Ricinus Communis Oil Research Articles

Effect of Immersion of Denture Base Thermoplastic Nylon in Alkaline Peroxide and 10% Castor Oil (Ricinus Communis Oil) on Color Stability and Flexural Strength

Discoloration and flexural strength of denture bases are important factors affecting the comfort and durability of denture users. This study aims to determine the effect of immersion of nylon thermoplastic denture base in alkaline peroxide solution and 10% castor oil (Ricinus Communis Oil) on color stability and flexural strength. This study used a laboratory experimental design with samples of cylindrical (20 x 2 mm) thermoplastic nylon resin for color stability test and rectangular (65 x 10 x 3 mm) for flexural strength test. There were two study groups: one control group and two treatment groups immersed in alkaline peroxide and 10% castor oil solution, with two time variables, 8 days and 12 days. The total number of samples was 60, with each group having 10 samples. The color stability test used a colorimeter, and the flexural strength test used a universal testing machine. The results showed that there was no effect of soaking the nylon thermoplastic denture base in alkaline peroxide on color stability, with a value of p = 0.412 for 8 days and p = 0.179 for 12 days. In addition, there was no effect of immersion in alkaline peroxide and 10% castor oil on flexural strength, with p value = 0.076 for 8 days and p = 0.917 for 12 days. The implication of this study is that immersion in alkaline peroxide and castor oil solution does not affect the color stability or flexural strength of nylon thermoplastic denture bases, making them safe for long-term use.

Effect on combustion performance and emission behavior of diesel engine fueled with hybrid biodiesel produced from a novel ternary oil mixture incorporated with nano additive

ABSTRACT Global energy demand has been above 80% fossil fuels for decades, creating a greater and more complicated energy crisis. Biodiesel is a great alternate energy source for future energy demand. Producing biodiesel from a mixture of waste and non-edible oils may be a practical solution to address the growing global need of biodiesel. In this study, hybrid biodiesel is produced from a ternary oil mixture of Waste cooking oil, Ricinus communis oil, and Melia azedarach oil. The hybrid biodiesel blends are prepared by 10% blending (HB10), 20% blending (HB20) and 30% blending (HB30) and 30ppm multiwall carbon nanotube has been added in the blended fuel through sonicating process. At steady 1500rmp and variable load (0–100%), the engine behavior has been examined. The results show that the hybrid biodiesel blend (HB10) with 30ppm MWCNT has shown highest cylinder pressure of 70.9 bar, maximum mean gas temperature 1467.56°C. The engine shows 34.08% rise in net heat release and 9.13% rise in exhaust gas temperature as compare to diesel. The maximum rise in break thermal efficiency of 19.74% and minimum reduction in break specific fuel consumption of 13.79% is noticed in comparison to B00. The highest reduction of HC emission is found as 20.83% for HB20MWCNT30 and 19.34% for HB30MWCNT30 as compare to B00. The inclusion of multiwall carbon nanotube in hybrid biodiesel reduces the HC, CO, NOx and smoke emission and increases CO2 emission as compare to respective hybrid biodiesel blend and diesel. The hybrid biodiesel-diesel blend, with multiwall carbon nanotube can be utilized efficiently in diesel engine with improved overall engine behavior.

Co-integration and Causality Analysis of “Castor” (Ricinus communis Oil) Markets in India

Castor (Ricinus communis L.) is a major industrial oilseed crop. Because of its numerous uses in the manufacturing of a wide range of industrial uses, castor oil has risen significantly in importance in the global economy. The study examined market integration in major Castor markets in India, including Dhanera, Patan, Kurnool, and Yemmiganur. The co-integration analysis conducted revealed a high level of market integration, as evidenced by the significant positive and negative values of weekly Castor prices across all markets. Unit root tests indicated that the markets were non-stationary, but became stationary when analyzed at the first difference. Further analysis using Johansen's tests identified three cointegrating equations among the markets. The results of the Vector Error Correction Model (VECM) demonstrated long-term price influences between markets. Specifically, Dhanera was found to be influenced by its own price, as well as by prices in Patan and Yemmiganur. Patan, on the other hand, was influenced by its own price, as well as by prices in Dhanera and Yemmiganur. Additionally, Kurnool and Yemmiganur were influenced by prices in neighboring markets.

