Search results for: electro catalyst

Authors: Mulatu Kassie Birhanu

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Electro-oxidation of glycerol is an important process to convert the less price glycerol into other expensive (essential) and energy-rich chemicals. In this study, nickel was electro-deposited on laboratory-made carbon ceramic electrode (CCE) substrate using electrochemical techniques that is cyclic voltammetry (CV) to prepare an electro-catalyst (Ni/CCE) for electro-oxidation of glycerol. Carbon ceramic electrode was prepared from graphite and methyl tri-methoxy silane (MTMOS) through the processes called hydrolysis and condensation with methanol in acidic media (HCl) by a sol-gel technique. Physico-chemical characterization of bare CCE and modified (deposited) CCE (Ni/CCE) was measured and evaluated by Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). Electro-oxidation of glycerol was performed in 0.1 M glycerol in alkaline media (0.5 M NaOH). High-Performance Liquid Chromatography (HPLC) technique was used to identify and determine the concentration of glycerol, reaction intermediates and oxidized products of glycerol after its electro-oxidation is performed. The conversion (%) of electro-oxidation of glycerol during 9-hour oxidation was 73% and 36% at 1.8V and 1.6V vs. RHE, respectively. Formate, oxalate, glycolate and glycerate are the main oxidation products of glycerol with selectivity (%) of 75%, 8.6%, 1.1% and 0.95 % at 1.8 V vs. RHE and 55.4%, 2.2%, 1.0% and 0.6% at 1.6 V vs. RHE respectively. The result indicates that formate is the main product in the electro-oxidation of glycerol on Ni/CCE using the indicated applied potentials.

Keywords: carbon-ceramic electrode, electrodeposition, electro-oxidation, Methyltrimethoxysilane

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Authors: S. Limpattayanate, M. Hunsom

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A comparison of activity and stability of the as-formed Pt/C, Pt-Co, and Pt-Pd/C electrocatalysts, prepared by a combined approach of impregnation and seeding, was performed. According to the activity test in a single proton exchange membrane (PEM) fuel cell, the oxygen reduction reaction (ORR) activity of the Pt-M/C electro catalyst was slightly lower than that of Pt/C. The j0.9 V and E10 mA/cm2 of the as-prepared electrocatalysts increased in the order of Pt/C>Pt-Co/C>Pt-Pd/C. However, in the medium-to-high current density region, Pt-Pd/C exhibited the best performance. With regard to their stability in a 0.5 M H2SO4 electrolyte solution, the electro chemical surface area decreased as the number of rounds of repetitive potential cycling increased due to the dissolution of the metals within the catalyst structure. For long-term measurement, Pt-Pd/C was the most stable than the other three electrocatalysts.

Keywords: ORR activity, stability, Pt-based electrocatalysts, PEM fuel cell

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Authors: Wenjun Zhang, Thao Thi Le, Dongyup Shin, Jong Min Kim

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Electrochemical hydrogen peroxide (H₂O₂) synthesis holds significant promise for decentralized environmental remediation through the electro-Fenton process. However, challenges persist, such as the absence of robust electrocatalysts for the selective two-electron oxygen reduction reaction (2e⁻ ORR) and the high cost and sluggish kinetics of conventional electro-Fenton systems in treating highly concentrated wastewater. This study introduces an efficient water treatment system for removing substantial quantities of organic pollutants using an advanced electro-Fenton system coupled with a high-valent NiO catalyst. By employing a precipitation method involving crystal facet and cation vacancy engineering, a trivalent Ni (Ni³⁺)-rich NiO catalyst with a (111)-domain-exposed crystal facet, named {111}-NivO, was synthesized. This catalyst exhibited a remarkable 96% selectivity and a high mass activity of 59 A g⁻¹ for H₂O₂ production, outperforming all previously reported Ni-based catalysts. Furthermore, an advanced electro-Fenton system, integrated with a flow cell for electrochemical H₂O₂ production, was utilized to achieve 100% removal of 50 ppm bisphenol A (BPA) in 200 mL of wastewater under heavy-duty conditions, reaching a superior rapid degradation rate (4 min, k = 1.125 min⁻¹), approximately 102 times faster than the conventional electro-Fenton system. The hyper-efficiency is attributed to the continuous and appropriate supply of H₂O₂, the provision of O₂, and the timely recycling of the electrolyte under high current density operation. This catalyst also demonstrated a 93% removal of total organic carbon after 2 hours of operation and can be applied for efficient removal of highly concentrated phenol pollutants from aqueous systems, which opens new avenues for wastewater treatment.

