Verified email at mecheng.iust.ac.ir
School of Mechanical Engineering
Iran University of Science and Technology
PhD, Mechanical Engineering (2017), Iran University of Science and Technology, Tehran, Iran.
MSc, Mechanical Engineering (2012), Iran University of Science and Technology, Tehran, Iran.
BSc, Mechanical Engineering (2009), Shahrekord University, Shahrekord, Iran.
Gasification- Combustion- Droplet and Spray- Renewable Energy- Computational Fluid Dynamic
Rasoul Shahsavan Markadeh, Arash Arabkhalaj, Hojat Ghassemi, and Pouria Ahmadi
Energy Sources, Part A: Recovery, Utilization and Environmental Effects, ISSN: 15567036, eISSN: 15567230, Pages: 849-863, Published: 2 April 2020 Informa UK Limited
Rasoul Shahsavan Markadeh, Arash Arabkhalaj, Hojat Ghassemi, and Asghar Azimi
International Journal of Heat and Mass Transfer, ISSN: 00179310, Volume: 148, Published: February 2020 Elsevier BV
Asghar Azimi, Arash Arabkhalaj, Rasoul Shahsavan Markadeh, and Hojat Ghassemi ISSN: 00162361, Volume: 230, Pages: 52-63, Published: 15 October 2018 Elsevier BV
Abstract In this paper, evaporation of heavy fuel oil (HFO) droplet under atmospheric pressure is studied through a fully transient approach. The HFO is considered as a multi-component liquid with temperature-dependent properties. The performance of this fully transient approach is evaluated for different fuels and results are compared with available experimental data for gasoline and diesel fuel. The comparison shows excellent agreements, and also reveals the flexibility of this approach for interpretation and justification of the evaporation process details by using of internal distribution of temperature and composition. Based on distillation curve, several multi-component compositions are presented for the HFO. The composition is broken down into several pseudo-components and the effects of number of components and their method of selecting are studied comparatively. It shows that despite the wide range of compositions of heavy fuels, a compound consists of a few numbers of pseudo-components can be a suitable representative for them. Also pseudo-components should be chosen with equal interval temperature and narrow boiling temperature range. The effects of environment temperature on the evaporation of droplets are investigated in a parametric study. The results show that internal temperature distribution is not very sensitive to the ambient temperature due to the high boiling temperature of heavy components of the fuel. Also wide span of temperature in the heavy fuel droplet makes it possible to predict the initial condition of pyrolysis and thermal cracking of heavier components.
Rasoul Shahsavan Markadeh and Hojat Ghassemi
Numerical Heat Transfer; Part A: Applications, ISSN: 10407782, eISSN: 15210634, Pages: 721-742, Published: 19 May 2018 Informa UK Limited
AbstractA discrete multicomponent (DMC) model for droplet evaporation in convective ambient is developed. Three different sets of correlations for Nusselt and Sherwood number are examined. The model is compared with experimental data for single and multicomponent droplet evaporation at different conditions and the most suitable set of correlations is selected. Having validated model, the diesel droplet evaporation under different ambient conditions and compositions is investigated. Increasing of oxygen mass fraction in N2–O2 mixture ambient from 0 to 1 first decreases and then increases the lifetime. Steam addition enhances the evaporation rate and it affects evaporation more significantly at higher temperatures. Exhaust gas recirculation (EGR) results in slight variations in droplet lifetime and its heating period.
