Production of biodiesel from Citrus limetta seed oil

The production of biodiesel from edible oils may cause negative impact to any country through food crisis which may lead to economic imbalance. Hence, this study focuses on viability of extracting the oil from the Citrus limetta seeds for biodiesel production for the first time. Composition of C. limetta oil was determined by gas chromatography. C. limetta biodiesel was produced by simple transesterification process, and further physiochemical properties were analyzed as per the standards. This study also describes the suitable characterization and optimization parameters used for conversion of C. limetta seed oil into biodiesel.     

A multi-variant approach to optimize process parameters for biodiesel extraction from rubber seed oil

Biodiesel is biodegradable, non-toxic and has the capacity for sustainable development, energy conservation and environmental preservation. Apart from yielding high value latex, the rubber plant supply large amount of rubber seed, which are currently underutilized. Extracting biodiesel from rubber seed is a viable option which demands attention for research to consolidate and optimize the process parameters. Design of experiments (DOE) is a powerful statistical approach which is used for optimizing the process parameters through two stage esterification process, relating acid and alkaline as catalyst. Reducing the acid value is the primary objective for process optimization in acid esterification process, whereas, maximizing the monoester yield is the objective for the alkaline-esterification process. Different saturated and unsaturated monoesters present in the biodiesel were quantified using gas chromatograph in order to determine the yield percentage, which ensures the quality of the biodiesel. The fuel was tested for properties such as viscosity, calorific value and carbon residue using standard test procedures and found to be analogous with diesel, which makes it possible to use this alternate fuel in the existing engine without any modification.     

Characterization and effect of using rubber seed oil as fuel in the compression ignition engines

Vegetable oils pose some problems when subjected to prolonged usage in compression ignition engines because of their high viscosity and low volatility. The common problems are poor atomization, carbon deposits, ring sticking, fuel pump failure, etc. Converting the high viscosity vegetable oil into its blends or esters can minimize these problems. The various blends of rubber seed oil and diesel were prepared and its important properties such as viscosity, calorific value, flash point, fire point, etc. were evaluated and compared with that of diesel. The blends were then subjected to engine performance and emission tests and compared with that for diesel. It was found that 50–80% of rubber seed oil blends gave the best performance. Long run tests were conducted using optimized blend and diesel. It was found that blend fueled engine has higher carbon deposits inside combustion chamber than diesel-fueled engine. Utilization of blends requires frequent cleaning of fuel filter, pump and the combustion chamber. Hence, it is recommended that rubber seed oil–diesel blend fuel is more suitable for rural power generation.     

Performance and emission evaluation of a diesel engine fueled with methyl esters of rubber seed oil

Recent concerns over the environment, increasing fuel prices and scarcity of its supply have promoted the interest in development of the alternative sources for petroleum fuels. At present, biodiesel is commercially produced from the refined edible vegetable oils such as sunflower oil, palm oil and soybean oil, etc. by alkaline-catalyzed esterification process. This process is not suitable for production of biodiesel from many unrefined non-edible vegetable oils because of their high acid value. Hence, a two-step esterification method is developed to produce biodiesel from high FFA vegetable oils. The biodiesel production method consists of acid-catalyzed pretreatment followed by an alkaline-catalyzed transesterification. The important properties of methyl esters of rubber seed oil are compared with other esters and diesel. Pure rubber seed oil, diesel and biodiesel are used as fuels in the compression ignition engine and the performance and emission characteristics of the engine are analyzed. The lower blends of biodiesel increase the brake thermal efficiency and reduce the fuel consumption. The exhaust gas emissions are reduced with increase in biodiesel concentration. The experimental results proved that the use of biodiesel (produced from unrefined rubber seed oil) in compression ignition engines is a viable alternative to diesel.     

Production of biodiesel from low priced,renewable and abundant date seed oil

The present work is definitely an approach towards attaining price competency of bio-diesel to petroleum diesel. The oils extracted from abundantly available waste of Zahidi, Basra and Khazravi date seeds were used to produce biodiesel using acid (HCl), base (KOH), immobilized enzyme (lipase), immobilized enzyme/acid (lipase/HCl) and immobilized enzyme/base (lipase/KOH) catalyzed processes. Mixed catalysis (immobilized enzyme + acid or immobilized enzyme + base) resulted in better yields in comparison to acid or base catalysis. The properties of biodiesel were evaluated by fuel standard tests and the results were compared with EN14214 and ASTM D6751 standards. Biodiesel produced from date seed oil was found to have a high cetane number (55–60.3), low iodine value (44–50) and good flash point (135–140 °C). Pour point of pure biodiesel produced from Khazravi and Zahidi was found to range from 2 to −2 °C. Biodiesel produced from Basra exhibited good pour point (−4.7 to −8.3 °C) in comparison to other varieties. The components present in biodiesel produced from various date varieties were determined by gas chromatographic-mass spectrometric analyses (GCMS). The fatty acid (%) detected in date seed biodiesel were oleic acid (33.4–47.4), lauric acid (19–28), palmitic acid (13.6–19.2), myristic acid (13.6–17.44) and linoleic acid (6.4–8.5). A special feature of date seed oil biodiesel was the presence of considerable amounts of low chain fatty acids.     

