Biodiesel production over copper vanadium phosphate

In the present study, copper vanadium phosphate (CuVOP) with three-dimensional network structure was synthesized by hydrothermal method, and was characterized by Infrared spectrum (IR), elemental analysis (EA), EDXRF (energy dispersive X ray fluorescence) etc. Moreover, soybean oil was used as feedstock for producing biodiesel, and biodiesel was produced by CuVOP-catalyzed transesterification process. Response surface methodology was employed to statistically evaluate and optimize the conditions for the maximum conversion to biodiesel, and the effects of amount of catalyst, ratio of methanol to oil, reaction time and reaction temperature were investigated by the 2⁴ full-factorial central composite design. The maximum conversion is obtained at amount of catalyst of 1.5%, methanol/oil molar ratio of 6.75, reaction temperature of 65 °C and reaction time of 5 h. Copper vanadium phosphate CuVOP resulted very active in the transesterification reaction for biodiesel production.     

Optimization of heterogeneous biodiesel production from waste cooking palm oil via response surface methodology

Heterogeneous transesterification of waste cooking palm oil (WCPO) to biodiesel over Sr/ZrO₂ catalyst and the optimization of the process have been investigated. Response surface methodology (RSM) was employed to study the relationships of methanol to oil molar ratio, catalyst loading, reaction time, and reaction temperature on methyl ester yield and free fatty acid conversion. The experiments were designed using central composite by applying 2⁴ full factorial designs with two centre points. Transesterification of WCPO produced 79.7% maximum methyl ester yield at the optimum methanol to oil molar ratio = 29:1, catalyst loading = 2.7 wt%, reaction time = 87 min and reaction temperature = 115.5 °C.     

Preparation, characterization and application of heterogeneous solid base catalyst for biodiesel production from soybean oil

A solid base catalyst was prepared by neodymium oxide loaded with potassium hydroxide and investigated for transesterification of soybean oil with methanol to biodiesel. After loading KOH of 30 wt.% on neodymium oxide followed by calcination at 600 °C, the catalyst gave the highest basicity and the best catalytic activity for this reaction. The obtained catalyst was characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), N₂ adsorption-desorption measurements and the Hammett indicator method. The catalyst has longer lifetime and maintained sustained activity after being used for five times, and were noncorrosive and environmentally benign. The separate effects of the molar ratio of methanol to oil, reaction temperature, mass ratio of catalyst to oil and reaction time were investigated. The experimental results showed that a 14:1 M ratio of methanol to oil, addition of 6.0% catalyst, 60 °C reaction temperature and 1.5 h reaction time gave the best results and the biodiesel yield of 92.41% was achieved. The properties of obtained biodiesel are close to commercial diesel fuel and is rated as a realistic fuel as an alternative to diesel.     

Biodiesel from Milo (Thespesia populnea L.) seed oil

There is a need to seek non-conventional seed oil sources for biodiesel production due to issues such as supply and availability as well as food versus fuel. In this context, Milo (Thespesia populnea L.) seed oil was investigated for the first time as a potential non-conventional feedstock for preparation of biodiesel. This is also the first report of a biodiesel fuel produced from a feedstock containing cyclic fatty acids as T. populnea contains 8,9-methylene-8-heptadecenoic (malvalic) and smaller amounts of two cyclopropane fatty acids besides greater amounts of linoleic, oleic and palmitic acids. The crude oil extracted from T. populnea seed was transesterified under standard conditions with sodium methoxide as catalyst. Biodiesel derived from T. populnea seed oil exhibited fuel properties of density 880 kg m⁻³, kinematic viscosity 4.25 mm²/s; cetane number 59.8; flash point 176 °C; cloud point 9 °C; pour point 8 °C; cold filter plugging point 9 °C; sulfur content 11 mg kg⁻¹; water content 150 mg kg⁻¹; ash content 15 mg kg⁻¹; and acid value as KOH 250 mg kg⁻¹. The oxidative stability of 2.91 h would require the use of antioxidants to meet specifications in standards. Generally, most results compared well with ASTM D6751 and EN 14214 specifications.     

