جستجوی مقالات مرتبط با کلیدواژه "biodiesel" در نشریات گروه "شیمی"

The quest for alternative energy sources, driven by the challenges of fossil fuels, has led to the development of biofuels. This study focuses on producing biodiesel from waste avocado oil through transesterification. Initially, oil was extracted from the peels and seed of avocado pear using an extraction technique. The extracted oil was then pre-treated with methanol and sulfuric acid (H₂SO₄) to reduce its free fatty acid content to less than 1.0 wt%. This study compares two expert systems, Adaptive Neuro-Fuzzy Inference System (ANFIS), and Response Surface Methodology (RSM), for modeling and optimizing biodiesel production from avocado oil. The performance of these optimization tools was evaluated using statistical indices. The results showed that ANFIS outperformed RSM with a low error value, the Standard Error of Prediction (SEP)=0.7653, the Mean Absolute Error (MAE)=0.1413, the Root Mean Squared Error (RMSE)=0.4103, the Average Absolute Deviation (AAD)=0.2955%, the Mean Squared Error (MSE)=0.1683, and a high coefficient of determination (R² = 0.9976). Both models predicted high biodiesel yields (>85%), with ANFIS achieving a slightly higher yield (88.21%) compared to RSM (86.20%). The properties of the biodiesel produced under optimized conditions were compared with American Society for Testing and Materials (ASTM) D6751 and European Norm (EN) 14214 standards and were found to be within acceptable limits, indicating the fuel’s suitability.

Biodiesel production from waste cooking oil (WCO) holds promise as a renewable and sustainableenergy source. However, high levels of free fatty acids (FFAs) in WCO require efficient pre-treatment before transesterification. Utilizing solar energy for heterogeneous catalytic reactionsoffers an alternative to thermal-driven processes. TiO2EFBA, synthesized via the wet impregnationmethod, exhibits distinctive physicochemical properties confirming the successful incorporationof titanium dioxide (TiO2) onto the metal oxides of empty fruit bunches ash (EFBA), thereby en-hancing the catalyst’s performance and stability. Results showed that TiO2EFBA exhibits superiorFFA conversion compared to TiO2alone. Under optimized reaction conditions, employing 4 wt%TiO2EFBA catalyst, 20:1 methanol to oil molar ratio, and 2 h reaction time at room temperatureunder Ultra Violet (UV) light, achieves a remarkable 78% conversion rate of FFAs in WCO.Mechanistic investigation reveals the crucial role of electron/hole (e−/h+) species in reducingFFAs by suppressing the e−/h+mechanism. Notably, TiO2EFBA facilitates easy separation andcan be reused for 10 cycles, demonstrating its stability as a heterogeneous photocatalyst.

The density of the biodiesel, butanol, and diesel components, binary mixtures of biodiesel + butanol, biodiesel + diesel, and butanol + diesel components, and ternary mixture of biodiesel + butanol + the densities of diesel were experimentally determined at temperatures of (29315, 31315, 33315, 35315) *10-2K, under standard atmospheri pressure. Measurements with a step length of 0.1 have been performed in the interval from 0 to 1. Densities were measured with an Anton Paar DMA 4100 M densitometer. Observations indicated that, the amount of additional molar volume for binary systems of biodiesel + butanol was negative with increasing temperature, which indicated the physical interactions between butanol and biodiesel; while in ternary systems, different behavior had been observed at different temperatures. The Redlich-Kister (R-K) formula was utilized to approximate the excess molar volumes of binary systems, with coefficients being determined vi a polynomial theory. Ultimately, standard deviations and correlation coefficients were computed to validate the subsequent experimental data based on the R.K model The excess molar volume in the 0.6 molar fractions of biodiesel, 0.2 diesel, 0.2 butanol in the biodiesel+diesel+butanol ternary system reached to highest negative value of -1.094 cm3/mol with increasing temperature.