Keywords: hydrogen peroxide production, nickel oxides, crystal facet and cation vacancy engineering, wastewater treatment, flow cell, electro-Fenton

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Authors: Bita Bayatsarmadi, Shi-Zhang Qiao

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Oxygen reduction reaction (ORR) performance of iron and nitrogen co-doped porous carbon nanoparticles (Fe-NPC) with various physical and (electro) chemical properties have been investigated. Fe-NPC nanoparticles are synthesized via a facile soft-templating procedure by using Iron (III) chloride hexa-hydrate as iron precursor and aminophenol-formaldehyde resin as both carbon and nitrogen precursor. Fe-NPC nanoparticles shows high surface area (443.83 m2g-1), high pore volume (0.52 m3g-1), narrow mesopore size distribution (ca. 3.8 nm), high conductivity (IG/ID=1.04), high kinetic limiting current (11.71 mAcm-2) and more positive onset potential (-0.106 V) compared to metal-free NPC nanoparticles (-0.295V) which make it high efficient ORR metal-free catalysts in alkaline solution. This study may pave the way of feasibly designing iron and nitrogen containing carbon materials (Fe-N-C) for highly efficient oxygen reduction electro-catalysis.

Keywords: electro-catalyst, mesopore structure, oxygen reduction reaction, soft-template

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Authors: Nabi Ullah

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The single-step solvothermal method is used to prepare Cu/CuSe as an electrocatalyst for methanol electro-oxidation reaction (MOR). 1,3-butane-diol is selected as a reaction medium, whose viscosity and complex formation with Cu(II) ions dictate the catalyst morphology. The catalyst has a macroporous structure, which is composed of nanoballs with a high purity, crystallinity, and uniform morphology. The electrocatalyst is excellent for MOR, as it delivers a current density of 37.28 mA/mg at a potential of 0.6 V (vs Ag/AgCl) in the electrolyte of 1 M KOH and 0.75 M methanol at a 50 mV/s scan rate under conditions of cyclic voltammetry. The catalyst also shows good stability for 3600 s with negligible charge transfer resistance and a high electrochemical active surface area (ECSA) value of 0.100 mF/cm².

Keywords: MOR, copper selenide, electocatalyst, energy application

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Authors: Akan C. Offong, E. J. Anthony, Vasilije Manovic

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A modified steady-state numerical model is developed for the electrochemical reduction of CO₂ to formic acid. The numerical model achieves a CD (current density) (~60 mA/cm²), FE-faradaic efficiency (~98%) and conversion (~80%) for CO₂ electro-reduction to formic acid in a microfluidic cell. The model integrates charge and species transport, mass conservation, and momentum with electrochemistry. Specifically, the influences of Bi-Sn based nanoparticle catalyst (on the cathode surface) at different mole fractions and 1-ethyl-3-methyl imidazolium tetra-fluoroborate ([EMIM][BF₄]) electrolyte, on CD, FE and CO₂ conversion to formic acid is studied. The reaction is carried out at a constant concentration of electrolyte (85% v/v., [EMIM][BF₄]). Based on the mass transfer characteristics analysis (concentration contours), mole ratio 0.5:0.5 Bi-Sn catalyst displays the highest CO₂ mole consumption in the cathode gas channel. After validating with experimental data (polarisation curves) from literature, extensive simulations reveal performance measure: CD, FE and CO₂ conversion. Increasing the negative cathode potential increases the current densities for both formic acid and H₂ formations. However, H₂ formations are minimal as a result of insufficient hydrogen ions in the ionic liquid electrolyte. Moreover, the limited hydrogen ions have a negative effect on formic acid CD. As CO₂ flow rate increases, CD, FE and CO₂ conversion increases.

Keywords: carbon dioxide, electro-chemical reduction, ionic liquids, microfluidics, modelling

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Authors: Sijo Varghese

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A space craft (E. M. Tractor) which is intended to deflect or tug the asteroids which possesses threat towards the planets is the whole idea behind this paper. In this case "Electro Magnetic Induction" is used where it is known that when two separate circuits are connected to the electro magnet and on application of electric current through the one circuit in to the coil induces magnetic fields which repels the other circuit.( Faraday's law of Electromagnetic Induction). Basically a Spacecraft is used to attach a large sheet of aluminum on to the surface of the asteroid, the Spacecraft acts as an electro magnet and the induced magnetic field would eventually repel the aluminum intern repelling the asteroid. This method would take less time as compared to use of gravity( which requires a larger spacecraft and process will take a long time).