Study on the use of MgAl hydrotalcites as solid heterogeneous catalysts for biodiesel production

This paper, reports experimental work on the use of new heterogeneous solid basic catalysts for biodiesel production: double oxides of Mg and Al, produced by calcination, at high temperature, of MgAl lamellar structures, the hydrotalcites (HT). The most suitable catalyst system studied are hydrotalcite Mg:Al 2:1 calcinated at 507 °C and 700 °C, leading to higher values of FAME also in the second reaction stage. One of the prepared catalysts resulted in 97.1% Fatty acids methyl esters (FAME) in the 1st reaction step, 92.2% FAME in the 2nd reaction step and 34% FAME in the 3rd reaction step. The biodiesel obtained in the transesterification reaction showed composition and quality parameters within the limits specified by the European Standard EN 14214. 2.5% wt catalyst/oil and a molar ratio methanol:oil of 9:1 or 12:1 at 60–65 °C and 4 h of reaction time are the best operating conditions achieved in this study. This study showed the potential of Mg/Al hydrotalcites as heterogeneous catalysts for biodiesel production.     

A comparative study of vegetable oil methyl esters (biodiesels)

In the present study, rubber seed oil, coconut oil and palm kernel oil, which are locally available especially in Kerala (India), are chosen and their transesterification processes have been investigated. The various process variables like temperature, catalyst concentration, amount of methanol and reaction time were optimized. Biodiesel from rubber seed oil (with high free fatty acid) was produced by employing two-step pretreatment process (acid esterification) to reduce acid value from 48 to 1.72 mg KOH/g with 0.40 and 0.35 v/v methanol-oil ratio and 1.0% v/v H₂SO₄ as catalyst at a temperature of 63(±2) °C with 1 h reaction time followed by transesterification using methanol-oil ratio of 0.30 v/v, 0.5 w/v KOH as alkaline catalyst at 55(±2) °C with 40 min reaction time to yield 98-99% biodiesel. Coconut oil and palm oil, being edible oils, transesterification with 0.25 v/v methanol-oil ratio, 0.50% w/v KOH as at 58(±2) °C, 20 min reaction time for coconut oil and 0.25% v/v methanol-oil ratio, 0.50% w/v KOH as alkaline catalyst at 60(±2) °C for palm kernel oil will convert them to 98-99% biodiesel. The brake thermal efficiency of palm oil biodiesel was higher with lower brake specific fuel consumption, but rubber seed oil biodiesel(ROB) showed less emission (CO and NO_x) compared to other biodiesels.     

Property modification of jatropha oil biodiesel by blending with other biodiesels or adding antioxidants

The feasibility of biodiesel production from jatropha (Jatropha curcas) oil was investigated with respect to the biodiesel blending properties and its oxidation stability with antioxidants. The JME (jatropha oil methyl esters) had the cetane number of 54, cold filter plugging point of −2 °C, density of 881 kg/m³ at 15 °C, ester content of 99.4 wt.%, iodine value of 96.55 g I₂/100 g, kinematic viscosity of 4.33 mm²/s at 40 °C, and oxidation stability of 3.86 h. Furthermore, the JME was blended with palm oil biodiesel and soybean oil biodiesel at various weight ratios and evaluated for fuel properties as compared to the relevant specifications. In addition, several antioxidants at concentrations between 100 and 1000 ppm were studied for their potential to improve the oxidation stability of the JME. The relationship between the IP (induction period) in the measurement of the oxidation stability associated with the antioxidant consumption in the JME was described by first-order reaction rate kinetics. Moreover, the ln IP (natural logarithm of the IP) at various concentrations of pyrogallol showed a linear relationship with the test temperature. The oxidation stability at ambient temperatures was predicted on the basis of an extrapolation of the temperature-dependent relationship.     

High quality biodiesel from yellow oleander (Thevetia peruviana) seed oil

Yellow oleander (Thevetia peruviana Schum.) seed oil has been investigated to produce biodiesel. Transesterification of the oil to biodiesel was carried out in methanol by batch reaction using a heterogeneous catalyst derived from the trunk of Musa balbisiana Colla (one variety of banana plant). 96 wt.% of the oil is converted to biodiesel at 32 °C in 3 h. The wt.% composition of the biodiesel is methyl oleate 43.72, methyl palmitate 23.28, methyl linoleate 19.85, methyl stearate 10.71 and methyl arachidate 2.41. Fuel properties conform to standards set for ASTM D6751, EN 14214, BS II and BS III, and in certain aspects better. The biodiesel is free from sulfur and has exhibited a high cetane number of 61.5.     

