The present work studies and identifies the different variables that affect the output parameters involved in a single cylinder direct injection compression ignition (CI) engine using jatropha biodiesel. Response su...The present work studies and identifies the different variables that affect the output parameters involved in a single cylinder direct injection compression ignition (CI) engine using jatropha biodiesel. Response surface methodology based on Central composite design (CCD) is used to design the experiments. Mathematical models are developed for combustion parameters (Brake specific fuel consumption (BSFC) and peak cylinder pressure (Pmax)), performance parameter brake thermal efficiency (BTE) and emission parameters (CO, NOx, unburnt HC and smoke) using regression techniques. These regression equations are further utilized for simultaneous optimization of combustion (BSFC, Pmax), performance (BTE) and emission (CO, NOx, HC, smoke) parameters. As the objective is to maximize BTE and minimize BSFC, Pmax, CO, NOx, HC, smoke, a multi- objective optimization problem is formulated. Non- dominated sorting genetic algorithm-II is used in predict- ing the Pareto optimal sets of solution. Experiments are performed at suitable optimal solutions for predicting the combustion, performance and emission parameters to check the adequacy of the proposed model. The Pareto optimal sets of solution can be used as guidelines for the end users to select optimal combination of engine outputand emission parameters depending upon their own requirements.展开更多
Cetane number(CN)-a prime indicator of diesel fuel quality,is a quantity indicating the combustion behaviour of diesel fuel and compression required for ignition in diesel engines.This study examines the determination...Cetane number(CN)-a prime indicator of diesel fuel quality,is a quantity indicating the combustion behaviour of diesel fuel and compression required for ignition in diesel engines.This study examines the determination of CN of Jatropha biodiesel blends with mineral diesel using their physical properties,and their variations of CN with percentage composition of Jatropha biodiesel in the blends.Jatropha biodiesel,converted through a transesterification process of its oil,is obtained and blended with diesel to obtain blend B10(10%biodiesel and 90%diesel)on a volumetric basis,at 25℃ ambient temperature and the same basis was employed for blends B20,B30,B40 and B50.The specific gravity and mid-distillation characteristic were obtained using a hydrometer and distillation curve apparatus based on ASTM D1298 and D86 standards respectively.The CN of Jatropha oil,its biodiesel and Jatropha biodiesel blends with diesel were analytically determined,employing the empirical relationship between measured physical properties of a two-variable cetane index equation.The results show that the CN of the Jatropha biodiesel increases significantly(about 29%)after transesterification compared with that of the Jatropha oil.Moreover,the specific gravity and CN of the blends increase with the percentage composition of Jatropha biodiesel in the blends.The CN of Jatropha biodiesel is 44.10,which is 8.7%higher than that of mineral diesel(40.62).It can be implied from the research outcomes that blending Jatropha biodiesel with diesel increases the CN of the blends,thus,could be used as cetane point(number)enhancer.展开更多
Oil was extracted from seeds of Jatropha Curcas,in high yields(up to 40% by weight).The extracted Jatropha oil was converted in a laboratory reactor to biodiesel by transesterification.Analysis of Jatropha oil and Jat...Oil was extracted from seeds of Jatropha Curcas,in high yields(up to 40% by weight).The extracted Jatropha oil was converted in a laboratory reactor to biodiesel by transesterification.Analysis of Jatropha oil and Jatropha biodiesel by GC/MS and GC/SIMDIS showed that Jatropha oil could be readily converted to a biodiesel product through NaOH catalyzed transesterification.The resulting biodiesel has desirable properties such as high cetane number and low flash point,which are major improvements over the properties of commercial biodiesel fuels.展开更多
