A new route for the synthesis of La-Ca oxide supported on nano activated carbon via vacuum impregnation method for one pot esterification- transesterification reaction

Advanced carbon nanorod promoted binary CaO-La2O3 system with improved physical properties, tailored surface morphology and chemistry were developed in vacuum-impregnating methods. The nanostructured catalyst (CaO–La2O3/AC nanocatalyst) was prepared to convert high FFA waste cooking oil into biodiesel via one step esterification-transesterification reaction. The novel catalyst was characterized by FTIR, SEM, XRD, TGA, BET, TPD-CO2 and TPD-NH3. The high catalytic activity of the nanocatalyst was mainly depends on the high acid and basic density of active sites that contributed from the synergic effect between mesoporous carbon and binary metallic system, which allowed more occurrence of simultaneous esterification-transesterification process of high FFA waste oil without additional pretreatment step. Result showed maximum 98.6±0.5% with acid value 0.4±0.5 mg KOH/g of triglyceride conversion under optimal condition at 3% of catalyst, methanol:oil ratio of 16:1, 100 °C within 4h of reaction. Furthermore, bi-metallic catalyst with stable carbon nanorod support capable to maintained high reusability with high FAME yield (> 98%) with low acid value (<0.5 mg KOH/g) for 5 cycles

Characterization of Mn-Doped Vanadium Phosphorus Oxide (VPO) Catalyst: Effect of Ball Milling

The effect of ball milling on the structure and surface reactivity of the Mn-doped vanadium phosphorus oxide (V–P–O) catalyst is discussed. Mn-doped VOHPO4·½H2O precursor was prepared via organic method. The precursor was ball milled in isopropyl alcohol using agate balls for 60 min at 800 rpm. XRD, BET surface area measurements, SEM, O2-TPD, H2-TPR and TPD of NH3 were used to characterize properties of the final catalysts. The results revealed that mechanical treatment of Mn-doped V–P–O catalyst increased surface area as well as reduced particle size of the material. Furthermore, process also increased exposure of (001) crystallographic plane of VOHPO4·½H2O precursor. The secondary structure of the milled material is also lost. The total amount of oxygen desorbed (from O2-TPD) and removed (by H2-TPR) from milled material is higher compared to the unmilled one. The surface acidity of the catalyst was also increased after milling process, as evidenced by lower desorption temperature and higher total amount of the ammonia desorbed

INFLUENCE OF ORGANIC SPECIES ON THE CHARACTERISTICS OF Mo-V OXIDES

Abstract This study investigates on the effect of organic species on the characteristics of molybdenum-vanadium mixed oxide catalysts. The MoV precursors were prepared by homogeneous precipitation method using urea hydrolysis. The oxides were later treated with three organic species namely polyvinyl alcohol (PVA), malic acid (MA) and adipic acid (AA). The solutions were refluxed in a prescribed time. The solid obtained were calcined and subsequently denoted as MoV(PVA), MoV(MA) and MoV(AA). Interesting results in which high surface area values (S BET ) were obtained in the range between 10 to 20 m 2 g -

Síntesis de ésteres de acetato hexilo, mediante transesterificación química a partir de palma como base sintética de fluidos para sondeos

