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Direct production of biodiesel by both esterification and transesterification of renewable oils with acid value (AV) of 9.6-28.9 mg KOH/g using calcined blast furnace dust is studied. Blast furnace dust calcined at 600-700 degrees C obviously promotes efficient biodiesel production because of the crystal form transformation from lead sulfate particles in dust into active lead oxide, lead sulfide, and lead particles. It is found for the first time that lead oxide, lead sulfide and lead particles can resist saponification from fatty acids to catalyze raw renewable oils to biodiesel with catalytic activity order as follows: lead oxide > lead > lead sulfide > lead sulfate. Biodiesel production process is optimized according to an orthogonal design with biodiesel yield of 92 wt% obtained at AV of 9.6 mg KOH/g (82 wt% after 5 cycles). Biodiesel yield of 84 wt% is achieved at AV of 28.9 mg KOH/g with acidity of 0.18 mmol/g. Calcined blast furnace dust presents potential applications in the production of biodiesel from renewable oils with high AVs. (C) 2021 Elsevier Ltd. All rights reserved.

The conversion of high acid value (AV) waste cooking oils (WCOs) into biofuels was studied using the cracking process over spent fluid catalytic cracking (SFCC) catalysts. The processing of WCO was carried out in a fluid catalytic cracking lab-scale unit with temperatures ranging from 450 to 520 °C. From 480 °C, whatever the spent catalysts, WCOs with AV in range of 6–22 mgKOH/g can be converted to liquid fuels with the near zero AV (AV

Ceiba pentandra, non-edible oil (acid value of 21 mg KOH/g estimated using ASTM D664 methodology) is employed as a source for producing biodiesel using lipase immobilized on mesoporous material as a catalyst. Optimum conditions for maximum yield (96.4%) were the temperature of 33 °C, methanol to oil molar ratio of about 13.3:1 with a water content of 14.5%. From the reusability studies, it can be observed that greater than 85% conversion could be obtained up to 10 cycles, thereby proving the significant efficacy of the catalyst. Density, flash point, cloud point, calorific value, and cetane number of the produced biodiesels were 885 kg/m3, 152 °C, −3 °C, 38.44 kJ/kg and 57.2, respectively meeting the ASTM standards specified for biodiesel. The performance and emissions characteristics of 20% biodiesel (CIB20) and petroleum diesel were studied in a VCR under varying speeds in a full load condition. Blended biofuel showed a 13% lower mean brake power (BP) and 25% higher mean specific fuel consumption (SFC) compared to diesel fuel. Though NOx emission of the blended diesel was 31% higher than that of petroleum diesel, Hydrocarbon, CO2, and CO emissions were 8.4%, 13.7%, and 5.08% lower than that of diesel fuel, respectively.

In this paper, cloisite 30B (CL) was converted to tosylated cloisite (TCL) as new heterofunctional support. Lipase from Candida rugosa was covalently immobilized on the TCL (TCLL) and used to produce biodiesel from waste frying oil (WFO). The effects of reaction time and temperature, the molar ratio of methanol/oil, and the water content on the biodiesel yield were also explored. The hydrolytic activity of TCLL was 1.96 ± 0.04 U mg−1, with the immobilization yield of 93.6% and expressed activity of 90.2%. The maximum yield of biodiesel (97.1 ± 1.1%) was obtained at 50 °C for 8 h with a 15:1 M ratio of methanol to WFO and water content 10 wt%. The features of produced biodiesel, such as acid value, iodine value, density, and viscosity, met the specifications in the reported standard test methods. After 24 h incubation at 80 °C, the relative yield of biodiesel for TCLL was 20.3%, while the relative yield for the free enzyme was almost zero. The relative yield of biodiesel for TCLL and free lipase was 70.6% and 33.4%, respectively, after 30 days of storage. Also, TCLL showed a relative yield of 61.3% in the biodiesel production after being used for 10 cycles.

Crude oil extracted from tilapia heads and oils obtained from different steps of its refinement process (physically degummed, chemically degummed, neutralized, and bleached oils) were used as raw materials for biodiesel production. Extraction and refinement of the oil and, after, production and economic viability of the different biodiesels were performed. The heads corresponded to 45% of waste from Nile tilapia and of extractions yield was around 80–85% of the crude oil. The highest biodiesel yields were with the neutralized oil (80.35%, w w−1) and chemically bleached oil (83.55%, w w−1). The lowest biodiesel production costs were by the physical degumming, chemical degumming, and neutralization steps, which presented an average cost of 0.181 US$ kg−1. Neutralized oil in the transesterification reaction, besides presenting the lowest biodiesel production cost, provided a suitable product with the acid value, kinematic viscosity, and flash point according to ASTM standard for biodiesel. Regardless of the refinement process, the degradation ranges of the oil samples were 350–550 °C. TLC, GC, and FTIR confirmed the triglycerides conversion from tilapia oil into biodiesel. Based on results, Nile tilapia neutralized oil showed suitable characteristics, becoming a promising source for biodiesel production of the quality and economically viable.