Keywords: asteroids, electro magnetic induction, gravity, electro magnetic tractor

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Authors: Mohamed Gar Alalm

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This study aims to investigate various operating conditions that affect the performance of the electro-Fenton process for degradation of pesticides. Stainless steel electrodes were utilized in the electro-Fenton cell due to their relatively low cost. The favored conditions of current intensity, pH, iron loading, and pesticide concentration were deeply discussed. Complete removal of pesticide was attained at the optimum conditions. The degradation kinetics were described by pseudo- first-order pattern. In addition, a response surface model was developed to describe the performance of electro-Fenton process under different operational conditions. The model indicated that the coefficient of determination was (R² = 0.995).

Keywords: electro-Fenton, stainless steel, pesticide, wastewater

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Authors: S. Vasailor, C. Rattanakawin

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Electro-winning of copper metal from dilute sulfate solution (13.7 g/L) was performed in a lab electrolytic cell with stainless-steel cathode and lead-alloy anode. The effects of various parameters including cell voltage, electro-winning temperature and time were studied in order to acquire an appropriate current efficiency of copper deposition. The highest efficiency is about 95% obtaining from electro-winning condition of 3V, 55°C and 3,600 s correspondingly. The cathode copper with 95.5% Cu analyzed using atomic absorption spectrometry can be obtained from this single-winning condition. In order to increase the copper grade, solvent extraction should be used to increase the sulfate concentration, say 50 g/L, prior to winning the cathode copper effectively.

Keywords: copper metal, current efficiency, dilute sulfate solution, electro-winning

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Authors: Ali Gharib, Leila Vojdanifard, Nader Noroozi Pesyan, Mina Roshani

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We describe an efficient method for oxidation of alcohols to related aldehydes and ketones by hydrogen peroxide as oxidizing agent, under reflux conditions. Nano-graphene oxide (NGO) as a heterogeneous catalyst was used and had their activity compared with other various catalysts. This catalyst was found to be an excellent catalyst for oxidation of alcohols. The effects of various parameters, including catalyst type, nature of the substituent in the alcohols and temperature, on the yield of the carboxylic acids were studied. Nano-graphene oxide was synthesized by the oxidation of graphite powders. This nanocatalyst was found to be highly efficient in this reaction and products were obtained in good to excellent yields. The recovered nano-catalyst was successfully reused for several runs without significant loss in its catalytic activity.

Keywords: nano-graphene oxide, oxidation, aldehyde, ketone, catalyst

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Authors: Sarina Sulaiman, N.Khairudin , P.Jamal, M.Z. Alam, Zaki Zainudin, S. Azmi

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In this study, fish bone waste was used as a new catalyst for biodiesel production. Instead of discarding the fish bone waste, it will be utilized as a source for catalyst that can provide significant benefit to the environment. Also, it can be substitute as a calcium oxide source instead of using eggshell, crab shell and snail shell. The XRD and SEM analysis proved that calcined fish bone contains calcium oxide, calcium phosphate and hydroxyapatite. The catalyst was characterized using Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD).

Keywords: calcinations, fish bone, transesterification, waste catalyst

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Authors: Maryam Kiani

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In order to enhance the efficiency and stability of an electrocatalyst for formic acid electro-oxidation reaction (FAOR), we developed a method to create Pt/Ni nanoparticles with carbon black. These nanoparticles were prepared using a simple impregnation reduction technique. During the observation, it was found that the nanoparticles had a spherical shape. Additionally, the average particle size remained consistent, falling within the range of about 4 nm. This approach aimed to obtain a loaded Pt-based electrocatalyst that would exhibit improved performance and stability when used in FAOR applications. By utilizing the impregnation reduction method and incorporating Ni nanoparticles along with Pt, we sought to enhance the catalytic properties of the material. By incorporating Ni atoms into the Pt structure, the electronic properties of Pt are modified, resulting in a delay in the chemisorption of harmful CO intermediate species. This modification also promotes the dehydrogenation pathway of the formic acid oxidation reaction (FAOR). Through electrochemical analysis, it has been observed that the Pt3Ni-C catalyst exhibits enhanced performance in FAOR compared to traditional Pt catalysts. This means that the addition of Ni atoms improves the efficiency and effectiveness of the Pt3Ni-C catalyst in facilitating the FAOR process. Overall, the utilization of these alloy nanoparticles as electrocatalysts represents a significant advancement in fuel cell technology.

