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Yingjie Li - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous NO/CO2 removal by Cu-modified biochar/CaO in carbonation step of Calcium Looping Process
Chemical Engineering Journal, 2020Co-Authors: Wan Zhang, Yingjie Li, Yuqi Qian, Boyu Li, Yuzhuo Wang, Zeyan WangAbstract:Abstract A novel method to realize the simultaneous NO/CO2 removal by Cu-modified biochar and CaO in the carbonation stage of Calcium Looping was proposed. Cu-modified biochar was added in the carbonation stage as a NO reductant, meanwhile CaO was added as a CO2 sorbent. The simultaneous NO/CO2 removal performance of Cu-modified coconut shell char/CaO in the carbonation stage of Calcium Looping was investigated in a bubbling fluidized bed reactor. CO is generated by the oxidation of the coconut shell char in the presence of O2 in the carbonation. Cu-modified biochar and the generated CO efficiently reduce NO. Cu in Cu-modified biochar shows a strong catalysis on NO reduction by both char and CO. Besides, Cu enhances the conversion of CO to CO2, which is absorbed by CaO. CaO also catalyzes NO removal by CO, but the catalytic effect gradually becomes weak as the carbonation proceeds. When Cu content in Cu-modified coconut shell char is 0.77%, mass ratio of Cu-modified biochar to CaO is 1:16 and O2 concentration is 3%, NO removal and CO2 capture efficiencies of Cu-modified biochar/CaO in the carbonator are 94% and 80% at 650 °C, respectively. To reach the same NO removal efficiency of 94% in the carbonator, the required addition amount of Cu-modified biochar is only approximately 20% of untreated biochar.
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simultaneous no co2 removal by cu modified biochar cao in carbonation step of Calcium Looping Process
Chemical Engineering Journal, 2020Co-Authors: Wan Zhang, Yingjie Li, Yuqi Qian, Boyu Li, Yuzhuo Wang, Zeyan WangAbstract:Abstract A novel method to realize the simultaneous NO/CO2 removal by Cu-modified biochar and CaO in the carbonation stage of Calcium Looping was proposed. Cu-modified biochar was added in the carbonation stage as a NO reductant, meanwhile CaO was added as a CO2 sorbent. The simultaneous NO/CO2 removal performance of Cu-modified coconut shell char/CaO in the carbonation stage of Calcium Looping was investigated in a bubbling fluidized bed reactor. CO is generated by the oxidation of the coconut shell char in the presence of O2 in the carbonation. Cu-modified biochar and the generated CO efficiently reduce NO. Cu in Cu-modified biochar shows a strong catalysis on NO reduction by both char and CO. Besides, Cu enhances the conversion of CO to CO2, which is absorbed by CaO. CaO also catalyzes NO removal by CO, but the catalytic effect gradually becomes weak as the carbonation proceeds. When Cu content in Cu-modified coconut shell char is 0.77%, mass ratio of Cu-modified biochar to CaO is 1:16 and O2 concentration is 3%, NO removal and CO2 capture efficiencies of Cu-modified biochar/CaO in the carbonator are 94% and 80% at 650 °C, respectively. To reach the same NO removal efficiency of 94% in the carbonator, the required addition amount of Cu-modified biochar is only approximately 20% of untreated biochar.
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Simultaneous NO/SO 2 removal by coconut shell char/CaO from Calcium Looping in a fluidized bed reactor
Korean Journal of Chemical Engineering, 2020Co-Authors: Boyu Li, Yingjie Li, Wan Zhang, Yuqi Qian, Zeyan WangAbstract:A simultaneous NOx/SO2 removal system using bio-char and CaO combined with Calcium Looping Process for CO2 capture was proposed. The simultaneous NO/SO2 removal performance of coconut shell char/CaO experienced CO2 capture cycles was investigated in a fluidized bed reactor. The effects of reaction temperature, mass ratio of CaO to coconut shell coke, CaO particle size and number of CO2 capture cycles from Calcium Looping Process were discussed. The NO removal efficiency of char is improved under the catalysis of CaO. The reaction temperature plays an important role in the simultaneous NO/SO2 removal. Coconut shell char/CaO achieve the highest NO and SO2 removal efficiencies at 825 oC, which are 98% and 100%, respectively. The mass ratio of CaO to coconut shell char of 60: 100 is a good choice for the simultaneous NO/SO2 removal. Smaller CaO particle size contributes to higher NO and SO2 removal efficiencies of coconut shell char/CaO. The NO and SO2 removal efficiencies of coconut shell char and cycled CaO from Calcium Looping declined slightly with the number of CO2 capture cycles. In addition, the Ca-based materials balance in Process of simultaneous NOx/SO2 removal combined with Calcium Looping is given. The novel simultaneous NO/SO2 removal method using bio-char and cycled CaO from Calcium Looping Process appears promising.