In present study, heterogeneous Nano-CaO catalyst was synthesized from waste egg shell (WES) and its potential was investigated for direct transesterification of Chlorella pyrenoidosa. Catalyst was synthesized by calcination-hydration–dehydration (C–H-D) process and found to have crystalline structure with average size of 23.65 nm and 64.51 m2/g of surface area as confirmed by XRD and BET analysis. SEM-EDX analysis further confirmed that obtained Nano catalyst is mesoporous with average pore size of 9.28 nm. Response surface methodology (RSM) was applied for optimization of direct transesterification by varying the catalyst dosage (%), reaction temperature (°C) and time (min). The maximum yield of FAME (93.44%) was obtained with combination of 2.06% wt/wt catalyst with 180 min of time and 60 °C temperature. Further, biodiesel was characterized for iodine value, cloud point, pour point, cetane number, higher heating value, acid value and density, which were about 204.14 gI2/100g,-4.5 °C, 5.4 °C, 32.29, 38.03 MJ/kg, 0.83 mgKOH/g, 0.85 g/cm3 respectively. The reusability and stability of Nano-CaO catalyst was found up to 6 cycles. Findings of this research study support that Nano-CaO catalyst derived from WES is a low cost and sustainable source of catalyst that can be effectively used for biodiesel production.

The objective of this paper was to optimize, by composite central design coupled to response surface methodology, the enzymatic biodiesel production from oil coming from fish waste, and to characterize the obtained product. The lipase from Thermomyces lanuginosus immobilized on octadecyl metacrylate beads was used as biocatalyst. Optimal conditions were temperature of 35 °C, 10% w/w of biocatalyst content and 216 rpm of agitation rate. Under optimal conditions, an experimental biodiesel yield of 75.3% was obtained after 24 h of reaction time. The biodiesel presented an acid value (0.9 ± 0.28 mg KOH/g) that was higher than the established limits, while other parameters like density (0.89 ± 0.01 g/mL), viscosity (5.3 ± 0.004 mm2/s), calorific value (38.1 ± 0.21 MJ/kg) and cloud point (10.5 ± 0.47 °C), complied with the recommendations of the ASTM D6751 standard.

High methanol/oil ratio together with reaction temperature with increase reaction time are some of the major drawbacks affecting the use of inorganic heterogeneous catalysts for simultaneous esterification and transesterification of oils. In this study, a novel bio-based bifunctional catalyst (BBFC) was prepared from sulfonated calcined corncobs and calcined poultry droppings by wet impregnation method. Characterization of the BBFC was done using X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy. Its catalytic activity in simultaneous esterification and transesterification of neem seed oil (NSO) having high free fatty acid content of 4.426% was investigated, with process parameters optimized using response surface methodology (RSM). Result revealed that the BBFC is highly bifunctional, possessing both acidic and basic oxides. Biodiesel yield of 92.89 wt% with an acid value of 0.23 mg KOH/g was obtained at optimum conditions of methanol/oil ratio, reaction temperature and time of 14.76:1, 61.90 °C and 72.65 min respectively using a catalyst loading of 2.58 wt%. The economic viability of the catalyst was also investigated and results shows that using recovered catalyst from the process gave a biodiesel yield of over 89 wt% after two successive cycles.

Antioxidant additives are commonly used to prevent biodiesel oxidation. Most antioxidant studies have focused on the effects of chemosynthetic antioxidants, but there has been limited research on natural antioxidants. In this study, a cheap and readily available natural antioxidant, Pyrola extract, was applied for biodiesel protection. An immersion test that exposes biodiesel to copper chips was used to compare the antioxidant activities between Pyrola extract and the commercial antioxidants, pyrogallol and BHT. Pyrola extract performs much better than pyrogallol (PY) and BHT on all of the quality characteristics of biodiesel, including acid value, iodine value, peroxide value, and corrosion rate of the coppers. Analysis by gas chromatography also indicates that Pyrola extract helps to maintain the original components of the biodiesel. Due to the simple extraction process and low cost raw materials, Pyrola extract may be a potential antioxidant for protecting biodiesel.

The present study investigated honne oil methyl esters (HOME) production from crude honne seed oil (HSO) using a novel catalyst synthesized from a blend of cocoa pod husk and plantain peel. A two-step esterification-transesterification method was used for the HOME production. For the esterification, the crude HSO was pretreated with H2SO4 to reduce its very high acid value to an acceptable level prior to transesterification to biodiesel. Characterization of the calcined cocoa pod husk-plantain peel ash (CCPA) showed that K (50.95%), Mg (2.49%) and Ca (2.30%) were the major metals present, thereby confirming its heterogeneity. Physisorption isotherms obtained for the CCPA indicate it is composed of nanoparticles that are mesoporous in nature. The initial high acid value of the oil (35.5 g KOH/g oil) was reduced to 1.68 ± 0.57 g KOH/g oil via esterification at a temperature of 65 °C, MeOH:HSO molar ratio of 50:1 and H2SO4 of 2 vol% after 2.5 h. The best operating condition that gave maximum HOME yield (98.98 ± 0.04 wt%) was CCPA amount of 4.5 wt%, reaction temperature of 65 °C, time of 2.5 h and MeOH:pretreated HSO molar ratio of 15:1. The HOME produced satisfied standard limits set for biodiesel.

In this work, activated carbon (AC) powder prepared by lotus leaves was impregnated with CuFe2O4 nanoparticles and the AC/CuFe2O4 nanoparticles were then encapsulated with CaO. Therefore, the AC/CuFe2O4@CaO was used as an efficient and novel nanocatalyst to produce biodiesel from chicken fat. In order to determine the physical characteristics of the AC/CuFe2O4@CaO nanocatalyst, a number of analyses were performed, including Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray (EDX), X-Ray Diffractometer (XRD), Fourier-Transform Infrared Spectrometer (FTIR) and Thermal Gravimetric Analysis (TGA) analyses. The results of EDX analysis showed that the catalyst was well synthesized. Also, TEM analysis proved that the catalyst consists of nanoscale particles. In addition, impacts of various factors including methanol/oil molar ratio, catalyst concentration, reaction time and temperature on the produced biodiesel from the chicken fat were investigated. The results showed that the best biodiesel yield of 95.6% could be achieved at a methanol/oil molar ratio of 12:1, catalyst concentration of 3 wt%, reaction time of 4 h, and reaction temperature of 65 °C which was a considerable amount. Moreover, the characteristics of the biodiesel fuel such as density, kinematic viscosity, pour point, flash point, cloud point, Ca content, acid number, and oxidation stability were measured and compared to ASTM D6751 and EN14214 international standards. The results illustrated that biodiesel was not suitable for cold weather, while very good outcomes were observed in terms of the flash point. Besides, biodiesel had density, viscosity, acid number, and oxidation stability within the range of above mentioned standards.

