Experimental Investigations of Oxidation Stability of Biodiesel Produced from Manketti Seeds Oil (Schinziophyton rautanenii)

This research article published by ACS Publications, 2011In this study, biodiesel from Manketti seeds oil (Schinziophyton rautanenii) was investigated to determine its suitability for use as a petrodiesel substitute. The fuel-related properties of Manketti oil methyl ester (MOME) were determined and compared to global biodiesel standards. Most of the determined fuel properties of MOME fulfilled the minimum requirements of ASTM D6751 and EN 14214 biodiesel standards. However, MOME did not meet EN 14214 oxidation stability requirements (6 h). The stability of biodiesel is very critical, and biodiesel requires antioxidants to meet storage requirements and to ensure fuel quality at all points along the distribution chain. This study evaluated the effectiveness of three antioxidants: 1,2,3-trihydroxybenzene (pyrogallol, PY), 3,4,5-trihydroxybenzoic acid (propyl gallate, PG), and 2-tert-butyl-4-methoxyphenol (butylated hydroxyanisole, BHA) on the oxidation stability of MOME. The result showed that the effectiveness of these antioxidants was in the order of PY > PG > BHA. Overall, the biodiesel derived from Manketti seeds oil can be used as partial substitute for mineral diesel

Comparison of synergistic effect of ethylene-propane and ethylene-DME on soot formation of ethylene-air flame

Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.In this study, the synergistic effects of ethylene-propane and ethylene-dimethyl ester (DME) mixtures on soot formation were investigated experimentally using a co-flow diffusion flame burner. The soot volume fraction, soot particle diameter, and number density were measured and compared to the homogenous mixture. Addition of DME and propane to the ethylene fuel increased soot volume fraction in the ethylene flames. The ethylene-propane has more pronounced synergistic effect in comparison to the ethylene–DME flames. This is due to the fact that during the decomposition of propane some methyl radicals are generated. The reactions related to these methyl radicals promote the formation of propargyl radicals consequently the formation of benzene through propargyl selfreaction and finally to the soot formation. Although DME decomposition produces methyl, C-O bond in the DME removes some carbon from the reaction path to form soot. Hence the soot formation in ethylene-DME mixture is much lower than that of ethylene-propane mixture.cs201

An experimental study of the dual-fuel performance of a small compression ignition diesel engine operating with three gaseous fuels

A dual-fuel engine is a compression ignition (CI) engine where the primary gaseous fuel source is premixed with air as it enters the combustion chamber. This homogenous mixture is ignited by a small quantity of diesel, the ‘pilot’, that is injected towards the end of the compression stroke. In the present study, a direct-injection CI engine, was fuelled with three different gaseous fuels: methane, propane, and butane. The engine performance at various gaseous concentrations was recorded at 1500 r/min and quarter, half, and three-quarters relative to full a load of 18.7 kW. In order to investigate the combustion performance, a novel three-zone heat release rate analysis was applied to the data. The resulting heat release rate data are used to aid understanding of the performance characteristics of the engine in dual-fuel mode. Data are presented for the heat release rates, effects of engine load and speed, brake specific energy consumption of the engine, and combustion phasing of the three different primary gaseous fuels. Methane permitted the maximum energy substitution, relative to diesel, and yielded the most significant reductions in CO2. However, propane also had significant reductions in CO2 but had an increased diffusional combustion stage which may lend itself to the modern high-speed direct-injection engine

Engine performance, exhaust emissions and combustion characteristics of a CI engine fuelled with croton megalocarpus methyl ester with antioxidant

This research article published by Elsevier Ltd., 2011The use of biodiesel as a substitute for petroleum-based diesel has become of great interest for the reasons of combating the destruction of the environment, the price of petroleum-based diesel and dependency on foreign energy sources. But for practical feasibility of biodiesel, antioxidants are added to increase the oxidation stability during long term storage. It is quite possible that these additives may affect the clean burning characteristics of biodiesel. This study investigated the experimental effects of antioxidants on the oxidation stability, engine performance, exhaust emissions and combustion characteristics of a four cylinder turbocharged direct injection (TDI) diesel engine fuelled with biodiesel from croton megalocarpus oil. The three synthetic antioxidants evaluated its effectiveness on oxidation stability of croton oil methyl ester (COME) were 1, 2, 3 tri-hydroxy benzene (Pyrogallol, PY), 3, 4, 5-tri hydroxy benzoic acid (Propyl Gallate, PG) and 2-tert butyl-4-methoxy phenol (Butylated Hydroxyanisole, BHA). The fuel sample tested in TDI diesel engine include pure croton biodiesel (B100), croton biodiesel dosed with 1000 ppm of an effective antioxidant (B100 + PY1000), B20 (20% croton biodiesel and 80% mineral diesel) and diesel fuel which was used as base fuel. The result showed that the effectiveness of the antioxidants was in the order of PY > PG > BHA. The brake specific fuel consumption (BSFC) of biodiesel fuel with antioxidants decreased more than that of biodiesel fuel without antioxidants, but both were higher than that of diesel. Antioxidants had few effects on the exhaust emissions of a diesel engine running on biodiesel. Combustion characteristics in diesel engine were not influenced by the addition of antioxidants in biodiesel fuel. This study recommends PY and PG to be used for safeguarding biodiesel fuel from the effects of autoxidation during storage. Overall, the biodiesel derived from croton megalocarpus oil can be utilized as partial substitute for mineral diesel