Biodiesel synthesis from Hevea brasiliensis oil employing carbon supported heterogeneous catalyst: Optimization by Taguchi method

The present work illustrates the parametric effects on biodiesel production from Hevea brasiliensis oil (HBO) using flamboyant pods derived carbonaceous heterogeneous catalyst. Activated carbon (AC) was prepared maintaining 500 °C for 1 h and steam activated at optimised values of activation time 1.5 h and temperature 350 °C. Carbonaceous support was impregnated with KOH at different AC/KOH ratios. The transesterification process was optimized and significant parameters affecting the biodiesel yield was identified by Taguchi method considering four parameters viz. reaction time, reaction temperature, methanol to oil ratio and catalyst loading. The physicochemical properties of Hevea brasiliensis methyl ester (HBME) were examined experimentally at optimised condition and found to meet the global American standards for testing and materials (ASTM). The optimum condition observed to yield 89.81% of biodiesel were: reaction time 60 min, reaction temperature 55 °C, catalyst loading 3.5wt% and methanol to oil ratio 15:1. Contribution factor revealed that among four parameters considered, catalyst loading and methanol to oil ratio have more prominent effect on biodiesel yield. The cost for preparing carbonaceous catalyst support was estimated and observed to be fairly impressive. Thus, Hevea brasiliensis oil (HBO) could be considered as suitable feedstock and flamboyant pods derived carbon as effective catalyst for production of biodiesel.     

Optimization of biodiesel production from waste fish oil

The present study deals with the production of biodiesel using waste fish oil. The research assesses the effect of the transesterification parameters on the biodiesel yield and its properties, including temperature (40–60 °C), molar ratio methanol to oil (3:1–9:1) and reaction time (30–90 min). The experimental results were fitted to complete quadratic models and optimized by response surface methodology. All the biodiesel samples presented a FAME content higher than 93 wt.% with a maximum, 95.39 wt.%, at 60 °C, 9:1 of methanol to oil ratio and 90 min. On the other hand, a maximum biodiesel yield was found at the same methanol to oil ratio and reaction time conditions but at lower temperature, 40 °C, which reduced the saponification of triglycerides by the alkaline catalyst employed. Adequate values of kinematic viscosity (measured at 30 °C) were obtained, with a minimum of 6.30 mm²/s obtained at 60 °C, 5.15:1 of methanol to oil ratio and 55.52 min. However, the oxidative stability of the biodiesels produced must be further improved by adding antioxidants because low values of IP, below 2.22 h, were obtained. Finally, satisfactory values of completion of melt onset temperature, ranging from 3.31 °C to 3.83 °C, were measured.     

Waste capiz (Amusium cristatum) shell as a new heterogeneous catalyst for biodiesel production

The waste Capiz shell was utilized as raw material for catalyst production for biodiesel preparation. During calcination process, the calcium carbonate content in the waste capiz shell was converted to CaO. This calcium oxide was used as catalyst for transesterification reaction between palm oil and methanol to produce biodiesel. The biodiesel preparation was conducted under the following conditions: the mole ration between methanol and palm oil was 8:1, stirring speed was 700 rpm, and reaction temperature was 60 °C for 4, 5, and 6 h reaction time. The amount of catalyst was varied at 1, 2, 3, 4, and 5 wt %. The maximum yield of biodiesel was 93 ± 2.2%, obtained at 6 h of reaction time and 3 wt % of amount of catalyst. In order to examine the reusability of catalyst developed from waste of capiz (Amusium cristatum) shell, three transesterification reaction cycles were also performed.     