The high acid value of pyrolysis oil obtained from biologic oil is the main drawback that not only affects the properties of pyrolysis oil, but also leads to the corrosion of equipment. Herein, pyrolysis oil obtained from rubber seed oil was upgraded via esterification using ZrO2/SBA-15 as a solid acid catalyst. Using ZrO2/SBA-15 as a catalyst, the acid value of the esterified pyrolysis oil obtained from rubber seed oil was only 1.2 mg KOH•g−1. The density and kinematic viscosity both reached the standard range of 0# diesel oil. The excellent catalytic activity of ZrO2/SBA-15 was studied using NH3-TPD and Py-IR. Furthermore, the conversion reached 96.7% when the ZrO2/SBA-15 catalyst was re-used three times, which shows the ZrO2/SBA-15 catalyst possessed excellent catalytic activity and stability for upgrading pyrolysis oil via esterification.

In this study, a simple and robust derivatisation-free method has been developed using a gas chromatograph (GC), which has been validated as a suitable analysis for free fatty acids (FFAs) of waste cooking oil (WCO). As biodiesel synthesis from high acid value WCO involves pre-treatment steps, a non-catalytic approach has been employed for biodiesel production. This work has focused on the esterification of FFAs of high acidity feedstock for fatty acid methyl esters (FAME) production. The effect of four independent controllable factors, i.e. methanol to oil (M:O) molar ratio, temperature, pressure and time on FFAs conversion has been investigated. Response Surface Methodology (RSM) via Central Composite Design (CCD) has been implemented for designing experimental runs and optimising the process variables for maximum FFAs conversion. Four quadratic regression models have been developed representing empirical relationship between reaction variables and responses. The adequacy of the predicted models has been checked by numerous statistical validation techniques including analysis of variance (ANOVA) at 95% confidence level. The developed optimum conditions have been reported at 25:1, 256 °C, 110 bar and 16.6 min for M:O molar ratio, temperature, pressure and time, respectively. The predicted optimal conditions have been validated experimentally with 0.22% relative error.

Esterification of lauric acid with a new homogeneous acid catalyst, ammonium ferric sulphate (AFS), was used to get optimised reaction conditions in order to get the best methyl esters conversion by using the statistical modelling approach of response surface methodology (RSM). AFS acts as a new source of homogeneous acid catalyst and was optimised in this study to produce methyl ester. The Central Composite Design (CCD) and RSM were used to determine the relationship between reaction time, methanol to lauric acid molar ratio and catalyst loading to determine the optimum condition for the esterification process. This work reports the novel results of the optimum conditions obtained for esterification of lauric acid, which are 1.5 h of reaction time, 6:1 M ratio of methanol to lauric acid and 8 wt% loading of AFS catalyst to give the highest conversion rate of methyl esters at 99.8%. These reaction conditions were successfully applied and verified on the esterification of palm fatty acid distillate (PFAD) which demonstrated the ability of AFS to act as an acid catalyst in the esterification process with a conversion rate of 81.2% of methyl esters. Acid value of PFAD was also decreased from 185 to 41 mg KOH/g PFAD.

The corrosive character of Moringa oleifera Lam biodiesel was evaluated through static immersion tests with different carbon steels (CS1015 and CS4140) in absence and presence of the antioxidant tert-butylhydroquinone (TBHQ), at room temperature in the absence of light for 84 days. Biodiesel parameters, including oxidation stability (induction period, IP), total acid number (TAN) and iron concentration released from carbon steel, were monitored. The produced biodiesel presented an IP value of 4.9 h, which was increased to 6.2 h after the addition of 500 mg kg−1 TBHQ. After 84 days of immersion, IP values decreased in the first 21 days due to the contact with the metallic coupon, while TBHQ retarded this process. TAN value increased in 20% but the values were below the recommended limits ( 3 h) by the high Fe content.

The main objective of this work comprises the investigation of biodiesel production from rapeseed oil using potassium impregnated Fe3O4-CeO2 nanocatalyst. The various concentration of potassium impregnated Fe3O4-CeO2 was screened for catalytic conversion of rapeseed oil to triglyceride methyl ester. The 25 wt % potassium impregnated Fe3O4-CeO2 nanocatalyst showed best biodiesel production. Nanocatalyst was characterized by FTIR, XRD, SEM, TEM, BET and Hammett indicator for basicity test. The characterization of biodiesel was performed with GC-MS, 1H and 13C NMR. Moreover, the optimum reaction parameters such as catalyst amount (wt %), oil to methanol ratio, reaction time and reaction temperature for transesterification reaction was analyzed and yield was determined by 1H NMR. The maximum yield of 96.13% was obtained at 4.5 wt % catalyst amount, 1:7 oil to methanol ratio at 65 °C for 120 min. The properties of biodiesel such as acid value and kinematic viscosity were observed as 0.308 mg KOH/g and 4.37 mm2/s respectively. The other fuel parameters such as flash point and density were also determined. The reusability of catalyst was observed and it showed stability up to five cycles without considerable loss of activity. The recovery of excess methanol after transesterification reaction was achieved using distillation process setup.