The global appeal of biofuels is increasing due to rising energy demands and the depletion of fossil fuel resources. Biodiesel stands out as a promising alternative to petroleum diesel, offering a cleaner energy solution. This study addresses key challenges associated with biodiesel, such as reduced calorific value, high nitrous oxide emissions, and production costs, as well as the environmental impact of petroleum diesel, including global warming.This research focuses on the development of a novel biobased catalyst derived from palm kernel shell and eggshell. The carbon-based biomass, primarily waste palm kernel shell, was pyrolyzed to produce the catalyst. Characterization of the catalyst was performed using scanning electron microscopy (SEM), X-ray fluorescence (XRF), and Fourier transform infrared spectroscopy (FTIR). The catalyst was synthesized via the incipient wetness impregnation (IWI) technique, resulting in a bifunctional catalyst suitable for the transesterification process.The catalyst demonstrated high efficiency in the transesterification process for biodiesel production. Optimal conditions yielded an 88.14% biodiesel conversion at an oil-to-methanol molar ratio of 1:14, catalyst loading of 5 wt.%, reaction temperature of 70°C, and reaction time of 99.244 minutes. The synthesized biodiesel met the ASTM D6751 standards as specified by the International Organization for Standardization (ISO).

This study extensively analyzed the use of used cooking oil as biodiesel and liquid insulation in the electrical and energy sectors. Biodiesel offers a sustainable alternative to traditional diesel, while liquid insulation ensures the efficient operation of electrical equipment. The research covered biodiesel's properties, engine performance, and handling, along with liquid insulation's effectiveness. Findings revealed favorable fuel characteristics of biodiesel from used cooking oil, compatible with most engines and emitting fewer pollutants. Liquid insulation showcased exceptional insulating properties suitable for various electrical applications. Biodiesel's advantages include moderate density, lower viscosity, higher flash point, and low acid value, making it an eco-friendly transportation alternative. Cold flow properties support its use in colder climates, with a cloud point of -4°C and a pour point of -9°C. Its high cetane number and calorific value and good oxidative stability index highlight its energy efficiency, contributing to cleaner emissions. Engine tests revealed higher torque, power output, and lower fuel consumption (5.8 L/100 km) compared to conventional diesel, suggesting improved fuel economy. Biodiesel showed lower CO2, CO, NOx, PM, HC, and SO2 emissions, supporting environmental friendliness. Proper handling practices and liquid insulation's dielectric properties, such as a breakdown voltage of 40 kV, dielectric constant of 2.4, high resistivity of 2.5 x 1011 Ωm, and low thermal conductivity (0.19 W/m-K), were emphasized. This research enhances understanding of renewable resource attributes and their potential for long-term energy solutions. Biodiesel production from used cooking oil and its use as liquid insulation promise to reduce environmental impacts and promote eco-friendly practices in the energy and electrical sectors. Adoption of these technologies can significantly contribute to a greener, more sustainable future.

Biodiesel production faces challenges due to high raw material costs, a significant obstacle to its development as an alternative to traditional diesel. This study investigates biodiesel production from waste cooking oil using inexpensive catalysts like CaO on discarded glass and potassium hydroxide on discarded glass. Experiments showed over 90% and 97% purity, respectively, using catalysts like CaO/DG and KOH/DG in a glass reactor, with the highest purity achieved with 20 wt.% and 25 wt.% loading of these catalysts on discarded glass. The high cost of raw materials hinders biodiesel production, but the use of these catalysts offers a viable alternative to diesel fuels.

The study investigated the efficiency of biodiesel conversion from jatropha oil-based free fatty acid using an acid-based catalyzed transesterification bioprocess. The maximum Jatropha biodiesel yield was 80% in a 1-hour reaction using a 0.03:1 acid catalyst to oil and a 2:1 alcohol-to-oil ratio. At the same time, the optimum biodiesel yield was in a 2-hour reaction for step 2 by using a 0.03:1 ratio of base catalyst to oil and a 5:1 ratio of alcohol to oil. The Fourier Transform Infrared Spectrometer analysis of Jatropha Biodiesel (JB) revealed a methyl peak (O-CH3) at 1436.07 cm-1, indicating compatibility with pure mineral diesel, high speed (1295.67rpm), brake horsepower(30.6906KW), mechanical efficiency (53.10%), and lower specific fuel consumption (15.5879 mL/KW. compared with other Jatropha biodiesel blends.

