissions, the fuel blends resulted in an average reduction in carbon monoxide (CO) and hydrocarbon (HC) emissions. However, the CMME and COME blends resulted in increased emissions of nitrogen oxides (NO) whereas CIME emits lower NO compared to pure diesel. It is concluded that B10 and B20 biodiesel blends can be used as diesel fuel substitutes without additional modifications.
Production and comparative fuel properties of biodiesel from non-edible oils: Jatropha curcas, Sterculia foetida and Cei...Published: 01 September 2013 by Elsevier BV in Energy Conversion and Management
A comparative evaluation of physical and chemical properties of biodiesel synthesized from edible and non-edible oils an...Published: 01 September 2013 by Elsevier BV in Energy
Traditionally, biodiesel has been produced from edible oils due to their low free fatty acids. However, their use has elevated some issues such as food versus fuel and many other problems that have negatively affected their economic viability. Therefore, exploration of non-edible oils may significantly reduce the cost of biodiesel especially in poor countries which can barely afford the high cost of edible oils. This paper aims to produce biodiesel from several edible and non-edible oils that are readily available in the South East Asian market. These oils include; Jatropha curcas, Calophyllum inophyllum, Sterculia foetida, Moringa oleifera, Croton megalocarpus, Patchouli, Elaeis guineensis (palm), Cocos nucifera (coconut), Brassica napus (canola) and Glycine Max (soybean) oils. This was followed by an investigation of physico-chemical properties of the produced biodiesel. This paper also discusses the concept of biodiesel blending to improve some of the properties of these feedstocks. For instance, blending of SFME and CoME improves the viscosity of SFME from 6.3717 mm2/s to 5.3349 mm2/s (3:1), 4.4912 mm2/s (1:1) and 3.879 mm2/s (1:3). The properties of other biodiesel blends were estimated using the polynomial curve fitting method.
International experience on incentive program in support of fuel economy standards and labelling for motor vehicle: A co...Published: 01 September 2013 by Elsevier BV in Renewable and Sustainable Energy Reviews
A global comparative review of biodiesel production from jatropha curcas using different homogeneous acid and alkaline c...Published: 01 August 2013 by Elsevier BV in Renewable and Sustainable Energy Reviews
Investigation of physical and chemical properties of potential edible and non-edible feedstocks for biodiesel production...Published: 01 May 2013 by Elsevier BV in Renewable and Sustainable Energy Reviews
Non-edible vegetable oils: A critical evaluation of oil extraction, fatty acid compositions, biodiesel production, chara...Published: 01 February 2013 by Elsevier BV in Renewable and Sustainable Energy Reviews
Entropy generation analysis of nanofluid flow in a circular tube subjected to constant wall temperaturePublished: 01 October 2012 by Elsevier BV in International Communications in Heat and Mass Transfer
Due to their improved thermal conductivity, nanofluids have the potential to be used as heat transfer fluids in thermal systems. However adding particles into nanofluids will increase the viscosity of the fluid flow. This demonstrates that there is a trade-off between heat transfer enhancement and viscosity. It might not be ideal to achieve a heat transfer enhancement along with a relatively high pumping power. This study presents an analytical investigation on the entropy generation of a nanofluid flow through a circular tube with a constant wall temperature. Nanofluid thermo-physical properties are obtained from literature or calculated from suitable correlations. The present study focuses on water based alumina and titanium dioxide nanofluids. Outcome of the analysis shows that titanium dioxide nanofluids offer lower total dimensionless entropy generation compared to that of alumina nanofluids. Addition of 4% titanium dioxide nanoparticles reduces the total dimensionless entropy generation by 9.7% as compared to only 6.4% reduction observed when using alumina. It is also noted that dimension configurations of the circular tube play a significant role in determining the entropy generation.
