High Free Fatty Acid Content Research Articles

Experimental Study on the Esterification of Fat Trap Grease in a Continuous Reactor

In this work, the esterification reaction of fat trap grease (FTG) with high free fatty acid (FFA) content (166 mgKOH/g) was studied using methanol as a reagent and sulfuric acid as catalyst, in a continuous chaotic mixer-reactor. Esterification reached its chemical equilibrium in 1 h compared to 5 h in a mechanically stirred batch reactor. The effects of catalyst concentration, feeding flow rate and temperature on FFA conversion were examined. And the results show that at 5.4% w/w of H2SO4 and a mass flow rate of 8 g/s, a maximum conversion rate of 97% was achieved. It was observed that the water produced during the esterification reaction can slow the reaction progress. Therefore, water removal effect on reaction progress, using different techniques, was examined. It was proven that the water removal highly improved the reaction rate. The total removal of water reduced the reaction time from 1 h to 35 min in continuous reactor.

Non-catalytic Transesterification of Waste Cooking Oil with High Free Fatty Acids Content Using Subcritical Methanol: Process Optimization and Evaluation

Palm cooking oil consumption in Indonesia is very high, and as a result, the used cooking oil which mostly ends up as the waste is also high. Direct discharge of waste cooking oil (WCO) into the environment causes serious environmental pollution problems. WCO contains triglyceride and free fatty acid, which can be converted into biodiesel. In this study, the conversion of WCO into biodiesel was conducted using non-catalytic subcritical methanol process. The effect of the ratio of WCO to methanol (w/v), temperature, and pressure on the recovery of biodiesel was investigated under constant reaction time of 4 h. Based on the Response Surface Methodology (RSM); temperature, pressure, and WCO to methanol ratio (w/v) gave a significant effect on the recovery of fatty acid methyl ester (FAME). From the experimental result, the maximum FAME recovery obtained was 93.29% with the purity up to 97% (200 °C, 5.5 MPa, 3:10), while the predicted recovery calculated by RSM was 91.93% with the optimum condition: 200 °C, 5.5 MPa for WCO to methanol ratio 0.3061 (w/v). The experimental verification showed satisfactory agreement between the observed and predicted values with only 1.36% of error. Therefore, subcritical methanol has good prospects to be applied further in lieu of conventional process to utilize waste oil with high free fatty acid content.

Soybean Lecithin High in Free Fatty Acids for Broiler Chicken Diets: Impact on Performance, Fatty Acid Digestibility and Saturation Degree of Adipose Tissue.

Simple SummaryThe search of alternatives for soybean oil, as a dietary energy source, has generated a lot of interest in broiler feeding due to economic and supply reasons. Soybean lecithin, as a co-product derived from the soybean oil degumming process, and its blending with other by-products derived from the vegetable oil refining process such as acid oils, may represent an alternative energy source for broiler chicken diets formulation. The current study has demonstrated that soybean lecithin high in free fatty acids can be included in grower–finisher diets, as a partial replacer of soybean oil or in combination with an acid oil, without impairing performance or fatty acid digestibility and causing minor changes in the fatty acid composition of the abdominal fat pad.Two experiments were conducted to evaluate the inclusion of soybean lecithin with a high free fatty acid content (L) in starter and grower–finisher broiler diets, as well as its influence on performance, energy and fatty acid (FA) utilization and the FA profile of the abdominal fat pad (AFP). A basal diet was supplemented with soybean oil (S; Experiment 1) or acid oil (AO; Experiment 2) at 3%, and increasing amounts of L (1%, 2% and 3%) were included in replacement. The inclusion of L did not modify performance parameters (p > 0.05). The S replacement by L reduced energy and total FA utilization (p ≤ 0.05) in starter diets; however, in grower–finisher diets, a replacement up to 2% did not modify energy and FA utilization (p > 0.05). The AO substitution by L produced no modifications on energy and FA utilization (p > 0.05) during the starter phase, while the blend of 1% of AO and 2% of L resulted in the best combination in terms of the FA digestibility. The FA profile of the AFP reflected the FA composition of diets. The addition of L could replace, up to 2% or be blended with AO in broiler grower–finisher diets as an energy source.