Fish oil is a sustainable, abundant, and low-cost raw material, as it is extracted from fish processing waste. This work suggests that fish oil is appropriate for biodiesel production and evaluates its potential through ethyl esters (EE). Initially, fish oil showed an acid value of 10.86 ± 0.05 mg KOH g−1. But after a neutralization reaction, the acid value was reduced to 0.68 ± 0.01 mg KOH g−1. Alkaline transesterification reactions were performed on a laboratory scale, using a central composite rotational design with three variables and a triplicate over the center point. We studied the appropriate concentrations of ethanol and catalysts, and the temperature that provide the best EE yield. The results showed the optimal condition is with 0.7% of a NaOH catalyst, a temperature of 54 °C, and an ethanol:oil molar ratio of 11.7:1. In such conditions, it was possible to acquire an EE yield of 96.4% with a low acid value of 0.32 ± 0.08 mg KOH g−1, which presented physicochemical properties consistent with the parameters by the Petroleum National Agency's (ANP). In the conditions studied, the results showed high levels of EE from the residual fish oil. This suggests that this raw material, rich in unsaturated fatty acid, can be beneficial for biodiesel.

This study investigated the pyrolysis of plant acidified oil, aiming to upgrade the quality of oil for fuel use. The decomposition temperature of plant acidified oil was in the range of 300oC-500 °C in 10 K/min according to TG-DTG. The Py-GC-MS results showed that except alkane, alkene and oxygen containing compound, plant sterol derivatives were also detected. The ESI FT–ICR MS results showed the presence of some products produced from hydrogenation and polymerization reaction occurred in pyrolysis process. The yield of the liquid product reached the maximum of 90% at 500 °C. The acid value and viscosity of pyrolysis products were relative high compared with diesel oil. The calorific value has no difference with that of diesel oil. According to above experiments, it was confirmed that pyrolysis components and characteristic of plant acidified oil was different with vegetable oil or fatty acid. Plant acidified oil was potential renewable source to obtain bio-fuel oil using pyrolysis method.

In this present investigation, lipid extraction was performed in marine macro algae Ulva fasciata using soxhlet and super critical fluid extraction apparatus. The ultrasonic pretreatment was done for the algal biomass. Extraction parameters for High extraction yield of algal oil were obtained at 5% moisture content, 0.25 mm particle size, 90 °C, 180 min time, 5:1 solvent-to-solid ratio and solvent flow rate 1 l/hr. After the optimization process 9.85% of oil extraction was obtained from Ulva fasicata algal biomass. The aromatic groups, indicating the presence of 12-Hydroxy-9-octadecenoic acid was confirmed by FT-IR analysis. Thus the algal oil obtained from Ulva fasicata biomass can be used for the biodiesel production. The saturated fatty acid (SFAs) was found to be 75.43% in the produced algal oil. The properties like Acid value, Iodine number, specific gravity, Saponification value, calorific value, Flash point, Fire point and kinematic viscosity was also characterized.

Utilization of waste resources to cultivate microalgae for biofuel production has the potential to improve the economics along with sustainable reuse of discarded nitrogen and phosphorous sources. The present investigation aims to cultivate an oleaginous microalga (Chlorella minutissima) in stagnant non-potable pond (SNP) water collected from different seasons (summer, winter and rainy) for biomass and lipid synthesis. The C. minutissima showed enhanced biomass productivity (245 mg/L/d) and lipid content (47 %) when grown in SNP water as compared to basal media, synthetic wastewater and recycled media respectively. The adaption in the SNP media by C. minutissima was attributed to an increase in cell size (∼2 folds) with decrease in total protein content (∼2 folds) and total carbohydrate content (∼1 fold) respectively. The fatty acid profile indicated the presence of C16:0, C16:2, C18:0, C18:1 and C18:2 as major methyl esters in the derived biodiesel. Further, the measured biodiesel properties such as specific density (0.90 g/cm3), kinematic viscosity (3.24 mm2/s), flash point (143 °C), iodine value (40.14 g I2/100 g) and acid value (3.24 mgKOH/g) abided by the ASTM D6751-02 and EN14214 standards. Therefore, such kind of SNP's have dual advantage; microalgal cultivation for biodiesel production and providing economical solution for bioremediation.

A highly active bi-functional catalyst system for the conversion of high free fatty acid content oil feedstock, and waste cooking oil to fatty acid methyl ester (FAME), is described. Tungsten loaded CaO/hydroxyapatite materials containing both basic, and acidic sites were derived from addition of 12-phosphotungstic acid to powdered bovine bone (BV), followed by calcination at 750 °C. Addition of 10% tungsten afforded 10 W/BV, which catalyzes FAME production from high acid value oil feedstock (24.38 mg KOH/g of oil) in 7 h at 120 °C at a methanol:oil ratio of 6:1. Conversion of waste cooking oil to FAME via simultaneous transesterification/esterification can be achieved in 5 h at 100 °C and at a methanol:oil ratio of 6:1, significantly more efficient than achievable using other bi-functional catalyst systems. The 10 W/BV catalyst system, readily prepared from a cheap, biomass derived support containing basic sites, is reusable, and allows for the production of fuel quality FAME in high yields from waste cooking oil, allowing for sustainable use of an otherwise wasted resource.