Production and optimization study of biodiesel produced from non-edible seed oil

The fuel demand is increasing globally. Conventional fuel is toxic and causes global warming and pollution. Therefore, biodiesel is being used as an alternative to petroleum fuel because it is non-toxic and can be renewable. Nowadays, the non-edible feedstock is gaining more attention for the production of biodiesel because it can grow anywhere on land, has low cost, and does not cause an imbalance in the food economy. This study deals with the biodiesel production and optimization of biodiesel from Ricinus communis oil using sodium hydroxide (NaOH) and potassium hydroxide (KOH) as solid base catalysts. The free fatty acid content (22.14% mg KOH/g) of castor oil calculated before transesterification indicated that the pretreatment of raw oil with acid was required for biodiesel synthesis. Therefore, the esterification process was used to reduce the free fatty acid content of castor oil from 22.14% to 0.84%. After that, the transesterification process was used for the production of biodiesel using a catalyst (NaOH and KOH). The four different parameter reactions (i.e. Ratio (alcohol to oil), Time, Temperature, and catalyst amount) were used to optimize the yield of biodiesel production. Firstly, NaOH was used as the catalyst and different reactions were done by making changes in all parameters to get maximum yield. The same procedure was done to get maximum yield using KOH as the catalyst. The maximum yield obtained using NaOH and KOH was 94.6% and 96.2% respectively. In the future, initiatives to develop market, policy support, and certification plans for sustainability play a vital role in innovative advancement, gaining market trust, and attracting investment for biodiesel. These efforts enable biodiesel as a renewable energy source in advancing in low-carbon and sustainable future.

Techno-economic analysis of Castor (Ricinus communis) Oil Refinery Process Simulation

Castor (Ricinus communis) plants have been cultivated. Castor oil has been cultivated and has become one of the world’s major commodities, with the leading producer being India. Castor oil’s primary products and derivatives include Hydrogenated Castor Oil (HCO), polymers, lubricants, and biodiesel. Conventional extraction is usually done using a machine or hot water extraction methods. In large industries, extraction is carried out to obtain high purity with the help of solvents. Organic solvents are suitable for extraction, such as methanol, ethanol, and n-hexane, which are the most commonly used. This research aims to obtain techno-economic feasibility through a simulation of castor oil production using SuperPro Designer version 13.0. The extraction process is carried out in two stages: mechanical extraction followed by water degumming, neutralization, and adsorption with activated carbon. Production capacity and technology used are adjusted to existing companies and literature. From the results of the economic analysis, this production process is feasible with an IRR of 32.11%, a PBP of 3.25 years, and a BC Ratio of 1.05.

Experimental and theoretical assessment of phenomena linked with separation and purification of biodiesel from Ricinus communis seed oil

This study investigated the phenomena associated with the separation and purification of biodiesel produced from Ricinus communis oil seeds using experimental and theoretical approaches. The alkaline transesterification technique was used to produce the biodiesel from the Ricinus communis oil seeds which were later compared with standards based on EN and ASTM. Experimental investigation of the components in the mixture for separation and purification was conducted using the standard turbidimetric method for binodal solubility and tie-line compositions. The gas chromatographic technique was used to determine the composition of the homogeneous mixture. Novel components separation and purification of the Ricinus communis seed oil biodiesel was achieved using ternary diagrams highlighting the constituent components of the biodiesel at different temperatures for enhanced separation and purification. At the coexisting extract and raffinate phases, the orientation angle of the component compositions increases as the methanol concentration increases and temperature increases. The analysis of seed oil in terms of its physicochemical properties showed density, refractive index, acid value, and free fatty acid values of 905 kg/m3, 1.486, 0.79 mg KOH/g, and 0.390 mg KOH/g respectively. The fatty acid composition of the seed oil and biodiesel revealed that the major characteristics of the oil and biodiesel were defined by the presence of linoleic acid (C18:2) and a ricinoleic acid hydroxyl group (C18:1, OH) with compositions of approximately 30% and 20% respectively. Fourier Transform Infra-Red (FTIR) spectrometry analysis of the oil and biodiesel showed that the absorption spectrum in terms of the wave number (cm−1) ranged from 1000 to 4000 cm−1 with esters as the main functional group providing the main structural backbone. The presence of different fatty acids leads to lateral homogeneity of the biodiesel molecules which can serve to organize the molecules into discrete domains with different properties for enhanced separation and purification at the investigated temperatures. Optimal separation and purification were achieved at the different temperatures showing the castor oil biodiesel, glycerol, and methanol components system at the prevailing composition, time, and temperatures from the tie-lines and binodal solubility compositions. This approach provides a means for the design of a more efficient separation process for optimal biodiesel purification after production with knowledge of how the components are distributed in the ternary mixture after the transesterification reaction. This, leads to greater efficiency of the process, reducing material and operational costs and eliminating environmental issues linked with the biodiesel production process as the volume of wastewater generated would be hugely eradicated. The findings of this study will be useful in the setting up of a small-to-medium-size biodiesel production facility with improvement in the efficiency of product separation and purification.