Pre‐treatment of waste cooking oil with high free fatty acids content for biodiesel production: An optimization study via response surface methodology

AbstractBiodiesel is an alternative diesel fuel producing from vegetable oils or animal fats. At the present, most biodiesel is made from cooking oils with a very low amount of free fatty acid (FFA). Therefore, the cost of biodiesel is higher than petroleum diesel. However, the production cost of biodiesel can be reduced by using low‐cost feedstock oils such as waste cooking oil (WCO). There are some studies about acid‐catalyzed esterification process as a pretreatment of WCO with high FFA for biodiesel production. However, there have not many appropriate methods to optimize for this process. In this study, based on response surface methodology (RSM), a mathematical model was established which indicated the impact of independent experimental conditions as well as the relationship between these variables (MeOH/FFA molar ratio, H2SO4/FFA catalyst content, temperature and reaction time) to FFA conversion. This model was significant by comparison with both experimental value and predicted number of the FFA conversion, and showed strong agreement for experimental parameters. The FFA conversion of 90 % (FFA content of 0.40 wt%) was obtained in optimal conditions: MeOH/FFA molar ratio of 40.11, H2SO4/FFA catalyst content of 10.64 wt%, reaction temperature of 60 oC and reaction time of 5 h.

Tough thermosetting polyurethanes and adhesives from rubber seed oil by hydroformylation

ABSTRACTRubber seed oil (RSO), extracted from the seeds of rubber trees, is inedible oil with high free fatty acid content. In order to add value to RSO, we prepared a polyol with primary OH groups via hydroformylation/hydrogenation. Free hydroxy fatty acids formed in the process were utilized as reactive diluents, viscosity reducers, and adhesion promoters through hydrogen bonding with the substrate. The structures of the oil and polyol were analyzed using a range of analytical methods. The polyol had a hydroxyl number of 244 mg KOH g−1 and an acid number of 21 mg KOH g−1. The polyurethane prepared from this polyol and diphenylmethane diisocyanate was a highly crosslinked, tough material with a glass transition at 44 °C, high tensile strength and elongation, and attractive electrical properties. When used as a wood adhesive, it displayed extraordinary shear strength characterized by substrate wood failure rather than cohesive failure of the polymer. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48509.

Bioavtur Synthesis from Palm Fatty Acid Distillate through Hydrotreating and Hydrocracking Processes

Increasing concern in fossil fuel depletion and CO2 emissions create an urgent need for biofuel substitution. Bio-jet fuel is a possible alternative for conventional jet fuels which currently accounts for 2% of the world’s CO2 emission. Palm Fatty Acid Distillate (PFAD) is the byproduct of palm oil refinery process, which has a potential to become a promising raw material for the synthesis of bioavtur due to its high free fatty acid content. The oil-to-jet pathway is a possible route to produce bioavtur from PFAD, which includes hydrotreating, hydrocracking, and hydroisomerization processes. This research aims to investigate the hydrotreating and hydrocracking processes. The parameters that were investigated are temperature, solvent to PFAD ratio, catalyst loading, and pressure. The parameters variations were as follows: the temperature at 350oC and 400oC, the pressure at 40 bar and 32.5 bar, the solvent to PFAD ratio at 2:1 and 1:1, and the catalyst loading (%wt) at 1%, 2%, and 3%. Presulfided NiMo/γ-Al2O3 PIDO 120 1.3 was used for one-step hydrotreating and hydrocracking processes. Results indicated that the 400oC provided better free fatty acid (FFA) conversion. FFA is also almost completely removed when the catalyst used is 3% weight. Solvent to PFAD ratio affected the FFA conversion marginally, while higher catalyst loading (3%) improved the FFA conversion. Gas chromatography results show that the hydrocarbon chains are successfully hydrocracked into C9-C17. The best selectivity of the product to bioavtur range was calculated at 68.99%. Solvent ratio affects the hydrocracking more significantly than the catalyst loading. One sample with temperature operation 400oC and solvent to PFAD ratio 1:1 was in the range of conventional avtur density. With the method used in this study, it can be concluded that PFAD is a promising raw material for bioavtur.
 Keywords: Palm Fatty Acid Distillate (PFAD), hydrotreating, hydrocracking, bioavtur