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simultaneous no co2 removal performance of biochar limestone in Calcium Looping Process
Fuel, 2020Co-Authors: Wan Zhang, Yingjie Li, Yuqi Qian, Zeyan WangAbstract:Abstract A novel simultaneous NO/CO2 removal system using biochar and calcined limestone in the Calcium Looping Process was proposed. Coconut shell char and calcined limestone were added into a carbonator in the Calcium Looping Process as the NO reductant and CO2 sorbent, respectively. The simultaneous NO/CO2 removal performance of coconut shell char/calcined limestone in the Calcium Looping Process was investigated in a bubbling fluidized bed reactor. NO and CO2 in flue gases are effectively and simultaneously removed by coconut shell char/calcined limestone in the presence of O2. O2 plays an important role in NO removal by coconut shell char. The calcined limestone shows a strong catalytic effect on NO reduction by CO generated by the reaction of coconut shell char and O2. The calcined limestone supports active sites for NO reduction by CO. High CO concentrations and high carbonation temperatures have positive effects on NO reduction by CO with calcined limestone catalysis. However, the catalytic effect of calcined limestone is weakened by its carbonation, which is promoted by the high temperature and additional CO2 produced by the oxidation of char. The simultaneous NO removal and CO2 capture efficiencies can reach above 97% and 80%, respectively. The porous structure of coconut shell char is an important factor in enhancing NO reduction with calcined limestone catalysis in the presence of O2.
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Simultaneous NO/CO2 removal performance of biochar/limestone in Calcium Looping Process
Fuel, 2020Co-Authors: Wan Zhang, Yingjie Li, Yuqi Qian, Xiaotong Ma, Zeyan WangAbstract:Abstract A novel simultaneous NO/CO2 removal system using biochar and calcined limestone in the Calcium Looping Process was proposed. Coconut shell char and calcined limestone were added into a carbonator in the Calcium Looping Process as the NO reductant and CO2 sorbent, respectively. The simultaneous NO/CO2 removal performance of coconut shell char/calcined limestone in the Calcium Looping Process was investigated in a bubbling fluidized bed reactor. NO and CO2 in flue gases are effectively and simultaneously removed by coconut shell char/calcined limestone in the presence of O2. O2 plays an important role in NO removal by coconut shell char. The calcined limestone shows a strong catalytic effect on NO reduction by CO generated by the reaction of coconut shell char and O2. The calcined limestone supports active sites for NO reduction by CO. High CO concentrations and high carbonation temperatures have positive effects on NO reduction by CO with calcined limestone catalysis. However, the catalytic effect of calcined limestone is weakened by its carbonation, which is promoted by the high temperature and additional CO2 produced by the oxidation of char. The simultaneous NO removal and CO2 capture efficiencies can reach above 97% and 80%, respectively. The porous structure of coconut shell char is an important factor in enhancing NO reduction with calcined limestone catalysis in the presence of O2.
Chunmei Lu - One of the best experts on this subject based on the ideXlab platform.
