Effect of Ultrasonic During Preparation on Cu-Based Catalyst Performance for Hydrogenation of C02 to Methanol

2005 ◽  
Vol 5 (2) ◽  
pp. 111 ◽  
Author(s):  
M Nasikin ◽  
A Wahid
Keyword(s):  
High Pressure ◽  
Flow Reactor ◽  
Irradiation Time ◽  
Catalyst Activity ◽  
Research Work ◽  
Catalyst Preparation ◽  
Precipitation Method ◽  
Operation Condition ◽  
Gas Treatment ◽  
Co Precipitation

Indonesia is rich in natural gas resources. These resources contain hydrocarbons and impurities such as C02. C02 creates a difficulty in further gas treatment and also becomes an environmental problem. Therefore, it is needed to develop a concept to recover this kind of gas and to convert it into more useful chemicals. Catalytic hydrogenation to methanol is one of the technologies that can be considered. Conversion of C02 to methanol can be catalyzed by Cu-based catalyst. Reported tobe the best catalyst, this catalyst is selected as a catalyst for a pilot plant that is operated at a high pressure and a high temperature. However, further development is needed to rearrange the synthesis to be operated both at lower pressure and temperature. For this system, it is needed to increase its catalytic activity. One of the alternatives is to apply a catalyst preparation method using ultrasonic effect. In this research work, CuO/ZnO/AJp3 catalyst with Cr as a promoter was prepared by co-precipitation method. The effect of ultrasonic on catalyst performance, which was irradiated to the catalyst during preparation, was investigated. Co-precipitation was conducted by using carbonate salt for respective metal cations added to the catalyst. Ultrasonic wave was irradiated to the catalyst preparation chamber with 40kHZ and time variable. The characteristics of the catalyst were analyzed by BET method for surface area, while SEM and H2 chemical adsorption were conducted to determine active site dispersion. A high-pressure continuous flow reactor was used for catalyst activity and stability test. The test was conducted at an operation condition of 30 bars and 200-30QoC. The effect of ultrasonic on the CuO/ZnO/AJp3 catalyst shows that ultrasonic irradiation enhances the catalyst surface from 23 to 50 m2/g. SEM analysis shows the change of catalyst morphology to be more uniform and the catalyst particle becomes smaller. The activity test shows that the catalyst with 60 min irradiation time has the highest activity in the hydrogenation of C02 to methanol at 30 bars and at 275°C. Keywords: Hydrogenation, dispersion, methanol, and ultrasonic.

scholarly journals Study of Structural and Magnetic Properties, Trivalent Cation Substitution of Cobalt base Spinel Ferrites CoCr0.04LaxFe1.96-xO4 (0 ≤ x ≤ 0.12)

2020 ◽  
Author(s):  
G. MUSTAFA ◽  
Z. FAROOQ ◽  
M.R. AHMAD ◽  
H. ANWAR ◽  
H. AKHTAR ◽  
...  
Keyword(s):  
Saturation Magnetization ◽  
Research Work ◽  
Magnetic Behavior ◽  
Spinel Ferrites ◽  
Precipitation Method ◽  
Trivalent Cation ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
Morphological Studies ◽  
Co Precipitation

Abstract In this research work a series of polycrystalline trivalent cation (Cr3+, La3+) substituted cobalt ferrite with general formula CoCr0.04LaxFe1.96-xO4 where 0.00 ≤ x ≤ 0.12 (in steps of 0.02) was synthesized using co-precipitation method and were sintered at 900°C for 6 hours. The phase identification and confirmation of the structure were confirmed employing the X-ray diffraction (XRD) and FTIR techniques. The size of crystallite was found on average, in the range of 53-106 nano-meters. FTIR results confirmed spinel ferrites structure. Moreover the morphological studies were observed through SEM. The elemental analysis of the samples was done by EDX while, I-V characterization of the represented sample was recorded using two probe method. The measured electrical resistivity of materials increased as dopant content increased. The magnetic behavior of the materials was studied using vibrating sample magnetometer (VSM). The saturation magnetization values and magnetic coercivity values decreased with the increase of La3+ concentration. The saturation magnetization (Ms) of the ferrite materials decreased with the reduction of size.