Modeling and optimization of African pear seed oil esterification and transesterification using artificial neural network and response surface methodology comparative analysis

This study aimed at modeling and optimum conditions evaluation of the production of fatty acid methyl esters from high free fatty acid (FFA) and oil content African pear seed. The central composite design of response surface methodology (RSM) was employed for investigating the individual and interactive effect of the process variables (methanol/oil molar ratio, catalyst concentration, temperature and reaction time) on the FFA reduction and African pear seed oil methyl esters (APSOME) yield. A feed-forward neural network model with Levenberg-Marquardt backward propagation training algorithm was also employed to predict the responses. Temperature was found to be the most significant parameter with high F-values of 7.1 and 14.15 and low P-values of 0.0177 and 0.0019 for esterification and transesterification processes respectively. The observed optimum FFA reduction and biodiesel yield were 0.29 wt% and 94.55 wt% respectively, under the optimal conditions of 50 and 63.92 °C, 5.0 and 1.88 wt% catalyst concentration, 60 and 58 min reaction time and 13:1 and 6.86:1 methanol to oil molar ratios for esterification and transesterification processes respectively. At these optimal conditions, the validated experimental responses were 0.26 wt% and 95.027 wt% respectively. The performances of both ANN and RSM models showed adequate prediction of the response, with high coefficient of determination (R2) of 0.899 and 0.909 for esterification and 0.9195 and 0.944 for transesterification processes respectively. The fuel properties of the biodiesel produced at the optimum conditions were found to compare with ASTM D6751 and EN 14214 standard) while the GC–MS characterization showed that the biodiesel has high unsaturation. The overall results confirmed that the biodiesel production using African pear seed oil is viable

Facile one-pot synthesis of Cu-BTC metal-organic frameworks supported Keggin phosphomolybdic acid for esterification reactions

ABSTRACT In the present study, phosphomolybdic acid (HPMo) supported on Cu-BTC Metal-organic frameworks (MOFs) were prepared and utilized as a solid acid catalyst. The structure of the synthesized materials was characterized by using powder XRD, FT-IR, N2 adsorption-desorption, SEM, TEM, TG, and NH3-TPD techniques. These results exposed that HPMo was successfully encapsulated in the Cu-BTC cage and the Keggin structure of HPMo was maintained in the composite catalyst. In addition, the catalytic activity and recovery properties of the HPMo/Cu-BTC catalyst for the esterification of oleic acid with methanol into biodiesel were evaluated. These results showed that the HPMo/Cu-BTC catalyst exhibited high conversion (93.7%) and excellent reusability due to its mesoporous structure, excellent acidic activity, high BET surface area, large pore volume, and good thermal stability. Meanwhile, the kinetic studies of the esterification reaction revealed that it follows pseudo-first-order kinetics with a low activation energy of 37.5 KJ/mol. More interestingly, it shows potential application for esterification of free fatty acids (FFAs) or pretreatment of low-cost feedstocks contain high FFAs content for the green production of biodiesel.