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co2 capture using carbide slag modified by propionic acid in Calcium Looping Process for hydrogen production
International Journal of Hydrogen Energy, 2013Co-Authors: Yingjie Li, Jianli Zhao, Chunmei LuAbstract:Abstract Lime enhanced gasification (LEGS) Process based on Calcium Looping in which CaO is employed as CO2 sorbent is an emerging technology for hydrogen production and CO2 capture. In this work, carbide slag which was an industrial solid waste was utilized as CO2 sorbent in hydrogen production Process. Modification of carbide slag by propionic acid was proposed to improve its reactivity. The CO2 capture behavior of raw and modified carbide slags was investigated in a dual fixed-bed reactor (DFR) and a thermo-gravimetric analyzer (TGA). The results show that modification of carbide slag by propionic acid enhances its CO2 capture capacity in the multiple calcination/carbonation cycles. The favorable carbonation temperature and calcination temperature for modified carbide slag are 680–700 °C and 850–950 °C, respectively. Prolonged carbonation treatment is beneficial to CO2 capture of raw and modified carbide slags. The prolonged carbonation for 9 h in the 21st cycle increases the conversions of raw and modified carbide slags in this cycle. And then the carbonation conversions of the two sorbents were also improved in the subsequent cycles. Calcined modified carbide slag shows more porous microstructure compared with calcined raw one for the same number of cycles. Modification of carbide slag by propionic acid increases the surface area, pore volume and pore area. In addition, the volume and area of the pores in 20–100 nm in diameter were improved, which had been proved to be more effective to capture CO2. The microstructure of calcined modified carbide slag favors its higher CO2 capture capacity in the multiple calcination/carbonation cycles.
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utilization of lime mud from paper mill as co2 sorbent in Calcium Looping Process
Chemical Engineering Journal, 2013Co-Authors: Yingjie Li, Chunmei LuAbstract:Abstract Lime mud (LM), a solid waste that results from the causticization reaction in alkali recycling Process of paper manufacture industry, was utilized as CO 2 sorbent in Calcium Looping Process in this study. The carbonation behavior of LM in the calcination/carbonation cycles was investigated in a dual fixed-bed reactor and a thermo-gravimetric analyzer. The results show that the carbonation conversions of LM are lower than those of limestone at the same reaction conditions. It attributes to the high chlorine content in LM which leads to more pronounced sintering and decreases the CO 2 capture performance of LM. A pre-wash Process was employed to decrease the chlorine content in LM. Based on an overall consideration of various factors, the pre-wash Process is effective enough if the Cl/Ca molar ratio in LM is smaller than 1:100. Pre-washed lime mud (PLM) achieves higher carbonation rates and carbonation conversions, compared with LM. When calcined at 850 °C and carbonated at 700 °C, the carbonation conversion of PLM maintains at 36% after 100 cycles, which is 1.8 and 4.8 times as high as LM and limestone after the same number of cycles, respectively. The pore volume and surface area of calcined PLM were greater than those of calcined LM after the same number of cycles, especially the volume of the pores in the range of 10–100 nm in diameter. That is the reason why PLM exhibits higher CO 2 capture capacity than LM in the multiple calcination/carbonation cycles. The carbonation conversions of LM and PLM are further enhanced by hydration of their calcines.
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CO2 capture using carbide slag modified by propionic acid in Calcium Looping Process for hydrogen production