Transesterification of non-edible seed oil for biodiesel production: characterization and analysis of biodiesel

Evaluation of Radish (Raphanus sativus) seed oil (RSO) as a non-edible feedstock for biodiesel production was the main target of the present study. Extraction by solvent disclosed that radish seeds contains 33.50 wt.% of oil. Therefore, biodiesel production from it could be beneficial. Optimized base-catalyzed transesterification of RSO with methanol, ethanol and mixed methanol/ethanol was performed, to produce fatty acid methyl esters, fatty acid ethyl esters and mixed fatty acid methyl ethyl esters, respectively. The optimal yields of the methyl esters, ethyl esters and mixed methyl ethyl esters, were 95.55wt.%, 90.66 wt.% and 93.33 wt.%, respectively when the optimal reaction conditions were attained. Fuel properties of the parent oil were positively changed as consequence of transesterification reaction such that they fulfilled the standard limits as prescribed by ASTM D6751. Moreover, fuel properties of (biodiesels + petro diesel) blends conformed ASTM D7467-17 standards indicating their suitability as a fuel for diesel engines. Biodiesels form RSO were analyzed by thin layer chromatography and FTIR spectroscopy, and both techniques conformed its conversion into its corresponding alkyl esters.     

Biodiesel from kernel oil of sweet cherry (Prunus avium L.) seed

Kernel oil of sweet cherry seed (Prunus avium L.) was extracted with hexane in a Soxhlet extractor. Sweet cherry kernel oil contains more than 87% unsaturated fatty acids, such as oleic acid (43.7% by weight), linoleic acid (41.8% by weight), and linolenic acid. The biodiesel from kernel oil of sweet cherry seed in itself is not significantly different from biodiesel produced from common vegetable oils.     

Synthesis of biodiesel from waste vegetable oil with large amounts of free fatty acids using a carbon-based solid acid catalyst

A carbon-based solid acid catalyst was prepared by the sulfonation of carbonized vegetable oil asphalt. This catalyst was employed to simultaneously catalyze esterification and transesterification to synthesis biodiesel when a waste vegetable oil with large amounts of free fatty acids (FFAs) was used as feedstock. The physical and chemical properties of this catalyst were characterized by a variety of techniques. The maximum conversion of triglyceride and FFA reached 80.5 wt.% and 94.8 wt.% after 4.5 h at 220 °C, when using a 16.8 M ratio of methanol to oil and 0.2 wt.% of catalyst to oil. The high catalytic activity and stability of this catalyst was related to its high acid site density (–OH, Brönsted acid sites), hydrophobicity that prevented the hydration of –OH species, hydrophilic functional groups (–SO₃H) that gave improved accessibility of methanol to the triglyceride and FFAs, and large pores that provided more acid sites for the reactants.     

Improved transesterification of waste cooking oil into biodiesel using calcined goat bone as a catalyst

In this study, potassium hydroxide-treated animal bones were employed? as a solid heterogeneous catalyst in transesterification of waste cooking oil. This catalyst was characterized by the Fourier-transform infrared spectroscopy (FTIR), and it displayed high-catalytic activity for biodiesel production. Optimum conditions for biodiesel production were catalyst loading 6.0% (w/w) of oil, methanol/oil molar ratio 9:1, calcination temperature 800°C, reaction temperature 65°C, and reaction time of 5 h, which gave maximum biodiesel yield of 84%. Reusability of the catalyst was also confirmed by repeated use of the same catalyst three times without losing much of its activity. Hence, calcined goat bones were found to be a potentially applicable catalyst for biodiesel production at industrial scale.     

Is it better to import palm oil from Thailand to produce biodiesel in Ireland than to produce biodiesel from indigenous Irish rape seed?

