ORCID Profile
0000-0002-0074-3555
Current Organisations
University of Sydney
,
KACST
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Publisher: MDPI AG
Date: 21-10-2021
DOI: 10.3390/APP11219842
Abstract: In this study, a two-dimensional numerical model was developed to simulate operation conditions in the non-transferred plasma torch, used to synthesis nanosilica powder. The turbulent magnetohydrodynamic model was presented to predict the nitrogen plasma flow and heat transfer characteristics inside and outside the plasma torch. The continuity, momentum, energy, current continuity equations, and the turbulence model were expressed in cylindrical coordinates and numerically solved by COMSOL Multiphysics software with a finite element method. The operation conditions of the mass flow rate of ionized gas ranging from 78 sccm to 240 sccm and the current varying between 50 A to 200 A were systematically analyzed. The variation in the electrothermal efficiency with the gas flow rate, the plasma current, and the enthalpy was also reported. The results revealed that the increase in working current lead to a raise in the effective electric power and then an increase in the distribution of plasma velocity and temperature. The efficiency of the torch was found to be between 36% and 75%. The plasma jet exited the nozzle torch with a larger fast and hot core diameter with increasing current. The numerical results showed good correlation and good trends with the experimental measurement. This study allowed us to obtain more efficient control of the process conditions and a better optimization of this process in terms of the production rate and primary particle size. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize the primary nanosilica powder that was experimentally collected. The arc plasma method enabled us to produce a spherical silicon ultra-fine powder of about 20 nm in diameter.
Publisher: Elsevier BV
Date: 2022
Publisher: MDPI AG
Date: 31-01-2022
DOI: 10.3390/EN15031071
Abstract: Feeding IC engines with hydrogen-rich syngas as an admixture to hydrocarbon fuels can decrease pollutant emissions, particularly NOx. It offers a potential technique for low-environmental impact hydrocarbon fuel use in automotive applications. However, hydrogen-rich reformate gas (syngas) production via fuel reforming still needs more research and optimization. In this paper, we describe the effect of a plasma torch assembly design on syngas yield and composition during plasma-assisted reforming of gasoline. Additionally, erosion resistance of the cathode-emitting material under the conditions of gasoline reforming was studied, using hafnium metal and lanthanated tungsten alloy. The gasoline reforming was performed with a noncatalytic, nonthermal, low-current plasma system in the conditions of partial oxidation in an air and steam mixture. To find the most efficient plasma torch assembly configuration in terms of hydrogen production yield, four types of anode design were tested, i.e., two types of the swirl ring, and two cathode materials while varying the inlet air and fuel flow rates. The experimental results showed that hydrogen was the highest proportion of the produced syngas. The smooth funnel shape anode design in Ring 1 at air/fuel flow rates of 24/4, 27/4.5, and 30/5 g/min, respectively, was more effective than the edged funnel shape. Lanthanated tungsten alloy displayed higher erosion resistance than hafnium metal.
Publisher: Hindawi Limited
Date: 02-05-2022
DOI: 10.1155/2022/6977930
Abstract: The equivalence ratio ranges were found between 22.77 and 42.93 for the Saudi LPG/air mixture using a traditional Bunsen burner. An operation problem was found with a traditional Bunsen burner for the Saudi LPG/air mixture, especially in a lean mixture. Therefore, a Bunsen burner was successfully modified to overcome the limits of operation with different mixtures of Saudi LPG/air and a stable flame was obtained. The equivalence ratio ranges were found between 0.68 and 1.30 using the modified Bunsen burner. A premixed flame was used for the modified Bunsen burner. A MATLAB algorithm was successfully applied to flame image processing and measurement of laminar burning velocity. The laminar burning velocity was determined to be approximately 35 ± 0.91 cm/s under stoichiometric conditions using the modified Bunsen burner for the Saudi LPG/air mixture. The half-cone angle of the flame was found to be 16.20 ± 0.76°. The minimum flame height was observed to be 21.50 ± 0.22 mm above the Bunsen burner exit.
No related grants have been discovered for Dr. Ahmed Al-Harbi.