Keywords: electrocatalyst, impregnation reduction method, formic acid electro-oxidation reaction, fuel cells

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Authors: Ahmed I. Osman, Jehad K. Abu-Dahrieh, David W. Rooney, Jillian Thompson

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The effect of loading of copper on the catalytic performance of different alumina support during the dehydration of methanol to dimethyl ether (DME) was performed in a fixed bed reactor. There are two levels of loading; low loading (1, 2, 4 and 6% Cu wt/wt) and high loading (10 and 15% Cu wt/wt) on both AC350 (alumina catalyst calcined at 350) and AC550 (alumina catalyst calcined at 550), to study the effect of loading and the effect of the support during methanol dehydration to DME (MTD). The catalysts were characterized by TGA, XRD, BET, TPD-NH3, TEM and DRIFT-Pyridine. Under reaction conditions where the temperature ranged from 180-300˚C with a WHSV= 12.1 h-1 it was found that all the catalysts calcined at 550˚C showed higher activity than those calcined at 350˚C. In this study, the optimum catalyst was 6% Cu/AC550. This catalyst showed a high degree of stability, had one half activity of the pure catalyst (AC550) and double the activity of the optimum catalyst calcined at 350˚C (6% Cu/AC350). So, we recommended 6% Cu/AC550 for the production of DME from methanol.

Keywords: bio-fuel, nano composite catalyst, DME, Cu-Al2O3

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Authors: Haragobinda Srichandan, Ashish Pathak, Dong Jin Kim, Seoung-Won Lee

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The present investigation deals with bioleaching of spent petroleum catalyst using At. ferrooxidans and At. thiooxidans. The spent catalyst used in the present study was pretreated with acetone to remove the oily hydrocarbons. FESEM and XPS analysis indicated the presence of metals in sulfide and oxide forms in spent catalyst. Both At. ferrooxidans and At. thiooxidans were found to be highly effective in producing the acid. Bioleaching with At. ferrooxidans and At. thiooxidans led to higher recovery of metals compare to control. During bioleaching similar recoveries of metals were obtained using At. ferrooxidans and At. thiooxidans. This might be due to the presence of metals as soluble oxides and sulphides in the spent catalyst. At the end of bioleaching, about 87-90% Ni, 34% Al, 65-73% Mo and 92-97% V were leached using above bacteria. It is elucidated that bioleaching with At. thiooxidans is comparatively more advantageous due to lower cost of sulphur.

Keywords: At. ferrooxidans, bioleaching, metal recovery, spent catalyst

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Authors: Noreen Sajjad Ghulam Hussain

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Catalysts are prepared by simple physical mixing and thermal treatment of support and metal acetate precursors.The effect of metal ratio and metal loading to produce highly active catalyst for the oxidation of benzyl alcohol are studied.

Keywords: catalyst, acetates, benzyl alcohols

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Authors: Ahmed Shinkafi, Craig Lawson

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There is a great advancement towards the All-Electric Aircraft (AEA) technology. The AEA concept assumes that all aircraft systems will be integrated into one electrical power source in the future. The principle of the electro-thermal system is to transfer the energy required for anti/de-icing to the protected areas in electrical form. However, powering a large aircraft anti-icing system electrically could be quite excessive in cost and system weight. Hence, maximising the anti/de-icing efficiency of the electro-thermal system in order to minimise its power demand has become crucial to electro-thermal de-icing system sizing. In this work, an enhanced methodology has been developed for conceptual sizing of aircraft electro-thermal de-icing System. The work factored those critical terms overlooked in previous studies which were critical to de-icing energy consumption. A case study of a typical large aircraft wing de-icing was used to test and validate the model. The model was used to optimise the system performance by a trade-off between the de-icing peak power and system energy consumption. The optimum melting surface temperatures and energy flux predicted enabled the reduction in the power required for de-icing. The weight penalty associated with electro-thermal anti-icing/de-icing method could be eliminated using this method without under estimating the de-icing power requirement.

