Gholamreza Moradi; mahvash yari; Shima Bashiri; mahtab Abdolmaleki
Abstract
Biodiesel, as a renewable and environmentally friendly fuel, is a feasible alternative to fossil diesel, which has gained great popularity in recent years. However, due to some undesirable properties such as higher viscosity, biodiesel must be blended with diesel in order to be utilizable in a diesel ...
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Biodiesel, as a renewable and environmentally friendly fuel, is a feasible alternative to fossil diesel, which has gained great popularity in recent years. However, due to some undesirable properties such as higher viscosity, biodiesel must be blended with diesel in order to be utilizable in a diesel engine. Therefore, a reasonable approach is required for predicting the diesel-biodiesel blend properties. This study tries to estimate two substantial properties of blend, i.e. kinemattic viscosity (KV) and cetane number (CN), through neural network (NN) and empirical models which use pure properties of biodiesel (kinematic viscosity, boiling point, evaporation point, flash point, pour point, heat of combustion, cloud point, and specific gravity) as independent variables. In this regard, a three-layer feed-forward network with varying input parameters, training algorithms, transfer functions, and hidden neurons has been examined to predict the KV and CN of the diesel-biodiesel blend. Besides, the prediction capability of thirty empirical equations is investigated to determine the top equations describing blend properties. The result reveals that an ANN with three input parameters of biodiesel concentration (%), the CN of biodiesel, and biodiesel cloud point has the best prediction quality of CN with an R-value of 0.9961. Moreover, NN estimates the KV of blend with the highest correlation coefficient of 0.9985. The results corresponding to empirical equations also indicate that fractional-exponential equations are the best describer of the CN and KV of blend with R-values of 0.9947 and 0.9980, respectively.
Reaction Engineering, Kinetics and Catalysts,
Gholamreza Moradi; Hamed Hemmati; Sahar rostami
Abstract
In this work, the effect of the Si/Al ratio on the activity of zeolite supported bimetallic (Ni-Co) catalysts for Dry Reforming of Methane (DRM) has been studied. Samples are prepared with impregnation and sol-gel methods and then calcined at 550 °C for 2 h. The catalysts were characterized by XRD, ...
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In this work, the effect of the Si/Al ratio on the activity of zeolite supported bimetallic (Ni-Co) catalysts for Dry Reforming of Methane (DRM) has been studied. Samples are prepared with impregnation and sol-gel methods and then calcined at 550 °C for 2 h. The catalysts were characterized by XRD, XRF, FESEM, BET and TGA. All samples were tested in a micro reactor at three different temperatures (i.e. 700, 750, and 800 °C). Micro reactor test results showed that 800 °C was the proper temperature for DRM. The catalyst with 5 wt % of Ni and 2.5 wt % of Co supported on γ-Alumina have shown a higher H2/CO ratio than other samples. For the zeolite supported catalysts when Ni/Co=2/1, the surface area and pore volume decreased but the H2/CO ratio increased by increasing the Si/Al ratio. Reverse the Water Gas Shift (WGS) reaction was not very active when the catalyst and support showed a basic property. Also, the stability of the catalysts has been tested for 30h on stream.
Thermodynamics,
Gh. Moradi; H. Hemmati
Abstract
The Dry Reforming of Methane, which uses methane and carbon dioxide, the two greenhouse gasses, to produce synthesis gas, has received considerable attention recently. In this work, the equilibrium conversion that is the maximum possible conversion has been obtained experimentally and theoretically. ...
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The Dry Reforming of Methane, which uses methane and carbon dioxide, the two greenhouse gasses, to produce synthesis gas, has received considerable attention recently. In this work, the equilibrium conversion that is the maximum possible conversion has been obtained experimentally and theoretically. The equilibrium concentration for the Dry Reforming of Methane (DRM) has been calculated using Thermodynamic equilibrium and compared with the experimental equilibrium concentration. The reaction coordinate (ε), Gibbs free energy (G), reaction equilibrium constant (K), and reaction stoichiometric coefficients are used for the calculation of the reaction progress and the equilibrium composition in DRM at different temperatures. These parameters have been calculated by two primary methods, direct and Lagrange, and compared with an empirical equilibrium that has been revealed by the activity test on Ni/Al2O3 catalyst. The result shows that none of those can’t make an exact determination of empirical equilibrium compositions, but there was a relatively good agreement between the Lagrange method and the empirical equilibrium. No significant difference has been observed between these methods and empirical conditions at high temperature.