Thermodynamic evaluation of utilizing different ice thermal energy storage systems for cooling application in office bui...Published: 01 October 2012 by Elsevier BV in Energy and Buildings
Storage can establish balance between production and demand consumption level in almost all the energy conversion systems. The same principle is valid for cooling applications, especially when the system is supposed to operate daily during the year. This is the condition that exists in tropical climate of Malaysia. The statistical data shows that almost one-fourth of the AC energy use in the country is due to office buildings. Therefore, utilizing the cold thermal energy storage (CTES) technique can significantly reduce the energy demand. In this study, a macroscopic thermodynamic analysis of the application of five different CTES systems for an office building in Malaysia is presented. The building energy usage is recorded and the average pattern is applied for chiller selection, storage tank sizing and finally energy and exergy evaluation. The results show that all the systems are highly efficient in terms of energy with the minimum of 93% for ice harvesting and maximum of 98% for encapsulated technique. However, the exergetic evaluation implies a totally different scenario of the study. The maximum exergy efficiency is for ice on coil (internal) technique with an amount of 18%. It was also found that increasing the room set-point temperature by 5 °C can reduce the exergy efficiency by 4%.
A review on fuel economy test procedure for automobiles: Implementation possibilities in Malaysia and lessons for other ...Published: 01 August 2012 by Elsevier BV in Renewable and Sustainable Energy Reviews
Performance and emission analysis of hydrogen fueled compression ignition engine with variable water injection timingPublished: 01 July 2012 by Elsevier BV in Energy
Energetic, economic and environmental benefits of utilizing the ice thermal storage systems for office building applicat...Published: 01 July 2012 by Elsevier BV in Energy and Buildings
As the fossil fuels are depleting day by day, there is a need to find out an alternative fuel to fulfill the energy demand of the world. Biodiesel is one of the best available resources that have come to the forefront recently. In this paper, a detailed review has been conducted to highlight different related aspects to biodiesel industry. These aspects include, biodiesel feedstocks, extraction and production methods, properties and qualities of biodiesel, problems and potential solutions of using vegetable oil, advantages and disadvantages of biodiesel, the economical viability and finally the future of biodiesel. The literature reviewed was selective and critical. Highly rated journals in scientific indexes were the preferred choice, although other non-indexed publications, such as Scientific Research and Essays or some internal reports from highly reputed organizations such as International Energy Agency (IEA), Energy Information Administration (EIA) and British Petroleum (BP) have also been cited. Based on the overview presented, it is clear that the search for beneficial biodiesel sources should focus on feedstocks that do not compete with food crops, do not lead to land-clearing and provide greenhouse-gas reductions. These feedstocks include non-edible oils such as Jatropha curcas and Calophyllum inophyllum, and more recently microalgae and genetically engineered plants such as poplar and switchgrass have emerged to be very promising feedstocks for biodiesel production. It has been found that feedstock alone represents more than 75% of the overall biodiesel production cost. Therefore, selecting the best feedstock is vital to ensure low production cost. It has also been found that the continuity in transesterification process is another choice to minimize the production cost. Biodiesel is currently not economically feasible, and more research and technological development are needed. Thus supporting policies are important to promote biodiesel research and make their prices competitive with other conventional sources of energy. Currently, biodiesel can be more effective if used as a complement to other energy sources.
History and current status of the motor vehicle energy labeling and its implementation possibilities in MalaysiaPublished: 01 May 2012 by Elsevier BV in Renewable and Sustainable Energy Reviews
The road transport and particularly the passenger cars are responsible for increasing the share of transport energy consumption and harmful emissions level growth. The fuel economy label is an informative tool to influence customers and manufacturers to put special care to the energy efficiency issue. The implementation of fuel economy label for motor vehicles in Malaysia will prevent the up going trend of petroleum consumption which will be beneficial to consumer and society. As a consequence, the harmful greenhouse gas (GHG) emissions that are the main causes of the global warming and air pollution will be reduced. Studies in developed countries show that implementing the fuel economy label is beneficial for society, government and the environment. This paper focused on a review of international experiences on fuel economy label. It also attempts to discuss about the energy savings possibilities that lead to reduce GHG emissions by implementing the program. The last but not least recommendation is the fact that the sooner the fuel economy label applies for the passenger cars in Malaysia will be more beneficial for the country.