Structural, optical and high pressure electrical resistivity studies of pure NiO and Cu-doped NiO nanoparticles

2016 ◽  
Vol 30 (10) ◽  
pp. 1650056 ◽  
Author(s):  
M. Abila Marselin ◽  
N. Victor Jaya
Keyword(s):  
High Pressure ◽  
Electrical Resistivity ◽  
High Pressures ◽  
Precipitation Method ◽  
Nio Nanoparticles ◽  
Bridgman Anvil ◽  
Resistivity Measurements ◽  
Diamond Anvil ◽  
Set Up ◽  
Co Precipitation

In this paper, pure NiO and Cu-doped NiO nanoparticles are prepared by co-precipitation method. The electrical resistivity measurements by applying high pressure on pure NiO and Cu-doped NiO nanoparticles were reported. The Bridgman anvil set up is used to measure high pressures up to 8 GPa. These measurements show that there is no phase transformation in the samples till the high pressure is reached. The samples show a rapid decrease in electrical resistivity up to 5 GPa and it remains constant beyond 5 GPa. The electrical resistivity and the transport activation energy of the samples under high pressure up to 8 GPa have been studied in the temperature range of 273–433 K using diamond anvil cell. The temperature versus electrical resistivity studies reveal that the samples behave like a semiconductor. The activation energies of the charge carriers depend on the size of the samples.

scholarly journals Synthesis, Characterization and Catalytic Activity of NiO-CoO-MgO Nano-Composite Catalyst

2019 ◽  
Vol 19 (3) ◽  
pp. 675
Author(s):  
Salih Hadi Kadhim ◽  
Tariq Hussein Mgheer ◽  
Hussein Idrees Ismael ◽  
Khudheyer Jawad Kadem ◽  
Ahmed Saadon Abbas ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Mixed Oxides ◽  
Irradiation Time ◽  
Precipitation Method ◽  
Composite Catalyst ◽  
Celestine Blue ◽  
Force Microscopy ◽  
Atomic Force ◽  
Co Precipitation ◽  
Microscopy Techniques

The ternary NiO-CoO-MgO catalyst in three ratios 20:20:60, 25:25:50, and 30:30:40 for these component oxides respectively, were synthesized by co-precipitation method of their carbonates by addition of a precipitate agent in basic media, and then calcinated these carbonate to obtain of mixed oxides. The prepared catalysts were characterized by using Powder X-Ray Diffraction (PXRD), Fourier Infrared spectroscopy (FT-IR), and Atomic Force Microscopy techniques (AFM) were used for identification of the prepared catalysts. The result showed that the particle size of these catalyst ratios, were in the nano range and the smallest size was 25:25:50. The investigation of catalytic activity of prepared catalysts was done by photo decolorization of Celestine blue B dye from simulated industrial wastewaters in aqueous solution. The decolorization efficiency of dye reached 99.9% after irradiation time for 1 h. Study the effect of different reaction conditions such as the pH of the medium, the weight of semiconductor and temperature of mixture reaction were shown that the maximum degradation was observed in conditions at pH = 4, catalyst dosage = 0.08 g, and temperature = 303 K.

scholarly journals Preliminary Studies of Ca-Al-Layered Double Hydroxide (Ldh) and Its Effect on the Compressive Strength in Concrete

2020 ◽  
pp. 131-151
Author(s):  
Archibong Ukeme Donatus ◽  
Ojeagah Kenneth ◽  
Michael Christopher Ukuegboho ◽  
I. E. Chiedu ◽  
Obasuyi Emmanuel Idemudia
Keyword(s):  
Compressive Strength ◽  
Research Work ◽  
Load Test ◽  
Precipitation Method ◽  
Compressive Strength Test ◽  
Sem Micrograph ◽  
Compressive Strength Of Concrete ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Concrete Control