The proposed EU Directive on the promotion of Renewable Energy stipulates that only biofuels that achieve greenhouse emissions savings of 35% will be eligible for inclusion with respect to meeting the 2020 target of 10% for the share of biofuels. This paper examines biodiesel for use in Ireland, produced from two different sources: indigenous rape seed and palm oil imported from Thailand. The palm oil system generates more biodiesel per hectare than the rape seed system, and has less parasitic demand. Greenhouse-gas reductions of 29% and 55%, respectively were calculated for the rape seed and palm oil systems.     

Optimized alkali-catalyzed transesterification of wild mustard (Brassica juncea L.) seed oil

Biodiesel was developed from a non-edible oil source, i.e., wild mustard (Brassica juncea L) oil through optimized alkali-catalyzed transesterification with methanol using potassium hydroxide as a catalyst. Biodiesel yield of (95.54 % with 96.72 % w/w ester content) was obtained under optimal conditions of 0.75 % KOH w/w of oil, 6:1 methanol to oil molar ratio, 60°C temperature, and a duration of 45 min. Properties of wild mustard (Brassica juncea L) oil biodiesel were determined and found to be within the limits of ASTM D6751 specifications. As a result, wild mustard (Brassica juncea L), as an agricultural crop, might be a reasonable feedstock for biodiesel production.     

Pressurized ultrasonic production of biodiesel from Jatropha oil: optimization and energy analysis

The present study deals with the development of a biodiesel production reactor based on pressurized ultrasonic cavitation technique. Transesterification of Jatropha oil takes place by passing low-frequency ultrasonic irradiation in the reaction mixture flowing at pressurized conditions in the sonochemical reactor. Reaction variables such as reaction time, molar ratio, catalyst concentration, and pressure of the reaction mixture were investigated to find the optimal parameters for biodiesel production. The energy requirement decreases with increase in pressure. Very low value of Specific Energy Consumption (0.018 kWh/kg) and significantly high value of Energy Use Index (598.83) are obtained when the pressure of reaction mixture is 15 bar. Increasing the pressure thereafter, leads to nominal gains. Ultrasonic irradiation at high-pressure condition has an additional advantage of rapid reaction and lower requirement of alcohol to oil molar ratio and catalyst concentration. Fifteen bar pressure is optimal for biodiesel production.     

Optimization of biodiesel produced from watermelon (Citrullus vulgaris) using batch-type production unit

In the present work the production of a biodiesel from watermelon seed oil (Citrullus vulgaris) by methanol-induced transesterification using an alkaline catalyst (potassium hydroxide, KOH) has been examined. The influence of the operating variables such as agitation speed, temperature, reaction time, alcohol amount, and catalyst concentration was determined experimentally and found to be 550 rpm agitation rate, 60°C reaction temperature, 55 min reaction time, 20% of methanol, and 13 g of catalysts concentration for 2.5 liters of oil. The yield of biodiesel from the watermelon methyl ester (WME) under optimized conditions is found to be 91%. The properties of biodiesel are measured as per ASTM standards and compared with the base diesel.     

Comparative assessment of sal and kusum biodiesel properties

This paper focuses on the use of kusum and sal oils found abundantly in India, yet unexplored for biodiesel production. The fatty acid profiles of the feedstocks suggest that sal oil has 56.8% saturated fatty acid whereas kusum oil has 34.8%. The kinematic viscosities of methyl ester of sal and kusum oils were higher and the calorific values were lower than those of diesel. The oxidation stability of both the esters is more than 6 h. The physicochemical properties of the two esters were within permissible limits of ASTM standard. The blending of ester in diesel has resulted in better performance and lower emissions.     

Preparation of biodiesel from nonedible oils using a mixture of used lipases

Biodiesel was synthesized from nonedible oils using a lipase mixture composed of used and discarded Candida rugusa, Candida antactica-B (Novozyme-435), Pseudomonas cepacia, Rhizopus oryzae, and porcine pancreas Type II lipase. To avoid the lipase deactivation stepwise addition of 6 mmol of methanol to 1 mmol of oil lead to 93% biodiesel yield. Addition of 10 wt% of silica gel to the reaction mixture resulted in 97% biodiesel. The lipase mixture was recycled for five times and at the end of the fifth cycle 86% biodiesel was formed.     