In the present study the synthesis of a palm based ethylhexyl ester was examined through a transesterification reaction of palm oil methyl ester (POME) with 2-ethylhexanol (EH). A sodium methoxide in methanol solution was used as a catalyst. The reaction was carried out at a fixed pressure of 1.5 mbar by varying the temperature (80–140 °C), POME/2EH molar ratio (1:1.5–1:2.2), reaction time (0.5–4 h) and catalyst concentration (1–2% w/w). The reaction with 2-ethylhexanol involved a single step reversible reaction, thus, the reaction was completed in a very short time. The optimum conditions were obtained in less than 30 minutes with 1.5 mbar pressure, 70 °C, and 1:2 molar ratio of POME to 2EH. The analysis of the final product (ethylhexyl ester) was performed using gas chromatography which exhibited 98% of ethyl hexyl ester yield. The gas chromatography analysis of ethyl hexyl ester revealed two major esters peaks i.e. ethyl hexyl palmitate and ethylhexyl oleate.En el presente estudio se analizó la síntesis de ésteres de acetato de hexilo de palma mediante reacción de transesterificación de los ésteres metílicos de aceite de palma (PME) con 2-etilhexanol (EH). Como catalizador se utiliza una solución de metóxido de sodio en metanol. La reacción se lleva a cabo a presión fija de 1,5 mbar mediante la variación de temperatura (80–140 °C), relación molar POME/2EH (1:1.5–1:2.2), tiempo de reacción (0,5–4 h) y concentración de catalizador (1–2% w / w). La reacción con 2-etilhexanol implica un solo paso de una reacción reversible, por lo tanto, ésta se completa en un tiempo muy corto. Las condiciones óptimas se obtuvieron en menos de 30 min a 1,5 mbar, 70 °C y una relación molar de 1:2 de POME al 2EH. El análisis del producto final se realizó usando cromatografía de gases que mostró un rendimiento del 98% del etilhexil éster. El análisis de la cromatografía de gases del etilhexil éster muestra dos grandes picos correspondientes a los ésteres palmitato y oleato de etilhexilo

Enhanced syngas production from glycerol dry reforming over Ru promoted -Ni catalyst supported on extracted Al2O3

Crude glycerol, a by-product of biodiesel production, has drawn considerable attention to the importance of glycerol valorization through dry reforming reaction to obtain syngas. The selection of suitable catalysts is significantly important to enhance the catalytic activity in glycerol dry reforming (GDR) reactions. Hence, Ru with different loadings (i.e. 1%, 2%, 3%, 4%, 5%) doped in 15% Ni-extracted Al2O3(EA) was evaluated as catalyst via GDR process in this study. The catalyst prepared by ultrasonic-impregnation assisted technique was subjected to 8 h of CO2 reforming of glycerol. The reactant conversions and products yield was in the order of 3%Ru-15%Ni/EA > 5%Ru-15%Ni/EA > 4%Ru-15%Ni/EA > 2%Ru-15%Ni/EA > 1%Ru-15%Ni/EA > 15%Ni/EA, while the quantity of carbon deposited was in the order 15%Ni/EA > 1%Ru-15%Ni/EA > 2%Ru-15%Ni/EA > 4%Ru-15%Ni/EA > 5%Ru-15%Ni/EA > 3%Ru-15%Ni/EA. 3%Ru-15%Ni/EA attained the greatest glycerol conversions of 90%, H2 yield of 80% and CO yield of 72% with the lowest carbon deposition of 7.38%. The dispersion of Ni particles on EA support evidently improved after the promotion step with Ru, which minimized the agglomeration of Ni and smaller crystallite size. In addition, the introduction of Ru increased the oxygen storage capacity which significantly reduced the formation of carbon during the reaction. GDR's optimal reaction temperature obtained over 3%Ru-15%Ni/EA catalysts was at 1073 K (i.e. 93% glycerol conversion; 87% H2 yield; 79% CO yield). Over a 72 h time on stream at 1073 K, 3%Ru-15%Ni/EA catalyst had superior catalytic activity and stability. Overall, 3%Ru-15%Ni/EA catalyst was more coke-resistant than other promoted catalysts due to its accessible structure, higher oxygen storage capacity, moderate basicity, uniformly dispersed Ni phase and stronger Ru/Ni-EA interaction

Synthesis of MnO-NiO-SO4 2/ZrO2 solid acid catalyst for methyl ester production from palm fatty acid distillate

Biodiesel is a found promising alternative biofuel to popular fossil fuel because of to its renewable and biodegradable nature and thus is considered as environmentally benign. This paper reports on the synthesis of a novel heterogeneous manganese-nickel doped on sulfated zirconia catalyst (MnO-NiO-SO4−2/ZrO2) by using simple wet impregnation method for biodiesel production from palm fatty acid distillate (PFAD). The synthesized catalyst was characterized through ammonia temperature programmed desorption (TPD-NH3), X-ray diffraction (XRD), Fourier transform infrared (FTIR), pyridine adsorption via FTIR, scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA) techniques. The synthesized catalyst was tested for PFAD through esterification reaction where more than 97% of biodiesel yield was observed under the optimized reaction conditions of 15:1 methanol to PFAD ratio, 70 °C reaction temperature, 3 wt% catalyst loading and 3 h reaction time. The reusability of the catalyst was tested and found that it could be reused for at least five times without significant reduction in activity. Hence, the catalyst was found suitable for biodiesel production from low grade feedstock