In this study, broiler rendering fat obtained from a slaughterhouse was used to produce methyl ester. The acid value of the broiler rendering fat was 5.2 mg KOH g−1. Therefore, it was needed to perform two-step treatment to broiler rendering fat. For this purpose, sulfuric acid was used as a catalyst and methanol was used as alcohol for the first treatment reactions. The variables affecting the free fatty acid level including the ratio of alcohol, catalyst amount, and reaction time were investigated to determine the best strategy for the first step process. After reducing the free fatty acid level of the broiler rendering fat to less than 1%, the transesterification reaction was completed with the alkaline catalyst. Potassium hydroxide was used as catalyst and methanol was used as alcohol for transesterification reaction. The measured fuel properties of the broiler rendering fat methyl ester (BRFME) were compared to EN 14214:2012 + A1:2014 and ASTM D6751–15 biodiesel standards. The BRFME meet ASTM D6751–15 biodiesel standard. Also, the BRFME meets EN 14214:2012 + A1:2014 biodiesel standard except for oxidation stability. According to the results, the oxidation stability property of the BRFME should be improved and should be investigated in detail.

The pyrolysis characteristic of rice bran wax (RBW) and its bio-fuel oil were analyzed. TG, Py-GC-MS, TG-MS, FTIR, 1H NMR and 13C NMR were all carried out to analysis RBW pyrolysis characteristic and bio-fuel oil characteristic. TG results showed that RBW pyrolysis temperature was mainly in the temperature range of 350 °C–450 °C. The mean activation energy values calculated from KAS method and FWO method was 106.15 kJ/mol and 115.72 kJ/mol, respectively. The TG-MS results showed that main gas products were alkane and olefins. The Py-GC-MS also found the mainly components of pyrolysis products were alkane and alkene. The 1H NMR, 13C NMR and FTIR experiments were also carried out to confirm the component of bio-fuel oil. The results found that the main components of pyrolysis products were alkane and alkene. The bio-fuel oil properties were also analyzed. The acid value was very low. It was about 10 mg(KOH)/g. And the coke was found. The yield was about 8%. According to above results, it was confirmed that RBW maybe was a good bio-resource to obtain long carbon chain bio-fuel oil.

The chromium polluted water hyacinth was subjected to pyrolysis to understand its pyrolytic characteristic in a fixed bed. The results indicated that chromium has a positive effect on the bio-oil produced, accompanied by a decrease of gas yield and moderate formation of char. The maximum bio-oil yield obtained from Cr-WH pyrolysis reached the maximum of 63.1 wt.%. The acid number and high heating value of the Cr-WH pyrolytic bio-oil were 85.04 mgKOH/g and 26.72 MJ/kg, respectively. GC-MS analysis of the bio-oils showed that the amount of nitrogenous compounds, alcohols and phenols increased, while the number of esters reduced in the Cr-WH pyrolytic bio-oil which indicated that chromium promoted bond rupture of lignin and changed the degradation process of protein. Furthermore, after pyrolysis, Cr may transfer from the toxic state of ions into an amorphous state in the char, which reduce its harm to the environment.

Biolubricants are gaining increased attention because of their low toxicity, high biodegradability, and miscibility with additives. These features render them ideal for lubrication, especially in total-loss processes. In this study, housefly ( Musca domestica ) larvae were used as low-cost, non-food biolubricant feedstock. A larval lipid with high acid value (AV) of 63 mg KOH/g was used as feedstock for esterification to produce 2-ethylhexyl fatty acid esters (2-EH esters). We developed a method of producing high-purity 2-EH esters in which housefly larva free fatty acids (HLFFAs) were derived from larvae fed with kitchen waste. HLFFAs were esterified with 2-ethyl-1-hexanol (2-EHOH) catalysed with benzenesulfonic acid (BSA). The optimum esterification conditions were as follows: catalyst loading, 0.5 wt%; 2-EHOH-to-HLFFAs molar ratio, 3:1; temperature, 130 °C; and reaction time, 2 h. These conditions yielded 98.6% esterification rate. Excess 2-EHOH was removed by molecular distillation at 80 Pa and 110 °C. Residual fatty acids were neutralised by alkali refining. The chemical and physical properties, including the tribological properties, of the produced high-purity 2-EH esters (>99.7%) were also tested.

There is a growing trend in utilizing biological industrial wastes to produce biofuels. The dairy washed milk scum (DWMS) is one of such potential industrial waste and can be used as feedstock for the production of biodiesel. One of the inherent problems of DWMS biodiesel is its poor low temperature property. In this investigation, the influence of two bio-based cold flow improvers (CFIs) namely, ethyl acetoacetate (EAA) and ethyl levulinate (EL) was tested on low temperature properties of DWMS biodiesel. It was observed that the addition of 20% (v/v) of EAA and EL to DWMS biodiesel significantly decreased the cloud point (CP), cold filter plugging point (CFPP) and pour point (PP). The crystallization characteristics of neat biodiesel and biodiesel blended with CFIs (EAA and EL) were determined using differential scanning calorimetry (DSC). The viscosity, acid value and induction period, flash point of all samples were within the permissible limits of biodiesel standard (ASTM D6751-15c ) with all the blends of EAA and EL. The present work demonstrates that EAA and EL are suitable cold flow improvers for DWMS biodiesel.

This paper focused on the removal of free fatty acids from the ester phase. Transesterification was stopped by neutralization of the catalyst (KOH) by phosphoric acid addition to the reaction mixture. The advantages of this method are a very fast separation, an ester phase that does not contain potassium ions and free glycerol, and a relatively high purity of the glycerol phase. The disadvantage is the formation of free fatty acids, which were removed by the addition of calcium hydroxide, a reaction that formed solid calcium soaps that were removed by centrifugation. The conditions of removal (independent variables), such as the acid number of the input ester phase, molar ratio of calcium to FFAs and addition of water, were studied. The relations between independent and dependent variables (acid number, amount of calcium ions and water in the ester phase) are described. The model allowed for the calculation of conditions, so that the biodiesel fulfilled EN14214: a molar ratio of calcium to FFAs of 3.33:1, the addition of 1.45 μl water to 1 g of the ester phase and a reaction time of 3 h. This preparation of methyl ester is nearly without waste and does not use water for purification.