This research work involved the preliminary studies of CaAl-LDHs using co precipitation method and applying it in the preparation of concrete to evaluate the compressive strength in grade 15 concrete. Slum and compressive strength test were carried out on the concrete control and concrete mixed with CaAl-LDH, Scanning electron microscope (SEM) and X-Ray Diffractogram (XRD) was carried out on the synthesize LDH, concrete control, and concrete mixed with LDH. From the results obtained in the work failure load test, it was observed that there was an increase by 62.60% in the compressive strength of concrete mixed with 30kg of CaAl-LDHs, the SEM micrograph also shows the increase in the density and the less porosity of the concrete mixed with CaAl-LDH which explained the increase in the compressive strength of the concrete. CaAl-LDH has therefore shows a promising effect on the increase on the compressive strength of concrete.

scholarly journals Optical Examination on Zinc Sulphide Nanoparticles for Photovoltaic Applications

2019 ◽  
Vol 9 (2S2) ◽  
pp. 260-263
Keyword(s):  
Research Work ◽  
Visible Spectrum ◽  
Zinc Nitrate ◽  
Zinc Sulphide ◽  
Crystalline Size ◽  
Precipitation Method ◽  
Zinc Sulfide Nanoparticles ◽  
Optical Examination ◽  
Scherrer Formula ◽  
Co Precipitation

In this research work Zinc Sulphide nanoparticles are synthesized by co–precipitation method with zinc nitrate and sodium sulfide sources. The obtained particles are characterized to know its structure, crystalline pattern, crystalline size and other morphologies. The crystalline size of the material is calculated by Debye–Scherrer Formula. X–Ray Diffraction analysis, Scanning Electron Microscopy, Fourier Transform Analysis and UV–Visible spectrum analysis is performed to study the mentioned morphology and properties of the material synthesized. The central point of this research work is to study the behavior of Zinc sulfide nanoparticles for solar cell applications. Hence, luminescence property of the material is finally analyzed

scholarly journals Synthesis, electrical and magnetic properties of polymer coated magnetic nanoparticles for application in MEMS/NEMS

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Muhammad Arshad Javid ◽  
Muhammad Sajjad ◽  
Saeed Ahmad ◽  
Muhammad Azhar Shahid Khan ◽  
Khalid Nadeem ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Research Work ◽  
Precipitation Method ◽  
Cubic Phase ◽  
Conductivity Measurements ◽  
Xrd Pattern ◽  
Electrical And Magnetic Properties ◽  
Co Precipitation ◽  
Average Size

Abstract In this research work, polymer coated magnetic nanoparticles were prepared by co-precipitation method. The samples were characterized by XRD, SEM, EDS, VSM and two probe DC conductivity measurements. XRD pattern indicated the existence of a sole cubic phase of Fe3O4 with Miller indices (2 2 0), (3 1 1), (5 1 1), (4 4 0). An average size of magnetic nanoparticles was about 22.9 nm and it was reduced to 21.3 nm and 19.4 nm after 1 wt. %. and 2 wt. % coating of PEG-6000, respectively. The morphology and size of the samples were investigated by scanning electron microscope (SEM). EDX spectra confirmed the coating of PEG on magnetic nanoparticles. Magnetic properties were examined by vibrating sample magnetometer (VSM). Saturation magnetization (M s ) decreased as the concentration of PEG increased in the magnetic material. Electrical properties of uncoated and polymer coated Fe3O4 nanoparticles were studied by two-probe conductivity meter. This study concluded that the thermal flow of charge in polymer coated magnetic nanoparticles can be evaluated at micro and nano level.

scholarly journals Preparation and Activity of Precipitated Ni-MgO/Al2O3 Catalysts for the Partial Oxidation of Methane

2007 ◽  
Vol 7 (1 & 2) ◽  
pp. 108
Author(s):  
Luis F. Razon ◽  
Carlito M. Salazar ◽  
Hiroo Niiyama ◽  
Long The Nam Doan
Keyword(s):  
Partial Oxidation ◽  
Reaction Temperature ◽  
Flow Reactor ◽  
Fixed Bed ◽  
Catalyst Preparation ◽  
Partial Oxidation Of Methane ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Preparation Methods ◽  
Oxidation Of Methane