MgO/γ-alumina and CaO/γ-alumina heterogeneous base catalysts have been prepared by wet impregnation, using 10 wt.% of metal oxide precursors, and used in the transesterification reaction of castor oil (Riccinus communis) into biodiesel. Catalyst characterization includes X-Ray Diffraction (XRD), Fourie Transform InfraRed (FT-IR) spectroscopy, X-Ray Fluorescence (XRF), Surface Area Analyzer (SAA), average pore radius (BJH), and basicity. The catalyst performance was observed from the activity and selectivity of the catalyst in converting castor oil into methyl ester with batch system at 60°C for 2 hours. The castor oil biodiesel was analyzed using GC-MS to determine the selectivity of the catalyst towards methyl ricinoleate. The results showed that the addition of MgO and CaO to γ-alumina increased the basicity and average pore radius but decreased the specific surface area of γ-alumina. The FAME yields of γ-alumina, MgO/γ-alumina, CaO/γ-alumina, MgO, CaO, and KOH catalysts with 3 wt.% ratio were 81.15%, 82.17%, 82.45%, 82.02%, 82.16%, and 84.57%. The selectivity to methyl ricinoleate was the highest for CaO/γ-alumina catalyst which was 87.57% area GC. The yield of FAME at various weight ratios of CaO/γ-alumina (1, 2, 3, 4, and 5 wt.%) were 81.81%, 82.13%, 82.45%, 83.57%, and 83.96% and the selectivity to methyl ricinoleate was the largest at 4 wt.% CaO/γ-alumina catalyst which was 90.20% GC area. Castor oil biodiesel was analyzed according to the American Standard of Testing Materials (ASTM) method for biodiesel eligibility. ASTM test results for castor oil biodiesel showed a kinematic viscosity (40°C) of 15.76 mm2/s which is above the biodiesel standard because the kinematic viscosity of castor oil was also high. The flash point of 222.5°C, pour point <27°C, and cloud point of 15°C have fulfilled the requirements of the biodiesel standard.

Microalgae have garnered significant attention as a promising source for biodiesel production due to their rapid growth, high lipid content, and minimal resource requirements. This study delves into the forefront of microalgal biofuel research by investigating emerging co-cultivation strategies aimed at optimizing biomass production for biodiesel synthesis. Through a nuanced exploration of diverse microalgal strains, this work pioneers innovative co-cultivation techniques designed to enhance synergies between different species, thus maximizing overall productivity. Microalgae are excellent options for the production of biodiesel since they have high lipid content and grow quickly. Nonetheless, difficulties in maximizing lipid and biomass production have led the technological advancement microalgal productivity using photobioreactors, closed systems and monitoring and genetic Engineering The article delves into the impact of Co-cultivation on microalgal growth such as improved Biomass production, enhanced lipid content and quality and nutrient utilization and recycling.

Decreasing reserves of fossil fuels and environmental concerns like greenhouse gases havebrought increasing studies into renewable and low-carbon sources of energy. Biodiesel is arenewable and sustainable replacement for crude oil that has become increasingly importantas the world’s supply of petroleum decreases, and it is vitally important to conduct research onnew feedstocks with high effi ciency, competitive pricing, and ease of manufacture. Herein wereported nine diff erent biodiesels that were produced from the nine common vegetable oils ofcoconut oil, sesame oil, poppy oil, castor oil, bitter almond oil, olive oil, black seed oil, peanutoil, and pecan oil. The yields of the produced biodiesels are in the range of 50 to 98%, and thedensity and fl ashpoints of the produced biodiesels were in the ranges of 0.85 to 0.99 (g/cm 3 )and 150 to 222°C. Moreover, compositions of the produced biodiesels were analyzed by GCand the concentrations of the main fatty acid methyl esters (FAME) were reported andcompared. Lauric acid methyl ester, oleic acid methyl ester, linoleic acid methyl ester, ricinoleicacid methyl ester, and stearic acid methyl ester are the main components of the producedbiodiesels.

Diesel fuel can be substituted with biodiesel fuel. Burning biodiesel results in less pollution because its source is vegetable or animal fat. Waste cooking oil (WCO) was utilized in this study as a raw source to produce biodiesel. In the WCO under study, the percentage of free fatty acids (FFAs) was 4.09%. The process of turning used cooking oil waste into biodiesel involved two steps. The initial phase was studying the photocatalytic esterification of methanol with FFAs in WCO under visible irradiation using Cr (x%)-TiO2. Triglycerides and methanol were transesterified in the second stage, which was catalyzed by NaOH. When TiO2 was present, efficiency was shown to increase by 10% when compared to the absence of a photocatalyst. Cr-TiO2 photo-esterification reaction has an equivalent order of one. The realisation of the reaction under mild conditions was confirmed by the activation energy of 31.36 kJ/mol needed for the Cr-TiO2 photocatalyst to photo-esterify WCO. Our hypothesis for the esterification process took into account the formation of H+, CH3OO·, and R-COOH on the photocatalyst surface. OH- was thought to be the active species in the transesterification reaction process. The density of the produced biodiesel was 0.89 g.cm-3, per the data that were obtained. For biodiesel, the results yield a falling point of -5 and a cloud point of 0, respectively. The biodiesel made from waste oil had a viscosity of 4.1 mm2.s−1, which was within the standard range. The biodiesel sample made from waste oil has an acid value of 0.38 mg KOH

