Project description:Providing sufficient energy supply and reducing the effects of global warming are serious challenges in the present decades. In recent years, biodiesel has been viewed as an alternative to exhaustible fossil fuels and can potentially reduce global warming. Here we report for the first time the production of biodiesel from oleic acid (OA) as a test substrate using porous sulfonic acid functionalized banana peel waste as a heterogeneous catalyst under microwave irradiation. The morphology and chemical composition of the catalyst was investigated using Powder X-ray diffraction (PXRD) analysis, Fourier transform infrared (FTIR) spectroscopy, Thermogravimetric analysis (TGA), Transmission electron microscopy (TEM), and Scanning electron microscopy- Energy dispersive X-ray spectroscopy (SEM-EDX). The SEM-EDX analysis of the catalyst revealed the presence of sulfur in 4.62 wt% amounting to 1.4437 mmol g-1 sulfonic acids, which is accorded to the high acidity of the reported catalyst. Using response surface methodology (RSM), through a central composite design (CCD) approach, 97.9 ± 0.7% biodiesel yield was observed under the optimized reaction conditions (methanol to OA molar ratio of 20:1, the temperature of 80 °C, catalyst loading of 8 wt% for 55 min). The catalyst showed excellent stability on repeated reuse and can be recycled at least 5 times without much activity loss.
Project description:To produce biodiesel cost-effective, low-cost, high free fatty acid (FFA) oil feedstock is desirable. But high FFA creates difficulty during the base-catalyzed transesterification process by yield loss due to the formation of soap. However, these problems are overcome by the use of an acid catalyst. The acid catalysts can directly convert both triglycerides and FFAs into biodiesel without the formation of soaps or emulsions. The shortcomings of mostly used inorganic acids are that they work well for esterification of FFA present in low-cost oil, but their kinetics for transesterification of triglycerides present in oils is considerably slower. Corrosion of equipment is another major problem associated with an inorganic acid catalyst. The usage of an organic acid catalyst of the alkyl benzene sulfonic type, like 4-dodecyl benzene sulfonic acid (DBSA) minimizes these disadvantages of inorganic acid-catalyzed transesterification. The aim of the present investigation was to reduce the reaction time of transesterification of triglycerides further by using microwaves as a heating source in the presence of DBSA catalyst to achieve higher conversions under mild operating conditions. To optimize the transesterification variables for the higher conversion of biodiesel, the response surface methodology was employed to design the experiment. By using the DBSA catalyst under microwave heating at a temperature of 76 °C, conversion close to 100% in only 30 min of reaction time was obtained using a 0.09 molar ratio of catalyst to oil and 9.0 molar ratio of methanol to oil. A modified polynomial model was developed and was adequately fitted with the experimental data and could be used for understanding the effect of various process parameters. The catalyst to oil molar ratio and reaction temperature created a stronger effect on the biodiesel production than that exhibited by the methanol to oil molar ratio. It was observed that the microwave heating process outperformed conventional heating, providing a rapid, easy method for biodiesel synthesis from triglycerides in the presence of DBSA, an organic acid catalyst. The produced biodiesel was of good quality, as all the properties were within the prescribed limits of the ASTM D6751 standard.
Project description:Fenton or Fenton-like reactions have been widely used in various fields, including solar energy conversion to generate hydroxyl radicals, environmental remediation, biology, and life science. However, the slow Fe3+/Fe2+ cycle and narrow applicable pH range still present significant challenges. Here, a heterostructured CoFe-layered double hydroxide/MoS2 nanocomposite (CoFe-LDH/MoS2) was prepared via simple electrostatic interactions. The heterostructure establishes a robust interfacial contact, leading to an abundance of exposed Mo6+ sites. Consequently, the developed CoFe-LDH/MoS2+H2O2 system exhibited superior performance in the degradation of tetracycline (>85%) within 60 min across a wide pH range from acidic to basic. Moreover, the CoFe-LDH/MoS2 heterojunction catalysts exhibited exceptional resistance to common anions and efficiently degraded various organic pollutants. The mechanism study verified that the CoFe-LDH/MoS2 had high efficiency in producing 1O2 and ‧OH to degrade various organic pollutants. The present study will serve as a foundation for creating efficient catalyst systems for related environmental remediation.
