A bronsted basic ionic liquid as an efficient and environmentally benign catalyst for biodiesel synthesis from soybean oil and methanol

Morpholine basic ionic liquid was synthesized with N-methyl morpholine, N-butyl bromide, and KOH by two-step method and was used to catalyze the transesterification of soybean oil with methanol to biodiesel. The structure of the catalyst were examined by ¹H nuclear magnetic resonance. The effects of the molar ratio of methanol to oil, reaction temperature, and amount of catalyst on the biodiesel yield were investigated. Optimized biodiesel yield of 94.5% was achieved with catalyst amount of 3.0 wt%, and methanol to soybean oil molar ratio of 14:1 at reaction temperature of 60 °C for 6 h. The catalyst has maintained sustained activity after being employed to six cycles. The prepared biodiesel component was analyzed by gas chromatography-mass spectrometry (GC-MS) and the results showed that the biodiesel comprised of hexadecanoic acid methyl ester, 10, 13-octadecadienoic acid methyl ester, 9-octadecenoic acid methyl ester, and octadecanoic acid methyl ester, illustrating that fatty acids of soybean oil were converted completely.     

Use of bioethanol for biodiesel production

Faced with the energy crisis and environmental degradation, due to the massive use of fossil energy sources, biodiesel is an attractive alternative to diesel fuel. With a view to developing local biodiesel production, using bioethanol as a sustainable reactant for biodiesel production, rather than methanol, is leading to increasing interest, notably in emerging countries. Indeed, bioethanol, which is less toxic than methanol, is produced from local and renewable agricultural resources, being more sustainable and providing access to greater energy independence. However, some issues are limiting the process like purification problems, or the presence of water in bioethanol leading to a drop in yield. Although several studies have already been published on ethyl ester production, most of them primarily focus on homogeneous alkaline catalysis, and report various data. Therefore, this paper aims at presenting a review of previous studies on the subject.     

Are plant lipases a promising alternative to catalyze transesterification for biodiesel production?

Interest in the production of biodiesel—a clean renewable fuel—is increasing worldwide. Industrial-scale processes currently being developed use homogenous and heterogeneous chemical catalysis processes that are highly efficient but require very pure reagents and complex product purification steps, or high temperature and pressure processing conditions. Enzymatic catalysis using plant lipases as biocatalysts is an alternative which, contrary to chemical catalysis processes, is simple to perform, at low investment cost, and therefore potentially easier to disseminate, especially in developing countries. Although microbial lipases have been extensively studied, little research has been focused on the use of plant lipases in biodiesel production. These latter lipases can, however, be readily extracted from the plant organs that contain them (seeds, bran or latex) and they are less expensive to use than microbial lipases. The aim of the present article was thus to review published research findings and outline the most advanced knowledge concerning alkyl ester production catalyzed by plant lipases. This work focuses mainly on the conditions for using plant lipases in certain synthesis reactions (biomass selection, preparation and purification of lipase extracts) and current knowledge on reaction parameters that affect the catalytic activity. Moreover, biodiesel production using plant lipases and ethanol instead of methanol certainly seems to be in line with the development of innovative environment-friendly technologies.     

Catalytic production of biodiesel from soy-bean oil, used frying oil and tallow

Three fatty materials, soy-bean oil, used frying oil and tallow, were transformed into two different types of biodiesel, by transesterification and amidation reactions with methanol and diethylamine respectively. The ignition properties of these types of biodiesel were evaluated calculating the cetane index of the transesterification products, and the blending cetane number of the amide biodiesel blended with conventional diesel. Amide biodiesel enhances the ignition properties of the petrochemical diesel fuel, and it could account for the 5% market share that should be secured to biofuels by 2005.     