Optimization of solid food waste oil biodiesel by ultrasound-assisted transesterification

Substitution of fossil diesel fuel by biodiesel is a realistic alternative due to its compatibility with commercial diesel engines. However, detractors consider that traditional raw materials used for biodiesel production may compete with human feeding (edible vegetables oils), land and water. So, new raw materials are needed. Annually, around 1.3 billion ton of food are discarded or wasted. This huge figure has led researchers to seek for new applications to this carbon source. The main goal of this work is biodiesel production optimization (with and without auxiliary energy assistance), and further characterization, by using the lipid fraction included in solid food waste, collected from local restaurants. Solid food waste oil (SFWO) characterization showed a fatty acid profile rich in oleic (C18:1), palmitic (C16:0) and linolenic (C18:2) acids, a remarkable fatty acid composition suitable for biodiesel production. Due to high free fatty acid content, acid esterification pre-treatment was conducted, followed by a basic transesterification optimization, by both conventional and ultrasound (US) assisted reactions. Response surface methodology was selected to perform the experimental design; optimal conditions for conventional transesterification were achieved at 6.08:1 methanol-to-oil molar ratio, 1.28% w/w catalyst and 52.5 °C reaction temperature, providing 93.23% w/w fatty acid methyl esters (FAME) conversion. Biodiesel quality was also analyzed with excellent results considering cold properties (cold filter plugging point below −3 °C), although oxidation stability did not fulfill European standard limit. US-assisted reaction was also compared with conventional transesterification in terms of energy consumption and reaction time, providing significant savings in both energy and reaction time (40 min reduction). As a conclusion, US-assisted SFWO biodiesel meets most European standard limits, following circular economy. To extend its use, blends with diesel fuel and antioxidant addition are recommended, besides long-term engine tests.

Biodiesel Production from Waste Edible Oil with Heterogeneous Catalysts (Nanoclay-Based Nanocatalysts)

The various benefits of biofuels versus fossil fuels due to recent global challenges and issues are the best approach toward low-cost economic production of renewable energy. This study is trying to obtain economic catalysts with easy fabrication technology. The synthesized catalysts were obtained using calcium oxide/nanoclay catalysts by an initial ion-exchange reaction of calcium oxide and nanoclays (montmorillonite). These catalysts have been synthesized for the first time by being stirred for 5 h at a temperature of 80 °C, and the colloidal supernatant is obtained and kept in an ultrasonic bath for 20 min. The solution was filtered, washed several times, the residual mixture on filter paper was dried in the oven at 50 °C for few hours, and the powder was calcined for 8 h in a furnace at 600 °C. After identification and characterization, using XRD, BET, and SEM, the results approved the formation of a new nanostructure in synthesized catalysts, which were suitable to be used in biodiesel production from waste oils with high free fatty acids content. The results of this study indicate that the catalysts production process is not complicated, and methyl ester production rates in all biodiesel samples were more than 97% (97.1–98.8%).

Characteristics of direct transesterification using ultrasound on oil extracted from spent coffee grounds

Spent coffee grounds (SCG), the residue after brewing coffee beverage, is a promising biodiesel feedstock due to its high oil contents (15‒20%). However, SCG should be pretreated to reduce the high free fatty acid content, which hampers transesterification reaction. To overcome this, we explored a direct transesterification reaction of SCG using ultrasound irradiation and identified the optimal sonication parameters. A high fatty acid methyl ester (FAME) content, up to 97.2%, could be achieved with ultrasound amplitude of 99.2 <i>μ</i>m, irradiation time of 10 min, and methanol to oil ratio of 7:1 in the presence of potassium hydroxide concentration of 1.25 wt.%. In addition, we demonstrated that ultrasound irradiation is an efficient method to produce biodiesel from untreated SCG in a short time with less energy than the conventional mechanical stirring method. The physical and chemical properties of the SCG biodiesel met the requirements for an alternative fuel to the current commercial biodiesel.

