Highest Fatty Acid Methyl Ester Research Articles

Esterification of high free fatty acids in supercritical methanol using sulfated angel wing shells as catalyst

In this research, shells of Cyrtopleura costata, commonly known as angel wing, were used to prepare sulfated calcined angel wing shell (CAWS) catalysts by a simple, low-cost method. The produced CAWS-SO4 catalyst was characterized by using X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR), temperature programmed desorption of CO2 and NH3 (CO2-TPD and NH3-TPD), BET surface area analysis and variable pressure scanning electron microscopy (VP-SEM). The esterification of palm fatty acid distillate (PFAD) by supercritical methanol was successfully performed to obtain the high fatty acid methyl esters (FAME) with yield of 98% at the optimum methanol/PFAD molar ratio of 6/1, 2wt.% catalyst loading, 290°C in 15min. The catalyst could also be reused up to seven cycles with a FAME yield higher than 80% in the last cycle. The characterization of spent catalyst has been performed by using XRD, FTIR, TPD-NH3 and SEM.

Effect of Soaking Pre-Treatment on Reactive Extraction/<i>in situ</i> Transesterification of <i>Nannochloropsis occulata</i> for Biodiesel Production

Microalgal phospholipid bilayer contributes to the molar excesses of methanol and high acid concentration required in reactive extraction to achieve high fatty acid methyl ester (FAME) yield. This study reports an investigation into the effects of pre-soaking Nannochloropsis occulata in methanol at 600:1 and 1000:1 methanol to oil molar ratios prior to acid-catalyzed in situ transesterification at 8.5:1 and 15:1 H2SO4 to oil molar ratios on the FAME yield. The results showed that the pre-soaked Nannochloropsis occulata produced a higher FAME yield at the two tested methanol to oil molar ratios and acid concentrations than the un-soaked, resulting in a reduction in methanol volume and acid concentration. A maximum FAME yield of 98.4% ± 1.3% was obtained for the pre-soaked Nannochloropsis occulata at 1000:1 methanol to oil molar ratio and 15:1 H2SO4 to oil molar ratio. Both the phosphorus mass balance and conversion of the isolated phospholipids into FAME revealed that pre-soaking solubilizes the phospholipid bilayer to some degree, and contributes to an increased FAME yield.

Enhancement of lipid productivity by adopting multi-stage continuous cultivation strategy in Nannochloropsis gaditana

In the present study, a novel process-based cultivation system was designed to improve lipid productivity of Nannochloropsis gaditana, an oleaginous microalga that has high potential for biofuel production. Specifically, four flat-panel photobioreactors were connected in series, and this system was subjected to continuous chemostat cultivation by feeding fresh medium to the first reactor at dilution rates of 0.028 and 0.056day−1, which were determined based on Monod kinetics. The results show that the serially connected photobioreactor system achieved 20.0% higher biomass productivity and 46.1% higher fatty acid methyl ester (FAME) productivity than a conventional single photobioreactor with equivalent dilution rate. These results suggest that a process-based approach using serially connected photobioreactors for microalgal cultivation can improve the productivity of lipids that can be used for biofuel production.

A biodiesel production process catalyzed by the leaching of alkaline metal earths in methanol: from a model oil to microalgae lipids