The non-edible oils are believed to be one of the major feedstock for the production of biodiesel in future.In the present study,we investigated the production of Jatropha oil methyl esters(JOMEs) via alkali-catalyz...The non-edible oils are believed to be one of the major feedstock for the production of biodiesel in future.In the present study,we investigated the production of Jatropha oil methyl esters(JOMEs) via alkali-catalyzed transesterification route.The biophysical characteristics of Jatropha oil were found within the optimal range in accordance with ASTM standards as a substitute diesel fuel.The chemical composition and production yield of as-synthesized biodiesel were confirmed by various analytical techniques such as FT-IR,1H NMR,13 C NMR and gas chromatography coupled with mass spectrometry.A high percentage conversion,~96.09%,of fatty acids into esters was achieved under optimized transesterification conditions with 6 :1 oil to methanol ratio and 0.9 wt% Na OH for 50 min at ~60°C.Moreover,twelve fatty acids methyl esters(FAME) were quantified in the GC/MS analysis and it was interesting to note that the mass fragmentation pattern of saturated,monounsaturated and diunsaturated FAME was comparable with the literature reported values.展开更多
An environmentally benign process was devel-oped for the transesterification of Jatropha curcas L. seed oil with methanol using artificial zeolites loaded with potassium acetate as a heterogeneous catalyst. After calc...An environmentally benign process was devel-oped for the transesterification of Jatropha curcas L. seed oil with methanol using artificial zeolites loaded with potassium acetate as a heterogeneous catalyst. After calcination for 5 h at 823 K, the catalyst loaded with 47 wt.% CH3COOK exhibited the highest efficiency and best catalytic activity. The easily prepared cata-lysts were characterized by means of X-ray dif-fraction and IR spectroscopy, as well as Hammett indicator titration. The results revealed a strong dependence of catalytic activity on ba-sicity. The optimum reaction conditions for transesterification of J. curcas oil were also in-vestigated. The methyl ester content in the bio-diesel product exceeded 91% after 4h reaction at reflux temperature in the presence of 2% solid catalyst and no water washing process is needed during workup.展开更多
Ethyl ester biodiesel has been produced from a non-edible Jatropha curcas oil. Oil was extracted from the plant seed using n-hexane at 60°C and pretreated by alkaline refining process to reduce the free fatty aci...Ethyl ester biodiesel has been produced from a non-edible Jatropha curcas oil. Oil was extracted from the plant seed using n-hexane at 60°C and pretreated by alkaline refining process to reduce the free fatty acid level to less than 1%. Base-catalysed transesterification reaction with absolute ethanol using potassium hydroxide catalyst was adopted for the conversion. Various physicochemical properties of the refined Jatropha curcas oil were investigated. The ethyl ester biodiesel produced was characterised for its fuel properties such as specific gravity at 15°C, flash point, pour point, kinematic viscosity, cetane number, iodine value and higher heating value using American Society for Testing and Materials Standard Methods. The crude and refined Jatropha curcas oil yields were 58.16% and 52.5%. The physicochemical analysis revealed FFA, saponification value and peroxide value of refined Jatropha curcas oil to be 0.58 mg KOH/g, 159.9 and 1.92 m E/kg respectively. The fatty acid composition obtained from gas chromatography (GC) revealed that the oil contained 44.85% oleic acid as the dominant fatty acid, while Margaric 0.01% and Behenic 0.02% the least. The biodiesel yield was 57.6%, and its measured fuel properties conformed with ASTM 6751 and EN 14214 standards.展开更多
Progeny studies of Jatropha curcas and Pongamia pinnata were carried with respect to bioproductivity,pod and seed characters which is one of the selection methods in tree improvement programmes. Variations in bioprodu...Progeny studies of Jatropha curcas and Pongamia pinnata were carried with respect to bioproductivity,pod and seed characters which is one of the selection methods in tree improvement programmes. Variations in bioproductivity and biodiesel parameters of both the plants were compared every 6 months for 4 years of investigation and analyzed by analysis of variance and correlation coefficient by Pearson's method using software Graphpad instat 3.06(for Windows and Mac). P. pinnata has better germination rate(71.4 %), 100 pod weight(PW)(311.59 g) and 100 seed weight(SW)(173.46 g) as compared to J. curcas for germination rate(43.2 %), 100 PW(111.29 g) and 100 SW(67.46 g). P. pinnata has