Decrease of Free Fatty Acid Levels in Cooking Oil Using Sugar Cane

Edible Oil has a fairly high economic value. Cooking oil is generally used for cooking. With the condition of oil prices increasing so many times it is necessary to recycle again so as not to pollute the environment. Used cooking oil has a lot of high free fatty acid content, so it is necessary to reduce fatty acids by using absorbent ingredients. Sugarcane bagasse can be used as a purification ingredient of used cooking oil by soaking. This study aims to determine the level of soaking bagasse against free fatty acid numbers. Variable immersion for 0 hours, 24 hours, 48 hours, and 72 hours. The results of the percentage of Free Fatty Acid (ALB) levels after done, soaking time for 0 hours is 0.36%, 24 hours is 0.34%, 48 hours is 0.33%, and 72 hours is 0.29%.©2019 JNSMR UIN Walisongo. All rights reserved.

Monitoring Enzymatic Hydroesterification of Low-Cost Feedstocks by Fourier Transform InfraRed Spectroscopy

Enzymatic hydroesterification is a heterogeneous catalyzed process suitable for the conversion of low-cost feedstocks in biodiesel production, namely, because of its tolerance to high free fatty acid contents. The current study describes the use of Fourier transform infrared spectroscopy (FTIR) to monitor biodiesel production using enzymatic hydroesterification and, as raw materials, acid oil from soapstock and olive pomace oil. Acid oil (~34 wt.% FFA) and olive pomace oil (~50 wt.% FFA) were first hydrolyzed (35 °C, 24 h, 200 rpm, 3 wt.% of lipase from Thermomyces lanuginosus, and 1:0.5 water:oil ratio, w:w), and then enzymatic esterification was performed (35 °C, 7 h, 200 rpm, 2 wt.% of lipase from Thermomyces lanuginosus, and 2:1 molar ratio of methanol to acid). FTIR analyses were conducted on the products using a Jasco FT/IR-4100 with a scanning range of 4000–650 cm−1 at 4 cm−1 spectral resolution and 54 scans. For free fatty acid (FFA) quantification, the C=O band at 1708 cm–1 was used, corresponding to the carboxylic acid, whereas for fatty acid methyl ester (FAME) quantification, the peak corresponding to C=O at 1746 cm−1 was considered, which corresponded to the ester. The results were calibrated using volumetric titration and gas chromatography analyses, concerning FFA and FAME quantification, respectively. The best conditions for analysis were determined, and a calibration method was established. FTIR has shown to be a simple, fast, and clean technique suitable to monitor hydroesterification of low-cost feedstocks.

Metal hydrated-salts as efficient and reusable catalysts for pre-treating waste cooking oils and animal fats for an effective production of biodiesel

A very efficient chemical pre-treatment method that uses cheap and safe hydrated-salts as catalysts for the conversion of waste cooking oils and animal fats having a high Free Fatty Acids (FFAs) content into an oily feedstock convertible into biodiesel through a conventional route (basic catalysis) was investigated. These hydrated-salts allow FFAs to be efficiently (>99%) esterified with alcohols under very mild conditions (343 K, 2 h). At the end of this treatment, a very convenient separation of products was verified. Two different phases were eventually obtained: an upper alcoholic phase, which contains most of the unreacted alcohol, water obtained by direct-esterification (>95%), and the salt that was used as catalyst (recovery >99%); and a lower oily-phase mainly composed of glycerides, methyl-esters derived from direct-esterification of FFAs (residual acidity of about 0.8 mg KOH/g), and part of unreacted alcohol (7–10%wt). Such a separation was convenient because the oily-phase could be directly trans-esterified through conventional base-catalysis, without any further pre-treatments, thus avoiding production of salty-waste. Also, the alcoholic phase could be recovered and directly re-used for new pre-treatments cycles of fresh waste-oils. A final scheme of the proposed process was discussed and the relevant advantages with respect to conventional routes were highlighted.