Optimization and kinetics of biodiesel production of Ricinus communis oil and used cottonseed cooking oil employing synchronised ‘ultrasound + microwave’ and heterogeneous CaO catalyst

Current novel work investigates synchronized ultrasound and microwave (MW + US) applications with an appropriation of Ricinus communis oil (RCO) and used cottonseed cooking oil (UCCO) blends for biodiesel production. The study aims at process optimization, kinetic and energy analysis of biodiesel production where fuel properties improved. The effect of oil/methanol proportion, CaO %, RCO + UCCO blend ratio, and reaction time is examined using Box-Behnken investigational design. The appropriation of blended oil proportion as a process parameter has been deliberated for the first time. The optimized conditions were methanol:oil ratio: 9.7:1; CaO wt%: 2.8 wt%, reaction time: 12.3 min, and 59:41 of RCO:UCCO blend proportion with highest biodiesel yield of 92.11 ± 0.06%. The blended oil transesterification kinetics followed the pseudo-first-order, with activation energy 1.8 times lower than the conventional process. Blended oil biodiesel showed ∼7.5% enhanced calorific value and two-time viscosity reduction than RCO biodiesel. Fuel properties found equivalent to ASTM-D6751 biodiesel standards.

Anticorrosion behavior of bioemulsions on metal-environment interface

The influence of Ricinus communis oil on electrochemical corrosion of steel in oil-in-water emulsions under controlled hydrodynamic condition was investigated. Emulsions from renewable biobased sources have gained prominent role in food and pharmaceutical industries as green excipients. The emulsion system under study was prepared from ricinus communis oil, hexadecyl polyglucoside and brine solution in which ricinus communis oil constitute the non-polar phase and surfactant constitute polar phase. The efficiency and effectiveness of these emulsion system highly influenced by their constituents and composition. Thus the stability of the as-prepared emulsion is analyzed through the optimization of various emulsion formulation factors such as viscosity, and creaming rate. The stability of emulsion was observed to increase with viscosity since it makes the particles to distribute evenly. The application of the emulsion on metallic surface under controlled hydrodynamic conditions was studied using potentiodynamic polarization Tafal plots. The newly formulated emulsion showed corrosion inhibition on the tested alloy steel and their corrosion rate was reduced to 0.5598 mm/year.The antimicrobial activity of this versatile emulsion was also assessed using in-vitro assay. This emulsion formulation can be used economically in industrial application as it may reduce the preventive maintenance, replacement of corroded equipment and contamination of product.

Effect of alginate impression disinfection with sodium hypochlorite and castrol oil on Candida albicans counts and dimensional stability of the study model

Alginate is the most common used material because it is easy to use, affordable, and well accepted by patients. When impressing, alginate would be in contact with the surface of the oral cavity and saliva. It caused the microflora, like Candida albicanswould adhere to the surface so that it can cause cross-infection. Cross-infection prevention could be done by disinfecting the impression material before filling with gypsum. The main things of choosing a disinfectant is that the disinfectant material could eliminate microorganisms and affect the dimensional stability of impression material. This study aimed to determine the effect of alginate impression disinfection with sodium hypochlorite and castor oil (Ricinus communis oil) on the Candida albicanscounts and the dimensional stability of the study model. The samples of Candida albicanswas counted by colony counter andthe dimensional stability test by digital caliper. This study showed that alginate impression desinfection with castor oil had almost the same effectiveness as sodium hypochlorite in reducing the Candida albicanscounts, but dimension was changed even though the value of the dimensional changes is still within the tolerance limit.