The effect of catalyst preparation methods, NiO/MgO molar ratio and reaction temperature on the performance of Ni-MgO catalysts supported on Al2O3 in the partial oxidation of methane to syngas were investigated in a fixed-bed flow reactor. Three catalyst preparation methods (all slight variants of the precipitation method) produced comparable results in CH4 conversion, CO and H2 selectivities. Energy Dispersive X-Ray (EDX) analysis and the color of the catalysts after reaction showed that catalysts produced by simultaneous dissolution of the nickel and magnesium salts may have better carbon deposition resistance. NiO/MgO molar ratio significantly affected the performance of the catalyst. When the NiO/MgO ratio decreased, activity decreased. At a NiO/MgO molar ratio of 1/2 and a reduction temperature of 850°C, CH4 conversion and CO selectivity increased when reaction temperature increased while H2 selectivity remained almost the same. The catalyst gave excellent activity and remained stable after 5h time-on-stream.

Removal of sulfate from wet FGD wastewater by co-precipitation with calcium hydroxide and sodium aluminate

2018 ◽  
Vol 77 (5) ◽  
pp. 1336-1345 ◽  
Author(s):  
Jicheng Yu ◽  
Jia Lu ◽  
Yong Kang
Keyword(s):  
Ph Value ◽  
Sodium Aluminate ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Operation Condition ◽  
Sulfate Removal ◽  
Aluminum Hydroxides ◽  
Initial Ph ◽  
Co Precipitation

Abstract Chemical precipitation method was adopted to remove sulfate from wet flue gas desulfurization (FGD) wastewater and mixtures of Ca(OH)2 (CH) and NaAlO2 (SA) were used as precipitants. The mechanisms of sulfate removal were explored according to the experimental and simulated results. These showed that three kinds of precipitations, which were gypsum, ettringite and co-precipitation onto aluminum hydroxides, were formed when sulfate in water reacted with CH and SA. The optimum operation condition for removing sulfate was that the molar ratio of CH/SA was 2, the initial pH value 5, the precipitant dosage 15 g/L, the reaction time 20 min, and the reaction temperature 55 °C. The sulfate was reduced from 4,881 mg/L to 784 mg/L under the optimized condition. In addition, the heavy metals and fluoride were also mostly removed. The post treatments of the supernatant illustrated that removal of sulfate from wet FGD wastewater by co-precipitation with CH and SA was a better choice.

scholarly journals Methane steam reforming at low temperature over Ni-MgO-Al2O3 catalysts: activity and resistance to coking

2018 ◽  
Vol 72 (2) ◽  
pp. 1
Author(s):  
Monika Pańczyk ◽  
Andrzej Denis ◽  
Kazimierz Stołecki ◽  
Tadeusz Krzysztof Borowiecki
Keyword(s):  
Steam Reforming ◽  
Specific Activity ◽  
Catalyst Activity ◽  
Coke Formation ◽  
Nickel Catalysts ◽  
Precipitation Method ◽  
Methane Steam Reforming ◽  
Deep Minimum ◽  
Methane Steam ◽  
Co Precipitation

<p>The role of MgO as a factor improving the resistance to coking of the alumina supported nickel catalysts in the steam reforming of hydrocarbons is discussed.    A series of catalysts containing variable amounts of MgO, NiO and a constant amount of Al<sub>2</sub>O<sub>3</sub> was prepared by the co-precipitation method. It was found that the specific activity of the catalysts exhibits a broad but not deep minimum for the MgO contents from 8.5 to 27.3 wt.%. At the same time these catalysts reveal a high resistance to coking either in the reaction with methane or with <em>n</em>-butane. The most promising composition, in terms of the activity and simultaneous resistance to the coke formation, was found to be 27.3 wt.% of MgO and 39.0 wt.% of NiO. The analysis of various factors controlling the activity and resistance to coking leads to the conclusion that MgO reduces the catalysts acidity what, in consequence, reduces the rate of coke formation during the reforming reactions. Furthermore, The resistance to coking correlates well with the mean size of nickel crystallites, the same is observed for the specific catalyst activity.</p><p> </p>

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