strong correlation for plant height to canopy growth(CG)(0.948), collar diameter(CD)(0.994), number of branches per plant(NBP)(0.995) and to number of leaves per branch(NLB)(0.862) as compared to J.curcas which showed good correlation among plant height to CG(0.976), CD(0.970), NBP(0.988), NLB(0.920) and to number of pods per branch(0.657). However, J. curcas depicted negative correlation for pod breadth to seed length(SL)(-0.447), seed breadth(-0.248) and to seed thickness(ST)(-0.364) and among the 100 PW to SL(-0.199), ST(-0.220) and to 100 SW(-0.704). About 4 kg of P. pinnata seeds were required for each liter of crude oil which yields896 ml of biodiesel on transesterification as compared to5.66 kg of J. curcas seeds for a liter of crude oil, producing about 663 ml of biodiesel. The quality of biodiesel meets the major specification of American Society for Testing and Materials(ASTM) standards for biodiesel. The crude glycerin and seed cake obtained as byproduct during biodiesel production were also measured which can be purified and used in composting, animal feeds, pharmaceuticals and cosmetic industries.展开更多
As a follow-up to our previous study on the transesterification of Nigerian Jatropha curcas oil into Biodiesel using homogenous catalysis, kinetic study of the reaction is hereby presented. The kinetic study revealed ...As a follow-up to our previous study on the transesterification of Nigerian Jatropha curcas oil into Biodiesel using homogenous catalysis, kinetic study of the reaction is hereby presented. The kinetic study revealed that the rate of formation of biodiesel can be increased by increasing reaction temperature and oil to alcohol molar ratio. The optimum reaction condition was established to be 60°C (reaction temperature) and 1:6 (oil to alcohol ratio). Accordingly, the highest biodiesel yield obtained from homogeneously catalyzed transesterification of Nigerian Jatropha curcas (JC) oil into Biodiesel was 86.61% w/w at 60°C with oil to alcohol ratio of 1:6. Furthermore, kinetic study also revealed that conversion of triglyceride to diglyceride was the rate determining step (RDS) of the overall reaction because activation energy of its backward reaction is lower than that of the forward reaction, indicating unstable nature and higher potential energy of the diglyceride in comparison to the triglyceride.展开更多
In this study, the methanolysis of mixed crop oils (Hevea brasiliensis and Jatropha curcas L.) was investigated. Due to the oils contain high impurities, a particular pre-treatment of which was carried out. For alkali...In this study, the methanolysis of mixed crop oils (Hevea brasiliensis and Jatropha curcas L.) was investigated. Due to the oils contain high impurities, a particular pre-treatment of which was carried out. For alkali-catalyzed methanolysis, few parameters (such as: molar ratio, catalyst percentage, and reaction time) were studied. The results showed that the methanolysis optimum conditions were 5.5 of molar ratio, 0.9% w/w of catalyst, and 60 minutes of reaction time with the highest yield of 98.9%. The kinetics study indicated that first order reaction mechanism with reaction rate constant and activation energy were 1.5 × 10-2 minute-1 and 23.93 KJ?mol-1 respectively. As fuel, the physicochemical properties of biodiesel met the standard values required by ASTM D6751.展开更多
The need to mitigate climate change cannot be more emphasized, which arises, as a result of increases in CO<sub>2</sub> emissions due to anthropogenic activities. Given the current world energy problems of...The need to mitigate climate change cannot be more emphasized, which arises, as a result of increases in CO<sub>2</sub> emissions due to anthropogenic activities. Given the current world energy problems of high fossil fuel consumption which plays a pivotal role in the greenhouse effect, Jatropha curcas biodiesel has been considered a potential alternative source of clean energy (biodiesel is carbon neutral). However, the ability of Jatropha curcas, as a candidate source of alternative of clean energy, to grow in marginal and dry soils, has been poorly elucidated. This study, therefore aimed at investigating whether Jatropha curcas leaves could switch from carrying out C<sub>3</sub> photosynthetic pathway to Crassulacean Acid Metabolism (CAM) as a strategy to improve its water deficit tolerance. Thirty-five-day-old Jatropha curcas accessions, from three different climatic zones of