Project description:The optimum conditions to produce palm fatty acid distillate (PFAD)-derived-methyl esters via esterification have been demonstrated with the aid of the response surface methodology (RSM) with central composite rotatable design in the presence of heterogeneous acid catalyst. The effect of four reaction variables, reaction time (30-110 min), reaction temperature (30-70°C), catalyst concentration (1-3 wt.%) and methanol : PFAD molar ratio (3 : 1-11 : 1), were investigated. The reaction time had the most influence on the yield response, while the interaction between the reaction time and the catalyst concentration, with an F-value of 95.61, contributed the most to the esterification reaction. The model had an R 2-value of 0.9855, suggesting a fit model, which gave a maximum yield of 95%. The fuel properties of produced PFAD methyl ester were appraised based on the acid value, iodine value, cloud and pour points, flash point, kinematic viscosity, density, ash and water contents and were compared with biodiesel EN 14214 and ASTM D-6751 standard limits. The PFAD methyl ester was further blended with petro-diesel from B0, B3, B5, B10, B20 and B100, on a volumetric basis. The blends were characterized by TGA, DTG and FTIR. With an acid value of 0.42 (mg KOH g-1), iodine value of 63 (g.I2/100 g), kinematic viscosity of 4.31 (mm2 s-1), the PFAD methyl ester has shown good fuel potential, as all of its fuel properties were within the permissible international standards for biodiesel.
Project description:The dataset presented here are part of the data planned to produce biodiesel from flaxseed. Biodiesel production from flaxseed oil through transesterification process using KOH as catalyst, and the operating parameters were optimized with the help of face-centered central composite design (FCCD) of response surface methodology (RSM). The operating independent variables selected such as, methanol oil ratio (4:1 to 6:1), catalyst (KOH) weight (0.40-1.0%), temperature (35 °C-65 °C), and reaction time (30 min-60 min) were optimized against biodiesel yield as response. The maximum yield (98.6%) of biodiesel from flaxseed can achieved at optimum methanol oil ratio (5.9:1), catalyst (KOH) weight (0.51%), reaction temperature (59.2 °C), and reaction time (33 min). The statistical significance of the data set was tested through the analysis of variance (ANOVA). These data were the part of the results reported in "Optimization of process variables for biodiesel production by transesterification of flaxseed oil and produced biodiesel characterizations" Renewable Energy [1].
Project description:Tubocapsicum anomalum, a Chinese medicinal plant rich in anti-tumor withanolides, requires efficient extraction methods. In this paper, an HPLC method was first established for the detection of withanolides, and gradient elution was carried out using a methanol-water solvent system. It was found that the content of withanolides was the highest in the leaves of T. anomalum, followed by the stems and fruits, and almost none in the roots. During the actual picking process, the quantity of leaves collected was relatively small, while the number of stems was the highest. Therefore, the Box-Behnken response surface method was used to optimize the ultrasonic-assisted extraction process of withanolides from the stems of T. anomalum. The optimal extraction conditions were determined as follows: the liquid-solid ratio was 20:1, the extraction solvent was 70 % ethanol, the ultrasonic power was 250 W, the ultrasonic time was 40 min, and the ultrasonic temperature was 50 °C. Under these conditions, the average yields of tubocapsenolide A (Te-A) and tubocapsanolide A (Ta-A) can reach 2.87 ± 0.12 mg/g and 1.18 ± 0.05 mg/g, respectively. We further compared extraction rates of two withanolides from different parts of T. anomalum using ultrasonic and traditional extraction methods. Ultrasonic extraction significantly increased rates, with the highest yields from leaves, followed by stems and fruits. The results show that ultrasonic optimization can improve extraction rate, reduce time, lower costs, enhance quality, and increase yield. Therefore, the optimized ultrasonic-assisted extraction process was adopted to extract the aerial parts of T. anomalum and separate the components. After optimization, the extract underwent several chromatographic separations to isolate eight previously undescribed withanolides (1-8) and two artificial withanolides (9-10), in addition to fifteen known compounds (11-25). Their structures were established through extensive spectroscopic data analysis. The compounds were evaluated for their antiproliferative effects against multiple cancer cell lines, including human hepatocellular carcinoma cells (HepG2, Hep3B, and MHCC97-H), human lung cancer cells (A549), human fibro-sarcoma cancer cells (HT1080), human chronic myeloid leukemia cells (K562), and human breast cancer cells (MDA-MB-231 and MCF7). Compounds 1-3, 5, 7, 11, 13, 15-16, and 22 displayed significant activity with IC50 values of 5.14-19.87 μM. The above results indicate that ultrasonic-assisted extraction technology can be used to obtain new withanolides more efficiently from T. anomalum, thereby enhancing the utilization rate of T. anomalum resources.