Asghar Azimi, Arash Arabkhalaj, Hojat Ghassemi, and Rasoul Shahsavan Markadeh
International Journal of Thermal Sciences, ISSN: 12900729, Volume: 120, Pages: 354-365, Published: October 2017 Elsevier BV
Abstract The aim of the present study is an investigation of the impact of gas phase unsteadiness in the evaporation of single component fuel droplets. For this purpose, the results of quasi-steady (QS) approach and Abramzon-Sirignano model (AS) are compared with the fully transient (FT) approach. In the FT and QS approaches, species, momentum and energy conservation equations in gas phase and energy equation in liquid phase have been solved in consideration of totally variable properties. The results of the FT approach at atmospheric pressure for fuels with different volatilities, show a very good agreement with experimental data which are available in the literature. The results of different approaches are obtained for three different fuels, heptane, decane, and hexadecane at temperatures of 500 K and 800 K. By using two measures of unsteadiness related to the mass fraction of fuel vapor and surface temperature, the amount of the steadiness of processes in the gas phase has been checked and deviation of the QS approach and AS model from FT approach has been justified. The results indicate that the temperature and type of fuel have significant effects on unsteadiness. Increasing temperature and decreasing the fuel volatility, increase the deviation of the two approaches from FT approach. Also it is found that the QS approach gives better results for small diameters while the AS model shows better lifetime estimation for large diameters.
Arash Arabkhalaj, Asghar Azimi, Hojat Ghassemi, and Rasoul Shahsavan Markadeh
Applied Thermal Engineering, ISSN: 13594311, Volume: 125, Pages: 584-595, Published: 2017 Elsevier BV
Abstract This paper deals with multi-component droplet evaporation. For this purpose, species, momentum, and energy equations for the gas phase are solved numerically together with species and energy equations of the liquid phase. A fully transient (FT) approach with variable properties in terms of time and space is employed. The results are compared with available experimental data in the literature for binary- and multi-component droplets at various temperatures and satisfactory agreements are seen. In order to study the effect of volatility on the droplet evaporation, heptane, decane, and hexadecane are examined and multi-staged feature of evaporation is captured. Also, the range of droplet internal bubbling is estimated by investigating internal temperature and mass fraction variations. The results indicate that diffusion enthalpy term in the liquid phase plays a significant role in the deviation of multi-component droplet evaporation trend from the single component. Furthermore, the quasi-steady (QS) assumption in the gas phase of droplet evaporation is evaluated. The comparison between FT and QS approaches shows that the amount of heavier component in the droplet composition and increasing volatility difference of components increase the deviation of two approaches.
Hojat Ghassemi, Seyed Milad Mostafavi, and Rasoul Shahsavan-Markadeh
Journal of Energy Engineering, ISSN: 07339402, Volume: 142, Published: 1 December 2016 American Society of Civil Engineers (ASCE)
AbstractGasification of high-ash coal in dry and slurry entrained flow gasifiers is investigated through equilibrium modeling. Effects of oxygen- and steam-to-coal mass flow rate ratios in a dry-fed gasifier and also the effect of water concentration in slurry on composition, temperature, heating value, and cold gas efficiency are studied. It is observed that adding steam to the gasifier reduces oxygen consumption, and the optimum ratio of oxygen-to-coal mass flow (O/F) decreases. At high enough O/F ratios, the steam-to-coal mass flow (S/F) and water-to-coal mass flow (W/F) ratios have no significant influences on gasifier efficiency. It is also observed that for coal, which has a high ash content, dry-fed gasification is preferable. In this type of gasifier, optimum O/F and S/F ratios with respect to cold gas efficiency are determined to be 0.5 and 0.8, respectively. Simulation of the integrated gasification combined cycle (IGCC) in Thermoflow indicates that, for a typical 450-MW combined cycle, 56.6 kg...