Botswana, viz., Mmadinare (Central zone), Thamaga (Southern zone) and Maun (Northern zone), were subjected to water stress, by with-holding irrigation with half-strength Hoagland culture solution. Net photosynthetic rate, transpiration and stomatal conductance were measured at weekly intervals. The leaf pH was measured to determine whether there was a decrease in pH (leaf acidification) of the leaves during the night, when the plants experienced water deficit stress. All the accessions exhibited marked reduction in all the measured photosynthetic characteristics when experience water deficit stress. However, a measurable CO<sub>2</sub> uptake was carried out by leaves of all the accessions, in the wake of marked decreases in stomatal conductance. There is evidence to suggest that when exposed to water stress J. curcas accessions switch from C<sub>3</sub> mode of photosynthesis to CAM photosynthetic pathway. This is attested to by the slightly low leaf pH at night. Thamaga accession exhibited an earlier stomatal closure than the other two accessions. This resulted in Thamaga accession displaying a slightly lower dry weight than both Mmadinare and Maun accessions. It could be concluded that Jatropha curcas appeared to tolerate water deficit stress due to its ability of switching from C<sub>3</sub> photosynthetic pathway to the CAM photosynthetic pathway, but with a cost to biomass accumulation, as demonstrated by slightly more reduced CO<sub>2</sub> assimilation by Thamaga accession, than the other two accessions.展开更多
The present work is focusing on the synthesization and physico-chemical properties of Jatropha curcas biodiesel with diesel and alcohols.The densities of binary diesel(2)+1-alkanols(C_(3) or C_(4))(3)and ternary Jatro...The present work is focusing on the synthesization and physico-chemical properties of Jatropha curcas biodiesel with diesel and alcohols.The densities of binary diesel(2)+1-alkanols(C_(3) or C_(4))(3)and ternary Jatropha curcas biodiesel(1)+diesel(2)+1-alkanols(C_(3)or C_(4))(3)blends have been reported over full range of composition at temperatures within range 288.15 to 313.15 K.Also densities of Jatropha curcas biodiesel(1)+diesel or 1-alkanols(C_(3) or C_(4))(2)blends have been measured at 313.15 K.Excess molar volumes,V^E,V^E_(123)of binary and ternary blends were calculated from the measured data and the derived properties were correlated to composition using Redlich-Kister equation.A reasonable agreement was found between the measured and estimated values.Further,densities and excess molar volumes data were reasoned to discuss molecular interactions taking into consideration effect of composition and temperature.展开更多
Jatropha Curcas Linnaeous(Jatropha Curcas L)is a wonder plant with a variety of applications and enormous economic potential.Biodiesel,an alternative fuel from non edible vegetable oil of Jatropha Curcas plant,has the...Jatropha Curcas Linnaeous(Jatropha Curcas L)is a wonder plant with a variety of applications and enormous economic potential.Biodiesel,an alternative fuel from non edible vegetable oil of Jatropha Curcas plant,has the requisite potential of providing a promising and commercially viable alternative to diesel oil since it has the desirable physicochemical and performance characteristics comparable to diesel.This alternative fuel is eco-friendly,cost effective and has the huge potentiality for the future generations throughout the world.For effective cultivation of this plant, protection from different viral diseases is essential.In this paper,we describe the eco-epidemiological model of the plant Jatropha Curcas L for understanding the disease dynamics which helps to control the viral infection of the Jatropha Curcas plant cell.By this approach,this plant can grow ideally for the renewable green fuel of the future world.展开更多