Corrosive behavior of biodieseledieseleethanol (BDE) fuel blends upon exposure to metals, namely, mild steel, copper and aluminum was studied by static immersion at room temperature and 60 �C. The change of fuel properties, i.e., total acid number, density, viscosity, calorific value, flash point, and color changes were investigated. Moreover, fuel compositional changes, such as water content, oxidation product level, and metal elements in the fuel blends were examined. Finally, the effect of fuel blends on corrosion rate (CR), morphology of corrosion products, and chemical structure of metals were studied. Results revealed that the CR of metals in BDE fuels is in the order: aluminum < mild steel < copper at both temperature conditions. The degradation of fuel properties and corrosion rate of metals in BDE fuel blends are lower than neat biodiesel (B100), whereas higher than petroediesel (B0). Corrosiveness of B20D75E5 is lower than B20D70E10 upon exposure to metals.

This paper discusses the determination of the optimal conditions for enzymatic transesterification of model waste oil (with 4% acid value) with butanol. It was found that biodiesel synthesis by the enzymatic transesterification of waste rapeseed oil rich in free fatty acid with butanol can be very effective if the catalysis is carried out in two steps. Both transesterification steps were catalysed by Lipozyme RM IM. The optimal conditions for the first step were determined: temperature of 39 °C, butanol and oil molar ratio of 4.5, lipase concentration of 6%, and reaction time of 9.8 h, with an expected yield of 60.1%. The removal of glycerol, enzyme renewal and subsequent addition of 7.8% lipase, with a 1.5 butanol and oil molar ratio and 8-h incubation at 39 °C predicted a 96.7% yield and resulted in a 96.6% butyl ester yield.

Corrosive characteristics of biodiesel are important for long-term durability of engine parts. The effect of palm biodiesel on corrosion properties of ASTM 1045 mild steel was studied and compared with that of commercial diesel fuel (0# diesel). Static immersion tests were carried out at different temperatures (27, 50 and 80 °C) for 30, 60 and 120 d. The morphology and composition of corrosion products were characterized by SEM, FT-IR, XRD and XPS. The total acid number was used to investigate the change in acidity of fuel upon exposure. It was found that palm biodiesel is more corrosive than 0# diesel. Temperature and exposure time have critical impact on metal corrosion and degradation of fuels.

An efficient lipid transesterification method for marine microalga Chlorella sp. BDUG 91771 has been ascertained. Among the homogeneous alkali (NaOH), homogeneous acid (H2SO4), heterogeneous alkali (CaO), heterogeneous acid (Fe2(SO4)3) and two-step transesterification methods (NaOH and H2SO4 or H2SO4 and NaOH) tested with 100 mg lipid, 12-ml methanol, 2-h reaction time, reaction temperature 65 ± 1 °C with stirring for 2 h, homogeneous acid catalysis was graded the best and its biodiesel yield was determined to be 45%. Of the different homogeneous acids tested, H2SO4 was regarded seamless. A maximum methyl ester yield of 60% was observed with 3.5% H2SO4, 2.5-h reaction time, which correlated well with the central composite design. Evidently, the spectra of 1H NMR, 13C NMR, FTIR and GC-FID unveiled that biodiesel from Chlorella sp. BDUG 91771 encompasses fatty acid methyl esters (FAMEs). Gas chromatographic analysis revealed abundant palmitic acid, oleic acid and palmitoleic acid and it also had the desired Degree of Unsaturation (DU) of 56.33, Long Chain Saturated Factor (LCSF) of 1.97 and Cold Filter Plugging Point (CFPP) of −10.51. Further, density, viscosity, specific gravity, pour point, calorific value, acid value, total glycerol and ash content of algal biodiesel accords with the prescribed ASTM and European standard.

The production of biodiesel from waste palm cooking oil using acidic ionic liquid as a catalyst was investigated. Generally, alkaline based catalysts are used to catalyze the transesterification reaction, but for waste cooking oil where it contains high free fatty acids, direct usage is not possible due to separation of layers and saponification problems. In this study, a two-step process i.e. esterification and transesterification was performed. The ionic liquid butyl-methyl imidazolium hydrogensulfate (BMIMHSO 4 ) was found to be effective due to its longer side chain. The highest biodiesel Yield was obtained with 5 wt.% BMIMHSO 4 , methanol:oil of 15:1, 60 min reaction time, at 160 °C, and agitation speed of 600 rpm, reduced the waste cooking oil acid value lower than 1.0 mg KOH/g. The second step of transesterification catalyzed by KOH at 60 °C, 1.0 wt.% and 60 min of reaction time. The final yield was 95.65 wt.%. The synthesized biodiesel was analysed by 1 H NMR, FTIR TGA and GC, and its physiochemical properties were determined by standard ASTM methods.

This work investigated the potential of shea butter oil (SBO) as feedstock for synthesis of biodiesel. Due to high free fatty acid (FFA) of SBO used, response surface methodology (RSM) was employed to model and optimize the pretreatment step while its conversion to biodiesel was modeled and optimized using RSM and artificial neural network (ANN). The acid value of the SBO was reduced to 1.19 mg KOH/g with oil/methanol molar ratio of 3.3, H2SO4 of 0.15 v/v, time of 60 min and temperature of 45 °C. Optimum values predicted for the transesterification reaction by RSM were temperature of 90 °C, KOH of 0.6 w/v, oil/methanol molar ratio of 3.5, and time of 30 min with actual shea butter oil biodiesel (SBOB) yield of 99.65% (w/w). ANN combined with generic algorithm gave the optimal condition as temperature of 82 °C, KOH of 0.40 w/v, oil/methanol molar ratio of 2.62 and time of 30 min with actual SBOB yield of 99.94% (w/w). Coefficient of determination (R2) and absolute average deviation (AAD) of the models were 0.9923, 0.83% (RSM) and 0.9991, 0.15% (ANN), which demonstrated that ANN model was more efficient than RSM model. Properties of SBOB produced were within biodiesel standard specifications.

