scholarly journals Ni-γ-AL2O3 catalysts for obtaining nanocarbon by decomposition of natural gas

Author(s):  
Hikmet Ibrahimov ◽  
Sara Malikli ◽  
Zenfira Ibrahimova ◽  
Rahim Babali ◽  
Sevinc Aleskerova

Abstractγ-Al2O3 was synthesized by the Sol–gel method, Ni (NO3)2 was placed in the pores by the impregnation method, and Ni-γ-Al2O3 was obtained by pyrolysis in a hydrogen stream in a CVD device. By the method of chemical vapors phase deposition (CVD) on Ni-Al2O3 catalytic converter with decomposition of methane in the natural gas produced carbon nanotubes (CNT) (Chunduri et al. in Mater Express 4(3):235–241, 2014; Zhou et al. in Appl Catal B 208:44–59, 2017). The catalytic activity of the catalysts in methane decomposition was examined from 650 °C to 900 °C by the method of chemical vapors phase deposition (CVD), the yield of CNTs tends to increase with the growth at the ratio of natural gas supply to hydrogen. The specific surface increases with an increase of nickel content and can reach 265.5 m2/g for a sample of 2% Ni-A12O3 at 850 °C. Growth at the temperature of methane decomposition leads to reduction in its specific surface. It has been established that the use of the Ni-Cu/γ-Al2O3 catalytic system, in which copper acts as a stabilizing additive, makes it possible to double the maximum yield of the carbon product during the decomposition of natural gas.

2013 ◽  
Vol 634-638 ◽  
pp. 620-623 ◽  
Author(s):  
Jittima Junsawat ◽  
Nichakan Phumthiean ◽  
Payoon Senthongkaew ◽  
Supakit Achiwawanich

A preparation of novel cobalt-based catalyst on three-dimensionally ordered macroporous (3DOM) silica supporter using poly (methyl methacrylate) monolith as a template has been studied. Monodispersed PMMA colloids were synthesized via an emulsion polymerization, resulting in PMMA spheres with the diameter of 390-400 nm. Two processes were employed for the 3DOM Co/SiO2catalyst fabrications, a single-stage sol-gel synthesis (SG) and incipient wetness impregnation method (IM) on synthesized 3DOM SiO2. Both catalysts were characterized using X-ray Diffraction (XRD), X-ray Absorption Spectroscopy (XAS), Scanning Electron Microscope (SEM) and specific surface area analysis. The XRD and XAS results showed that the doped Co in the 3DOM Co/SiO2(SG) were the mix phase of Co(NO3)2and Co3O4, while, only Co3O4was found in the 3DOM Co/SiO2(IM). The SEM micrographs revealed that both catalysts feature periodic macroporous structure with mean pore diameter of 300-350 nm. Specific surface area of the 3DOM Co/SiO2(IM) and the 3DOM Co/SiO2(SG) catalysts are 195 m2/g and 286 m2/g, respectively.


2019 ◽  
Vol 6 (2) ◽  
pp. 56-63
Author(s):  
L. D. Pylypiv ◽  
І. І. Maslanych

There are investigated the influence of operating pressures in the gas supply system on the level of such energy indicators as efficiency, gas flow and gas overrun by gas equipment in residential buildings. There is established a relationship between the values of operating pressures in the gas supply system and the gas consumption level of household appliances. The causes of insufficient pressure in the gas networks of settlements are analyzed in the article. There is also developed an algorithm for calculating the change in the efficiency of gas appliances depending on the operational parameters of the gas network. It has been found that the most efficient operation of gas appliances is observed at an overpressure at the inlet of gas appliances of about 1200 Pa.To ensure the required quality of natural gas combustion among consumers and minimize gas consumption there are justified the following measures in the article: coordinating a domestic regulatory framework for assessing the quality of natural gas with international norms and standards; improving the preparation of gas coming from local wells before supplying it to gas distribution networks; auditing low pressure gas pipelines and reconstructing areas affected by corrosion; ensuring standard gas pressure in the network for the normal operation of domestic gas appliances; stating quality indicators of natural gas combustion by gas sales organizations.


2019 ◽  
pp. 64-72
Author(s):  
G.G. Arunyants

The results of analysis of problems of regulation of gas supply complex of Kaliningrad region and main ways to increase its efficiency, as well as basic solutions for creation of a software complex Т-GAZ-2 automated calculation of natural gas tariffs for ACS of gas supply system subjects, geographically distributed and information connected to the regional automated information and control system (RAIS).


2010 ◽  
Vol 3 (4) ◽  
pp. 31-64 ◽  
Author(s):  
Marte Fodstad ◽  
Kristin Tolstad Uggen ◽  
Frode Rømo ◽  
Arnt-Gunnar Lium ◽  
Geert Stremersch

Author(s):  
Radwa A. El-Salamony ◽  
Sara A. El-Sharaky ◽  
Seham A. Al-Temtamy ◽  
Ahmed M. Al-Sabagh ◽  
Hamada M. Killa

Abstract Recently, because of the increasing demand for natural gas and the reduction of greenhouse gases, interests have focused on producing synthetic natural gas (SNG), which is suggested as an important future energy carrier. Hydrogenation of CO2, the so-called methanation reaction, is a suitable technique for the fixation of CO2. Nickel supported on yttrium oxide and promoted with cobalt were prepared by the wet-impregnation method respectively and characterized using SBET, XRD, FTIR, XPS, TPR, and HRTEM/EDX. CO2 hydrogenation over the Ni/Y2O3 catalyst was examined and compared with Co–Ni/Y2O3 catalysts, Co% = 10 and 15 wt/wt. The catalytic test was conducted with the use of a fixed-bed reactor under atmospheric pressure. The catalytic performance temperature was 350 °C with a supply of H2:CO2 molar ratio of 4 and a total flow rate of 200 mL/min. The CH4 yield was reached 67%, and CO2 conversion extended 48.5% with CO traces over 10Co–Ni/Y2O3 catalyst. This encourages the direct methanation reaction mechanism. However, the reaction mechanism over Ni/Y2O3 catalyst shows different behaviors rather than that over bi-metal catalysts, whereas the steam reforming of methane reaction was arisen associated with methane consumption besides increase in H2 and CO formation; at the same temperature reaction.


Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 697
Author(s):  
Tae-Young Kim ◽  
Seongbin Jo ◽  
Yeji Lee ◽  
Suk-Hwan Kang ◽  
Joon-Woo Kim ◽  
...  

Fe-Ni and Co-Fe-Ni catalysts were prepared by the wet impregnation method for the production of high-calorific synthetic natural gas. The influence of Ni addition to Fe and Co-Fe catalyst structure and catalytic performance was investigated. The results show that the increasing of Ni amount in Fe-Ni and Co-Fe-Ni catalysts increased the formation of Ni-Fe alloy. In addition, the addition of nickel to the Fe and Co-Fe catalysts could promote the dispersion of metal and decrease the reduction temperature. Consequently, the Fe-Ni and Co-Fe-Ni catalysts exhibited higher CO conversion compared to Fe and Co-Fe catalysts. A higher Ni amount in the catalysts could increase C1–C4 hydrocarbon production and reduce the byproducts (C5+ and CO2). Among the catalysts, the 5Co-15Fe-5Ni/γ-Al2O3 catalyst affords a high light hydrocarbon yield (51.7% CH4 and 21.8% C2–C4) with a low byproduct yield (14.1% C5+ and 12.1% CO2).


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