Biodiesel is a renewable fuel that can be made from vegetable oil and waste restaurant greases by catalysed transesterification reactions. Over 5 billion gallons of biodiesel was produced in 2010. The European Union a...Biodiesel is a renewable fuel that can be made from vegetable oil and waste restaurant greases by catalysed transesterification reactions. Over 5 billion gallons of biodiesel was produced in 2010. The European Union and United States are seeing the sigmoidal portion of the growth curve in biodiesel production. Economic analysis such as profitability and annualized worth (AW) of a biodiesel plant in Taiwan is presented. With the revenue from glycerine byproduct recovery and with lower raw material costs, biodiesel may be profitable especially during days of higher gasoline prices. Multiple reactions of the consecutive-competive type may be used to model the methonolysis of trigylcerides. The reaction rate constant ratios and residence time in the reactor are important parameters in determining higher selectivity of FAME, fatty acid methyl ester product yield over glycerol by-product production. Illustrations of higher FAME yield, higher glycerol yield and cross-over from FAME to glycerol are shown for some values of reaction rate constant ratios and reaction scheme from triglycerides to diglycerides, monoglycerides and glycerol along with formation of FAME in each step by addition of methanol and catalyst is shown. Product distribution curves are presented in Figures 2-5 for different values or reaction rate constant ratios.展开更多
文摘The present work studies and identifies the different variables that affect the output parameters involved in a single cylinder direct injection compression ignition (CI) engine using jatropha biodiesel. Response surface methodology based on Central composite design (CCD) is used to design the experiments. Mathematical models are developed for combustion parameters (Brake specific fuel consumption (BSFC) and peak cylinder pressure (Pmax)), performance parameter brake thermal efficiency (BTE) and emission parameters (CO, NOx, unburnt HC and smoke) using regression techniques. These regression equations are further utilized for simultaneous optimization of combustion (BSFC, Pmax), performance (BTE) and emission (CO, NOx, HC, smoke) parameters. As the objective is to maximize BTE and minimize BSFC, Pmax, CO, NOx, HC, smoke, a multi- objective optimization problem is formulated. Non- dominated sorting genetic algorithm-II is used in predict- ing the Pareto optimal sets of solution. Experiments are performed at suitable optimal solutions for predicting the combustion, performance and emission parameters to check the adequacy of the proposed model. The Pareto optimal sets of solution can be used as guidelines for the end users to select optimal combination of engine outputand emission parameters depending upon their own requirements.
文摘Cetane number(CN)-a prime indicator of diesel fuel quality,is a quantity indicating the combustion behaviour of diesel fuel and compression required for ignition in diesel engines.This study examines the determination of CN of Jatropha biodiesel blends with mineral diesel using their physical properties,and their variations of CN with percentage composition of Jatropha biodiesel in the blends.Jatropha biodiesel,converted through a transesterification process of its oil,is obtained and blended with diesel to obtain blend B10(10%biodiesel and 90%diesel)on a volumetric basis,at 25℃ ambient temperature and the same basis was employed for blends B20,B30,B40 and B50.The specific gravity and mid-distillation characteristic were obtained using a hydrometer and distillation curve apparatus based on ASTM D1298 and D86 standards respectively.The CN of Jatropha oil,its biodiesel and Jatropha biodiesel blends with diesel were analytically determined,employing the empirical relationship between measured physical properties of a two-variable cetane index equation.The results show that the CN of the Jatropha biodiesel increases significantly(about 29%)after transesterification compared with that of the Jatropha oil.Moreover,the specific gravity and CN of the blends increase with the percentage composition of Jatropha biodiesel in the blends.The CN of Jatropha biodiesel is 44.10,which is 8.7%higher than that of mineral diesel(40.62).It can be implied from the research outcomes that blending Jatropha biodiesel with diesel increases the CN of the blends,thus,could be used as cetane point(number)enhancer.
文摘Oil was extracted from seeds of Jatropha Curcas,in high yields(up to 40% by weight).The extracted Jatropha oil was converted in a laboratory reactor to biodiesel by transesterification.Analysis of Jatropha oil and Jatropha biodiesel by GC/MS and GC/SIMDIS showed that Jatropha oil could be readily converted to a biodiesel product through NaOH catalyzed transesterification.The resulting biodiesel has desirable properties such as high cetane number and low flash point,which are major improvements over the properties of commercial biodiesel fuels.
