A Mini Review on the Cold Flow Properties of Biodiesel and its Blends

© Copyright © 2020 Hazrat, Rasul, Mofijur, Djavanroodi, Khan, Azad, Bhuiya and Silitonga. Biodiesels are renewable fuel that may be produced from various feedstock using different techniques. It is endorsed in some countries of the world as a viable substitute to diesel fuel. While biodiesel possesses numerous benefits, the cold flow properties (CFP) of biodiesel in comparison with petro-diesel are significantly less satisfactory. This is due to the presence of saturated and unsaturated fatty acid esters. The poor CFP of biodiesel subsequently affects performance in cold weather and damages the engine fuel system, as well as chokes the fuel filter, fuel inlet lines, and injector nozzle. Previously, attempts were made to minimize the damaging impact of bad cold flow through the reduction of pour point, cloud point, and the cold filter plugging point of biodiesel. This study is focused on the biodiesel CFP-related mechanisms and highlights the factors that initialize and pace the crystallization process. This review indicates that the CFP of biodiesel fuel can be improved by utilizing different techniques. Winterisation of some biodiesel has been shown to improve CFP significantly. Additives such as polymethyl acrylate improved CFP by 3-9 ° C. However, it is recommended that improvement methods in terms of fuel properties and efficiency should be carefully studied and tested before being implemented in industrial applications as this might impact biodiesel yield, cetane number, etc

Recent development of biodiesel combustion strategies and modelling for compression ignition engines

The combustion phenomena of biodiesel and its blends are not the same as fossil diesel combustion in compression ignition (CI) engines due to their different physio-chemical fuel properties. The combustion of biodiesels is just like the combustion of fossil diesel which emits toxic gases such as nitric oxides (NOx) and particulate matter (PM), CO, HC etc. The paper has been critically reviewed the recently developed combustion strategies for biodiesel combustion in CI engine. Low temperature combustion (LTC) is one of the recently developed strategies that have three different categories, namely homogeneous charge, premixed charge and reactive controlled compression ignition which have been briefly discussed here. The study identified that LTC strategy can significantly reduce PM and NOx emission by combustion of biodiesel. However, CO and HC emission increases due to higher rate of exhaust gas recirculation (EGR). It also identified that CI engine produces lower break thermal efficiency and higher break specific fuel consumption (BSFC) under LTC combustion strategies. A good predictive combustion model can help to address all these drawbacks in LTC strategy. The study concluded that a hybrid k-ε and k-ω turbulent model namely, shear-stress transport (SST) k-ω turbulence combustion model can help to predict more efficient combustion of biodiesel in CI engines under LTC strategy. These combinations are capable of improving engine efficiency by limiting harmful emissions of biodiesel combustion in CI engine

Prospects, feedstocks and challenges of biodiesel production from beauty leaf oil and castor oil: A nonedible oil sources in Australia

This study critically reviewed the prospects, feedstocks and challenges of biodiesel production from two non-edible oil sources, namely Beauty leaf oil (BLT) (Calophyllum inophyllum) and Castor oil (Ricinus communis). The recent developments and the lifecycle assessment (LCA) of these species such as their habitat, growth, oil content, free fatty acid profile and biodiesel characteristics are briefly discussed. Different oil extraction techniques and biodiesel conversion methods are also presented. The properties of the pure biodiesel and their blends are compared with petroleum diesel under different ASTM and European standards. Furthermore, the literatures on engine performance and emission studies using these biodiesels are reviewed and presented in tabular form. The review found that BLT oil can be catalytically transesterified to produce biodiesel as a potential alternative transport fuel in Australia. The review concludes that castor oil is not only an alternate fuel resource, but it also holds good lubricating properties and hence is a potential bio-lubricant source for internal combustion engines. Further research is needed on combustion, corrosion, tribo-corrosion, long term engine durability tests and tribological performance tests before recommending commercial scale biodiesel production from BLT oil and Castor oil

A review on socio-economic aspects of sustainable biofuels

Copyright © 2016 Inderscience Enterprises Ltd.Biofuels are renewable eco-fuel, produced from biological resources. They are classified into 1st, 2nd and 3rd generations based on their feedstocks. The 2nd and 3rd generation biofuels are called advanced and sustainable biofuel. The study reviewed and discussed about socio-economic aspects of the sustainable biofuel in Australia because economy is seen to be a key driver for use of biofuels. Recent researches focused on sustainable biofuel production, their commercialisation worldwide. The world biofuel scenario is presented in this study which shows that total biofuel production is progressively moving towards advanced biofuels. Australian total biofuel production, consumption and available present production facilities are also outlined. The study briefly discussed about Australian energy economy such as energy export, import and trades etc. The study concluded that the 2nd generation biofuel can be considered as sustainable alternatives to petroleum fuel in transport sector providing great economic and environmental benefits to Australia

Prospects of 2nd generation biodiesel as a sustainable fuel - Part 2: Properties, performance and emission characteristics