Arash Arabkhalaj, Hojat Ghassemi, and Rasoul Shahsavan Markadeh
International Journal of Energy Research, ISSN: 0363907X, eISSN: 1099114X, Pages: 1638-1651, Published: 10 October 2016 Wiley
Summary In the present study, a coal-integrated gasification combined cycle power plant is simulated. A high-ash coal and low-ash coal are considered to compare the performance of the plant. The combined cycle is in typical commercial size with 450 MW capacity. The feeds are Tabas and Illinois #6 coals which approximately contain more than 30% and 10% ash and have higher heating values of 22.7 MJ/kg and 26.8 MJ/kg, respectively. Energy and exergy analyses are done by aspen plus® and ees, respectively. Energy analysis shows that the overall efficiencies of power plants using high-ash and low-ash coals are 33% and 28%, respectively. The result shows that in high-ash case, 52 kg/s coal, 10 kg/s water, and 1050 kg/s air and in low-ash case, 48 kg/s coal and 820 kg/s air are required for providing mentioned power, approximately. Exergy analysis shows that maximum exergy destruction is in heat recovery steam generator unit. Investigating the emissions shows that high percent of ash in the coal composition has slight effects on the IGCC pollution. Finally, from thermodynamic viewpoint, it is concluded that the high-ash coal, like the conventional one, can be used as thermally efficient and environmentally compatible feed of IGCCs. Copyright © 2016 John Wiley & Sons, Ltd.
M.Motahari Nezhad, M. Beheshti, S. Shahraki, H. Ghassemi, and R. Shahsavan-Markadeh
Thermochimica Acta, ISSN: 00406031, Volume: 632, Pages: 86-90, Published: 20 May 2016 Elsevier BV
Abstract We have provided a detailed numerical model for simulating flame propagation in a premixed counterflow configuration. It is an unsteady state, one-dimensional model based on the heat and mass balance equations. Attention is focused on the impact of the non-dimensional numbers namely Lewis number, Damkohler number, and Zeldovich number on the flame temperature profile. Also, we have explored what happens when we continue the solutions for higher heat losses. It was found that with increasing the Lewis number the flame temperature decreases, while a further increase in Lewis number results in constant value of the flame temperature. Model predictions have been compared with available data from the literature, which have showed fully good agreement.
Mohammad Sajjad Barzegar Khaleghi, Rasoul Shahsavan Markadeh, and Hojat Ghassemi
Petroleum Science and Technology, ISSN: 10916466, eISSN: 15322459, Pages: 531-538, Published: 18 March 2016 Informa UK Limited
ABSTRACTIn this study, gasification of mazut, as a heavy fuel oil with high sulfur content, is studied by an equilibrium model. Effects of equivalence ratio and adding steam as a gasifying agent on gasifier performance are studied. It was found that for highest cold gas efficiency, equivalence ratio and H2O/fuel ratio are 0.3 and 0.2, respectively. Based on these findings, it was estimated that using 31 kg/sec mazut, 445 MW electricity can be produced in an integrated gasification combined cycle. It also conclude that all produced mazut in Iran's refineries has the potential of 11000 MW power generation.
S.M. Beheshti, H. Ghassemi, and R. Shahsavan-Markadeh
Journal of Cleaner Production, ISSN: 09596526, Volume: 112, Pages: 995-1000, Published: 20 January 2016 Elsevier BV
Abstract Biomass gasification–proton exchange membrane fuel cell (BG–PEMFC) system is of major interest in the context of clean power generation and improving energy efficiency. Based on the previous work [Beheshti SM, Ghassemi H, Shahsavan-Markadeh R. Process simulation of biomass gasification in a bubbling fluidized bed reactor. Energy Conversion and Management 2015; 94: 345–352], we developed an Aspen Plus model to simulate the steady-state behavior of an integrated gasification system and a PEMFC stack by coupling Aspen Plus simulator and dedicated FORTRAN subroutines. Effects of critical parameters, including current density, feed gas humidity, equivalence ratio, steam/biomass ratio, and biomass moisture content on the cell potential and gasification efficiency were discussed. The results indicate that the higher feed humidity (cathode humidity) is more favorable for the improvement of voltage output. It is also found that the biomass moisture content has a negative impact on the potential of cell, although it is negligible. Model predictions were compared with experimental data from the literature, which showed fully good agreement.