Improving biodiesel yield of animal waste fats by combination of a pre-treatment technique and microwave technology

Recently, due to its low cost there has been increased attention on Animal Waste Fats (AWFs) as a feedstock for biodiesel production. Advanced microwave technology has also been reported by many researchers to enhance the transesterification in biodiesel production. However, esterification of free fatty acids in the feedstock reported here has not attracted so much attention. AWFs come with its challenges namely, high free fatty acid (FFA) content and high water content. This study utilizes AWFs (tallow) containing very large amount of FFA; (25 wt%, 18 wt%, and 9.4 wt% FFA/AWFs) as feedstock for fatty acid methyl ester (FAME) production. A simple thermal pre-treatment technique followed microwave assisted esterification with methanol (MeOH) was conducted in a batch process to reduce the FFA content to as low as 1 wt% FFA, which is then suitable for the alkaline transesterification process. The pre-treatment of AWFs at 88 °C to first reduce water and decrease viscosity, followed by an operating microwave power of 70 W producing a power density 1.147 mW/m3, achieved a 15% increase in reduction of FFA over 30 W microwave power and conventional thermal method. Under optimum conditions, using 2.0 wt.wt% sulphuric acid catalyst/AWFs and 1:6 M ratio AWF/MeOH, the FFA conversion of 93 wt % was achieved. The results indicated that the pre-treatment and microwave application provided a faster route to high FFA reduction of AWFs during esterification process. The proposed technology is promising for the potential scale up industrial application.

Bio-oil recovery from olive mill wastewater in sub-/supercritical alcohol-water system

Olive mill wastewater was converted into bio-oil via thermochemical liquefaction with alcohol/water mixtures in an autoclave (998 ml). The influence of operating conditions on the yield of liquefaction products was investigated. Liquefaction experiments were performed at various reaction temperatures in the range of 240–320 °C. Experimental results indicated that alcohol (methanol or ethanol)/water mixtures had synergistic effects on olive mill wastewater direct liquefaction. The ratio 50% (w/w) co-solvent of either ethanol-water or methanol-water and a reaction temperature of 280 °C were found to be the most effective. Under these conditions and for a reaction time of 30 min, the bio-oil yield was 92.31 wt% for ethanol-water and 77.97 wt% for methanol-water. The bio-oil produced with methanol-water mixture has higher energy content (43.20 MJ/kg) compared to the one obtained with ethanol-water mixture (39.21 MJ/kg). In addition, Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry analyses showed high esters concentrations and low free fatty acid content in the obtained bio-oils.

Sulfated Fly‐Ash Catalyzed Biodiesel Production from Maize Acid Oil Feedstock: A Comparative Study of Taguchi and Box‐Behnken Design

AbstractIn the present investigation, the waste utilization approach has been followed for the bioenergy production. The focus is on the fly ash utilization for the development of heterogeneous catalyst synthesis under solvent‐free conditions. The fly ash is one of the environmental pollutant and unwanted material in thermal power plants. The sulfated fly ash (SFA) catalyst is synthesized by the sulfonation of waste fly ash. This catalyst has been characterized by various analysis such as elemental, thermal, spectral, surface area, acidity and basicity etc. The catalyst has been found to exhibit various phases such as Quartz, Mullite, Hematite, Lime etc. and thermally stable upto 550 °C. The results obtained from NH3‐TPD and CO2‐TPD analysis, confirms the presence of acid (0.401 mmol / g) and basic (0.197 mmol / g) sites in the SFA catalyst. Further, the utility of SFA catalyst has been demonstrated in the biodiesel production via esterification reaction from maize acid oil (MAO) feedstock containing high free fatty acid (FFA) (127.21 mg KOH / g). The maize acid oil is one of the biowaste feedstock, mainly a by‐product obtained from the refining of crude maize oil. Taguchi method and Box‐Behnken Design (BBD) have been applied to investigate the effect of different reaction parameters on the biodiesel production. The use of SFA catalyst has been found to be advantageous especially, in the biodiesel production from feedstock with high FFA content.

