Browsing by Author "Ayoub, Muhammad"

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Parametric study for N2O conversion and reduction using cobalt-oxide-based catalysts Lisandra
(John Wiley & Sons Inc., 2022-08-29) Rocha-Meneses, Lisandra; Inayat, Abrar; Ayoub, Muhammad; Ullah, Sami; Naqvi, Salman R; Farrukh, Sarah; Mustafa, Ahmad; Abdullah, Ahmad Z; Bhat, Aamir H
Nitrous oxide is a highly reactive gas with several well-known environmental impacts. Its presence in the atmosphere can decrease the stratospheric ozone levels, cause an increase in the greenhouse gas emissions, and contribute to acid-rain formation. Therefore, in this paper the potential and performance of different types of cobalt oxide (Co3O4) catalysts in N2O decomposition and conversion was studied. For this, the catalytic activity of these materials was tested in a differential fixed-bed reactor, operated under steady state conditions. The results obtained in this study show reduced CoO achieved 100% N2O conversion at 250°C; that CoO has a great performance (>95%) in the absence of oxygen and humidity, regardless of the W/F; even at low space velocities (0.1g-sec/mL) and in the absence of humidity the N2O conversion efficiency is still very high (100%); 10% La/CoO has a higher catalytic activity than 10% Ba/CoO, 10% Na/CoO, and 10% W/CoO. The highest catalytic activity (>90%) was reported in samples with 50%La/CoO, even in the presence of 5% H2O and 15% O2.
Thermal degradation characteristics, kinetic and thermodynamic analyses of date palm surface fibers at different heating rates
(Elsevier BV, 2022-12) Inayat, Abrar; Jamil, Farrukh; Ahmed, Shams Forruque; Ayoub, Muhammad; Abdul, Peer Mohamed; Aslam, Muhammad; Mofijur, M; Khan, Zakir; Mustafa, Ahmad
The potential of the least-exploited date pam waste was presented as feedstock for bio-oil production. The surface fibers of the date palm are widely available as waste material in the Gulf region, the Middle East, and Africa. Chemical composition analysis and physiochemical characterization showed that surface fibers are valuable feedstock for energy production. Surface fibers were analyzed thermogravimetrically at different heating rates (10, 20, and 30 ◦C /min) in an inert atmosphere. Decomposition was carried out in three stages: dehydration, devolatilization, and solid combustion. Kinetic analysis was performed on the devolatilization region using the Coats–Redfern model–fitting method using twenty–one reaction mechanisms from four different solid-state re- action mechanisms. Two diffusion models: one–way transport (g(x) = α2 ) and Valensi equation (g(x) = α+(1-α) × ln(1-α)) showed the highest regression coefficient (R2 ) with the experimental data. The activation energy (Ea) and the pre-exponential factor (A) was estimated to be 91.40 kJ/mol and 1.59 × 103 –29.39 × 103 min− 1 , respectively. The kinetic parameters were found to be dependent on the heating rate. The surface fibers’ ther- modynamic parameters ΔH, ΔG, and ΔS were 80–97, 151–164, and − 0.17- − 0.18 kJ/mol, respectively. This indicates that the pyrolysis of surface fibers is endothermal and not spontaneous. Since there is not much experimental work on the pyrolysis of surface fibers available in the literature, the reported results are crucial for designing the pyrolysis process.