基金financial and moral support from the National Centre for Physics Islamabad,Pakistan to carry out of this present research workDeanship of Scientific Research at King Saud University for it’s funding of this research through the Research Group Project no RGP-VPP-345
文摘The non-edible oils are believed to be one of the major feedstock for the production of biodiesel in future.In the present study,we investigated the production of Jatropha oil methyl esters(JOMEs) via alkali-catalyzed transesterification route.The biophysical characteristics of Jatropha oil were found within the optimal range in accordance with ASTM standards as a substitute diesel fuel.The chemical composition and production yield of as-synthesized biodiesel were confirmed by various analytical techniques such as FT-IR,1H NMR,13 C NMR and gas chromatography coupled with mass spectrometry.A high percentage conversion,~96.09%,of fatty acids into esters was achieved under optimized transesterification conditions with 6 :1 oil to methanol ratio and 0.9 wt% Na OH for 50 min at ~60°C.Moreover,twelve fatty acids methyl esters(FAME) were quantified in the GC/MS analysis and it was interesting to note that the mass fragmentation pattern of saturated,monounsaturated and diunsaturated FAME was comparable with the literature reported values.
文摘An environmentally benign process was devel-oped for the transesterification of Jatropha curcas L. seed oil with methanol using artificial zeolites loaded with potassium acetate as a heterogeneous catalyst. After calcination for 5 h at 823 K, the catalyst loaded with 47 wt.% CH3COOK exhibited the highest efficiency and best catalytic activity. The easily prepared cata-lysts were characterized by means of X-ray dif-fraction and IR spectroscopy, as well as Hammett indicator titration. The results revealed a strong dependence of catalytic activity on ba-sicity. The optimum reaction conditions for transesterification of J. curcas oil were also in-vestigated. The methyl ester content in the bio-diesel product exceeded 91% after 4h reaction at reflux temperature in the presence of 2% solid catalyst and no water washing process is needed during workup.
文摘Ethyl ester biodiesel has been produced from a non-edible Jatropha curcas oil. Oil was extracted from the plant seed using n-hexane at 60°C and pretreated by alkaline refining process to reduce the free fatty acid level to less than 1%. Base-catalysed transesterification reaction with absolute ethanol using potassium hydroxide catalyst was adopted for the conversion. Various physicochemical properties of the refined Jatropha curcas oil were investigated. The ethyl ester biodiesel produced was characterised for its fuel properties such as specific gravity at 15°C, flash point, pour point, kinematic viscosity, cetane number, iodine value and higher heating value using American Society for Testing and Materials Standard Methods. The crude and refined Jatropha curcas oil yields were 58.16% and 52.5%. The physicochemical analysis revealed FFA, saponification value and peroxide value of refined Jatropha curcas oil to be 0.58 mg KOH/g, 159.9 and 1.92 m E/kg respectively. The fatty acid composition obtained from gas chromatography (GC) revealed that the oil contained 44.85% oleic acid as the dominant fatty acid, while Margaric 0.01% and Behenic 0.02% the least. The biodiesel yield was 57.6%, and its measured fuel properties conformed with ASTM 6751 and EN 14214 standards.