The Effect of Melatonin on Locomotor Behavior and Muscle Physiology in the Sea Cucumber Apostichopus japonicus.

Melatonin is a highly conserved hormone in evolutionary history. It occurs in numerous organisms and plays a role in the endocrine and immune systems. Locomotor behavior is a basic behavior in animals and is an important indicator of circadian rhythms, which are coordinated by the nervous and endocrine systems. To date, the effect of melatonin on locomotor behavior has been studied in vertebrates, including syrian hamsters, sparrows, rats, zebrafish, goldfish, and flatworms. However, there have been few studies of the effects of melatonin on locomotor behavior in marine invertebrates. The goals of present study were to show the existence of melatonin in the sea cucumber Apostichopus japonicus and to evaluate its effect on locomotor activity. In addition, muscle tissues from control and melatonin-treated sea cucumbers were tested using ultra performance liquid chromatography and quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) to determine the changes of metabolic activity in muscle. Melatonin was present in the coelomic fluid of A. japonicus at a concentration of ∼135.0 ng/L. The total distance traveled and number steps taken over 9 h after melatonin administration decreased with increasing concentration of the melatonin dose. Mean and maximum velocity of movement and stride length and stride frequency also decreased, but their differences were not statistically significant. Overall, these results suggest that melatonin administration had a sedative effect on A. japonicus. The levels of 22 different metabolites were altered in the muscle tissues of melatonin-treated sea cucumbers. Serotonin, 9-cis retinoic acid, all-trans retinoic acid, flavin mononucleotide in muscles were downregulated after melatonin administration. Moreover, a high free fatty acid (FFA) concentration and a decrease in the adenosine 5′-triphosphate (ATP) concentration in the muscle tissues of the melatonin-treated group were detected as well. These results suggest that the sedative effect of melatonin involves some other metabolic pathways, and the reduced locomotor modulator—serotonin, inhibited fatty acid oxidation and disturbed oxidative phosphorylation are potential physiological mechanisms that result in the inhibitory effect of melatonin on locomotion in sea cucumbers.

Lab and pilot plant FAME production through enzyme-catalyzed reaction of low-cost feedstocks

The current production of biodiesel is carried out chemically, using noble vegetable oils of high cost, with low content of water and free fatty acids (FFA). The reduction of the costs of the biodiesel chain necessarily requires the use of low-cost raw materials, which come from discards or industrial waste. In this context, this work reports the production of fatty acid methyl esters (FAME) using residual raw materials from the soybean oil industry (low cost), containing high free fatty acids content (98.5% wt). For conversion, the enzymatic process was employed using the low cost commercially available lipase (Eversa® Transform 2.0) supplied by Novozymes (Denmark). The results optimized in the laboratory presented yields >96% of FAME, demonstrating the viability of the process. In this way a pilot scale experiment (1 m3) was performed, successfully reaching yield of >97% FAME. From the results obtained, the enzymatic process becomes a promising alternative for the production of biodiesel, due to the possibility of using raw materials of low cost, high content of FFA and of low quality, with favorable economic issues, renewability and benefits sustainable development.

A novel process for biodiesel production from sludge palm oil

Typically, sludge palm oil (SPO) which discharged from the palm oil refining process, is a low cost material of potential value, due to its high free fatty acid content. Accordingly, there is potential for upgrading low grade oil into valuable biofuel. In this work, we present a novel method for biodiesel production from SPO. The process consists of two steps (i) free fatty acid (FFA) extraction (ii) enzymatic esterification. Firstly, SPO was saponified by hydroalcoholic solution into soap and glycerol. Secondly, the FFAs obtained were further converted into biodiesel via enzymatic esterification catalyzed by immobilised alginate-PVA lipase beads.•Biodiesel production from sludge palm oil could be completed.•A modified fatty acid extraction was used for SPO fatty acid preparation.•Immobilised alginate-PVA lipase beads were used as biocatalyst for esterification reaction.