International Journal of Hydrogen Energy, 2013Co-Authors: Rongyue Sun, Changtian Liu, Jianli Zhao, Yingjie Li, Chunmei LuAbstract:Lime enhanced gasification (LEGS) Process based on Calcium Looping in which CaO is employed as CO2 sorbent is an emerging technology for hydrogen production and CO2 capture. In this work, carbide slag which was an industrial solid waste was utilized as CO2 sorbent in hydrogen production Process. Modification of carbide slag by propionic acid was proposed to improve its reactivity. The CO2 capture behavior of raw and modified carbide slags was investigated in a dual fixed-bed reactor (DFR) and a thermo-gravimetric analyzer (TGA). The results show that modification of carbide slag by propionic acid enhances its CO2 capture capacity in the multiple calcination/carbonation cycles. The favorable carbonation temperature and calcination temperature for modified carbide slag are 680-700 C and 850-950 C, respectively. Prolonged carbonation treatment is beneficial to CO2 capture of raw and modified carbide slags. The prolonged carbonation for 9 h in the 21st cycle increases the conversions of raw and modified carbide slags in this cycle. And then the carbonation conversions of the two sorbents were also improved in the subsequent cycles. Calcined modified carbide slag shows more porous microstructure compared with calcined raw one for the same number of cycles. Modification of carbide slag by propionic acid increases the surface area, pore volume and pore area. In addition, the volume and area of the pores in 20-100 nm in diameter were improved, which had been proved to be more effective to capture CO2. The microstructure of calcined modified carbide slag favors its higher CO2 capture capacity in the multiple calcination/carbonation cycles. Copyright © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
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sequential so2 co2 capture of Calcium based solid waste from the paper industry in the Calcium Looping Process
Industrial & Engineering Chemistry Research, 2012Co-Authors: Yingjie Li, Shuimu Wu, Chunmei LuAbstract:In this work, the sequential SO 2 and CO 2 capture behavior of lime mud (LM) as a solid waste from the paper industry was investigated in the Calcium Looping Process. In order to minimize the unfavorable effects of impurities such as Na and Cl on CO 2 and SO 2 capture of LM, the LM was prewashed with distilled water. The prewash treatment improves the cyclic CO 2 capture capacity of the LM during multiple carbonation/calcination cycles. The ultimate carbonation conversion of the treated LM is 1.8 and 4.8 times greater than those of the raw LM and the limestone, respectively. The microstructure analysis shows that the surface area and pore volume of the LM are significantly increased after the prewash treatment. With increasing the sulfation temperature from 850 to 950 °C, both the raw LM and the treated one show an increase in the sulfation conversion after the same number of cycles. Interestingly, the effect of the sulfation temperature decreases with increasing the number of cycles. For the raw LM or the treated LM, the sulfation conversion after 50 cycles is higher than that after 15 or 100 cycles. That is related to the change in pore size of the raw LM and the treated LM after multiple cycles. Compared with the raw LM and the limestone, the sulfation conversion of the treated LM is greater after the same number of cycles and at the same reaction time.
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Sequential SO2/CO2 Capture of Calcium-Based Solid Waste from the Paper Industry in the Calcium Looping Process
Industrial & Engineering Chemistry Research, 2012Co-Authors: Yingjie Li, Shuimu Wu, Chunmei LuAbstract:In this work, the sequential SO 2 and CO 2 capture behavior of lime mud (LM) as a solid waste from the paper industry was investigated in the Calcium Looping Process. In order to minimize the unfavorable effects of impurities such as Na and Cl on CO 2 and SO 2 capture of LM, the LM was prewashed with distilled water. The prewash treatment improves the cyclic CO 2 capture capacity of the LM during multiple carbonation/calcination cycles. The ultimate carbonation conversion of the treated LM is 1.8 and 4.8 times greater than those of the raw LM and the limestone, respectively. The microstructure analysis shows that the surface area and pore volume of the LM are significantly increased after the prewash treatment. With increasing the sulfation temperature from 850 to 950 °C, both the raw LM and the treated one show an increase in the sulfation conversion after the same number of cycles. Interestingly, the effect of the sulfation temperature decreases with increasing the number of cycles. For the raw LM or the treated LM, the sulfation conversion after 50 cycles is higher than that after 15 or 100 cycles. That is related to the change in pore size of the raw LM and the treated LM after multiple cycles. Compared with the raw LM and the limestone, the sulfation conversion of the treated LM is greater after the same number of cycles and at the same reaction time.
Shwetha Ramkumar - One of the best experts on this subject based on the ideXlab platform.