Evaluation of the Oxidation Stability of Biodiesel Produced from Moringa oleifera Oil

This research article published by ACS Publications, 2011Biodiesel is considered as an alternative fuel to petroleum-based conventional diesel fuel. Dependent upon the raw material, biodiesel can contain more or less unsaturated fatty acids in its composition, which are susceptible to oxidation reactions accelerated by exposure to oxygen and high temperatures. The present study evaluated the oxidative stability of biodiesel produced by methanolysis of Moringa oleifera oil, primarily available on the African continent. The evaluation was conducted by means of the Rancimat instrument, at a temperature of 110 °C, with an air flow of 10 L/h. Moringa oil methyl ester (MOME) displayed an oxidation stability of 5.05 h. Thus, MOME met the oxidative stability requirement in the American Society for Testing and Materials (ASTM) D6751 standard, which prescribes a minimum of 3 h, but did not meet the minimum requirement prescribed in the EN 14214 standard, which is 6 h. Also, this study evaluated the effectiveness of four antioxidants, 1,2,3-trihydroxybenzene [pyrogallol (PY)], 3,4,5-trihydroxybenzoic acid [propyl gallate (PG)], 2-tert-butyl-4-methoxyphenol [butylated hydroxyanisole (BHA)], and 2,6-di-tert-butyl-4-methylphenol [butylated hydroxytoluene (BHT)], on the oxidation stability of MOME. The result showed that the effectiveness of these antioxidants was in the order of PY > PG > BHA > BHT

Impact of antioxidant additives on the oxidation stability of biodiesel produced from Croton Megalocarpus oil

This research article published by Elsevier Ltd., 2011The increase in crude petroleum prices, limited resources of fossil fuels and environmental concerns have led to the search of alternative fuels, which promise a harmonious correlation with sustainable development, energy conservation, efficiency and environmental preservation. Biodiesel is well positioned to replace petroleum-based diesel. Biodiesel is a non-toxic, biodegradable and renewable biofuel. But the outstanding technical problem with biodiesel is that, it is more susceptible to oxidation owing to its exposure to oxygen present in the air and high temperature. This happens mainly due to the presence of varying numbers of double bonds in the free fatty acid molecules. This study evaluates oxidation stability of biodiesel produced from Croton megalocarpus oil. Thermal and Oxidation stability of Croton Oil Methyl Ester (COME) were determined by Rancimat and Thermogravimetry Analysis methods respectively. It was found that oxidation stability of COME did not meet the specifications of EN 14214 (6 h). This study also investigated the effectiveness of three antioxidants: 1,2,3 tri-hydroxy benzene (Pyrogallol, PY), 3,4,5-tri hydroxy benzoic acid (Propyl Gallate, PG) and 2-tert butyl-4-methoxy phenol (Butylated Hydroxyanisole, BHA) on oxidation stability of COME. The result showed that the effectiveness of these antioxidants was in the order of PY > PG > BHA

Alkaline catalyzed biodiesel production from moringa oleifera oil with optimized production parameters

The utilization of non-edible feedstock such as moringa oleifera for biodiesel production attracts much attention owing to the issue with regards to avoiding a threat to food supplies. In this study, the optimization of biodiesel production parameters for moringa oleifera oil was carried out. The free fatty acid value of moringa oil was found to be 0.6%, rendering the one step alkaline transesterification method for converting moringa fatty acids to their methyl esters possible. The optimum production parameters: catalyst amount, alcohol amount, temperature, agitation speed and reaction time were determined experimentally and found to be: 1.0 wt% catalyst amount, 30 wt% methanol amount, 60 °C reaction temperature, 400 rpm agitation rate and 60 min reaction time. With these optimal conditions the conversion efficiency was 82%. The properties of the moringa biodiesel that was produced were observed to fall within the recommended international biodiesel standards. However, moringa biodiesel showed high values of cloud and pour points of 10 °C and 3 °C respectively, which present a problem as regards use in cold temperatures.Biodiesel Moringa oleifera oil Transesterification Optimization

Experimental investigation on peculiarities of the filtration combustion of the gaseous fuel-air mixtures in the porous inertia media

This study investigates peculiarities of the filtration combustion (FC) of the gaseous fuel-air mixtures in a porous inertia media (PIM). Combustion wave velocities and temperatures were measured for hydrogen-air, propane-air and methane-air mixtures in the PIM at different mixture filtration velocities. It is shown that the dependences of the combustion wave velocities on the equivalence ratio are V-shaped, It was further confirmed that the FC in the PIM has more contrasts than similarities with the normal homogeneous combustion. One of the interesting observations in the present study, which is not common in normal homogenous combustion, is the shifting of the fuel-air equivalent ratio at the minimum combustion wave velocity from the stoichiometric condition (¢ = 1). For a hydrogen-air mixture, the fuel-air equivalence ratio at the minimum combustion velocity shifts from the stoichiometric condition to the rich region, while for the propane-air and methane-air mixtures the fuel-air equivalence ratio at the minimum combustion velocity shifts toward fuel-leaner conditions. The measured maximum porous media temperatures in the combustion waves are found to be weakly dependent on the mixture filtration velocities. In general, the effects of the mixture filtration velocities on the measured maximum porous media temperatures are not significant

Evaluation of Evaporative Emissions from Gasoline Powered Motor Vehicles under South African Conditions

IngenieursweseMeganiese & Megatroniese IngenieurswesePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]