固定化脂肪酶在离子液体中催化合成生物柴油

通过硅胶载体涂布法对细菌Burkholderia cepacia GX-35所产的脂肪酶进行固定化。比较了自制固定化脂肪酶在4种离子液体中催化合成生物柴油的效果,其中文章研究新设计并合成的一种离子液体溴代1-乙基-2-甲基咪唑[EMIM]Br对催化反应起促进作用。通过对转酯率的测定,研究了固定化脂肪酶在[EMIM]Br中的最适反应条件:最适反应温度为35℃,[EMIM]Br加入量为花生油质量分数的60%,最佳醇类为乙醇,加水量为花生油质量分数的5%,乙醇与花生油之比为9∶1,固定化脂肪酶加入量为花生油的20%,反应时间为6 h。固定化脂肪酶在[EMIM]Br中稳定性好,使用6次之后转酯率下降不明显。试验结果表明,与不加[EMIM]Br相比,加[EMIM]Br能有效提高生物柴油的转化率。     

Characterization and transesterification of Iranian bitter almond oil for biodiesel production

In the present work the production of biodiesel using bitter almond oil (BAO) in a potassium hydroxide catalyzed transesterification reaction was investigated. The BAO was obtained from resources available in Iran and its physical and chemical properties including iodine value, acid value, density, kinematic viscosity, fatty acid composition and mean molecular weight were specified. The low acid value of BAO (0.24 mg KOH/g) indicated that the pretreatment of raw oil with acid was not required. The fatty acid content analysis confirmed that the contribution of unsaturated fatty acids in the BAO is high (84.7 wt.%). Effect of different parameters including methanol to oil molar ratio (3–11 mol/mol), potassium hydroxide concentration (0.1–1.7% w/w) and reaction temperature (30–70 °C) on the production of biodiesel were investigated. The results indicated that these parameters were important factors affecting the tranesterification reaction. The fuel properties of biodiesel including iodine value, acid value, density, kinematic viscosity, saponification value, cetane number, flash point, cloud point, pour point and distillation characteristics were measured. The properties were compared with those of petroleum diesel, EN 14214 and ASTM 6751 biodiesel standards and an acceptable agreement was observed.     

Comparison and effect of Cinder supported with Manganese and Lanthanum oxide for biodiesel production

In this study, comparison and effect of Cinder supported with Lanthanum and Manganese oxide as catalyst for transesterification of triglyceride to methyl ester is proposed. The reaction mechanism along with the effects of methanol to oil molar ratio, amount of catalyst to oil, reaction temperature were also discussed. Moreover reusability of catalyst, catalyst resistance toward Free Fatty Acid and water were also discussed. The results show that yield of biodiesel produced with Mn:La:Cinder catalyst was 99% at ≥150 °C in 6 h. Cinder supported with Mn shows conversion of triglycerides from soybean oil in reaction with methanol after 6 h was over 99% at 150 °C. For both catalyst 3wt% of catalyst based on oil, 24:1 methanol/oil molar ratio was reused for 7 times with regeneration. The catalysts displayed great resistance toward 2.5% water and 1% wt fatty acids.     

Manufacturing of zeolite based catalyst from zeolite tuft for biodiesel production from waste sunflower oil

In the present work, zeolite based catalyst was prepared from zeolite tuft by impregnation methods. The zeolite tuft was initially treated with hydrochloric acid (16%) and then several KOH/zeolite catalysts were prepared by impregnation in KOH solutions. Various solutions of KOH with different molarities (1–6 M) were used. Further modification for the catalyst was performed by a 2nd step impregnation treatment by heating and stirring the KOH/zeolite to 80 °C for 4 h. The zeolite tuft and the prepared catalysts were characterized by several analytical techniques in order to explore their physicochemical properties. These tests include: X-Ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), Zero point of Charge (PHzpc), Fourier Transform Infrared (FT-IR), Energy-dispersive X-Ray analysis (EDX) and X-Ray Diffraction (XRD). The catalysts were then used for transesterification of waste sunflower vegetable oil in order to produce biodiesel. Among the different catalysts prepared, the 1–4M KOH/TZT catalyst provided the maximum biodiesel yield of 96.7% at 50 °C reaction temperature, methanol to oil molar ratio of 11.5:1, agitation speed of 800 rpm, 335 μm catalyst particle size and 2 h reaction time. The physicochemical properties of the produced biodiesel comply with the EN and ASTM standard specifications.     

