Srinivas Seethamraju | IIT Bombay (original) (raw)
Papers by Srinivas Seethamraju
Volume 2: Economic, Environmental, and Policy Aspects of Alternate Energy; Fuels and Infrastructure, Biofuels and Energy Storage; High Performance Buildings; Solar Buildings, Including Solar Climate Control/Heating/Cooling; Sustainable Cities and Communities, Including Transportation; Thermofluid..., 2014
New energy plants coming online must be both economical and efficiently balanced to satisfy deman... more New energy plants coming online must be both economical and efficiently balanced to satisfy demanding requirements in the future. A balance of plant analysis was performed to determine the techno-economic feasibility of a 100 barrel oil equivalent (boe) per day, compact Gas to Liquid (GTL) methanol plant. Methanol itself is emerging as a possible alternative to gasoline; but it is also the precursor to dimethyl ether (DME), which has recently received a lot of attention as a low emitter of particulate matter and nitrous oxides, which can replace diesel in trucking applications and liquefied petroleum gas (LPG) in domestic applications. Production of synthesis gas (syngas) from methane gas was modeled via partial oxidation of fuel-rich mixtures in engine cylinders using GT-ISE. Two ignition modes were studied: spark ignition (SI) and homogeneous charge compression ignition (HCCI). The use of the engine as a compressor was also studied in order to reduce net compression requirements a...
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Clean Technologies and Environmental Policy
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Process Integration and Optimization for Sustainability, 2021
The effects of various operating and design parameters in reactive distillation for methanol synt... more The effects of various operating and design parameters in reactive distillation for methanol synthesis using a polar solvent (tetraglyme) and Cu–Zn-Al2O3 catalyst on the process performance are investigated in this simulation work. It is observed that trade-offs exist between the reaction (reactant conversion) and separation (methanol purity) as these parameters are varied. The most sensitive parameters are the solvent flow rate, temperature of feed streams, reflux ratio, and cooling duties on the stages. Following the parametric studies, optimization of the RD column was performed to maximize the methanol production and recovery. The optimum case resulted in a methanol productivity of 2.7 mol/kgcatalyst h which is an increase of 12.5%, and CO and H2 conversions of 44% and 31% vis-a-vis 39% and 28%, respectively, in the base case. The product purity in the distillate for the optimum case also improved to 87% from 82.4% in the base case. The observed catalyst loading in the optimum cases is explained on the basis of the approach to equilibrium for the methanol synthesis reaction. Based on comparison with the conventional packed bed reactor, it is concluded that a more active catalyst for liquid phase methanol synthesis is needed to make RD competitive in terms of methanol productivity.
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Industrial & Engineering Chemistry Research, 2010
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Chemical Engineering and Processing - Process Intensification, 2019
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Volume 8: Energy, 2020
Biogas, a promising alternative fuel, a substitute for fossil fuels, is predominantly a mixture o... more Biogas, a promising alternative fuel, a substitute for fossil fuels, is predominantly a mixture of methane and carbon dioxide. Both are major greenhouse gases. Methane has a long-term effect on the environment while carbon dioxide is recycled by the plants. Hence, capture and burning of biogas to consume methane as a fuel is desired both from energy and environmental outlook. The presence of a large amount of carbon dioxide in biogas, however, impairs combustion in engines resulting into slow burning and higher hydrocarbon and carbon monoxide emissions. Dry reforming, a conversion process of biogas to synthesis gas (syngas), a mixture of hydrogen and carbon monoxide, is a catalytic process that has the potential to greatly improve biogas combustion in engines. The researchers’ focus in dry reforming, however, has been for the generation of hydrogen for fuel cells and reactants for Fischer Tropsch process in industry — this approach aims towards maximum conversion of methane and carb...
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Energy & Fuels, 2014
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Process Integration and Optimization for Sustainability, 2020
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Fluid Phase Equilibria, 2012
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Energy & Fuels, 2013
Biomass gasification is receiving increasing attention as a potential source of sustainable devel... more Biomass gasification is receiving increasing attention as a potential source of sustainable development for the production of power, chemicals, and transportation fuels. A major hurdle, however, despite years of research, is the removal of tar formed during the biomass gasification process. In this paper, we model some of the tar handling options using the process simulator, Aspen Plus. While there is extensive experimental work reported in the literature on the tar conversion and absorption methods, the literature on modeling is sparse. Hence, as a part of the study, we present the challenges in modeling the tar handling methods. We report the performance of three frequently suggested tar handling options: uncatalyzed partial oxidation, catalytic steam reforming, and absorption. Some of the practical difficulties that need to be overcome with each of these methods are also discussed.