Increased global warming and declining fossil fuel reserves have stimulated the researchers to look for new sources of fuel, which should be renewable, locally available and environmentally benign. Biodiesel has been receiving increasing attention because of the relevance it gains from the rising petroleum price and its environmental advantages. This paper reviews and highlights several aspects of non-edible oils which are termed as 2nd generation biodiesel, such as the biodiesel's physico-chemical properties, and its effect on engine performances and emissions. In addition, the effect of biodiesel on engine power, fuel economy and emissions including regulated and non-regulated, and the corresponding effect factors are surveyed and analysed in detail. It is found from the review that the biodiesel fuel properties vary depending on the sources of feedstocks which have considerable impact on engine performances and emissions characteristics. The use of biodiesel leads to the substantial reduction in key pollutants namely particulate matter (PM), hydrocarbon (HC), and carbon monoxide (CO) emissions accompanying with the imperceptible power loss, slight increase in fuel consumption and slight increase in NOx emission on conventional diesel engines with no or fewer modification. This review introduces a potential guideline on further research for improving engine performance and emission characteristics using different 2nd generation biodiesels and their blends. The study provides a comparative baseline to make an easy comparison among the biodiesels in respect of fuel properties, engine performance and emission features. © 2015 Elsevier Ltd

A review on socio-economic aspects of sustainable Biofuels

Biofuels are renewable eco-fuel, produced from biological resources. They are classified into 1st, 2nd and 3rd generations based on their feedstocks. The 2nd and 3rd generation biofuels are called advanced and sustainable biofuel. The study reviewed and discussed about socio-economic aspects of the sustainable biofuel in Australia because economy is seen to be a key driver for use of biofuels. Recent researches focused on sustainable biofuel production, their commercialisation worldwide. The world biofuel scenario is presented in this study which shows that total biofuel production is progressively moving towards advanced biofuels. Australian total biofuel production, consumption and available present production facilities are also outlined. The study briefly discussed about Australian energy economy such as energy export, import and trades etc. The study concluded that the 2nd generation biofuel can be considered as sustainable alternatives to petroleum fuel in transport sector providing great economic and environmental benefits to Australia

Heat transfer augmentation in a circular tube with perforated double counter twisted tape inserts

© 2016 Elsevier Ltd.The present study explored the effects of perforated double counter twisted tapes on heat transfer and fluid friction characteristics in a heat exchanger tube. The twisted tapes with four different porosities of Rp = 1.2, 4.6, 10.4 and 18.6% were used as counter-swirl flow generators in the test section. The experiments were conducted in a circular tube in turbulent flow regime with Reynolds number ranging from 7200 to 50,000 using air as the working fluid under uniform wall heat flux boundary condition. The experimental results demonstrated that the Nusselt number, friction factor and thermal enhancement efficiency were increased with decreasing porosity except porosity of 1.2%. The results also revealed that the heat transfer rate of the tube fitted with tapes were significantly increased with corresponding increase in friction factor. In the range of the present investigation, heat transfer rate and friction factor were obtained to be around 80 to 290% and 111 to 335% higher than those of the plain tube values, respectively. Based on constant blower power, the highest thermal enhancement efficiency of 1.44 was achieved. In addition, the empirical correlations of Nusselt number, friction factor and thermal enhancement efficiency were developed based on the experimental data

Comparison of oil extraction between screw press and solvent (n-hexane) extraction technique from beauty leaf (Calophyllum inophyllum L.) feedstock

© 2019 Elsevier B.V. An experimental investigation was conducted to evaluate the effects of the processing of the raw materials, such as preparation and extraction, grating (whole and grated), drying and moisture conditioning of the seed kernels on the yield of oil extraction. Both mechanical and chemical methods were used to extract oil from the beauty leaf (BL) seed kernel using a screw press expeller and n-hexane as an oil solvent, respectively. Both whole kernel (WK) and grated kernel (GK) were used in screw press technique, whereas, only GK was used in n-hexane technique. The study indicated that the kernels prepared for 14.4 % moisture content (MC) produced the highest yield of oil in both methods. The highest oil yield of 86.4 % was obtained on the basis of the weight of the kernel in n-hexane method for the GK. On the other hand, the oil yield of 78.0 and 72.1 % was achieved using a screw press technique for the GK and WK, respectively. The gas chromatography (GC) analysis was conducted to determine the fatty acid compositions of beauty leaf oil. The physico-chemical properties of the beauty leaf oil (BLO) were evaluated. A comparison of fossil energy ratio (FER) was made between n-hexane and screw press methods. The FER in-hexane method was found 4.9, whereas, in screw press method it was found 3.4 and 3.1 for the GK and WK, respectively, which indicates that n-hexane method is more efficient than screw press technique. This study provides an understanding of the basis of selecting an appropriate oil extraction technique for oil extraction users in large scale applications

An experimental investigation into biodiesel stability by means of oxidation and property determination

This paper presents the experimental results carried out to evaluate the oxidation and storage stabilities of various biodiesel fuels. The biodiesel fuels are palm methyl ester (PME), jatropha methyl ester (JME), coconut oil methyl ester (COME), 20% blends of PME with diesel fuel and 20% blends of JME with diesel fuel. The ordinary diesel fuel was used for comparison purposes. Various ASTM standard methods were used to evaluate all the samples at the interval of 180 h over a 2160 h (three months) duration. Oxidation stability of the samples was measured by induction period (IP) using a Rancimat instrument. Other properties such as density, viscosity, flash point, total acid number (TAN), and total base number (TBN) were measured. The results show that almost all fuel samples met the standard specifications regarding IP. The trends for density, viscosity and TAN increased, while the TBN decreased due to oxidation. For the flash point, the trend also decreased, but the rate was very low. In overall consideration, among the biodiesels, COME was found to be better in respect to oxidation and storage stabilities. The results of this investigation will be used to sustainable development of biodiesel fuel from various stock resources.Associated Grant:The authors would like to thank Department of Mechanical engineering, University of Malaya, Ministry of Higher Education (MOHE) of Malaysia for HIR Grant No. UM.C/HIR/MOHE/ENG/07 and UMR Grant No: RG040-09AET for their financial support which made this study possible