A novel one-pot synthesis of tetragonal sulfated zirconia catalyst with high activity for biodiesel production from the transesterification of soybean oil

A sulfated zirconia catalyst has been prepared by a novel one-pot vapor-controlled synthesis route using ammonium persulphate as sulfate agent. A possible formation mechanism of the catalyst is proposed. The effect of calcination temperature and S/Zr molar ratio on the structural, textural and catalytic properties of the prepared catalyst were investigated in detail using X-ray diffraction (XRD), N₂ adsorption–desorption, ammonia temperature programmed desorption (NH₃-TPD), Fourier transform infrared spectroscopy (FTIR) and a scanning electron microscope (SEM) which was equipped with an energy dispersive spectroscope (EDS). The results indicated that the samples calcined at 500 °C possessed zirconia of pure tetragonal structure, more content of sulfur and better distribution of acid sites on the surface of zirconia compared with the samples calcined at 600  °C at fixed S/Zr molar ratio. Moreover, they showed excellent catalytic activity with 100% yields of biodiesel for the transesterification of soybean oil with methanol.     

Rapid and precise estimation of biodiesel by high performance thin layer chromatography

Various sophisticated chromatographic techniques employing gas chromatography (GC) and high performance liquid chromatography (HPLC) were used to quantify biodiesel in terms of conversion percentage of the oil feedstock. These techniques are time consuming. In the present study, a rapid and reproducible technique was developed using high performance thin layer chromatography (HPTLC) for the accurate quantification of the conversion percentage of triglycerides into biodiesel (fatty acid methyl esters/FAME). The oil substrate was transesterified by a conventional process using alkali catalyst. The monoglycerides, diglycerides, unreacted triglycerides, free fatty acid and biodiesel (FAME) product were analyzed by HPTLC. An absorption maximum of the mixture of standard methyl esters was determined to be 203.5 nm by spectroscopic scan. The conversion percentage was calculated from the corresponding peak areas of the glycerides and biodiesel product, separated on thin layer chromatography using hexane, ethyl acetate and acetic acid (9:1:0.1) as mobile phase. In terms of reproducibility and precision of data and also the ease and quickness of simultaneous processing, HPTLC based analysis and quantification of biodiesel (FAME) proved to be an alternative to other conventional analytical techniques like GC and HPLC.     

Mixed and ground KBr-impregnated calcined snail shell and kaolin as solid base catalysts for biodiesel production

Mixed and ground activated snail shell and kaolin catalysts impregnated with KBr were investigated. The snail shell and kaolin were calcined, mixed, and ground prior to immersion with KBr solution and subsequent activation at 500 °C for 3 h. The precursor and catalysts were characterized by thermal gravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and Brunauer–Emmett–Teller surface area. The catalytic performance of the prepared catalysts was evaluated by transesterification of soybean oil with methanol. The effects of various parameters on biodiesel yield were investigated. A biodiesel yield of 98.5% was achieved using the catalyst prepared by 40% KBr-immersed, mixed, and ground snail shell and kaolin, which were activated at 500 °C. The transesterification conditions were as follows: reaction temperature, 65 °C; reaction time, 2 h; methanol-to-soybean oil molar ratio, 6:1; and catalyst amount (relative to the weight of soybean oil), 2.0 wt%. The solid catalyst could be reused for four times, and biodiesel yield remained over 73.6% for the fourth time.     

Integrated flow reactor that combines high-shear mixing and microwave irradiation for biodiesel production

A new simple flow system which is made up of a multi-rotor high-shear mixer connected to a multimode microwave reactor has been assembled. This simple loop reactor has been successfully used in the NaOH-catalyzed transesterification of refined palm oil in methanol. Thanks to optimal mass/heat transfer, full conversion was achieved within 5 min (biodiesel yield of 99.80%). High-quality biodiesel was obtained that is in accordance with international specifications and analytical ASTM standards. The procedure's high efficiency and low energy consumption should pave the way for process scale up.     

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.     