Keywords: aircraft, de-icing system, electro-thermal, in-flight icing

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Authors: Bashir Abubakar Abdulkadir, Anita Ramli, Lim Jun Wei, Yoshimitsu Uemura

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In this study, the ZnO/MCM-22 catalyst with different ZnO loading were prepared using conventional wet impregnation process and the catalyst activity was tested for biodiesel production from Jatropha oil. The effects of reaction parameters with regards to catalyst activity were investigated. The synthesized catalysts samples were then characterized by X-ray diffraction (XRD) for crystal phase, Brunauer–Emmett–Teller (BET) for surface area, pore volume and pore size, Field Emission Scanning electron microscope attached to energy dispersive x-ray (FESEM/EDX) for morphology and elemental composition and TPD (NH3 and CO2) for basic and acidic properties of the catalyst. The XRD spectra couple with the EDX result shows the presence of ZnO in the catalyst confirming the positive intercalation of the metal oxide into the mesoporous MCM-22. The synthesized catalyst was confirmed to be mesoporous according to BET findings. Also, the catalysts can be considered as a bifunctional catalyst based on TPD outcomes. Transesterification results showed that the synthesized catalyst was highly efficient and effective to be used for biodiesel production from low grade oil such as Jatropha oil and other industrial application where the high fatty acid methyl ester (FAMEs) yield was achieved at moderate reaction conditions. It was also discovered that the catalyst can be used more than five (5) runs with little deactivation confirming the catalyst to be highly active and stable to the heat of reaction.

Keywords: MCM-22, synthesis, transesterification, ZnO

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Authors: An-Ya Lo, Yi-Chen Chung, Yun-Chi Hsu, Chuan-Ming Tseng, Chiu-Yue Lin

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In this study, the ternary alloy catalyst Pt20RuxSny (where 20, x, y represent mass fractions of Pt, Ru, and Sn, respectively) was optimized for the preliminary study of bio-ethanol fuel cells (BAFC). The morphology, microstructure, composition, phase-structures, and electrochemical properties of Pt20RuxSny catalyst were examined by SEM, TEM, EDS-mapping, XRD, and potentiostat. The effect of Sn content on electrochemical active surface (EAS) and oxidation activity were discussed. As a result, the additional Sn greatly improves the efficiency of Pt20RuxSny, either x=0 or 10. Through discussing the difference between ethanol and glycol oxidations, the mechanism of tolerance against poisoning has been proved. Overall speaking, the catalytic activity are in the order of Pt20RuxSny > Pt20Rux > Pt20Sny in both ethanol and glycol systems. Finally, Pt20Ru10Sn15 catalyst was successfully applied to demonstrate the feasibility of using bio-alcohol.

Keywords: Pt-Sn alloy catalyst, Pt-Ru-Sn alloy catalyst, fuel cell, ethanol, ethylene glycol

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Authors: Mehrji Khosravan, Mostafa Fathali-Sianib, Davood Soudbar, Sasan Talebnezhad, Mohammad-Reza Ebrahimi

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The late transition metal catalyst of the end group of transition metals in the periodic table as Ni, Fe, Co, and Pd was grown up rapidly in polyolefin industries recently. These metals with suitable ligands exhibited special characteristic properties and appropriate activities in the production of polyolefins. The ligand 1,4-bis (2,6-diisopropyl phenyl) acenaphthene was synthesized by reaction of 2,6-diisopropyl aniline and acenaphthenequinone. The ligand was added to nickel (II) dibromide salt for synthesis the 1,4-bis (2,6 diisopropylphenyl) acenaphthene nickel (II) dibromide catalyst. The structure of the ligand characterized by IR technique. The catalyst then deposited on graphene and graphene oxide by vander walss-attachment for use in Ethylene slurry polymerization process in the presence of catalyst activator such as methylaluminoxane (MAO) in hexane solvent. The structure of the catalyst characterized by IR and TEM techniques and some of the polymers were characterized by DSC. The highest activity was achieved at 600 C for catalyst.

Keywords: α-diimine nickel (II) complex, graphene as supported catalyst, late transition metal, ethylene polymerization

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Authors: Talat Baran

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The Suzuki C(sp2)-C(sp2) coupling reaction is considered to be one of the best ways for the synthesis of biaryl compounds. There are many studies reporting the catalytic performance of palladium catalyst in Suzuki coupling reactions. Natural biopolymer (such as zeolite, carbon, silica, and chitosan) supporting catalysts have been lately attracted interest because of their low-cost, nontoxicity, and eco-friendliness. One of the most important natural biopolymer is cellulose, which is widely considered as an eco-friendly biopolymer due to its biodegradable, non-toxic and renewable nature. In this study, (1) cellulose supported Pd(II) catalyst was synthesized (2) its chemical structure was characterized by FT-IR, SEM/EDAX, XRD, TG-DTG, ICP-OES techniques (3) to investigate the performance of the catalyst in Suzuki coupling reactions by using microwave irradiation technique (4) reusability of the catalyst was done under optimum conditions. This cellulose supported Pd(II) catalyst exhibited high selectivity and efficiency in Suzuki coupling reactions under mild conditions (50°C). High TON and TOF values were recorded for the catalyst. Also, the reusability tests showed the catalysts could be used for several times in consequence of reusability tests.