基金supported by the project UGC-MRP No.F.No.-39-258/2010(SF),UGC,Government of India,New Delhi
文摘Progeny studies of Jatropha curcas and Pongamia pinnata were carried with respect to bioproductivity,pod and seed characters which is one of the selection methods in tree improvement programmes. Variations in bioproductivity and biodiesel parameters of both the plants were compared every 6 months for 4 years of investigation and analyzed by analysis of variance and correlation coefficient by Pearson's method using software Graphpad instat 3.06(for Windows and Mac). P. pinnata has better germination rate(71.4 %), 100 pod weight(PW)(311.59 g) and 100 seed weight(SW)(173.46 g) as compared to J. curcas for germination rate(43.2 %), 100 PW(111.29 g) and 100 SW(67.46 g). P. pinnata has strong correlation for plant height to canopy growth(CG)(0.948), collar diameter(CD)(0.994), number of branches per plant(NBP)(0.995) and to number of leaves per branch(NLB)(0.862) as compared to J.curcas which showed good correlation among plant height to CG(0.976), CD(0.970), NBP(0.988), NLB(0.920) and to number of pods per branch(0.657). However, J. curcas depicted negative correlation for pod breadth to seed length(SL)(-0.447), seed breadth(-0.248) and to seed thickness(ST)(-0.364) and among the 100 PW to SL(-0.199), ST(-0.220) and to 100 SW(-0.704). About 4 kg of P. pinnata seeds were required for each liter of crude oil which yields896 ml of biodiesel on transesterification as compared to5.66 kg of J. curcas seeds for a liter of crude oil, producing about 663 ml of biodiesel. The quality of biodiesel meets the major specification of American Society for Testing and Materials(ASTM) standards for biodiesel. The crude glycerin and seed cake obtained as byproduct during biodiesel production were also measured which can be purified and used in composting, animal feeds, pharmaceuticals and cosmetic industries.
文摘As a follow-up to our previous study on the transesterification of Nigerian Jatropha curcas oil into Biodiesel using homogenous catalysis, kinetic study of the reaction is hereby presented. The kinetic study revealed that the rate of formation of biodiesel can be increased by increasing reaction temperature and oil to alcohol molar ratio. The optimum reaction condition was established to be 60°C (reaction temperature) and 1:6 (oil to alcohol ratio). Accordingly, the highest biodiesel yield obtained from homogeneously catalyzed transesterification of Nigerian Jatropha curcas (JC) oil into Biodiesel was 86.61% w/w at 60°C with oil to alcohol ratio of 1:6. Furthermore, kinetic study also revealed that conversion of triglyceride to diglyceride was the rate determining step (RDS) of the overall reaction because activation energy of its backward reaction is lower than that of the forward reaction, indicating unstable nature and higher potential energy of the diglyceride in comparison to the triglyceride.
文摘In this study, the methanolysis of mixed crop oils (Hevea brasiliensis and Jatropha curcas L.) was investigated. Due to the oils contain high impurities, a particular pre-treatment of which was carried out. For alkali-catalyzed methanolysis, few parameters (such as: molar ratio, catalyst percentage, and reaction time) were studied. The results showed that the methanolysis optimum conditions were 5.5 of molar ratio, 0.9% w/w of catalyst, and 60 minutes of reaction time with the highest yield of 98.9%. The kinetics study indicated that first order reaction mechanism with reaction rate constant and activation energy were 1.5 × 10-2 minute-1 and 23.93 KJ?mol-1 respectively. As fuel, the physicochemical properties of biodiesel met the standard values required by ASTM D6751.