Utilization of waste freshwater mussel shell as an economic catalyst for biodiesel production

An economic and environmentally friendly catalyst derived from waste freshwater mussel shell (FMS) was prepared by a calcination-impregnation-activation method, and it was applied in transesterification of Chinese tallow oil. The as-prepared catalyst exhibits a “honeycomb” -like structure with a specific surface area of 23.2 m² g⁻¹. The newly formed CaO crystals are major active phase of the catalyst. The optimal calcination and activity temperature are 900 °C and 600 °C, respectively. When the reaction is carried out at 70 °C with a methanol/oil molar ratio of 12:1, a catalyst concentration of 5% and a reaction time of 1.5 h, the FMS-catalyst is active for 7 reaction cycles, with the biodiesel yield above 90%. The experimental results indicate that the FMS can be used as an economic catalyst for the biodiesel production.     

Preparation and catalytic performance of N-[(2-Hydroxy-3-trimethylammonium) propyl] chitosan chloride /Na2SiO3 polymer-based catalyst for biodiesel production

A novel polymer-based alkaline catalyst was prepared with sodium silicate (Na₂SiO₃) and N-[(2-Hydroxy-3-trimethylammonium) propyl] chitosan chloride (HTCC), interlinked by epichlorohydrin (ECH), for biodiesel production. The structure and properties of the catalyst were studied by Fourier transform infrared spectroscopy, thermogravimetry-mass spectrometry and transmission electron microscopy. The effects of the variables on the transesterificaton of soybean oil to biodiesel were investigated. It is found that Na₂SiO₃ was bridged on HTCC chains through ECH and well dispersed in HTCC matrix in nano size. The transesterification conversion reached at 97.0% under the reaction conditions of methanol/oil molar ratio of 6:1, catalyst loading of 4.0 wt.% at 55 °C for 60 min. After the second run, the catalytic activity kept stable, which was contributed to the stability and dispersion of Na₂SiO₃ in the catalyst.     

Opium poppy (Papaver somniferum L.) oil for preparation of biodiesel: Optimization of conditions

Opium poppy, Papaver somniferum L., is one of the ancient herbal medicines. In addition to this medical use of latex, opium that is extracted from the immature seed capsule, it is also used illegally for pleasure. It is being produced in great quantities in Turkey especially in Afyonkarahisar city. The seeds of opium poppy plant have high ratio oil content. The opium poppy seeds and oil of these seeds are purely used as an ingredient in production of bakery products. In this study, biodiesel evaluation of the opium poppy seeds that have a high oil ratio is aimed. Alkali catalyzed (NaOH) single-phase reaction was preferred to produce biodiesel from opium poppy oil. The parameters like catalyst concentration, methanol ratio, reaction temperature were optimized and biodiesel production was obtained with high yield in reaction time of 75 min. The methyl ester content in the opium poppy oil biodiesel was determined with Gas Chromatography–Frame Ionized Detector (GC–FID). In optimum conditions, methanol ratio and catalyst concentration was determined as 20 wt% and 0.5 wt%, respectively. The reaction temperature was optimized as 60 °C. Biodiesel was obtained from the opium poppy oil under optimum conditions. Some basic features of the produced methyl esters were determined.     

Self-assembled ionic liquid synthesis of nitrogen-doped mesoporous TiO2 for visible-light-responsive hydrogen production

Nitrogen-doped mesoporous TiO₂ has been synthesized by a simple solvent evaporation-induced self-assembly method using a nitrogen-containing ionic liquid concurrently as a nitrogen source and mesoporous template. After being evaporated and subsequently calcined at various temperatures (300–900 °C), the synthesized samples were thoroughly characterized by X-ray diffraction (XRD), Raman, small-angle X-ray scattering patterns (SAXS), N₂ adsorption-desorption isotherms, X-ray photoelectron (XPS) and UV–Vis diffuse reflectance (UV–Vis DR) spectroscopies. The obtained results suggest that the calcination temperature greatly influences the crystallization of TiO₂, formation of mesoporous structure, specific surface area and N-doping amounts. Among the fabricated photocatalysts, the samples calcined at 600 °C exhibit superior photocatalytic performance for hydrogen production in water/methanol solution under visible light illumination if compared to other synthesized samples and commercial TiO₂ (Degussa P25). The finding is possibly due to the synergy of more N-doping amounts on the well-defined mesoporous TiO₂ with highly anatase crystal phase and moderate surface area in the catalysts.     