Project description:This study aims to optimize the lipid content of Scenedesmus sp. for high-yield biodiesel production. Three factors affecting the culture conditions, namely salinity, nitrogen concentration, and light intensity, were selected and their effects on the maximum lipid content were investigated using the Box Behnken design. The results showed that the maximum lipid content (32.7% of algal dry weight) was obtained in the algal samples cultured under the optimized conditions. A core-shell magnetic nano-catalyst, NiFe2O4@SiO2/MgO, was synthesized and used to produce biodiesel via the transesterification reaction. The nano-catalyst was characterized by field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffraction analysis (XRD), vibrating sample magnetometry (VSM), elemental mapping techniques, transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). Using the Box Behnken design and keeping the temperature constant, the molar ratio of methanol to oil, the amount of catalyst, and the time were optimized to achieve the maximum yield of biodiesel. The maximum yield of biodiesel was 95.3% under the optimal conditions.
Project description:Solid calcium oxide (CaO) catalyst was prepared via the calcination of chicken eggshells as an environmentally friendly waste resource and incorporated in a continuous centrifugal contactor separator (CCCS) for intensified biodiesel synthesis. Biodiesel or fatty acid methyl esters (FAME) were produced via the transesterification of sunflower oil (containing 5 wt % tetrahydrofuran as a cosolvent) with methanol under 60 °C and separated from the glycerol and catalyst phases continuously in the CCCS. The influence of reaction parameters on biodiesel production was well modeled by response surface methodology. At an oil flow rate of 9 mL/min, an alcohol to oil molar ratio of 11:1, and a weight hourly space time (defined as the catalyst weight over the oil mass flow rate) of 0.050 h, an optimized FAME yield of 83.2% with a productivity of 638 kgFAME/(m3 reactor·h) was achieved. CaO catalyst was reused without significant activity loss for at least four cycles.
Project description:Biodiesel, a mixture of fatty acid methyl esters (FAME), is bio-renewable, non-toxic, biodegradable, and is an attractive alternative to petroleum diesel. This work studied the sonochemical transesterification of Lesquerella fendleri oil (LFO) using inexpensive solid Lewis acid (LA) catalysts with an aim to reduce environmental pollution and dependance on non-renewable fuel sources. Due to the presence of hydroxy fatty acid methyl esters (HFAME) in LFO (∼60%), in addition to producing biofuel it can also be used to generate chemically important estolides and cyclic lactones. AlCl3, SnCl2, and Sn(CH3COO)2 showed catalytic activity using direct immersion ultrasound (DI-US) among a list of LA catalysts investigated, with AlCl3 being the best catalyst. Ultrasound increased the reaction rate by facilitating carbocation formation of glyceridic carbons. Experiments were carried out at room temperature in a solvent range from 3:1 to 18:1 methanol-to-oil molar ratio and catalyst loading from 1 wt% to 6 wt% over 10 to 60 min sonication time at 48% ultrasound amplitude (roughly 17 W/cm2). Complete conversion (>99%) was achieved in 40 min with 5 wt% AlCl3 catalyst. A statistical regression analysis with STATA 14.0 software was performed to optimize process parameters. Chemical characterizations of the compounds were performed with nuclear magnetic resonance (NMR) spectroscopy (1H NMR & 13C NMR), and % conversion of FAMEs was calculated from the 1H NMR spectra. The fatty acid profile was determined by GC-FID and GC-MS analysis. FT-IR spectroscopic analysis and thermogravimetric analysis (TGA) were performed to investigate the infrared absorption pattern of the compound and the volatility difference between Lesquerella fendleri biodiesel and oil under nitrogen atmosphere. Results indicate that this is a fast, green, energy-efficient, sustainable, and industrially applicable method for biodiesel production from LFO.
Project description:Design of the biodiesel production from palm fatty acid distillate (PFAD) using process intensification approach is studied in technical, economic and environmental view points. Firstly, the transport phenomena analysis is performed to select the suitable intensified unit. The reactive distillation is selected and used in esterification - transesterification process and hydrolysis - esterification process. The optimum condition of reactive distillation in esterification - transesterification is achieved when the methanol is fed at the 3rd stage of the 4-stage column and the liquid holdup is maintained at 6 m3. The intensified esterification - transesterification process offers higher biodiesel yield and consumes less energy compared with the intensified hydrolysis - esterification process. The economic analysis shows that the intensified esterification-transesterification process is found to be economically feasible. Finally, environment assessment based on life cycle analysis (LCA) indicates that the environmental impact of both processes are similar.