Gravimetric and Statistical Analysis of Combined Protection Performance of <i>Lavandula latifolia</i> and <i>Ricinus communis</i> on Low Carbon Steel

The protection performance of admixed Lavandula latifolia and Ricinus communis (LLRC) oil distillates on low carbon steel in 0.5 M H2SO4 and HCl was performed by gravimetric measurement. Data output shows LLRC distillate effectively stifled the corrosion of the carbon steel with peak protection performance of 96.35% at 1% LLRC concentration in H2SO4 solution and 88.72% at 6% LLRC concentration in HCl solution. LLRC performed more effectively in H2SO4 solution than in HCl. The performance of LLRC in H2SO4 exhibited significant non dependence on observation time while LLRC concentration strongly influenced its performance. In HCl solution observation time and LLRC concentration influenced the performance output of LLRC distillate in different proportions. Statistical evaluation rated the influence of LLRC concentration the protection performance of LLRC at 90.66% compared to 2.22% for observation time, while the corresponding values in HCl are 55.37% for LLRC concentration and 21.04% for observation time. Calculated data for standard deviation shows relatively minimal variation from mean values with respect to LLRC concentration and observation time at lower LLRC concentration in H2SO4 solution. At higher LLRC concentration, the degree of variation increases due to relative instability with respect to exposure time. The standard deviation values in HCl are significantly and relatively higher than the values obtained in H2SO4 solution due to significant deviation from mean values which signifies extensive instability with respect to exposure time. The margin of error shows 91.7% and 93.3% of LLRC protection performance data in H2SO4 and HCl solution are greater than 80% inhibition efficiency at margin of error of +6.99% and +6.31%.

A BUCOLIC REMEDY OF FORMULATION AND EVALUATION OF POLYHERBAL HAIR OIL

Objective: The birth of cosmetics forms an incessant narrative throughout the past of man as they developed. The present study aimed to formulate polyherbal hair oil using various efficient herbs. Methods: Hair oil formulation of Cocos nucifera (oil), Ricinus communis (oil), Brassica juncea (oil), Trigonella foenum-graecum (Seeds), Murraya koenigii (Leaf), Hibiscus rosa-sinensis (Flowers), Nigella sativa (seeds), and Cinnamomum camphora in the form of polyherbal oil using boiling method. These ingredients are rich in various phytochemicals, vitamins, proteins, antioxidants, and so many other constituents which are important for the growth and rejuvenation of the hair cycle. Evaluation of hair oil carries out by various parameters such as sensitivity test, acid value, saponification value, phytochemical screening, pH, specific gravity, viscosity, and irritation test. Results: All the values of evaluation are within the acceptable limit. As compared to market formulations, this herbal oil having minimal or zero adverse effects. Conclusion: It is concluded that formulated hair oil boost hair growth, decrease hair fall, dandruff, gray hair, and gives lustrous and shiny hairs.

Optimization of Small Castor Seed (Ricinus Communis) Oil Extraction Yield Using Response Surface Methodology

The process conditions that affect the percentage yield of oil from small castor seed was optimized for maximum extraction. In this study, surface response methodology (RSM) that employed a two-factor, five-level factorial central composite design (CCD) was used. Thirteen (13) experiments with different combinations of reaction time and reaction temperature ranging from 1hr (60mins) to 10hrs (600mins) and 60oC to 100oC respectively were also performed. A quadratic model that is polynomial in nature was obtained to predict the percentage oil yield for the small castor seed. Within the experimental variables range, the optimal conditions were found to be 8.68hrs (520.92mins) and 94.14oC respectively. These values were fitted into the quadratic polynomial model that gave rise to the optimum value of small castor seed oil yield to be 55.76% with a p-value less than 0.05. The coefficient of determination R2 was obtained as 0.9530 representing 95.30% of variation in the original data. Our result also gave an adjusted R2 value of 91.95% and predicted R2 value of 66.59% which indicate that the model explains 67% variation in predicting original observations. The result of this study showed clearly the percentage yield of oil that could be extracted from small seeded varieties of castor seed and the optimum yield value possible at a certain reaction time and temperature. The result also established the reliability of response surface methodology to model and optimize the expression of oil from small seeded varieties of castor seed.