文摘The need to mitigate climate change cannot be more emphasized, which arises, as a result of increases in CO<sub>2</sub> emissions due to anthropogenic activities. Given the current world energy problems of high fossil fuel consumption which plays a pivotal role in the greenhouse effect, Jatropha curcas biodiesel has been considered a potential alternative source of clean energy (biodiesel is carbon neutral). However, the ability of Jatropha curcas, as a candidate source of alternative of clean energy, to grow in marginal and dry soils, has been poorly elucidated. This study, therefore aimed at investigating whether Jatropha curcas leaves could switch from carrying out C<sub>3</sub> photosynthetic pathway to Crassulacean Acid Metabolism (CAM) as a strategy to improve its water deficit tolerance. Thirty-five-day-old Jatropha curcas accessions, from three different climatic zones of Botswana, viz., Mmadinare (Central zone), Thamaga (Southern zone) and Maun (Northern zone), were subjected to water stress, by with-holding irrigation with half-strength Hoagland culture solution. Net photosynthetic rate, transpiration and stomatal conductance were measured at weekly intervals. The leaf pH was measured to determine whether there was a decrease in pH (leaf acidification) of the leaves during the night, when the plants experienced water deficit stress. All the accessions exhibited marked reduction in all the measured photosynthetic characteristics when experience water deficit stress. However, a measurable CO<sub>2</sub> uptake was carried out by leaves of all the accessions, in the wake of marked decreases in stomatal conductance. There is evidence to suggest that when exposed to water stress J. curcas accessions switch from C<sub>3</sub> mode of photosynthesis to CAM photosynthetic pathway. This is attested to by the slightly low leaf pH at night. Thamaga accession exhibited an earlier stomatal closure than the other two accessions. This resulted in Thamaga accession displaying a slightly lower dry weight than both Mmadinare and Maun accessions. It could be concluded that Jatropha curcas appeared to tolerate water deficit stress due to its ability of switching from C<sub>3</sub> photosynthetic pathway to the CAM photosynthetic pathway, but with a cost to biomass accumulation, as demonstrated by slightly more reduced CO<sub>2</sub> assimilation by Thamaga accession, than the other two accessions.
文摘The present work is focusing on the synthesization and physico-chemical properties of Jatropha curcas biodiesel with diesel and alcohols.The densities of binary diesel(2)+1-alkanols(C_(3) or C_(4))(3)and ternary Jatropha curcas biodiesel(1)+diesel(2)+1-alkanols(C_(3)or C_(4))(3)blends have been reported over full range of composition at temperatures within range 288.15 to 313.15 K.Also densities of Jatropha curcas biodiesel(1)+diesel or 1-alkanols(C_(3) or C_(4))(2)blends have been measured at 313.15 K.Excess molar volumes,V^E,V^E_(123)of binary and ternary blends were calculated from the measured data and the derived properties were correlated to composition using Redlich-Kister equation.A reasonable agreement was found between the measured and estimated values.Further,densities and excess molar volumes data were reasoned to discuss molecular interactions taking into consideration effect of composition and temperature.
基金supported by the Department of Mathematics,Jadavpur University,PURSE DST, Government of India
文摘Jatropha Curcas Linnaeous(Jatropha Curcas L)is a wonder plant with a variety of applications and enormous economic potential.Biodiesel,an alternative fuel from non edible vegetable oil of Jatropha Curcas plant,has the requisite potential of providing a promising and commercially viable alternative to diesel oil since it has the desirable physicochemical and performance characteristics comparable to diesel.This alternative fuel is eco-friendly,cost effective and has the huge potentiality for the future generations throughout the world.For effective cultivation of this plant, protection from different viral diseases is essential.In this paper,we describe the eco-epidemiological model of the plant Jatropha Curcas L for understanding the disease dynamics which helps to control the viral infection of the Jatropha Curcas plant cell.By this approach,this plant can grow ideally for the renewable green fuel of the future world.
文摘Biodiesel is a renewable fuel that can be made from vegetable oil and waste restaurant greases by catalysed transesterification reactions. Over 5 billion gallons of biodiesel was produced in 2010. The European Union and United States are seeing the sigmoidal portion of the growth curve in biodiesel production. Economic analysis such as profitability and annualized worth (AW) of a biodiesel plant in Taiwan is presented. With the revenue from glycerine byproduct recovery and with lower raw material costs, biodiesel may be profitable especially during days of higher gasoline prices. Multiple reactions of the consecutive-competive type may be used to model the methonolysis of trigylcerides. The reaction rate constant ratios and residence time in the reactor are important parameters in determining higher selectivity of FAME, fatty acid methyl ester product yield over glycerol by-product production. Illustrations of higher FAME yield, higher glycerol yield and cross-over from FAME to glycerol are shown for some values of reaction rate constant ratios and reaction scheme from triglycerides to diglycerides, monoglycerides and glycerol along with formation of FAME in each step by addition of methanol and catalyst is shown. Product distribution curves are presented in Figures 2-5 for different values or reaction rate constant ratios.