In recent years, there has been a substantial increase in energy demand due to industrialization development. This raises concern on issues such as depletion of fossil based energy and emission of green house gasses. Hence, optimization of energy use through the thermosyphon air preheater is one of the possible approaches to address this problem. It can be used to recover and transmit the heat from the hot air (flue gas) to the cold air used for combustion process in a boiler. This study focuses on the analytical analysis of the thermal performance of a thermosyphon operated with water and nanofluids. The thermo physical properties of the selected nanofluids and relevant formulations are taken from the literatures to perform the analysis. Study found that change of nanofluid properties such as thermal conductivity only plays minor role in enhancing the thermal performance of the thermosyphon. The study implied that the hot air velocity is capable of increasing the efficiency of a thermosyphon. It is found that 23% overall heat transfer enhancement is observed when the hot air velocity increases from 2.0 m/s to 4.75 m/s for water based (7%) alumina and (4%) titanium dioxide nanofluids.
This study attempts to predict the potential cost savings of employing ice thermal storage (ITS) systems in the office buildings cooling application in Malaysia over the next 20 years. During the past decades, huge amount of daytime peak power has been shifted to the off-peak hours by using cool thermal energy storage (CTES) systems around the world. However, the contribution of CTES systems in Malaysia is still small in comparison with its potential. This study is conducted for three different scenarios of retrofitting 10%, 25% and 50% of the existing conventional AC systems with new ITS systems. The overall results show that the full storage strategy can reduce the annual costs of the air conditioning system up to 35 percent while this reduction is limited to around 8 percent for load leveling strategy.
This paper evaluated the life cycle analysis (LCA) of electricity derived from rice husk combustion in the Malaysia rice mills. Due to environment and security constraint cause by fossil fuel, biomass like rice husk becomes an attractive solution to look at. However, the environment profile of the electricity production from rice husk must be assessed to ensure it environment safety. The unit processes that make up the system are the paddy production, transportation to the rice mill, rice mill processing and combustion of rice husk to generate electricity. This study used functional unit as, 1.5MWh of electricity generating at the energy plant. The result show transportation contributes more to climate change compare to other process. Then, the characterized data from rice huskderived electricity is compared with coal and natural gas derived electricity. The results indicate the performance of rice husk derived-electricity is better in the aspect of environment impact parameters.
Energy is fundamental to the quality of life in the earth. Meeting the growing demand for energy sustainably is one of the major challenges of the 21st century. Indonesia is a developing country and the world's fourth most populous nation. Total annual energy consumption increased from 300,147 GWh in 1980, 625,500 GWh in 1990, 1,123,928 in 2000 and to 1,490,892 in 2009 at an average annual increase of 2.9%. Presently, fossil-fuel-based energies are the major sources of energy in Indonesia. During the last 12 years, Indonesia has recorded the most severe reduction in fossil fuel supplies in the entire Asia-Pacific region. This reduction has stimulated promoting the usage of renewable energy resources capable of simultaneously balancing economic and social development with environmental protection. Biodiesel is an alternative and environmentally friendly fuel that will participate in increasing renewable energy supply. Jatropha curcas is one of biodiesel resources that offer immediate and sustained greenhouse gas advantages over other biodiesel resources. Globally, J. curcas has created an interest for researchers because it is non-edible oil, does not create a food versus fuel conflict and can be used to produce biodiesel with same or better performance results when testing in diesel engines. The present study is concerned with the prospect of biodiesel produced from J. curcas in Indonesia. The first part gives a summary and overview of energy resources and consumption in the country, second part discusses the potential of biodiesel as a powerful renewable energy resource and third part investigates the potential of J. curcas as a feedstock for biodiesel in Indonesia. The final part discusses the development of biodiesel market in Indonesia. The paper found out that the production of biodiesel from J. curcas offers many social, economical and environmental benefits for the country and can play a great role to solve the problem of energy crisis in Indonesia.
As a result of the successful implementation of the industrialization plan in 1985; Malaysia has changed from an agricultural economy into industrial based economy. The industrial sector represents the highest consuming sector across all other sectors and accounts for about 48% of all total energy demand. This paper is concerned with an energy saving, economic and environmental analysis of industrial boilers in Malaysia when using variable speed drives (VSD). The results obtained when reducing the speed of water pumps by 60% show that 4 GWh, 93.6% of energy, RM 863,375 and 2,160 ton of CO2 could be saved annually. These results represent high energy saving, environmental and economic benefits associated with this energy saving technology. ABBREVIATIONS