Keywords: palladium, cellulose, Schiff base, reusability

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Authors: Burcu Kiren, Alattin CAkan, Nezihe Ayas

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Hydrogen will be arguably the best fuel in the future as it is the most abundant element in the universe. Hydrogen, as a fuel, is notably environmentally benign, sustainable and has high energy content compared to other sources of energy. It can be generated from both conventional and renewable sources. The hydrolysis reaction of metal hydrides provides an option for hydrogen production in the presence of a catalyst. In this study, Ni/dolomite catalyst was synthesized by the wet impregnation method for hydrogen production by hydrolysis reaction of sodium borohydride (NaBH4). Besides, the synthesized catalysts characterizations were examined by means of thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Brunauer –Emmett – Teller (BET) and scanning electron microscopy (SEM). The influence of reaction temperature (25-75 °C), reaction time (15-60 min.), amount of catalyst (50-250 mg) and active metal loading ratio (20,30,40 wt.%) were investigated. The catalyst prepared with 30 wt.% Ni was noted as the most suitable catalyst, achieving of 35.18% H₂ and hydrogen production rate of 19.23 mL/gcat.min at 25 °C at reaction conditions of 5 mL of 0.25 M NaOH and 100 mg NaBH₄, 100 mg Ni/dolomite.

Keywords: sodium borohydride, hydrolysis, catalyst, Ni/dolomite, hydrogen

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Authors: Yingjeng James Li, Chih Chi Hsu, Chiao-Chih Hu

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Membrane electrode assemblies MEAs for proton exchange membrane PEM water electrolyzers were prepared by employing 175um perfluorosulfonic acid PFSA membranes as the PEM, onto which iridium oxide catalyst was coated on one side as the anode and platinum catalyst was coated on the other side as the cathode. The cathode catalyst ink was prepared so that the weight ratio of the catalyst powder to ionomer was 75:25, 70:30, 65:35, 60:40, and 55:45, respectively. Whereas, the ratio of catalyst powder to ionomer of the anode catalyst ink keeps constant at 50:50. All the MEAs have a catalyst coated area of 5cm*5cm. The test cell employs a platinum plated titanium grid as anode gas diffusion media; whereas, carbon paper was employed as the cathode gas diffusion media. The measurements of the MEA gases production rate were carried out by holding the cell voltage ranging from 1.6 to 2.8 volts at room temperature. It was found that the MEA with cathode catalyst to ionomer ratio of 65:35 gives the largest hydrogen production rate which is 2.8mL/cm2*min.

Keywords: electrolyzer, membrane electrode assembly, proton exchange membrane, ionomer, hydrogen

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Authors: Amit Keshav

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Waste bone, produced in large quantity (8-10 kg./day) from a slaughterhouse, could be a cheap (cost $0.20 per kg) substitute for commercial catalysts. In the present work, catalyst for esterification reaction was prepared from waste bone and characterized by various techniques. Bone was deoiled and then sulfonated. Fourier-transform infrared spectroscopy (FTIR) spectra of prepared catalyst predicted –OH vibration at 3416 and 1630 cm⁻¹, S-O stretching at 1124 cm⁻¹ and intense bands of hydroxypatite in a region between 500 and 700 cm⁻¹. X-ray diffraction (XRD) predicts peaks of hydroxyapatite, CaO, and tricalcium phosphate. Scanning electron microscope (SEM) was employed to reveal the presence of non-uniformity deposited fine particles on the catalyst surface that represents active acidic sites. The prepared catalyst was employed to study its performance on esterification reaction between acrylic acid and ethanol in a molar ratio of 1:1 at a set temperature of 60 °C. Results show an equilibrium conversion of 49% which is matched to the commercial catalysts employed in literature. Thus waste bone could be a good catalyst for acrylic acid removal from waste industrial streams via the process of esterification.Keywords— Heterogeneous catalyst, characterization, esterification, equilibrium conversion