Disinfection Effect of 10% Ricinus Communis Oil on Candida Albicans Counts of Heat Polymerized Acrylic Resin

Dentures is used to replace tooth loss. The most used denture base material is acrylic resin. The biological properties of acrylic resins give microorganisms the ability to colonize. Certain type of microorganism often found at the dentures base is Candida albicans. Denture’s disinfection is usually used to reduce Candida albicans. One of natural source that now is being widely researched is Ricinus communis oil. The purpose of this study was to analyze disinfection effect of Ricinus communis oil 10% on Candida albicans counts on heat polymerized acrylic resin. This research is an experimental laboratory study with a post-test only design. Samples was heat polymerization acrylic resin plates measuring 10 x 10 x 1 mm were made in the Department of Prosthodontic Faculty of Dentistry, Universitas Sumatera Utara with 10 plates for each for 10% Ricinus communis oil group and 0.2% chlorhexidine gluconate group (control). The Candida albicans colonies count was carried out in the Microbiology Laboratory, Faculty of Mathematics and Natural Sciences, Universitas Sumatera Utara using colony counter. The data obtained was statistically count with the Kruskal-Wallis Test. The result showed the decrease in Candida albicans count with the highest value in the 10% Ricinus communis oil group is 9 x 100 CFU/ml and the highest value in the 0.2% chlorhexidine gluconate group is 0 x 100 CFU/ml. The Kruskal-Wallis test showed significant results with p value of 0.0001 (p <0.05) indicating there was a disinfection effect of 10% Ricinus communis oil and 0.2% chlorhexidine gluconate on Candida albicans count of heat polymerized acrylic resin. The study concluded that 10% Ricinus communis oil effective at decreasing Candida albicans count.

PHYSICOCHEMICAL ANALYSIS AND CHARACTERIZATION OF BIODIESEL PRODUCTION FROM RICINUS COMMUNIS SEED OIL

The global energy concern with the availability of recoverable fossil fuel reserves and the environmental problems caused by those fossil fuels, considerable attention has been given to biodiesel production as an alternative to petro diesel worldwide. In this research, the seed oil of Ricinus communis (castor bean) was investigated for its viability as a feedstock for biodiesel production. The oil was extracted from the seed using petroleum ether .The oil quality characteristics of the seed oil were; Acid values for both Ricinus communis oil and biodiesel, 4.208 and3.93, and free fatty acids for both Ricinus communis and biodiesel were 1.2408 and 2.508, saponification value (SV) for both Ricinus communis and biodiesel,, 185.0 and 173.16, specific gravity (S.G) for both Ricinus communis and biodiesel, 0.976g/ml and 0.935g/ml. the PH value for both Ricinus communis and biodiesel, 6.67 and 6.8. Refractive index for both Ricinus communis and biodiesel, 1.37 and 1.191, moisture content of seed, 0.052. Colour for both and Ricinus communis oil and biodiesel is brown colour and amber colour, respectively. The oil was transesterified using methanol and concentrated sulphuric acid. And with other investigated oils from the literature and were found to fall within acceptable limits, this implies that Ricinus communis seed oil could be used as diesel in combustion engines in tropical climates like Nigeria.

Physical characteristics and utilization of ZSM-5 prepared from rice husk silica and aluminum hydroxide as catalyst for transesterification of Ricinus communis oil

Natural and synthetic zeolites are well-known materials sharing a wide range of applications, such as adsorbents, ion exchange, and catalysts. However, synthetic zeolites are more widely used, due to several limitations of natural zeolites, such as the presence of impurities and diverse compositions. In this study, rice husk silica (97.86% purity) and aluminum hydroxide were utilized for the preparation of ZSM-5, to study the effect of crystallization time on the physical characteristics and catalytic activity in the transesterification of Ricinus communis oil. The raw materials, with molar ratio of SiO2:0.025Al2O3:0.165Na2O:25H2O, were subjected to crystallization at 180 °C for 48, 72, 96, and 120 h, completed by 6 h calcination at 600 °C. The formation of ZSM-5 was demonstrated by FTIR, XRD, and SEM techniques, confirmed that the formation of ZSM-5 had taken place at 48 h crystallization, with no significant change with prolonged time. The PSA indicates the existence of two clusters of particles, and the BET confirmed the existence of the zeolites as porous materials, with the sample prepared with crystallization time of 96 h had the largest surface area and smallest pore diameter. This particular sample exhibited the highest activity, resulting in 96% conversion of Ricinus communis oil.