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Process simulation and economic analysis of the Calcium Looping Process clp for hydrogen and electricity production from coal and natural gas
Fuel, 2013Co-Authors: Daniel P. Connell, David A. Lewandowski, Nihar Phalak, Shwetha Ramkumar, Robert M. StatnickAbstract:Abstract The Calcium Looping Process (CLP) is being developed to facilitate carbon dioxide (CO 2 ) capture during the production of hydrogen (H 2 ) from syngas. The Process integrates CO 2 , sulfur, and halide removal with the water–gas shift (WGS) reaction in a single-stage reactor. In the CLP, a regenerable Calcium oxide (CaO) sorbent is used to chemically react with and remove CO 2 and other acid gases from syngas at high temperature (i.e., 550–700 °C). The removal of CO 2 drives the WGS reaction forward via Le Chatelier’s principle, obviating the need for a WGS catalyst and enabling the production of high-purity H 2 . The spent sorbent is heated in a calciner to regenerate CaO for reuse in the Process and to release a concentrated CO 2 stream, which can be dried and sequestered. The regenerated sorbent is then reactivated in a hydrator, to improve its recyclability, before being reintroduced into the H 2 production reactor. Techno-economic analyses were performed to evaluate the application of the CLP to a coal-to-H 2 plant, a steam methane reforming (SMR) plant, and an integrated gasification-combined cycle (IGCC) plant, all including ⩾90% CO 2 capture. In each case, use of the CLP resulted in a 9–12% reduction in the cost of H 2 or cost of electricity when compared with the use of conventional CO 2 capture and WGS technologies. The economic advantage afforded by the CLP is realized because of the large amount of high-quality heat produced in the Process, which is recovered to raise steam for electricity generation. This heat arises from the combustion of supplemental fuel in the CLP calciner and from the exothermic CO 2 removal, WGS, and hydration reactions, which are carried out at high temperature (i.e., ⩾500 °C) in the CLP. As a result of recovering this heat, the CLP-based coal-to-H 2 and SMR plants, which are designed to produce 26,000 kg/h H 2 , necessarily co-produce 320 MW e and 190 MW e of net electric power, respectively. Although the CLP can reduce the cost of producing H 2 from coal, the resulting cost is still about 26% greater than the cost of H 2 produced from natural gas using conventional WGS and CO 2 capture technologies, assuming coal and natural gas prices of $1.55/GJ and $6.21/GJ, respectively. The lowest cost of H 2 with CO 2 capture for these fuel prices is achieved by applying the CLP to an SMR plant.
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Process simulation and economic analysis of the Calcium Looping Process (CLP) for hydrogen and electricity production from coal and natural gas
Fuel, 2013Co-Authors: Daniel P. Connell, David A. Lewandowski, Nihar Phalak, Robert M. Statnick, Shwetha Ramkumar, Liang-shih. FanAbstract:The Calcium Looping Process (CLP) is being developed to facilitate carbon dioxide (CO2) capture during the production of hydrogen (H 2) from syngas. The Process integrates CO2, sulfur, and halide removal with the water-gas shift (WGS) reaction in a single-stage reactor. In the CLP, a regenerable Calcium oxide (CaO) sorbent is used to chemically react with and remove CO2 and other acid gases from syngas at high temperature (i.e., 550-700 °C). The removal of CO2 drives the WGS reaction forward via Le Chatelier's principle, obviating the need for a WGS catalyst and enabling the production of high-purity H2. The spent sorbent is heated in a calciner to regenerate CaO for reuse in the Process and to release a concentrated CO2 stream, which can be dried and sequestered. The regenerated sorbent is then reactivated in a hydrator, to improve its recyclability, before being reintroduced into the H2 production reactor. Techno-economic analyses were performed to evaluate the application of the CLP to a coal-to-H2 plant, a steam methane reforming (SMR) plant, and an integrated gasification-combined cycle (IGCC) plant, all including ≥90% CO2 capture. In each case, use of the CLP resulted in a 9-12% reduction in the cost of H2 or cost of electricity when compared with the use of conventional CO2 capture and WGS technologies. The economic advantage afforded by the CLP is realized because of the large amount of high-quality heat produced in the Process, which is recovered to raise steam for electricity generation. This heat arises from the combustion of supplemental fuel in the CLP calciner and from the exothermic CO2 removal, WGS, and hydration reactions, which are carried out at high temperature (i.e., ≥500 °C) in the CLP. As a result of recovering this heat, the CLP-based coal-to-H2 and SMR plants, which are designed to produce 26,000 kg/h H2, necessarily co-produce 320 MWe and 190 MWe of net electric power, respectively. Although the CLP can reduce the cost of producing H2 from coal, the resulting cost is still about 26% greater than the cost of H2 produced from natural gas using conventional WGS and CO2 capture technologies, assuming coal and natural gas prices of $1.55/GJ and $6.21/GJ, respectively. The lowest cost of H2 with CO 2 capture for these fuel prices is achieved by applying the CLP to an SMR plant. © 2012 Elsevier Ltd. All rights reserved.