Fuel characteristics of biodiesel derived from kernel oils of Sclerocarya birrea, Tylosema esculentum, Schiziophyton rautanenii and Jatropha curcas plants were investigated in comparison with petroleum diesel. The fuel properties under review include flash point, cloud point, kinematic viscosity, density, calorific value, acid value, and free fatty acids. These were determined and discussed in light of major biodiesel standards such as ASTM D 6751 (American Society for Testing and Materials) and EN 14214 (European standards). The best biofuel in terms of cold flow properties was S. rautanenii, with a cloud point of 0 degrees C and a pour point of -5 degrees C. The good cold flow properties demonstrate operational viability during the cold season. The heating values of S. birrea and S. rautanenii biodiesel fuels were found to be 9.2% and 10.3% lower than that of petroleum diesel while those of T. esculentum and J. curcas were both 9.7% lower. Other fuel properties analysed demonstrate that biodiesel fuels produced from kernel oils of S. birrea, T. esculentum, S. rautanenii and J. curcas plants have properties that are comparable to, and in some cases better than, those of petroleum diesel. The results of this study indicate the feasibility of producing quality biodiesel fuel from indigenous seed oils found in Botswana. A balanced allocation of resources however needs to be established to ensure that the cultivation of these oil-bearing plants does not compete with the cultivation of food crops. (C) 2014 Elsevier Ltd. All rights reserved.

The present work reports the production of biodiesel from Silurus triostegus Heckel fish oil (STFO) through alkaline-catalyzed transesterification by using potassium hydroxide (KOH) as an alkaline catalyst with methanol. Chemical and physical properties of the extracted oil were determined. It was found that STFO has a low acid value (1.90 mg KOH/g oil); hence no pre-treatment such as acid esterification is required to produce the biodiesel. The influence of the experimental parameters such as KOH concentration (0.25–1.0% w/w of oil), methanol to oil molar ratio (3:1, 6:1, 9:1 and 12:1), reaction temperature (32, 45 and 60 °C), reaction duration (30, 60, 90 and 120 min), type of the catalyst (potassium or sodium hydroxide) and step multiplicity (single- and two-step transesterification) on the yield of the biodiesel were investigated. The maximum biodiesel yield (96%) was obtained under the optimized parameters of the transesterification (KOH 0.50% w/w, 6:1 methanol to oil, at 32 °C for 60 min). The properties of the produced biodiesel were found to conform with the ASTM standard, indicating its suitability for internal combustion engines. Blending of the produced biodiesel with petro diesel with various volume percentages was investigated as well.

Herein we report the fast pyrolysis of dried, ground Scenedesmus sp. at two different reactor scales. Pyrolysis was performed at 480 °C and 1 bar in both an isothermal spouted bed reactor and a dynamic pyrolysis-GC/MS unit, each with 2 s vapor residence times. Bio-oil products were characterized on the basis of GC-MS, simulated distillation GC, elemental analysis, calorific content and total acid number. The ratio of crude oil: char obtained from the spouted bed reactor was 3.76 by weight, the average calorific content of the oil being 18.4 MJ/kg. The average total acid number (68 mg KOH/g) was lower than typical bio-oil produced via wood pyrolysis. Simulated distillation results indicated that a significant proportion of the oil corresponded to the boiling range typical for heavy gas oil (343 °C–524 °C). Elemental analysis showed the oil contained an average of 27.6 wt.% oxygen and 8.6 wt.% nitrogen, the relatively high nitrogen content being a consequence of the high protein content of the algae. According to GC-MS data, the oil consisted of various hydrocarbons as well as oxygenated and nitrogenous species, including indoles, fatty acids and amides. Pyrolysis-GC-MS was also performed on Scenedesmus sp. in order to provide insights into the nature of the primary pyrolysis products.

Biorefinery approach is introduced for the biodiesel production by utilizing low cost raw material, such as rice bran oil (RBO). The valorization of RBO was carried out by homogeneous transesterification process using response surface methodology (RSM) based on a two-variable central composition design (CCD). The process variables, temperature and catalyst concentration were found to have significant influence on biodiesel yield. The optimum combination derived via RSM for high ester yield (99.4%) was found to be 0.75% wt catalyst concentration at a reaction temperature of 45 °C. As biodiesel chemically is a long-chain alkyl methyl esters, its long-term fuel properties have become of great concern to the fuel industry. In order to determine the effects of long storage on oxidation stability, RBO biodiesel sample was stored for 24 months and the different physical–chemical properties were checked with respect to time. The results show that the acid value (AV), peroxide value (PV), and viscosity ( ν ) increased while the iodine value (IV) decreased. Based on results, correlations were obtained in terms of AV, IV, PV and ν as a function of time. Those correlations can be used to predict how long time biodiesel can safely be stored. AV, IV and PV of the biodiesel sample which was stored were within the limits in European biodiesel specifications (EN 14214).