Synthesis of Generation-2 polyamidoamine based ionic liquid: Efficient dendrimer based catalytic green fuel production from yellow grease

A new series of acidic, dendrimeric polyamidoamine based polymeric ionic liquids of [PAMAM3256Cn] were synthesized with a second generation polyamidoamine dendrimer, alkyl bromides and 1, 3-propane sultone via a two-step procedure. The structure of functional ionic liquids was characterized by Fourier-transform infrared spectroscopy, nuclear magnetic resonance spectroscopy. The polyamidoamine -1- dodecyl [PAMAM3256C12] catalyst was used for green fuel production via the transesterification of yellow grease. The influence of reaction variables on the green fuel yield was studied using this catalyst. The catalyst was effective having achieved a 93% green fuel yield from yellow grease after 6 h of reaction at 65 °C, using 306.8 mol (10 mmol) (wt % based on molar concentration of lipids) of [PAMAM3256C12] catalyst, a yellow grease-to-methanol molar ratio of 1:20 with a constant agitation speed 800 rpm. The catalyst was showed excellent stability for yellow grease transesterification over four cycles. Additionally, catalysts showed excellent transesterification activity of Jatropha curcas, Ricinus communis, and Pistacia chinensis oil, with green fuel yields of 90, 91, and 92%, respectively. The properties of green fuel were met the ASTM D6751-02 standards. Results indicate that the [PAMAM3256C12] catalyst system shows promising potential as a viable industrial-scale alternative.

Chemical and electrochemical corrosion studies of ricinus communis oil based poly(urethane-ricinoleamide) coatings

In view of the depletion and possible exhaust of fossil fuels in near future, enormous increase in the cost of petroleum products and production of volatile organic compounds (VOC) by synthetic polymers and their application, the proposed article reports the development of sustainable resource based high performance Ricinus communis oil (Castor Oil) [RC] poly(urethane-ricinoleamide) [PUR] corrosion resistant coatings on mild steel. The physico-mechanical properties were investigated using standard methods. The corrosion resistance performance of PUR coatings was evaluated by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in acid (3.5 wt% HCl) and alkaline (3.5 wt% NaOH) mediums. The weight loss measurement was also carried out under tap water (Cl- ion 63 mg/l; Conductivity 0.953 mS/A). Salt mist test (5 wt% NaCl) was performed on these coatings. The effect of additional –OH functionality of RC oil on the corrosion resistance performance of PUR coatings was also discussed. These investigations reveal that the PUR coatings provide protection to the mild steel by reducing the corrosion current density by 104 times as compare to bare MS. These coatings also exhibits higher corrosion resistance performance as compared to other reported sustainable resource based coating systems, hence show good potential for their commercial application.

A Potential Inhibition Process of Ricin Protein with the flavonoids Quercetin and Epigallocatechin Gallate. A Quantum-Chemical and Molecular Docking Study

Castor bean (Ricinus Communis) oil has been reported as one of the most important bio-based fuels; however, high amounts of toxic solid residue are generated in the production. This toxicity is due to several molecules, ricin protein being the most studied compound. The inhibition of the ricin protein is essential for eliminating its toxicity. The objective of this study is to predict the possible inhibition process via the interactions between the ricin protein and the flavonoids quercetin (Q) and epigallocatechin gallate (EGCG). The molecular structures of the complexes formed between the ricin protein and flavonoids were studied using quantum-chemical and molecular docking calculations to analyze the type of interaction, active site of the protein, binding energies, and different conformations in the inhibition process. Different methodologies were applied for the molecular structure determination; the best approximation was obtained with B3LYP/6-31G (d,p) theoretical methodology. Mappings of electrostatic potential (MEP) and frontier molecular orbitals were used for the identification of the probable sites of interaction, which were confirmed by molecular docking. The adjustment and alignment of flavonoid groups before and after the interaction, and charge transfer parameters, showed that Q and EGCG act as electron donors inside of the active site in ricin.