Screening of novel water/ionic liquid working fluids for absorption thermal energy storage in cooling systems

Absorption thermal energy storage (ATES) is significant for renewable/waste energy utilization in buildings. The ATES systems using ionic liquids (ILs) are explored to avoid crystallization and enhance the performance. Property model and cycle model have been established with verified accuracies. Based on the preliminary screening, seven ILs are found feasible to be ATES working fluids, while four ILs ([DMIM][DMP], [EMIM][Ac], [EMIM][DEP], and [EMIM][EtSO₄]) have been selected for detailed comparisons. The coefficient of performance (COP) and energy storage density (ESD) of the ATES using different H₂O/ILs are compared with H₂O/LiBr. Results show that the operating temperatures of LiBr are constrained by crystallization, limiting the COPs and ESDs under higher generation temperatures and lower condensation temperatures. With varying T_g, [DMIM][DMP] yields higher COPs with T_g above 100°C and [EMIM][Ac] yields comparable ESDs (67.7 vs 67.1 kWh/m³) with T_g around 120°C, as compared with LiBr. The maximum COP is 0.745 for [DMIM][DMP]. With varying T_c, [DMIM][DMP] yields higher COPs with T_c below 38°C and [EMIM][Ac] yields higher ESDs with T_c below 33°C, as compared with LiBr. The maximum ESD is 87.5 kWh/m³ for [EMIM][Ac]. With varying T_e, [DMIM][DMP] yields higher COPs with T_e above 8°C, as compared with LiBr. The maximum ESD of ILs is 104.0 kWh/m³ for [EMIM][EtSO₄]. Comparing with the volume-based ESDs, the differences between ILs and LiBr are smaller for the mass-based ESDs. This work can provide suggestions for the selection of novel working fluids for ATES for performance and reliability enhancement.     

Preparation and application of binary acid–base CaO–La2O3 catalyst for biodiesel production

A simple method was developed for biodiesel production from non-edible Jatropha oil which contains high free fatty acid using a bifunctional acid–base catalyst. The acid–base catalyst comprising CaO and La₂O₃ mixed metal oxides with various Ca/La atomic ratios were synthesized via co-precipitation method. The effects of Ca/La compositions on the surface area, acidity–basicity and transesterification activity were investigated. Integrated metal–metal oxide between Ca and La enhanced the catalytic activity due to well dispersion of CaO on composite surface and thus, increased the surface acidic and basic sites as compared to that of bulk CaO and La₂O₃ metal oxide. Furthermore, the transesterification reactions resulted that the catalytic activity of CaO–La₂O₃ series were increased with Ca/La atomic ratio to 8.0, but the stability of binary system decreased by highly saturated of CaO on the catalyst surface at Ca/La atomic ratio of 10.0. The highest biodiesel yield (98.76%) was achieved under transesterification condition of 160 °C, 3 h, 25 methanol/oil molar ratio and 3 wt.%. In addition, the stability of CaO–La₂O₃ binary system was studied. In this study, Ca–La binary system is stable even after four cycles with negligible leaching of Ca²⁺ ion in the reaction medium.     

High rate performance of a lithium polymer battery using a novel ionic liquid polymer composite

We present a new design of a lithium gel-polymer battery, fabricated with a (LILP) composite consisting of a lithium salt dissolved in an ionic liquid (binary Li-IL) and an ultra high molecular weight ionic liquid polymer (ILP). This polymer, with a Mw of over a million, was prepared by the bulk radical polymerization of a novel ionic liquid monomer, N,N-diethyl-N-(2-methacryloylethyl)-N-methylammonium bis(trifluoromethylsulfonyl)imide (DEMM-TFSI). The polymer could form a binary Li-IL solid at a concentration of only 5 wt%. We selected high power-active electrode materials, and combined them with the LILP system. The demonstration vapor-free cell had a higher discharge performance than a conventional lithium polymer battery: at 40 °C, it retained 83% of its discharge capacity at a 3 C current, and relatively good cycle performance. This is the first report of to knowledge that a lithium ion cell with a LILP system performed, in terms of cell performance and cycle durability, at a level of practical utility.