BACKGROUND A response surface methodology was used to study the reaction mechanism of strontium oxide (SrO) as a catalyst for a biodiesel production process using a model oil (composed of fatty acid methyl esters (FAME), free fatty acids (FFAs) and triglycerides). The influence of several factors (initial FAME content (0–30 wt%), initial FFAs content (oleic acid 0.20–2.7 wt%), temperature (40–60 °C), methanol to model oil ratio (11–43 wt%), catalyst to model oil ratio (0.5–2.5 wt%) and reaction time (5–30 min)) on the FAME yield, the FAME content, the pH of polar phase and the biodiesel alkalinity was studied. SrO was also compared with potassium hydroxide (KOH) for the conversion of Scenedesmus Obliquus microalgae esterified lipids after a first step of FFAs esterification with sulfuric acid into biodiesel with the following conditions: temperature: 60 °C; reaction time: 22.2 min; catalyst to microalgae ratio: 2.48 wt%; methanol to microalgae lipid ratio: 31.4 wt%. RESULTS With those operating conditions, KOH was able to reach a slightly higher FAME yield (32.6% g FAME g−1 lipid) than SrO (29.0% g FAME g−1 lipid). Moreover, the results showed a strong relationship between the pH of the polar phase (glycerol–methanol–water) and the FAME yield, which indicates that the reaction using alkaline metal earths is mostly catalyzed by a homogeneous reaction. CONCLUSION The fact that alkaline metal earths act as homogeneous catalysts make them less suitable for biodiesel production, because they are not inducing neutral pH, and they increase the risk of corrosion. © 2016 Society of Chemical Industry

Application of Fe(NO3)3-based as nitrogen source and coagulant for cultivation and harvesting of Chlorella sorokiniana

In this study, Chlorella sorokiniana was successfully cultivated in the recycled medium whose nitrogen was supplied directly from the coagulant, Fe(NO3)3. With a dosage of 0.80g/L, harvesting efficiency of 95% could be achieved. What is more, this amount of nitrate in the coagulant was enough to fully support the growth of C. sorokiniana during the 8day cultivation period, almost as much as the initial nitrogen content in the BG11 culture medium. Other nutrients had to be supplemented, however, with at least 50% amount as in the BG11 recipe. C. sorokiniana culture grown in recycled medium replenished with 50% of nutrients showed much higher Fatty acid methyl esters (FAME) productivity than the control, with 88.3mg/L/day. The recycle of the medium is certainly a way of reducing the water footprint for the purpose of microalgae-derived biodiesel production; better still, it may serve to lower the nutrient footprint.

Noncatalytic biodiesel synthesis from rubber seed oil via supercritical methanol and ethanol

This paper reports the production of fatty acid methyl esters (FAMEs) and fatty acid ethyl esters (FAEEs) by the transesterification reaction of rubber seed oil (RSO) in supercritical methanol and ethanol without using any catalyst. Experiment were carried out in a batch reactor, and reactions were studied at 260, 280, 300 and 320 oC at a pressure of 8.1-19 MPa with various mole ratios of ethanol – to - methanol from 0 to 100%. The extent of the reaction was explored using a convertibility parameter, which corresponds to the maximum ester content attainable from the feedstock. The highest FAME and FAEE contents achieved were 91.8 % and 86.4%, respectively. Results show that transesterification of RSO in methanol was more efficient than that in ethanol; the temperature had the strongest influence.

Ionic liquids in supercritical methanol greatly enhance transesterification reaction for high‐yield biodiesel production

SignificanceBiodiesel production is one of the most promising future alternatives to replacing fossil fuels. This work studies the use of ionic liquids (ILs) as potential catalysts in supercritical methanol for biodiesel production from non‐edible oil. The transesterification reaction of karanja oil was investigated in supercritical methanol in the presence of two respective ILs, [BMIM+][ ] and [Chol+][H2 ]. The reaction was performed in a one‐step batch process at several temperatures and percentages by weight of catalyst (w/woil). The results obtained show that the IL [Chol+][H2 ] allows a high yield of fatty acid methyl esters to be achieved in a short reaction time (above 95% in 45 min). A catalytic mechanism is also proposed for the IL that offered significant catalytic activity. This work investigates the effects of the use of ionic liquids as potential catalysts in supercritical methanol for the transesterification reaction of non‐edible oil. The reported reaction times to obtain biodiesel yields above 90% through the transesterification reaction of karanja oil range between 90 min and 8 h. ILs as catalysts in supercritical methanol drastically reduce reaction time (45 min) to obtain high fatty acid methyl ester yield (95.6%). © 2016 American Institute of Chemical Engineers AIChE J, 62: 3842–3846, 2016