Optimization of Protection Condition on the Stability of Castor (Ricinus communis) Oil Based Biodiesel using Response Surface Methodology

The effects of designed protection conditions such as different antioxidants (propyl gallate, PG and Pyrogallol, PY), antioxidant concentration (30 – 600 ppm), temperature (30˚C -120˚C) and storage period (3 – 5 days) on the oxidation stability of castor biodiesel were investigated work was to assess the effect of the antioxidants on the oxidative stability of castor biodiesel. Using the American Standard for Testing Materials (ASTM) recommended protocols to determine the changes in the physicochemical properties (acid value, p-anisidine value, peroxide value, totox value, density, kinematic viscosity and refractive index) of the castor biodiesel were measured. The protection conditions were optimized using the Response Surface Methodology (RSM) according to the Box–Behnken Design (Design Expert version 11 Statistical Software). The analysis of variance (ANOVA) of propyl gallate showed concentration levels and temperature as the most important factors in the biodiesel oxidation, whereas the day of storage was one of the lowest factors with the p-value of < 0.05 for most indicated process variables of both linear and quadratic model terms were significant. The changes in some important physicochemical values are indication of degradation occurring in the biodiesel under the set storage condition. The optimal storage conditions were observed in propygallol with the acid value (0.985 mg KOH/g), p-anisidine value (7.650 mg KOH/g) and Totox value 4.005 (mEq/kg) with the overall desirability of 0.923 based on comparatively lower acid, p-anisidine and Totox values, followed by PG. The combined use of PY/PG antioxidants didn't show a synergic or additive result that makes the mixture of those antioxidants unsuitable to boost the biodiesel stability based on their relatively higher Totox Value.

Green synthesis of biodiesel from Ricinus communis oil (castor seed oil) using potassium promoted lanthanum oxide catalyst: kinetic, thermodynamic and environmental studies

Large scale production of biodiesel from a lignocellulosic biomass using an efficient heterogeneous catalyst has several benefits like low production cost, reduction in CO2 emission along with other greenhouse gases, agricultural development and assurance of future energy supply. In present study, a solid base catalyst named as potassium (K) promoted lanthanum oxide (La2O3) has been synthesised by sol-gel auto-combustion method (Pechini's method) and introduced in transesterification of castor oil. Synthesized K promoted La2O3 catalyst was characterised by TGA-DTA, FT-IR, XRD, XPS, BET surface area analysis, HRSEM-EDX, Hammett indicator titration for basicity evaluation. Optimum K/La atomic ratio and catalyst activation temperature was investigated in terms of highest activity of the catalyst which was found at 1.5K/La atomic ratio and 900 °C calcination temperature for transesterification of castor oil. The following reaction influencing factors were optimised to be 1:16 oil to methanol molar ratio, 65 °C reaction temperature, 2 wt% catalyst loading, 500 rpm rotating speed of mechanical stirrer, 150 min reaction duration. Maximum 97.5% fatty acid methyl ester (FAME) conversion of castor oil was obtained under optimum circumstances. The product biodiesel was characterized by 1HNMR spectroscopy. Then reusability study and active metal leaching tests were performed simultaneously to find out the reason behind deterioration in activity of the catalyst during recycling process. It was found that the catalyst was efficient to produce 85.3% FAME conversion up to five reaction cycles at optimised reaction condition. The reaction activation energy (Ea) and pre-exponential factor (A) were estimated to be 47.13 kJ/mole and 9.93×105 per min respectively by the study of kinetics and thermodynamics regarding methyl esterification process of castor oil using K promoted lanthanum oxide catalyst. Additionally, the corresponding enthalpy of activation (ΔH#), entropy of activation (ΔS#) and Gibb’s free energy of activation (ΔG#) were evaluated to be 45.27 kJ.mol−1, −142.81 J.mol−1.K−1 and 93.53 kJ.mol−1 accordingly by the mean of Eyring-Polanyi’s plot. Turnover frequency and environmental studies implied that biodiesel production from castor oil using K promoted La2O3 is an efficient and green process.