Advancement in heterogeneous base catalyzed technology: An efficient production of biodiesel fuels

Price fluctuation of petroleum-based diesel, climate change, emerging mandate obligations, availability of new feedstock and the upgrading of conversion technologies are expected to drive biodiesel market to grow robustly in the next coming 10 years. However, the current bottleneck in biodiesel production is the lack of economical sustainable conversion technologies. Generally, industrial production of biodiesel is greatly relied on alkaline homogeneous transesterification reaction. Limitation of the technology, such as multistep process which incur extra pre-step for high acid oil treatment and post-step for biodiesel purification and alkali washing as diminished the economic feasibility and low environmental impact of the entire biodiesel process. Heterogeneous catalysis offers immense potential to develop simple transesterification process, including one step reaction, easy separation, reusability of catalyst, and green reaction. Thus, the aim of this paper is to review the biodiesel production technologies such as blending, micro-emulsion, pyrolysis, and transesterification. Furthermore, recent studies on heterogeneous catalyzed transesterification were presented by discussing the issues such as catalytic performance on different types of biodiesel feedstock, transesterification reaction conditions, limitations encountered by heterogeneous catalysts, and reusability of solid catalysts. The heterogeneous catalysts presented in this review is mainly focused on solid base catalysts, which include single metal oxides, supported metal oxide, binary metal oxide, hydrotalcite, and natural waste shell-based catalyst. Furthermore, current perspectives on application of heterogeneous catalyzed technology in biodiesel industry were discussed herein. (C) 2015 AIP Publishing LLC

Structural, thermal, and optical analysis of zinc boro-aluminosilicate glasses containing different alkali and alkaline modifier ions

In this article, structural, thermal, and optical properties of zinc boro-aluminosilicate glasses with addition of different alkali (Li, Na, and K) and alkaline oxides (Mg, Ca, Sr, and Ba) have been reported. 10 mol% of alkali and alkaline oxides were incorporated into Zinc boro-aluminosilicate glasses and all these glasses possess high optical quality. Samples were characterized using X-ray diffraction (XRD), scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDAX), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, Raman spectroscopy, thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), and optical absorption spectroscopy. The XRD and SEM measurements demonstrated the amorphous origin for all the prepared glasses and EDAX confirms that all the elements are presented in the prepared glasses. The presence of various functional groups such as triangular and tetrahedral-borate (BO3 and BO4) was confirmed by ATR-FTIR and Raman spectra, and both of the ATR-FTIR and Raman spectra show lower phonon energy for H3 (K2O) in alkali series, and H7 (BaO) for alkaline. From TGA analysis we found a lower weight loss < 0.1% in K2O, MgO, and BaO; and from the DSC profiles the glass transition temperature (Tg), onset crystallization temperature (Tx), crystallization temperature (Tc), and melting temperature (Tm) were identified and related different thermal parameters are evaluated. Alkali and alkaline influenced Zinc boro-aluminosilicate glasses demonstrate excellent glass stability. From the optical absorption spectra, we calculated cut-off wavelength and it shows spectral shifting to longer wavelength with alkali (Li → Na → K), and alkaline (Mg → Ca → Sr → Ba) modifiers. We investigated optical band gap energy also for allowed transitions in UV–visible region using three methods; direct, indirect, and absorption spectrum fitting (ASF)

Catalytic deoxygenation of triolein to green fuel over mesoporous TiO2 aided by in situ hydrogen production