In-situ transesterification of wet spent coffee grounds for sustainable biodiesel production

This work addresses in-situ transesterification of wet spent coffee grounds (SCGs) for the production of biodiesel. For in-situ transesterification process, the methanol, organic solvent and acid catalyst were mixed with wet SCG in one pot and the mixture was heated for simultaneous lipid extraction and transesterification. Maximum yield of fatty acid methyl esters (FAME) was 16.75wt.% based on the weight of dry SCG at 95°C. Comprehensive experiments were conducted with varying temperatures and various amounts of moisture, methanol, co-solvent and acid catalyst. Moderate polar and alcohol-miscible organic solvent is suitable for the high FAME yield. Unsaturated FAMEs are subject to oxidative cleavage by nitric acid and shorter chain (C6 and C10) FAMEs were mainly produced while sulfuric acid yielded long chain unsaturated FAMEs (C16 and C18). Utilization of wet SCGs as a biodiesel feedstock gives economic and environmental benefits by recycling the municipal waste.

Synthesis, characterization and performance of silica impregnated calcium oxide as heterogeneous catalyst in biodiesel production

Currently, biodiesel is produced by performing a transesterification reaction with homogeneous base catalysts such as potassium hydroxide (KOH) or sodium hydroxide (NaOH) dissolved in methanol. This production process can provide high fatty acid methyl ester (FAME) yields under mild conditions. However, the homogeneous catalytic process suffers some drawbacks of an inevitable production of wastewater from washing process of catalyst residues and unreusability of the catalysts. Thus, in this study, it is proposed to synthesize and characterize a renewable low cost heterogeneous hybrid catalyst through utilization of waste material; rice husk and egg shell for transesterification reaction. The hybrid catalyst was synthesized via wet impregnation method and then characterized using fourier transform infrared spectroscopy, x-ray diffraction, surface area and pore size distribution and scanning electron microscopy. The composition of FAME was determined by gas chromatography analysis and the properties of biodiesel such as density, viscosity, acid value and calorific value were also analyzed. The result show that the calcium oxide (CaO) supported with silica is more effective for the production of biodiesel compared to CaO individually. Furthermore, the synthesized catalyst was able to be efficiently recyclable and repeatedly used up to 6 times. The fuel properties of biodiesel produced in this study were found to meet the specification of ASTM standards. Therefore, it can be concluded that the hybrid catalyst derived from waste materials can be an excellent catalyst in biodiesel production. In addition, developing new catalysts from rice husk and egg shell will not only solve the issue of disposal of these wastes but will also simplify the purification process, whereby the catalysts can be separated from the product more easily.

Biodiesel production by methanolysis of waste lard from piglet roasting over quicklime

Waste lard from piglet roasting and quicklime (basically CaO) as a priceless fatty feedstock and a cheap solid catalyst, respectively were tested for the biodiesel production by methanolysis in a batch stirred reactor at moderate reaction temperatures (40–60°C) for the kinetic study. For comparison, unheated and heated pork lards, as well as pure CaO, were also included in this study. The mass transfer limitation was observed in the initial period of all methanolysis reactions. The kinetic model combining the changing- and first-order reaction rate laws with respect to triacylglycerols and fatty acid methyl esters (FAMEs), respectively was verified for all three lardy feedstocks and both catalysts. The catalytic activity of quicklime was the same as that of pure CaO. The activation energy was demonstrated to be independent of the feedstock and the catalyst (59.1±0.6kJ/mol), but the waste lard reacted faster than the unheated and heated pork lards. At the methanol-to-lard molar ratio of 6:1, the catalyst amount of 5% (based on the lard weight) and the reaction temperature of 60°C, a high FAME concentration in the final ester products (97.5%) within 60min were achieved with the waste lard and quicklime in two consecutive batches. The same kinetic model was applicable in a continuous packed-bed tubular reactor filled with quicklime bits (2.0–3.15mm) at the methanol-to-waste lard molar ratio of 6:1, the reaction temperature of 60°C and the residence time of 1h. Under these conditions, the biodiesel yield was 97.6%, while the FAME concentration in the biodiesel product was 96.5%.