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Industrial & Engineering Chemistry Research, 2010
ABSTRACT Fischer−Tropsch synthesis can be advantageously carried out in reactive distillation (RD... more ABSTRACT Fischer−Tropsch synthesis can be advantageously carried out in reactive distillation (RD) mode. Parametric studies like the effect of reflux ratio, pressure, etc. have been reported in our earlier work [Srinivas et al. Ind. Eng. Chem. Res. 2009, 48, 4719−4730] using Aspen Plus. As an extension of this work, multiparameter sensitivity analysis is performed on a simple RD configuration without side-draws or side-coolers in Aspen Plus, retaining the kinetic and thermodynamic models used previously. A feasible solution space in terms of reflux ratio, pressure, and total catalyst loading is identified and possible reasons for the bounds observed are provided. Changes in the column configuration toward various objectives like maximum conversion, maximum gasoline yield, or selectivity, etc. are also investigated. Regions of interest corresponding to different objectives are represented on a Da−reflux ratio plot.
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Industrial & Engineering Chemistry Research, 2009
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Industrial & Engineering Chemistry Research, 2009
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Industrial & Engineering Chemistry Research, 2008
ABSTRACT Fischer−Tropsch synthesis (FTS) is an area that is receiving revived interest worldwide ... more ABSTRACT Fischer−Tropsch synthesis (FTS) is an area that is receiving revived interest worldwide as a technology alternative to produce transportation fuels as well as chemicals from syngas. SASOL and Shell are two of the major players who operate FT reactors on a commercial scale. To have a balance between gasoline and diesel production, one needs to have both the low temperature (LTFT) and high-temperature (HTFT) processes operating in parallel. Heat-removal from the exothermic FT reactions was the main driver in the development of conventional FT reactors (fixed-bed, fluidized bed, or slurry type). However, the focus has recently shifted toward the product distribution as well. Reactive distillation (RD) is a proven reactive separation method that can enhance yields as well as improve product selectivity in multiple reactant/product systems. This paper aims to check if FTS is feasible in RD from a theoretical viewpoint. In-built thermodynamic procedures and power-law kinetics of Aspen Plus, along with a simplified kinetic model that predicts product distribution, were used in performing the simulations. Simulation results of the conventional reactors are compared with RD, and it is seen that the performance of RD is at par or better than the conventional reactors in terms of conversion, yield, and product distribution. Within the RD mode for FTS, results of some of the alternate column configurations are presented. The results indicate that FTS can be a potential candidate to be implemented using RD.
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Energy for Sustainable Development, 2007
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Industrial & Engineering Chemistry Research, 2009
ABSTRACT
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Volume 2: Economic, Environmental, and Policy Aspects of Alternate Energy; Fuels and Infrastructure, Biofuels and Energy Storage; High Performance Buildings; Solar Buildings, Including Solar Climate Control/Heating/Cooling; Sustainable Cities and Communities, Including Transportation; Thermofluid..., 2014
New energy plants coming online must be both economical and efficiently balanced to satisfy deman... more New energy plants coming online must be both economical and efficiently balanced to satisfy demanding requirements in the future. A balance of plant analysis was performed to determine the techno-economic feasibility of a 100 barrel oil equivalent (boe) per day, compact Gas to Liquid (GTL) methanol plant. Methanol itself is emerging as a possible alternative to gasoline; but it is also the precursor to dimethyl ether (DME), which has recently received a lot of attention as a low emitter of particulate matter and nitrous oxides, which can replace diesel in trucking applications and liquefied petroleum gas (LPG) in domestic applications. Production of synthesis gas (syngas) from methane gas was modeled via partial oxidation of fuel-rich mixtures in engine cylinders using GT-ISE. Two ignition modes were studied: spark ignition (SI) and homogeneous charge compression ignition (HCCI). The use of the engine as a compressor was also studied in order to reduce net compression requirements a...
Bookmarks Related papers MentionsView impact
Clean Technologies and Environmental Policy
Bookmarks Related papers MentionsView impact
Process Integration and Optimization for Sustainability, 2021
The effects of various operating and design parameters in reactive distillation for methanol synt... more The effects of various operating and design parameters in reactive distillation for methanol synthesis using a polar solvent (tetraglyme) and Cu–Zn-Al2O3 catalyst on the process performance are investigated in this simulation work. It is observed that trade-offs exist between the reaction (reactant conversion) and separation (methanol purity) as these parameters are varied. The most sensitive parameters are the solvent flow rate, temperature of feed streams, reflux ratio, and cooling duties on the stages. Following the parametric studies, optimization of the RD column was performed to maximize the methanol production and recovery. The optimum case resulted in a methanol productivity of 2.7 mol/kgcatalyst h which is an increase of 12.5%, and CO and H2 conversions of 44% and 31% vis-a-vis 39% and 28%, respectively, in the base case. The product purity in the distillate for the optimum case also improved to 87% from 82.4% in the base case. The observed catalyst loading in the optimum cases is explained on the basis of the approach to equilibrium for the methanol synthesis reaction. Based on comparison with the conventional packed bed reactor, it is concluded that a more active catalyst for liquid phase methanol synthesis is needed to make RD competitive in terms of methanol productivity.