Transesterification of jojoba oil,sunflower oil,neem oil,rocket seed oil and linseed oil by tin catalysts

The methanolysis of jojoba oil has been studied in the presence of tin powder, dibutyltin diacetate (C₄H₉)₂Sn(OOCCH₃)₂, dioctyltin diacetate (C₈H₁₇)₂Sn(OOCCH₃)₂, dibutyltin oxide (C₄H₉)₂SnO, dioctyltin oxide (C₈H₁₇)₂SnO, diphenyltin oxide (C₆H₅)₂SnO, dibutyltin chloride dihydroxide (C₄H₉)₂Sn(OH)₂Cl, butyltinhydroxide hydrate (C₄H₉)Sn(=O)OH.xH₂O, Ni nanoparticles and Pd nanoparticles act as catalysts. Among these, 1 weight % of dibutyltin diacetate shows the maximum conversion. Then, methanolysis of sunflower oil, neem oil, rocket seed oil and linseed oil into methyl esters studied in the presence of 1% dibutyltin diacetate as a catalyst and was compared their percentage conversions. The experimental yield for the conversion of jojoba oil, sunflower oil, neem oil, rocket seed oil and linseed oil into biodiesel was found to be 71%, 51%, 50.78%, 40.90% and 39.66%, respectively. The experimental yield of the conversion of jojoba oil into methyl esters was found to be increased up to 96% by increasing reaction time, without emulsion formation. The synthesis of jojoba seed oil biodiesel (JSOB), soybean oil biodiesel (SOB), neem oil biodiesel (NOB), rocket seed oil biodiesel (RSOB) and linseed oil biodiesel (LSOB) was confirmed by NMR (¹H & ¹³C) and FT-IR analyses of biodiesel.     

Optimization of biodiesel production from waste fish oil

The present study deals with the production of biodiesel using waste fish oil. The research assesses the effect of the transesterification parameters on the biodiesel yield and its properties, including temperature (40–60 °C), molar ratio methanol to oil (3:1–9:1) and reaction time (30–90 min). The experimental results were fitted to complete quadratic models and optimized by response surface methodology. All the biodiesel samples presented a FAME content higher than 93 wt.% with a maximum, 95.39 wt.%, at 60 °C, 9:1 of methanol to oil ratio and 90 min. On the other hand, a maximum biodiesel yield was found at the same methanol to oil ratio and reaction time conditions but at lower temperature, 40 °C, which reduced the saponification of triglycerides by the alkaline catalyst employed. Adequate values of kinematic viscosity (measured at 30 °C) were obtained, with a minimum of 6.30 mm²/s obtained at 60 °C, 5.15:1 of methanol to oil ratio and 55.52 min. However, the oxidative stability of the biodiesels produced must be further improved by adding antioxidants because low values of IP, below 2.22 h, were obtained. Finally, satisfactory values of completion of melt onset temperature, ranging from 3.31 °C to 3.83 °C, were measured.     

Two-stage processes of homogenous catalysed transesterification of high free fatty acid crude oil of rubber seed

Biodiesel is a diesel replacement and renewable fuel that is manufactured from vegetable oils, animal fats or waste cooking oils. The production of biodiesel from edible oil is currently much more expensive than hydrocarbon-based fuel, due to the relatively high cost of edible oils. The cost of biodiesel can be reduced by using non-edible oils instead of edible oils. The purpose of the present study was to develop a method of esterification of non-edible oil like rubber seed oil (Hevea brasiliensis). The high free fatty acid content oil reacts quickly with alkaline catalysts to form soap, which prevents the separation of biodiesel and glycerol. A two-step process was used instead of the simple alkaline catalysed transesterification process. It consisted of an acid catalysed pre-processing followed by the usual alkaline catalysed process. The physical and chemical properties of biodiesel were analysed. The quantification of methyl esters were done by high-performance liquid chromatography.     

Fuel properties of biodiesel from vegetable oils and oil mixtures. Influence of methyl esters distribution

In this work, the quality of biodiesel produced by basic transesterification from several vegetable oils (soybean, rapeseed, sunflower, high oleic sunflower, Cynara Cardunculus L., Brassica Carinata and Jatropha Curca) cultivated in Extremadura has been studied in detail. The influence of raw material composition on properties such as density, viscosity, cetane number, higher heating value, iodine and saponification values and cold filter plugging point has been verified. Other biodiesel properties such as acid value, water content and flash and combustion points were more dependent on characteristics of production process. Biodiesel produced by rapeseed, sunflower and high oleic sunflower oils transesterification have been biofuels with better properties according to Norm EN 14214. Finally, it has been tested that it is possible to use oils mixtures in biodiesel production in order to improve the biodiesel quality. In addition, with the same process conditions and knowing properties of biodiesel from pure oils; for biodiesel from oils mixtures, its methyl esters content, and therefore properties dependent this content can be predicted from a simple mathematical equation proposed in this work.