Combining nitrogen starvation with sufficient phosphorus supply for enhanced biodiesel productivity of Chlorella vulgaris fed on acetate

Heterotrophic cultivation of microalgae is attracting more attention due to its high production efficiency. In this study, Chlorella vulgaris was cultivated heterotrophically with acetate in batch systems. The effects of nitrogen deficiency and different phosphorus supply levels on biodiesel production were investigated. It was found that C. vulgaris can assimilate acetate and accumulate fatty acids simultaneously. The highest FAME (Fatty acid methyl ester) content (56%) of algae was obtained in nitrogen deficient media. Interestingly, the productivity of fatty acids under nitrogen starved conditions was three times greater than that under nitrogen sufficient conditions. Moreover, FAME productivity was further enhanced to 66mgL−1·d−1 by a sufficient phosphorus supply but there was no effect caused by phosphorus limitation. Furthermore, the conversion yields of acetate consumed to fatty acids produced (Chemical oxygen demand (COD)-based) in nitrogen starved media were also three times higher than those in nitrogen sufficient media. FAME productivity of C. vulgaris under nitrogen starvation was not improved by controlling the pH at stable values (7.5, 8.0, and 8.5), and even decreased when pH was controlled at 7.0 and 9.0.

Biodiesel Production from Chlorella protothecoides Oil by Microwave-Assisted Transesterification.

In this study, biodiesel production from microalgal oil by microwave-assisted transesterification was carried out to investigate its efficiency. Transesterification reactions were performed by using Chlorella protothecoides oil as feedstock, methanol, and potassium hydroxide as the catalyst. Methanol:oil ratio, reaction time and catalyst:oil ratio were investigated as process parameters affected methyl ester yield. 9:1 methanol/oil molar ratio, 1.5% KOH catalyst/oil ratio and 10 min were optimum values for the highest fatty acid methyl ester yield.

Biodiesel production using lipase immobilized on epoxychloropropane-modified Fe3O4 sub-microspheres

Superparamagnetic Fe3O4 sub-microspheres with diameters of approximately 200nm were prepared via a solvothermal method, and then modified with epoxychloropropane. Lipase was immobilized on the modified sub-microspheres. The immobilized lipase was used in the production of biodiesel fatty acid methyl esters (FAMEs) from acidified waste cooking oil (AWCO). The effects of the reaction conditions on the biodiesel yield were investigated using a combination of response surface methodology and three-level/three-factor Box–Behnken design (BBD). The optimum synthetic conditions, which were identified using Ridge max analysis, were as follows: immobilized lipase:AWCO mass ratio 0.02:1, fatty acid:methanol molar ratio 1:1.10, hexane:AWCO ratio 1.33:1 (mL/g), and temperature 40°C. A 97.11% yield was obtained under these conditions. The BBD and experimental data showed that the immobilized lipase could generate biodiesel over a wide temperature range, from 0 to 40°C. Consistently high FAME yields, in excess of 80%, were obtained when the immobilized lipase was reused in six replicate trials at 10 and 20°C.