Keywords: heterogeneous catalyst, characterization, esterification, equilibrium conversion

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Authors: Victor Chinecherem Ejeke, Raphael Eze Nnam

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The main objective of this research is to produce biodiesel from waste vegetable oil using activated eggshell waste as solid catalysts. A transesterification reaction was performed for the conversion to biodiesel. Waste eggshells were calcined at 700°C, 800°C and 900°C for a time period of 3hrs for the preparation of the renewable catalyst. The calcined waste eggshell catalyst was characterized using X-Ray Florescence (XRF) Spectroscopy, which revealed CaO as the major constituent (90.86%); this was further confirmed by X-Ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) analyses. The prepared catalyst was used for transesterification reaction and the effects of calcination temperature (700 to 900°C), Deep Eutectic Solvent DES loading (3 to 18 wt. %), Waste Egg Shell (WES) catalyst loading (6 to 14 wt. %) on the conversion to biodiesel were studied. The yield of biodiesel using a waste eggshell catalyst (91%) is comparable to conventional catalyst like sodium hydroxide with a yield of 80-90%. The maximum biodiesel production yield was obtained at a specific oil-to methanol molar ratio of 1:10, a temperature of 65°C and a catalyst loading of 14g-wt%. The biodiesel produced was characterized as being composed of methyl Tetradecanoate (C₁₄H₂₈O₂) 30.92% using the Gas Chromatographic (GC-MS) analysis. The fuel properties of the biodiesel (Flashpoint 138ᵒC) were comparable to commercial diesel, and hence it can be used in compression-ignition engines. The results indicated that the catalysts derived from waste eggshell had high potential to be used as biodiesel production catalysts in transesterification of waste vegetable oil with the advantage of reusability and also not requiring water washing steps.

Keywords: waste vegetable oil, catalyst , biodiesel , waste egg shell

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Authors: Seungho Shin, Keunwoo Choi, Ali Akbar, Sukkee Um

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In this study, the nanoscale transport properties and catalyst utilization of vertically aligned carbon nanotube (VACNT) catalyst layers are computationally predicted by the three-dimensional lattice Boltzmann simulation based on the quasi-random nanostructural model in pursuance of fuel cell catalyst performance improvement. A series of catalyst layers are randomly generated with statistical significance at the 95% confidence level to reflect the heterogeneity of the catalyst layer nanostructures. The nanoscale gas transport phenomena inside the catalyst layers are simulated by the D3Q19 (i.e., three-dimensional, 19 velocities) lattice Boltzmann method, and the corresponding mass transport characteristics are mathematically modeled in terms of structural properties. Considering the nanoscale reactant transport phenomena, a transport-based effective catalyst utilization factor is defined and statistically analyzed to determine the structure-transport influence on catalyst utilization. The tortuosity of the reactant mass transport path of VACNT catalyst layers is directly calculated from the streaklines. Subsequently, the corresponding effective mass diffusion coefficient is statistically predicted by applying the pre-estimated tortuosity factors to the Knudsen diffusion coefficient in the VACNT catalyst layers. The statistical estimation results clearly indicate that the morphological structures of VACNT catalyst layers reduce the tortuosity of reactant mass transport path when compared to conventional catalyst layer and significantly improve consequential effective mass diffusion coefficient of VACNT catalyst layer. Furthermore, catalyst utilization of the VACNT catalyst layer is substantially improved by enhanced mass diffusion and electric current paths despite the relatively poor interconnections of the ion transport paths.

Keywords: Lattice Boltzmann method, nano transport phenomena, polymer electrolyte fuel cells, vertically aligned carbon nanotube

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Authors: Elmeliani M’Hammed

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The work is carried out for the synthesis of antifungal effective against the fungus Fusarium oxysporum, Albedinis (Foa), the causative agent of bayoud, dates palm disease, through the use of raw clay as a green catalyst. The Aza-Michael reaction of amine addition to α, β-unsaturated alkene was carried out using the crude clay as a green catalyst to synthesize the antifungal agent bayoud. The reaction was carried out under favorable conditions, ambient temperature, without solvent, and a green catalyst "loves the environment" that the product that was synthesized gave us a high yield and excellent chemo selectivity.