In the work, vapor-liquid equilibrium (VLE) of pure and binary mixtures of the systems including fatty acid Ethyl or Methyl esters and alcohols is analyzed by two simple cubic equations of state; Cubic-Square-Well (CSW EoS) and the Peng-Robinson (PR EoS). To achieve this purpose, first, the parameters of equations of state for pure systems are optimized using experimental vapor pressure and liquid density. Two models show accepted accuracy, however, the PR EoS with AARD=1.01% demonstrations better results for pure systems. Then the results of the pure systems are used to correlate the phase behavior of the binary mixtures in low and high pressure using one binary interaction parameter in equilibrium systems. The results for binary fatty acid ester systems show deviations as AARD=0.45% and AARD=0.23% for PR and CSW EoSs, respectively. For alcohol+fatty acid ester binary systems the pressure deviations are AARD=5.04% and AARD=14.14% for PR and CSW EoSs, respectively. Therefore, the results show that the CSW and PR equations of state can be applied to calculate the phase behavior of these types of systems with good accuracy and simplicity, therefore, can be used in designing, modeling, and optimization of the biodiesel units.

Recently, the synthesis of biolubricants has been the focus of researchers because of their good lubricating properties and environmentally friendly products. This study was performed to optimize reaction parameters for the enzymatic transesterification reaction between waste edible oil methyl ester (biodiesel, FAME) and trimethylolpropane (TMP) by using Response Surface Methodology (RSM). The parameters that affect the enzymatic transesterification reaction were chosen as temperature (35–55°C), amount of catalyst (0–10 %wt. of mixture), TMP-to-FAME molar ratio (0.17-0.33), and reaction time (0–96 h), to produce TMP triester (biolubricant). Response surface methodology (RSM) and three-level–four-factor Central Composite Design (CCD) were employed to evaluate the effects of these synthesis parameters on the percentage conversion of FAME by transesterification. Enzyme amount and reaction time were the most important variables. The optimum reaction conditions were determined to be the temperature at 50°C; the amount of catalyst, 5%wt; molar ratio, 0.25 and 48 h of reaction time, under these conditions 91% TMP ester's yield was obtained. The interaction parameter of the lipase quantity with the FAME to TMP molar ratio was found to be the most important among all of the other parameters.

Petroleum resources are limited on a global scale. Due to non-renewability, these fossil-fuels are projected to be depleted in next 40-60 years if consumption continues at the current pace. Moreover, the price instability of crude oil poses a significant threat to nations with constrained financial and economic resources. To address these challenges, alternative energy sources are being explored, and there is ongoing emphasis on further progress in these areas. As an alternative fuel, biodiesel can be used in neat form or mixed with petroleum-based diesel. Therefore, we need to move towards alternative fuel like bio-diesel. Several alternative fuels have been studies among which biodiesel from waste soybean oil having great importance. Bio-diesel could be easily prepared from waste soybean oil, by the process of transesterification with alcohol in presence of sodium hydroxide or potassium hydroxide. India is the fourth largest producer of soybean in the world, and from last few decades, soybean oil is exclusively use as edible oil. In different food industries, several million tonnes of soybean oil uses every year. Therefore, huge amount of waste soybean oil is produced every year. In the present work, we attempt to synthesize biodiesel using waste soybean oil via transesterification, and characterize by physical, chemical, and spectroscopic instruments, and found the characteristics properties of this biodiesel is quite similar to petroleum diesel . Therefore, this synthesis may use biodiesel as an alternative for petroleum diesel.