Biodiesel production from soybean and Jatropha oils using cesium impregnated sodium zirconate as a heterogeneous base catalyst

Cesium modified sodium zirconate (Cs-Na₂ZrO₃) was prepared by ionic exchange from sodium zirconate (Na₂ZrO₃), which was synthesized via a solid state reaction. Both ceramics, i.e., pristine Na₂ZrO₃ and the Cs-Na₂ZrO₃, were used as basic heterogeneous catalysts in biodiesel production. Soybean and Jatropha oils were used as triglyceride sources for transesterification reactions. Parameters, such as catalyst concentration (between 0.5 and 3 wt%), reaction time, different methanol/vegetable oil molar ratios, and temperature of the reaction, were evaluated. The cesium cation influence was evaluated from the basic transesterification reactivity. The results showed that the introduction of cesium significantly modified the catalytic activity in biodiesel production. Cs enhanced the reaction kinetics in obtaining biodiesel and reduced the reaction time in comparison with pristine Na₂ZrO₃. The results showed that Cs-Na₂ZrO₃ as a basic heterogeneous catalyst exhibited the best fatty acid methyl esters (FAME) conversion for soybean oil (98.8%) at 1 wt%, 30:1 methanol/oil ratio, 65 °C, and 15 min. The best conditions for Jatropha oil (90.8%) were 3 wt%, 15:1 methanol/oil ratio, 65 °C, and 1 h. The impregnation of Na₂ZrO₃ with cesium represents a very exciting alternative heterogeneous base catalyst for biodiesel production.     

Biodiesel from low cost feedstocks: The effects of process parameters on the biodiesel yield

Biofuel (e.g. biodiesel) has attracted increasing attention worldwide as blending component or direct replacement for fossil fuel in fuel energized engines. The substitution of petroleum-based diesel with biodiesel has already attained commercial value in many of the developed countries around the world. However, the use of biodiesel has not expanded in developing countries mostly due to the high production cost which is associated with the expensive high-quality virgin oil feedstocks. This research focuses on producing of biodiesel from low cost feedstocks such as used cooking oil (UCO) and animal fat (AF) via alkaline catalyzed transesterification process investigating the effects of process parameters, for example (i) molar ratio of feedstock to methanol (ii) catalyst concentration (iii) reaction temperature and (iv) reaction period on the biodiesel yield. The biodiesel was successfully produced via transesterification process from low cost feedstocks. It was also observed that the process parameters directly influenced the biodiesel yield. The optimum parameters for maximum biodiesel yields were found to be methanol/oil molar ratio of 6:1, catalyst concentration of 1.25 wt% of oil, reaction temperature of 65 °C, reaction period of 2 h and stirring speed of 150 rpm. The maximum biodiesel yields at the optimum conditions were 87.4%, 89% and 88.3% for beef fat, chicken fat and UCO, respectively. The results demonstrate high potential of producing economically viable biodiesel from low cost feedstocks with proper optimization of the process parameters.     

Hydrogen by glycerol steam reforming on a nickel–alumina catalyst: Deactivation processes and regeneration

Hydrogen energy has attracted considerable attention because of its efficiency and environmental benefits, and the increasing demand requires finding renewable sources of raw materials to produce it. Glycerol, by-product of biodiesel production and coming from renewable raw materials, could be a bio-renewable substrate to produce hydrogen. The glycerol steam reforming to obtain hydrogen was evaluated using a 5.1 wt% Ni impregnated on Al₂O₃ catalyst, characterized by nitrogen adsorption, XRD, and FTIR. Deactivation processes were analyzed in successive cycles of reaction at 700 °C, atmospheric pressure, 5 h⁻¹ WHSV, and 3:1 water:glycerol molar ratio, during 12 h. Between reaction cycles, regenerating took place using a He/Air stream. Hydrogen was the main product on the fresh catalyst, following by CO and CH₄; during reaction, carbonaceous deposits deactivated catalyst, decreasing H₂ and increasing both CO and CH₄. Carbonaceous deposits were characterized by TPO, showing a main peak centered at 690 °C; the carbon content reached 11.9%.     

Optimization of biodiesel production from camelina oil using orthogonal experiment

Camelina oil is a low-cost feedstock for biodiesel production that has received a great deal of attention in recent years. This paper describes an optimization study on the production of biodiesel from camelina seed oil using alkaline transesterification. The optimization was based on sixteen well-planned orthogonal experiments (OA₁₆ matrix). Four main process conditions in the transesterification reaction for obtaining the maximum biodiesel production yield (i.e. methanol quantity, reaction time, reaction temperature and catalyst concentration) were investigated. It was found that the order of significant factors for biodiesel production is catalyst concentration > reaction time > reaction temperature > methanol to oil ratio. Based on the results of the range analysis and analysis of variance (ANOVA), the maximum biodiesel yield was found at a molar ratio of methanol to oil of 8:1, a reaction time of 70 min, a reaction temperature of 50 °C, and a catalyst concentration of 1 wt.%. The product and FAME yields of biodiesel under optimal conditions reached 95.8% and 98.4%, respectively. The properties of the optimized biodiesel, including density, kinematic viscosity, acid value, etc., were determined and compared with those produced from other oil feedstocks. The optimized biodiesel from camelina oil meets the relevant ASTM D6571 and EN 14214 biodiesel standards and can be used as a qualified fuel for diesel engines.     