H. Ghassemi, S.M. Beheshti, and R. Shahsavan-Markadeh ISSN: 00162361, Volume: 162, Pages: 258-263, Published: 15 December 2015 Elsevier BV
In this study, a kinetic model for extra-heavy oil gasification has been developed. It is a zero dimensional, steady state model based on global reaction kinetics and is capable of predicting performance parameters of the process. Effects of parameters, including fuel water content and equivalence ratio on tar yield, gasification temperature and performance parameters such as syngas higher heating value (HHV), carbon conversion efficiency (CCE), cold gas efficiency (CGE) have been discussed. The results indicate that the higher equivalence ratio is more favorable for carbon conversion and tar cracking; however, it lowered gas caloric value and cold gas efficiency. It is also found that the higher carbon conversion and lower tar yield are possible at higher fuel water content. The model is validated by experimental and thermodynamic data and found relatively to be in good agreement.
Sayyed Mohsen Beheshti, Hojat Ghassemi, Rasoul Shahsavan-Markadeh, and Sylvain Fremaux
Environmental Technology (United Kingdom), ISSN: 09593330, eISSN: 1479487X, Pages: 1327-1333, Published: 19 May 2015 Informa UK Limited
Gasification is a thermochemical process in which solid or liquid fuels are transformed into synthesis gas through partial oxidation. In this paper, a kinetic model of rice husk gasification has been developed, which is interesting for the applications of the syngas produced. It is a zero-dimensional, steady-state model based on global reaction kinetic, empirical correlation of pyrolysis and is capable of predicting hydrogen yield in the presence of sorbent CaO. The model can also be used as a useful tool to investigate the influence of process parameters including steam/biomass ratio, CaO/fuel ratio (CaO/Fuel), and gasification temperature on hydrogen efficiency, CO2 capture ratio (CCR), and average carbonation conversion (Save). Similar to hydrogen formation, CCR also increases with increasing CaO/Fuel, but an opposite trend is exhibited in Save. Model predictions were compared with available data from the literature, which showed fairly good agreement.
S.-M. Beheshti, H. Ghassemi, and R. Shahsavan-Markadeh
Petroleum Science and Technology, ISSN: 10916466, eISSN: 15322459, Pages: 218-225, Published: 17 January 2015 Informa UK Limited
Production of hydrogen rich gases from heavy oils via potassium-catalyzed steam gasification is a promising approach toward cleaner fuel production, suitable for fuel cell applications. The authors developed a zero-dimensional mathematical model to simulate the steam gasification of Orimulsion with KOH as a catalyst, based on an equilibrium model. The model is compared with the numerical results and data from an experimental study, showing a good agreement with it. This research activity presents a large number of predicted data of catalytic gasification, aiming to survey the effects of reaction temperature, gasification pressure, steam/fuel ratio, and KOH/fuel ratio on gas product compositions. It also provides useful indications for its optimal choice. Results illustrate that the pressurized operation slightly increases methane concentration as well as the production of higher heating value gas, while decreasing the hydrogen concentration.
S.M. Beheshti, H. Ghassemi, and R. Shahsavan-Markadeh
Energy Conversion and Management, ISSN: 01968904, Pages: 345-352, Published: April 2015 Elsevier BV
Abstract A detailed process model was developed to simulate the air–steam gasification of biomass in a bubbling fluidized bed for hydrogen and syngas production by coupling Aspen Plus simulator and dedicated FORTRAN subroutines. Effects of critical parameters, including gasification temperature, steam/biomass ratio (SBR), equivalence ratio (ER), and biomass particle size (BPS) on the composition of fuel gas were discussed. The results indicate that the high temperature is more favorable for production of useful syngas (H 2 and CO) and hydrogen yield (HY). The simulation results also demonstrate that ER is the most important factor in the process; higher ER contributed to higher carbon conversion, tar reforming, and gas yield, however, it lowered gas caloric value and cold gas efficiency. However, steam injection recognized as a key factor to produce more hydrogen rich gas in the SBR range studied, but had a major effect on CO 2 formation. The model is validated by experimental data and found relatively to be in good agreement.