Bookmarks Related papers MentionsView impact
Industrial & Engineering Chemistry Research, 2010
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Chemical Engineering and Processing - Process Intensification, 2019
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Volume 8: Energy, 2020
Biogas, a promising alternative fuel, a substitute for fossil fuels, is predominantly a mixture o... more Biogas, a promising alternative fuel, a substitute for fossil fuels, is predominantly a mixture of methane and carbon dioxide. Both are major greenhouse gases. Methane has a long-term effect on the environment while carbon dioxide is recycled by the plants. Hence, capture and burning of biogas to consume methane as a fuel is desired both from energy and environmental outlook. The presence of a large amount of carbon dioxide in biogas, however, impairs combustion in engines resulting into slow burning and higher hydrocarbon and carbon monoxide emissions. Dry reforming, a conversion process of biogas to synthesis gas (syngas), a mixture of hydrogen and carbon monoxide, is a catalytic process that has the potential to greatly improve biogas combustion in engines. The researchers’ focus in dry reforming, however, has been for the generation of hydrogen for fuel cells and reactants for Fischer Tropsch process in industry — this approach aims towards maximum conversion of methane and carb...
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Energy & Fuels, 2014
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Process Integration and Optimization for Sustainability, 2020
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Fluid Phase Equilibria, 2012
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Energy & Fuels, 2013
Biomass gasification is receiving increasing attention as a potential source of sustainable devel... more Biomass gasification is receiving increasing attention as a potential source of sustainable development for the production of power, chemicals, and transportation fuels. A major hurdle, however, despite years of research, is the removal of tar formed during the biomass gasification process. In this paper, we model some of the tar handling options using the process simulator, Aspen Plus. While there is extensive experimental work reported in the literature on the tar conversion and absorption methods, the literature on modeling is sparse. Hence, as a part of the study, we present the challenges in modeling the tar handling methods. We report the performance of three frequently suggested tar handling options: uncatalyzed partial oxidation, catalytic steam reforming, and absorption. Some of the practical difficulties that need to be overcome with each of these methods are also discussed.
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Industrial & Engineering Chemistry Research, 2010
ABSTRACT Fischer−Tropsch synthesis can be advantageously carried out in reactive distillation (RD... more ABSTRACT Fischer−Tropsch synthesis can be advantageously carried out in reactive distillation (RD) mode. Parametric studies like the effect of reflux ratio, pressure, etc. have been reported in our earlier work [Srinivas et al. Ind. Eng. Chem. Res. 2009, 48, 4719−4730] using Aspen Plus. As an extension of this work, multiparameter sensitivity analysis is performed on a simple RD configuration without side-draws or side-coolers in Aspen Plus, retaining the kinetic and thermodynamic models used previously. A feasible solution space in terms of reflux ratio, pressure, and total catalyst loading is identified and possible reasons for the bounds observed are provided. Changes in the column configuration toward various objectives like maximum conversion, maximum gasoline yield, or selectivity, etc. are also investigated. Regions of interest corresponding to different objectives are represented on a Da−reflux ratio plot.
Bookmarks Related papers MentionsView impact
Industrial & Engineering Chemistry Research, 2009
Bookmarks Related papers MentionsView impact
Industrial & Engineering Chemistry Research, 2009
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Industrial & Engineering Chemistry Research, 2008
ABSTRACT Fischer−Tropsch synthesis (FTS) is an area that is receiving revived interest worldwide ... more ABSTRACT Fischer−Tropsch synthesis (FTS) is an area that is receiving revived interest worldwide as a technology alternative to produce transportation fuels as well as chemicals from syngas. SASOL and Shell are two of the major players who operate FT reactors on a commercial scale. To have a balance between gasoline and diesel production, one needs to have both the low temperature (LTFT) and high-temperature (HTFT) processes operating in parallel. Heat-removal from the exothermic FT reactions was the main driver in the development of conventional FT reactors (fixed-bed, fluidized bed, or slurry type). However, the focus has recently shifted toward the product distribution as well. Reactive distillation (RD) is a proven reactive separation method that can enhance yields as well as improve product selectivity in multiple reactant/product systems. This paper aims to check if FTS is feasible in RD from a theoretical viewpoint. In-built thermodynamic procedures and power-law kinetics of Aspen Plus, along with a simplified kinetic model that predicts product distribution, were used in performing the simulations. Simulation results of the conventional reactors are compared with RD, and it is seen that the performance of RD is at par or better than the conventional reactors in terms of conversion, yield, and product distribution. Within the RD mode for FTS, results of some of the alternate column configurations are presented. The results indicate that FTS can be a potential candidate to be implemented using RD.
Bookmarks Related papers MentionsView impact
Energy for Sustainable Development, 2007
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Industrial & Engineering Chemistry Research, 2009
ABSTRACT
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