Quantification of Nonanal and Oleic Acid Formed During the Ozonolysis of Vegetable Oil Free Fatty Acids or Fatty Acid Methyl Esters

AbstractThe ozonolysis of unsaturated lipids is a process that has been used to generate aldehydes, acids, alcohols, and other biobased chemical intermediates. Reported here is a method that can be used to measure the formation of nonanal and oleic acid during the ozonolysis of unsaturated vegetable oil fatty acids or their methyl esters to indicate the extent of the ozonolysis reaction. Derivatization was performed using boron trifluoride in methanol solution to transform nonanal and oleic acid into nonanal dimethyl acetal and oleic acid methyl ester, respectively. Undecanal and 10‐heptadecenoic acid were used as internal standards and separation was performed using gas chromatography coupled with a flame ionization detector. The method was validated by performing a standard addition procedure in which nonanal or oleic acid standards were spiked into samples collected during the ozonolysis of oleic acid or canola oil fatty acid methyl ester (FAME). Linear regression results indicated that the measured nonanal and oleic acid are in good agreement with the actual amounts of nonanal and oleic acid added to the sample with at least 98 % recovery. The application of the method was demonstrated by the successful measurement of nonanal and oleic acid formed throughout the ozonolysis process for high oleic canola oil FAME.

Coupling transesterifications for no-glycerol biodiesel production catalyzed by calcium oxide

In this study, a method consisting in coupling transesterifications for no-glycerol biodiesel production catalyzed by CaO was put forward. The transesterification between rapeseed oil and methanol was greatly improved by integrating glycerol and dimethyl carbonate (DMC) transesterification. From this result, it was found that the high fatty acid methyl ester (FAME) yield of 92.6% (with ultra-traces of glycerol as a by-product) was obtained at 65 °C under normal pressure, which is as high as the previously reported supercritical DMC method for no-glycerol biodiesel production at a reaction temperature of 350 °C and under pressures up to 17.8 MPa. Moreover, this new method has high water tolerance, and a yield of over 82% of FAME is still achieved in the presence of 0.2% of water. The optimized reaction conditions, such as the molar ratio of DMC to methanol, the catalyst dosage and the reaction time, were investigated to produce high-quality biodiesel. The fuel properties determined and discussed in light of EN 14214 (European standards) demonstrate that the biodiesel produced using this new method has good flow properties with a cloud filter plugging point of –10 °C and a pour point of –9.4 °C. Furthermore, the amount of free glycerol was found to be as low as 0.018% in the biodiesel obtained directly from this new method without any further processing. The results of this study indicate the feasibility of producing quality biodiesel fuels without glycerol by coupling transesterifications.

A new approach in maximizing and direct utilization of whole Jatropha curcas L. kernels in biodiesel production – Technological improvement

The direct (trans)esterification of whole Jatropha curcas L. (JCL) kernels in subcritical solvent mixture of water, methanol and acetic acid was explored. A high fatty acid methyl ester (FAME) yield of 96.56% could be achieved at a solvent (water: acetic acid: methanol = 1:5:15, v/v/v) to solid ratio of 7 cm3 g−1. The reaction mixture was pressurize with carbon dioxide and reacted for 1 h at 523 K and 12.5 MPa. Qualitative tests on the recovered polar fractions of the product were found to have radical scavenging activities. The characteristics of the spent kernel residues were also studied. The method employed in this study provides an alternative approach to better utilize JCL kernels and cut down the number of production steps.

Biodiesel synthesis over millimetric γ-Al2O3/KI catalyst

The use of spherical millimetric gamma-alumina (γ-Al2O3) as a catalyst support for the production of biodiesel from palm oil was demonstrated. The catalyst support was produced using dripping method, and KI catalyst was loaded on the support using impregnation method. The highest FAME (fatty acid methyl ester) yield of 98% was obtained when the reaction was carried out under the conditions of catalyst to oil ratio of 0.6 g (4wt.%, gcat./goil) using 0.24gKI/gγ-Al2O3 of catalyst loading, reaction time of 4 h, temperature of 60 °C and methanol to palm oil molar ratio of 14:1. XRD (X-ray diffraction) analysis showed the formation of K2O and KAlO2 phases on the KI/γ-Al2O3 catalyst which were possibly the active sites for the transesterification reaction. The highest number and strength of basic sites generated from the solid phase reaction of the KI/γ-Al2O3 catalyst loaded with 0.24 g kF/g γ-Al2O3 were confirmed by temperature programmed desorption of CO2 (CO2-TPD) analysis. The nitrogen adsorption–desorption isotherms was revealed a mesoporous structure of the catalysts. The leaching of potassium species in reused catalysts was observed, as verified by XRF (X-ray fluorescence). KI/γ-Al2O3 had a long life time and maintained sustained activity even after being repeatedly used for 11 cycles. The biodiesel yield was comparable to that produced from smaller catalysts. Thus, the catalyst could be potential for industrial use, as they can be handled safely, easily separated from the process fluid and used in fixed bed reactor to minimize pressure drop.