Sylvain Fremaux, Sayyed-Mohsen Beheshti, Hojat Ghassemi, and Rasoul Shahsavan-Markadeh
Energy Conversion and Management, ISSN: 01968904, Pages: 427-432, Published: February 2015 Elsevier BV
Abstract A research scale fluidized-bed reactor has been built and used to study the effect of steam/biomass ratio, time duration of experiments, reactor temperature, and biomass particle size on hydrogen yield and tar content in produced syngas during steam gasification of biomass. Batch experiments were performed with wood residue crushed into three different sizes of 0.5–1 mm (small), 1–2.5 mm (medium), and 2.5–5 mm (large), at reactor temperatures of 700, 800, and 900 °C. As the steam/biomass ratio increases, a decrease in formation of CO, accompanied by an increase in the hydrogen concentration, is observed. As expected, an increase in reactor temperature leads to a significant increase of H 2 output and tar reforming. The obtained results show that hydrogen yield increases as time duration of the experiment is increased. It is also found that a reduction in particle diameter leads to a significant improvement in hydrogen yield.
H. Ghassemi, S.-M. Beheshti, and R. Shahsavan-Markadeh
Petroleum Science and Technology, ISSN: 10916466, eISSN: 15322459, Pages: 2666-2673, Published: 13 November 2014 Informa UK Limited
The purpose of this study was to investigate the influence of water content on the concentration of Orimulsion pyrolysis products, calorific value of product gas, cold gas efficiency, and coke formation coefficient. To achieve this objective, a numerical algorithm, based on thermochemical equilibrium, was developed to simulate the pyrolysis process. To improve the model accuracy, the model was first modified by a common method available in the literature. The modified model in the term of products yield was compared with the experiments literature and observed a reasonable agreement between the numerical results and experimental data. The produced gas HHV in pyrolysis process was found to be sensitive to water content, while cold gas efficiency and the coke formation coefficient were less sensitive. Finally, based on the simulated results, an optimal condition is suggested to improve produced gas HHV in Orimulsion pyrolysis process.
S.-M. Beheshti, H. Ghassemi, and R. Shahsavan-Markadeh
Petroleum Science and Technology, ISSN: 10916466, eISSN: 15322459, Pages: 2674-2681, Published: 13 November 2014 Informa UK Limited
Gasification is a thermochemical process that produces useful and environmentally friendly by-products. Here the effects of various parameters such as equivalence ratio, pressure, and steam gasifying on the gasification process of waste lubricant oil are investigated based on Gibbs free energy minimization approach. The model is validated by reported data and found to be in good agreement. Various gasification performance parameters such as cold gas efficiency, carbon conversion efficiency, gasification temperature, pressure, and heating value of produced gas were determined based on a parametric study. The use of CaO catalyst has also been investigated for the production of hydrogen-rich gas with in situ CO2 capture in steam gasification of waste oil. The results indicate that an appropriate steam/fuel ratio and more catalyst are favorable for getting a higher H2 ratio and a lower CO2 output.
Hojat Ghassemi and Rasoul Shahsavan-Markadeh
Energy Conversion and Management, ISSN: 01968904, Pages: 18-24, Published: March 2014 Elsevier BV
Abstract In this paper by means of a modified equilibrium model based on Gibbs free energy minimization, performance of biomass gasification process is studied. Effects of parameters such as equivalence ratio, gasification temperature, fuel type and its moisture content, and gasifying agent, are investigated. Model results show that temperature has significant influence on cold gas efficiency more remarkably at lower temperature and has negligible effect on syngas heating value. Enriching the air with O 2 increases gas higher heating value (HHV) and for larger amount of oxygen it shows a maximum as equivalence ratio increases. Cold gas efficiency for higher oxygen amount is larger and its maximum obtained at lower equivalence ratio. By increasing the H/C molar ratio of biomass, cold gas efficiency increases but biomass O/C ratio shows adverse effect. Moisture content of biomass has negative effects on cold gas efficiency and HHV. For higher equivalence ratio this negative effect decreases.
• Shahsavan Markadeh R., Arabkhalaj A., Ghassemi H., Ahmadi P., "4-E Analysis of Heavy Oil Based IGCC", Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, Accepted.