Alkaline-catalyzed transesterification of Silurus triostegus Heckel fish oil: Optimization of transesterification parameters

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.     

Hydroprocessing of Jatropha oil over NiMoCe/Al2O3 catalyst

The non-sulfided NiMoCe/Al₂O₃ catalyst was developed to produce green diesel from the hydroprocessing of Jatropha oil. The NiMoCe/Al₂O₃ catalysts were prepared by impregnation and characterized by N₂-BET, SEM, XRD and TPD-H_ads techniques. The straight chain alkanes ranging from C15 to C18 were the main components in product oil. The maximum yield of C15-C18 alkanes of 80%, selectivity of 90% and conversion of 89% were obtained at 370 °C, 3.5 MPa and 0.9 h⁻¹. Influence of reaction temperature (280–400 °C) and reaction time (10–163 h) on the composition of product oil were discussed. The experimental results demonstrated that a suitable amount of metal Ce doping on the NiMo/Al₂O₃ catalyst presented stable catalytic performance and enhanced Jatropha oil conversion as well as C15-C18 fraction selectivity.     

New trends in biodiesel production: Chemical interesterification of sunflower oil with methyl acetate

In this study, the chemical interesterification of oil with methyl acetate using potassium hydroxide, methoxide and polyethylene glycolate as catalysts was investigated. The reactions were performed at 50 °C using the range methyl acetate 12 mol mol⁻¹ of refined sunflower oil to a value of 100 mol mol⁻¹ and the range of potassium methanolate to oil was 100-500 mmol mol⁻¹. The effect of methanol and water on the catalyst and reagents was to reduce the yield of triacetin, forming diacetin, monoacetin and glycerol instead. A compromise between the product yield, reaction kinetics and methyl acetate recovery was achieved with the conditions methyl acetate to oil 50 mol mol⁻¹ and catalyst to oil 100 mmol mol⁻¹ when potassium methoxide was used as a catalyst and the reagents were dehydrated. Under these conditions, equilibrium was reached within the first 15 min of the reaction. The mass fractions of fatty acid methyl esters (FAME) and triacetin in the product were 76.7% and 17.2%, respectively, with a mass fraction of 4.7% for the intermediate diacetinmonoglyceride. Diacetin, monoacetin and glycerol were also found at a mass fraction of 1.2%.     

Ethanolysis of waste cottonseed oil over lithium impregnated calcium oxide: Kinetics and reusability studies

A series of Li/CaO catalysts has been prepared by impregnating 0.5–5.0 wt% Li in CaO by wet chemical method. Prepared Li/CaO catalysts have been characterized by powder X-ray diffraction, scanning electron and transmission electron microscopy and Brunauer–Emmett–Teller (BET) surface area studies, in order to establish the structure and surface morphology of the catalyst. Hammett indicator test study was performed to determine the basic strength of the Li/CaO catalysts. The prepared Li/CaO catalysts have been employed as a heterogeneous catalyst for the transesterification of waste cottonseed oil (having 2.8 wt% free fatty acid contents) with ethanol. Under optimal reaction conditions viz., ethanol/oil molar ratio of 12:1, catalyst to oil weight fraction of 5% and 65 °C reaction temperature, 98% fatty acid ethyl ester yield was obtained in 2.5 h of reaction duration. Under the optimized reaction conditions, the pseudo first order constant and Arrhenius activation energy were found to be 0.03 min⁻¹ and 70.0 kJ mol⁻¹, respectively. Further Li/CaO catalyst was also found to be effective for the ethanolysis and methanolysis of vegetable oils having up to 3.4 wt% free fatty acids. The use of 3-Li/CaO catalyst is advantageous considering that it not only utilizes waste cottonseed oil as a feedstock, but also renewable and nontoxic alcohol, ethanol, for the biodiesel production.