Showing 2 results for Eghbal Ahmadi
Volume 6, Issue 3 (Fall 2022)
Abstract
Subject
In this study, the steam reforming of the methanol process was analyzed based on three different inputs including temperature, pressure, and H2O/CH3OH ratio with the use of different Artificial Intelligence methods.
Methodology
In the first step, Cu-Zn/ZrO2 catalysts were synthesized via the co-precipitation method, and then experimental tests of steam reforming of methanol were performed at a temperature range of 180 –500 °C, the pressure of 1-11 bar, and the H2O/CH3OH ratio of 0.75-3.75 on the Cu-Zn/ZrO2 catalyst in a fixed bed reactor. Afterward, three different methods of Mamdani fuzzy type-1, Mamdani fuzzy type-2, and Sugeno fuzzy were applied in order to develop the models. Using these methods, the developed models only required the heuristics derived from the expert’s knowledge and some experimental data, without needing the calculation of complex kinetic as well as thermodynamic parameters related to the corresponding process. In addition, the structures of the developed fuzzy models were optimized to improve the model performance according to the analysis of the initial results. The model developments didn’t require a high number of experimental data, and this feature is especially interesting when dealing with the process conditions in which data gathering is expensive or the accuracy of data is low.
The main results
The overall accuracy as well as the properties of the developed models were compared. The type-2 Mamdani fuzzy model proved to be the best model, using which, the methanol conversion, H2 yield, and CO yield were predicted with accuracies of 67%, 91%, and 83%, respectively.
Volume 6, Issue 4 (Winter 2022)
Abstract
Subject
Petroleum coke calcination is a chemical process during which the petroleum coke loses moisture and volatile combustible materials due to the increase in temperature and ultimately improves the physical properties of the calcined coke. In this study, A 2-Dim model was developed for the petroleum coke calcination process via rotary kiln using the CFD approach. Understanding the temperature, concentration, and fluid movement behavior are the main goals for developing the simulation model, by using which the rotary kiln control and design can be performed.
Methodology
Comsol Multiphysics was applied to develop the simulation model. Petroleum coke rotary kiln calcination consists of two solid and gas phases, which cross each other counter-currently. All governing physics in the system, including chemical reactions, heat transfer via conduction, convection, and radiation, intra-phase and interphase mass transfer, evaporation or evolution of components from the solid phase into the gas phase, fluid turbulency and all complex relationships were considered. Using the finite element method, the governing equations of the model were solved, and consequently, the variation of temperature, components concentration, and fluid velocity was calculated.
The main results
It is concluded that tertiary air injection significantly affects the temperature profile and combustion reactions in the bed (About 100 degrees increase in temperature). In addition, the maximum temperature of 1910 °C has been achieved in the kiln. Concentration changes of components in the gas phase were also seen mainly in the bed entrance and in the areas near the tertiary air injection. Comparing the results with similar works showed the high accuracy of the developed model