• Shahsavan Markadeh R., Ghassemi H., "A discrete multicomonent droplet evaporation model; effects of O2-enrichment, steam injection and EGR on evaporation of diesel droplet", Numerical Heat Transfer, Part A: Applications, (2018), 73, 721-742.
• Azimi A, Arabkhalaj A., Shahsavan Markadeh R., Ghassemi H.,"Fully transient modeling of the heavy fuel oil droplets evaporation", Fuel, (2018), 230, 52-63.
• Arabkhalaj A., Azimi A., Ghassemi H., Shahsavan Markadeh R., "A fully transient approach on evaporation of multi-component droplets", Applied Thermal Engineering, (2017), 125, 584–595
• Azimi A., Arabkhalaj A., Ghassemi H., Shahsavan Markadeh R., "Effect of unsteadiness on droplet evaporation", International Journal of Thermal Sciences, (2017), 120, 354-365.
• Shahsavan Markadeh R., Ghassemi H., "Modeling of biodiesel droplet evaporation: effects of operating conditions and fuel composition", Modares Mechanical Engineering, (2016) 16, 342-352, (in Persian).
• Arabkhalaj A., Ghassemi H., Shahsavan Markadeh R., "Thermodynamic evaluation of Integrated Gasification Combined Cycle; Comparison between high-ash and low-ash coals", International Journal of Energy Research, (2016) 40, 1638-1651.
• Ghassemi H., Mostafavi S.M., Shahsavan-Markadeh R., "Modeling of high ash coal gasification in an entrained flow gasifier and an IGCC plant", Journal of Energy Engineering-ASCE, (2016) 142, 04015052.
• Barzegar Khaleghi M.S., Shahsavan Markadeh R., Ghassemi H., "Thermodynamic evaluation of mazut gasification for using in power generation", Petroleum Science and Technology, (2016) 34, 531-538.
• Beheshti S.M., Ghassemi H., Shahsavan-Markadeh R., "An advanced biomass gasification-proton exchange membrane fuel cell (BG-PSMFC) system for power generation", Journal of Cleaner Production, (2016) 112, 995-1000.
• Ghassemi H., Beheshti S.M., Shahsavan-Markadeh R., "Mathematical modeling of extra-heavy oil gasification at different fuel water contents", Fuel, (2015) 162, 258-263.
• Beheshti S.M., Ghassemi H., Shahsavan-Markadeh R., "Process simulation of biomass gasification in a bubbling fluidized bed reactor", Energy Conversion and Management, (2015) 94, 345-352.
• Beheshti S.M., Ghassemi H., Shahsavan-Markadeh R., Fremaux S.,"Hydrogen-rich gas production via CaO sorption-enhanced steam gasification of rice husk: A modeling study", Environmental Technology, (2015) 36, 1327-1333.
• Fremaux S., Beheshti S.M., Ghassemi H., Shahsavan-Markadeh R., "An experimental study on hydrogen-rich gas production via steam gasification of biomass in a research-scale fluidized bed", Energy Conversion and Management, (2015) 91, 427-432.
• Beheshti S.M., Ghassemi H., Shahsavan-Markadeh R., "Modeling steam gasification of Orimulsion in presence of KOH: A strategy for high-yield hydrogen production", Petroleum Science and Technology, (2015), 33, 218-225.
• Beheshti S.M., Ghassemi H., Shahsavan-Markadeh R., "A Comprehensive Study on gasification of petroleum wastes based on a mathematical model", Petroleum Science and Technology, (2014), 32, 2674-2681.
• Ghassemi H., Beheshti S.M., Shahsavan-Markadeh R., "Pyrolysis of Orimulsion: A comprehensive model based on chemical equilibrium", Petroleum Science and Technology, (2014), 32, 2666-2673.
• Ghassemi H., Shahsavan-Markadeh R., "Effects of various operational parameters on biomass gasification process; a modified equilibrium model", Energy Conversion and Management, (2014), 79, 18-24.