The greenhouse gases contributed by combustion of fossil fuel has urged the need for sustainable green fuel production. Deoxygenation is the most reliable process to convert bio-oil into green fuel. In this study, the deoxygenation of triolein was investigated via mesoporous TiO2 calcined at different temperature in the absence of external H2. The high conversion of fuel-liked hydrocarbons showed the in situ H2 produced from the reaction. The mesoporous TiO2 calcined at 500 °C (M500) demonstrated the highest activity, around 76.9% conversion was achieved with 78.9% selectivity to hydrocarbon. The reaction proceed through second order kinetic with a rate constant of 0.0557 g−1trioleinh−1. The major product of the reaction were diesel range saturated and unsaturated hydrocarbon (60%) further the formation of in situ H2. It is interesting to observe that higher calcination temperature improve crystallinity and remove surface hydroxyls, meanwhile increase the acid density and medium strength acid site. The conversion of triolein increased linearly with the amount of medium strength acid sites. This result suggests that medium-strength acidity of catalyst is a critical factor in determining deoxygenation activities. In addition, the presence of mesopores allow the diffusion of triolein molecules and improve the selectivity. Hence, mesoporous TiO2 with Lewis acidity is a fascinating catalyst and hydrogen donor in high-value green fuel

Structural and optical studies of Er3+-doped alkali/alkaline oxide containing zinc boro-aluminosilicate glasses for 1.5 um optical amplifier applications

In the present work, we report on the optical spectral properties of Er3+ -doped zinc boro-aluminosilicate glasses with an addition of 10 mol % alkali/alkaline modifier regarding the fabrication of new optical materials for optical amplifiers. A total of 10 glasses were prepared using melt−quenching technique with the compositions (40-x)B2O3 − 10- SiO2 − 10Al2O3 − 30ZnO − 10Li2O − xEr2O3 and (40-x)B2O3 − 10SiO2 − 10Al2O3 − 30ZnO – 10MgO − xEr2O3 (x = 0.1, 0.25, 0.5, 1.0, and 2.0 mol %). We confirm the amorphous-like structure for all the prepared glasses using X-ray diffraction (XRD). To study the functional groups of the glass composition after the melt−quenching process, Raman spectroscopy was used, and various structural units such as triangular and tetrahedral-borates (BO3 and BO4 ) have been identified. All the samples were characterized using optical absorption for UV, visible and NIR regions. Judd-Ofelt (JO) intensity parameters (Ωλ , λ = 2, 4 and 6) were calculated from the optical absorption spectra of two glasses LiEr 2.0 and MgEr 2.0 (doped with 2 mol % of Er3+). JO parameters for LiEr 2.0 and MgEr 2.0 glasses follow the trend as Ω6>Ω2>Ω4 . Using Judd–Ofelt intensity parameters, we obtained radiative probability A (S−1 ), branching ratios (β), radiative decay lifetimes τrad (μs) of emissions from excited Er+3 ions in LiEr 2.0 and MgEr 2.0 to all lower levels. Quantum efficiency (η) of 4 I13/2 and 4 S3/2 levels for LiEr 2.0 and MgEr 2.0 with and without 4D7/2 level was calculated using the radiative decay lifetimes τrad. (μs) and measured lifetimes τexp. (μs). We measured the visible photoluminescence under 377 nm excitation for both LiEr and MgEr glass series within the region 390–580 nm. Three bands were observed in the visible region at 407 nm, 530 nm, and 554 nm, as a result of 2H9/2 → 4 I15/2 , 2H11/2 → 4 I15/2 and 4 S3/2 → 4 I15/2 transitions, respectively. Decay lifetimes for emissions at 407 nm, 530 nm, and 554 nm were measured and they show single exponential behavior for all the LiEr and MgEr glass series. From the photoluminescence and radiative decay lifetimes (τrad), we calculated the full-width at half-maximum (FWHM), emission cross-section ( ) and bandwidth gain (FWHM ) parameters. Near-infrared photoluminescence under 980 nm excitation was measured for all the LiEr and MgEr glass series in the region 1420–1620 nm. NIR emissions show a broadband centered at ∼1530 nm due to the transition of Er3+: 4 I13/ 2 → 4 I15/2 . Decay lifetimes for NIR emission at ∼1530 nm were measured and they show a quite exponential nature for all the LiEr and MgEr glass series. From the NIR emission spectra and decay lifetimes, we calculated the full-width at half-maximum (FWHM), the emission cross-section ( ) and the bandwidth gain (FWHM ) for the NIR emission and it shows FWHM of 50–70 nm for prepared glasses, emission cross-section of (∼3.5) 10−20 cm2 , while bandwidth gain was (∼25) 10−26 cm3