Methyl ester is the name given to monoalkyl esters of vegetable and animal oils. Since methyl ester has fuel properties that are comparable to those of diesel fuel, it is becoming more popular as a substitute fuel for use in diesel engines. The amount of free fatty acids (FFA) in the oil determines how methyl ester is produced. In this study, the titration method was used to calculate the FFA values of the crude cottonseed oil (CCSO) and one-time Used Cottonseed Oil (UCSO), with values 0.56 % and 1.26 %, respectively. The UCSO is transformed into methyl ester by employing a heterogeneous alkali catalyzed transesterification reaction. It involves the addition of methanol to bleach and degummed UCSO in the presence of heterogeneous catalysts CaO-blend derived from calcinated eggshells and coconut shell blend. Reaction variables including the methanol-to-oil ratio, reaction temperature, reaction time and catalyst concentration control the transesterification process. The Box-Behnken design was employed to optimize the aforementioned parameters using the response surface methodology (RSM). Numerous factors that affect the generation of biodiesel have been plotted using the response surface plot and contour plot. An optimized UCSO methyl ester yield of 92.00 % was obtained at a 1:10.80 molar ratio, 2.5 wt. % catalyst concentration, 80 minute reaction time, and 60 °C reaction temperature. The experimental yield was 92.10 %, as determined by the optimized yield based on these parameters. This shows that the response surface methodology is a successful strategy for increasing the yield. The regression model proved successful, as observed by the error values between the predicted and actual outcomes being less than 1 % UCSOME conversion. For this study, adequate precision was 8.9518. As a result, the model can be utilized to explore the design space. Each succeeding cycle of reuse produced 91.60 %, 85.50 %, 81.60 %, 78.60 %, 74.20 %, and 72.87 % of the biodiesel. The measurements for viscosity, density, and flash point of UCSO were 33-36 mm2/s at 311 K, 911-916 kg/m3 at 288 K, and 504-510 K, respectively. UCSO methyl ester (UCSOME) had a viscosity between 3.6 and 3.7 mm2/s and a density between 875 and 880 at 311 K. While the flash points of the UCSOME are measured at 435–440 K as opposed to 504-510 K. The saponification value of cottonseed oil was 188.32 mg/g while that of biodiesel was 165.87 mg/g. Thus, biodiesel fatty acid methyl ester possesses a distinctive FTIR absorption of carbonyl (C=0) stretching vibrations near 1740-1744 cm-1 and C-O bending vibrations in the range of 1196 cm-1.

The world''s rising industrialization and motorization are to blame for the rise in demand for petroleum products. As a result, alternative fuels that can be made with locally available materials must be sought. Biodiesel is a liquid fuel similar to diesel that is created from biological sources that are renewable. Methyl esterification is a process that may turn any type of vegetable oil or animal fat into biodiesel, which is subsequently suitable for use in diesel engines. Our present investigations, aims to examine the difficulties in producing biodiesel from neem oil and to look into the characteristics of the fuel, which is fully made of mono alkyl esters produced by the transesterification process. For this experimental operation, a single cylinder, four-stroke, kirlosker diesel engine with a 1500 rpm, 3.72 kw brake power, 110 mm stroke length, 80 mm bore, and 17.5 compression ratio was used.At 1kg, 2.5kg, and 4kg loads and 2B, 3.5B, 5B, and 6B blends, the brake power efficiency, brake thermal efficiency, mechanical efficiency, specific fuel consumption, and emission characteristics were computed and examined. Biodiesel outshines diesel oil, according to the data.

In the present study the production of biodiesel was performed by using raw material like soybean oil by trans-esterification process. According to the American Society for Testing and Materials (ASTM), the international specification free glycerol in biodiesel should not be more than 0.02 mass %. To achieve the biodiesel with the ASTM specification, biodiesel was separated using prepared PAN ultrafiltration membranes. The polyacronitrile ultra filtration membranes were prepared on supporting material of woven fabric by phase inversion technique of membrane casting. The prepared membranes were characterized in terms of its molecular weight cut off and flux of the membranes. Different molecular weights of the BSA solutions were used to determine the molecular weight cut off of the membranes. Then the obtained 6KDa and 15KDa Ultra filtration PAN membranes were used to separate the glycerol from (FAME) free acid methyl ester. It was observed that the both membranes were separated glycerol from the biodiesel below 0.02 mass % which meets the requirements of the ASTM specification of glycerol. The permeate side of the 6KDa membrane was estimated to be 0.017 mass % of glycerol, whereas, 15 KDa membrane was 0.02 mass % . The glycerol percentage in retained side membranes were increased with time.