A kind of solid catalyst of Fe(Ⅱ)–Zn double-metal cyanide (DMC) complexes was prepared through co-reaction of potassium ferrocyanide, zinc chloride and complexing agent of tert-butanol. This catalyst was characterized by using several techniques such as XRD, TG/FT-IR, EA, BET and SEM. And it proved to be highly active for the simultaneous transesterification of triglycerides and esterification of free fatty acids (FFAs). Results show that the catalyst has a hybrid-structure comprised of both crystal and amorphous species. Its good water-resistance depends on the amorphous state, which has surface hydrophobicity. Zn 2+ may be the active site of catalysis. The effect of various factors on the reaction was also studied, including different co-complexing agents, DMC concentration, reaction temperature, methanol/oil molar ratio, reaction time, water and fatty acid content and so on. The yield rate reached 98% under the optimum conditions, and the recovery rate maintained more than 90% after 10 batches.

Fatty acid methyl esters prepared from canola, palm, soybean, and sunflower oils by homogenous base-catalyzed methanolysis were stored for 12 months at three constant temperatures (− 15, 22, and 40 °C) and properties such as oxidative stability, acid value, kinematic viscosity, low temperature operability, and iodine value were periodically measured. Oxidative stability was significantly reduced upon extended storage and acid value as well as kinematic viscosity were increased by only small increments, with these effects more pronounced at elevated temperatures. Iodine value and low temperature operability were essentially unaffected by extended storage. Based on these findings, it is not recommended that acid value or kinematic viscosity be used as indicators of storage stability of biodiesel, nor is it recommended that iodine value be used as a predictor of oxidative stability or indicator of oxidative degradation.

Influence of phosphorus lipids on formation of deposits and performance of plant oil pressure stoves was investigated. Refined coconut oil with an original phosphorous content of 5.9 mg/kg was used as base for fuel blends by adding lecithin to adjust increased phosphorous concentrations of 32.2, 51.6 and 63.0 mg/kg. The fuel blends were analysed for acid value, iodine value, total contamination, ash content and Conradson carbon residue according to standard methods. In burning trials, the specific fuel consumption, the required frequency of nozzle cleaning and the amount of deposits in the vaporizer were measured. Results showed an exponential increase of deposits in the vaporizer when phosphorous content was increased: deposits amounted to 0.12 g/kg of consumed fuel for unblended coconut oil and 0.92 g/kg for the blend with the highest phosphorous content. Furthermore, increased phosphorous content caused higher fuel consumption of 0.375 kg/h compared to 0.316 kg/h for the control.

The low temperature operability, kinematic viscosity, and acid value of poultry fat methyl esters were improved with addition of ethanol, isopropanol, and butanol with increasing alcohol content. The flash point decreased and moisture content increased upon addition of alcohols to poultry fat methyl esters. The alcohol type did not result in a statistically significant difference in low temperature performance at similar blend ratios in poultry fat methyl esters. In addition, blends of ethanol in poultry fat methyl esters afforded the least viscous mixtures, whereas isopropanol and butanol blends were progressively more viscous, but still within specifications contained in ASTM D6751 and EN 14214. Blends of alcohols in poultry fat methyl esters resulted in failure of the flash point specifications found in ASTM D6751 and EN 14214. Flash points of butanol blends were superior to those of isopropanol and ethanol blends, with the 5 vol.% butanol blend exhibiting a flash point (57 °C) superior to that of No. 2 diesel fuel (52 °C). Blends of alcohols in poultry fat methyl esters resulted in an improvement in acid value with increasing content of alcohol. An increase in moisture content of biodiesel was observed with increasing alcohol content, with the effect being more pronounced in ethanol blends versus isopropanol and butanol blends. Finally, none of the alcohol–methyl ester samples exhibited a phase separation at sub-ambient temperatures.

In this study, a pilot scale of 100 t/year biodiesel production system, mainly consisting of a fixed-bed and a down-stream plug-flow reactors, was setup to test different feedstock oils, especially a kind of high-acidified oil, trap grease, for their feasibility as biodiesel feedstock in China. The tested oils include three kinds of typical oil from Guangdong Province, China: rapeseed oil, Chinese wood oil, and trap grease. At the same time the optimum residence time for a plug-now reactor to perform transesterification reaction was investigated in this study. At the temperature of 65 degrees C, methanol/oil molar ratio of 6:1 and KOH load of 1.2 wt% of oil, the optimum residence time was found to be 19 min. A type of ion-exchange resin was used to fill in the fixed-bed reactor and used as the esterification catalyst for pretreating on the high-acidified oil. For the fresh catalyst, the acid value of trap grease could be reduced from 114 mg KOH/g to about 2 mg KOH/g after 13 h at temperature 75 degrees C, catalyst load of 15 wt% of oil, methanol addition of 20 wt% of oil. The lifetime test for the catalyst indicated that its life is over 30 days. The quality of biodiesel derived from three feedstock oils is compared with newly published China BD100 standard of GB/T20828-2007. A comparison of the results reveals that the biodiesel generated through this system could satisfactorily meet China BD100 standard. It indicates that the designed process in this system has a good adaptability for different kinds of oil. (C) 2009 Elsevier Ltd. All rights reserved.

In this study, both edible (coconut oil, palm oil, groundnut oil, and rice bran oil) and non-edible oils (pongamia, neem and cotton seed oil) were used to optimize the biodiesel production process variables like catalyst concentration, amount of methanol required for reaction, reaction time and reaction temperature. The fuel properties like specific gravity, moisture content, refractive index, acid value, iodine number, saponification value and peroxide value were estimated. Based on the cetane number and iodine value, the methyl esters obtained from palm and coconut oils were not suitable to use as biodiesel in cold weather conditions, but for hot climate condition biodiesel obtained from the remaining oil sources is suitable.