Keywords: raw clay, amines, alkenes, environment, antifungal, bayoud, date palms

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Authors: S. Bouafia Chergui, Nihal Oturan, Hussein Khalaf, Mehmet A. Oturan

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The aim of this work was to compare the degradation of a mixture of three cationic dyes by advanced oxidation processes (electro-Fenton, photo-Fenton) in aqueous solution. These processes are based on the in situ production of hydroxyl radical, a highly strong oxidant, which allows the degradation of organic pollutants until their mineralization into CO2 and H2O. Under optimal operating conditions, the evolution of total organic carbon (TOC) and electrical energy efficiency have been investigated for the two processes.

Keywords: photo-fenton, electro-fenton, energy efficiency, water treatment

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Authors: Komal Kumar, Sreedevi Upadhyayula

Abstract:

In this study, a two-stage process was established for the synthesis of HMF esters using ionic liquid acid catalyst. Ionic liquid catalyst with different strength of the Bronsted acidity was prepared in the laboratory and characterized using 1H NMR, FT-IR, and 13C NMR spectroscopy. Solid acid catalyst from the ionic liquid catalyst was prepared using the immobilization method. The acidity of the synthesized acid catalyst was measured using Hammett function and titration method. Catalytic performance was evaluated for the biomass conversion to 5-hydroxymethylfurfural (5-HMF) and levulinic acid (LA) in methyl isobutyl ketone (MIBK)-water biphasic system. A good yield of 5-HMF and LA was found at the different composition of MIBK: Water. In the case of MIBK: Water ratio 10:1, good yield of 5-HMF was observed at ambient temperature 150˚C. Upgrading of 5-HMF into monoesters from the reaction of 5-HMF and reactants using biomass-derived monoacid were performed. Ionic liquid catalyst with -SO₃H functional group was found to be best efficient in comparative of a solid acid catalyst for the esterification reaction and biomass conversion. A good yield of 5-HMF esters with high 5-HMF conversion was found to be at 105˚C using the best active catalyst. In this process, process A was the hydrothermal conversion of cellulose and monomer into 5-HMF and LA using acid catalyst. And the process B was the esterification followed by using similar acid catalyst. All monoesters of 5-HMF synthesized here can be used in chemical, cross linker for adhesive or coatings and pharmaceutical industry. A theoretical density functional theory (DFT) study for the optimization of the ionic liquid structure was performed using the Gaussian 09 program to find out the minimum energy configuration of ionic liquid catalyst.

Keywords: biomass conversion, 5-HMF, Ionic liquid, HMF ester

Procedia PDF Downloads 216

Authors: Dinda A. Utami, Muhammad N. Alfarizi

Abstract:

The purpose of this study was to determine the ability of zeolite catalyst for the trans- esterification reaction in biodiesel production from animal fat. The ability of the zeolite as a catalyst is determined by the structure and composition of the zeolite. An important factor that determines the properties of zeolites in catalysis includes adsorption capability to the compound of the reactants. Zeolites with a pore size of specific properties selectively adsorbing molecules. A molecule can be adsorbed by either the zeolite cavities if the size and shape of the molecule in accordance with the size and shape of the cavity in the zeolite. At this time, it is common to use homogeneous catalysts for biodiesel. We know these catalysts have some disadvantages in its use. Such as the difficulty of separation of the product with the catalyst, the generation of waste that is harmful to the environment due to residual catalysts can’t be reused, and the difficulty of handling and storage. But nowadays, solid catalyst developed technically to improve the efficiency of biodiesel production. In this case of study, we used trans-esterification process wherein the triglyceride is reacted with an alcohol with zeolite as a solid catalyst and it will produce biodiesel and glycerol as a byproduct. Development of solid catalyst seems to be the perfect solution to address the problems associated with homogeneous catalysts.

Keywords: biodiesel, animal fat, trans esterification, zeolite catalyst

Procedia PDF Downloads 220

Authors: Jian Huang, Weixin Qian, Haitao Zhang, Weiyong Ying

Abstract:

Cobalt-gadolinium catalyst for Fischer-Tropsch synthesis was prepared by impregnation method with commercial silica gel, and its texture properties were characterized by BET, XRD, and TPR. The catalytic performance of the catalyst was tested in a fixed bed reactor. The results showed that the addition of gadolinium to the cobalt catalyst might decrease the size of cobalt particles, and increased the dispersion of catalytic active cobalt phases. The carbon number distributions for the catalysts was calculated by ASF equation.

Keywords: Fischer-Tropsch synthesis, cobalt-based catalysts, gadolinium, carbon number distributions

Procedia PDF Downloads 347