Synthesis and Evaluation of Catalytic Activity of Calcined Sodium Silicate for Transesterification of Waste Cooking Oil to Biodiesel

Biodiesel production from waste cooking oil (WCO) using heterogeneous sodium silicate catalyst is presented in this article. The conversion of WCO to biodiesel exploited the potential of the catalyst to convert high free fatty acid (FFA) content feedstock to biodiesel directly, thereby by-passing the esterification state whereby FFA content of the feedstock is reduced prior to transesterification reaction. In the study, effect of reaction temperature and reaction time on the activity of the catalyst during transesterification of WCO to biodiesel was investigated. The transesterification reaction was conducted in a batch reactor with 2.51 g of the catalysts and at WCO to methanol ratio of 1:6. In addition, the reaction temperature was varied between 25 o C to 63 o C, and the reaction time was varied from 0 to 180 minutes at a 30 minute step increase. The fatty acid methyl ester (FAME) yield increased with reaction time and reaction temperature and the highest FAME yield of 30% was obtained at 63 o C after 180 minutes. However, further studies are required for in-depth understanding of the activity and kinetics of the catalyst for biodiesel production from WCO.

Biodiesel Production from Waste Cooking Oil over Mesoporous SO42−/Zr-SBA-15

Biodiesel production from waste cooking oils over SO42−/Zr-SBA-15 catalyst was successfully carried out and investigated. SO42−/Zr-SBA-15 catalyst was prepared by one-step process using anhydrous zirconium nitrate as zirconium resource, and endowed with the strong Lewis acid sites formed by supporting the zirconium species onto the SBA-15 surface. The as-prepared SO42−/Zr-SBA-15 showed excellent triglyceride conversion efficiency of 92.3% and fatty acid methyl esters (FAME) yield of 91.7% for the transesterification of waste cooking oil with methanol under the optimized reaction conditions: the methanol/oil molar ratio of 30, the reaction temperature of 160 °C, the reaction time of 12 h and 10wt% of catalyst. It was noticed that the as-prepared SO42−/Zr-SBA-15 materials with the higher area surface of mesoporous framework and the surface acidity displayed excellent stability and reusability, maintaining high FAME yield of (74±1)% after seven runs of reaction.

Biosynthesis of high yield fatty acids from Chlorella vulgaris NIES-227 under nitrogen starvation stress during heterotrophic cultivation

In this study the heterotrophic cultivation of Chlorella vulgaris NIES-227 fed with glucose was investigated systematically using six media types; combinations of nitrogen repletion/depletion and phosphorus repletion/limitation/depletion. It was found that a high yield of fatty acids (0.88 of fed glucose-COD) and a high content of fatty acid methyl esters (FAMEs) (89% of dry weight) were obtained under nitrogen starved conditions. To our knowledge it is the first report on such high COD conversion yield and FAME content in microalgae. The dominant fatty acid (>50%) was methyl oleate (C18:1), a desirable component for biodiesel synthesis. FAME content under nitrogen starved conditions was significantly higher than under nitrogen sufficient conditions, while phosphorus had no significant influence, indicating that nitrogen starvation was the real “fatty acids trigger” in heterotrophic cultivation. These findings could simplify the downstream extraction process, such as the extrusion of oil from soybeans, and could reduce operating costs by improving the fatty acid yield from waste COD.