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Calcium Looping Process for clean coal conversion design and operation of the subpilot scale carbonator
Industrial & Engineering Chemistry Research, 2012Co-Authors: Nihar Phalak, Shwetha Ramkumar, Niranjani Deshpande, Alan Wang, William S Y Wang, Robert M. StatnickAbstract:The Calcium Looping Process (CLP), which is being developed at The Ohio State University (OSU), is a clean coal technology for the production of hydrogen (H2) and electricity from coal-derived syng...
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Calcium Looping Process clp for enhanced steam methane reforming
Industrial & Engineering Chemistry Research, 2012Co-Authors: Shwetha Ramkumar, Nihar PhalakAbstract:Carbon dioxide (CO2) capture using Calcium-based sorbents for post- and pre-combustion applications has the potential to become a viable technology. When applied to a pre-combustion system, the presence of Calcium sorbents facilitates Process intensification by combining the CO2 removal step with the reactions generating the fuel gas [syngas, hydrogen (H2), etc.] in a single step. Such a Process is also capable of producing a high-purity sequestration-ready CO2 stream. The enhanced steam methane reforming (SMR) using the Calcium Looping Process (CLP) has been investigated in this work. The CLP comprises three reactors: the carbonation reactor or carbonator where the thermodynamic constraint of the reforming and water gas shift (WGS) reaction is overcome by the incessant removal of the CO2 product resulting in the production of high-purity H2, the calciner where the Calcium sorbent is regenerated and a sequestration-ready CO2 stream is produced, and the hydrator where the regenerated sorbent is reactivated...
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Calcium Looping Process (CLP) for enhanced steam methane reforming
Industrial and Engineering Chemistry Research, 2012Co-Authors: Shwetha Ramkumar, Nihar Phalak, Liang-shih. FanAbstract:Carbon dioxide (CO2) capture using Calcium-based sorbents for post- and pre-combustion applications has the potential to become a viable technology. When applied to a pre-combustion system, the presence of Calcium sorbents facilitates Process intensification by combining the CO2 removal step with the reactions generating the fuel gas [syngas, hydrogen (H2), etc.] in a single step. Such a Process is also capable of producing a high-purity sequestration-ready CO2 stream. The enhanced steam methane reforming (SMR) using the Calcium Looping Process (CLP) has been investigated in this work. The CLP comprises three reactors: the carbonation reactor or carbonator where the thermodynamic constraint of the reforming and water gas shift (WGS) reaction is overcome by the incessant removal of the CO2 product resulting in the production of high-purity H2, the calciner where the Calcium sorbent is regenerated and a sequestration-ready CO2 stream is produced, and the hydrator where the regenerated sorbent is reactivated to improve its multicyclic performance. The exothermic carbonation and WGS reaction convert the highly endothermic SMR into a heat neutral Process, thus reducing the temperature of reforming from >900 to 650 °C. Experiments conducted using methane in a bench-scale fixed bed reactor have indicated that high purity H2 (?95?99%, dry basis) can be produced using the CLP with in situ CO2 capture. Attempts to maintain the sorbent reactivity over multiple cycles using hydration have yielded encouraging results. Carbon dioxide (CO2) capture using Calcium-based sorbents for post- and pre-combustion applications has the potential to become a viable technology. When applied to a pre-combustion system, the presence of Calcium sorbents facilitates Process intensification by combining the CO2 removal step with the reactions generating the fuel gas [syngas, hydrogen (H2), etc.] in a single step. Such a Process is also capable of producing a high-purity sequestration-ready CO2 stream. The enhanced steam methane reforming (SMR) using the Calcium Looping Process (CLP) has been investigated in this work. The CLP comprises three reactors: the carbonation reactor or carbonator where the thermodynamic constraint of the reforming and water gas shift (WGS) reaction is overcome by the incessant removal of the CO2 product resulting in the production of high-purity H2, the calciner where the Calcium sorbent is regenerated and a sequestration-ready CO2 stream is produced, and the hydrator where the regenerated sorbent is reactivated to improve its multicyclic performance. The exothermic carbonation and WGS reaction convert the highly endothermic SMR into a heat neutral Process, thus reducing the temperature of reforming from >900 to 650 °C. Experiments conducted using methane in a bench-scale fixed bed reactor have indicated that high purity H2 (?95?99%, dry basis) can be produced using the CLP with in situ CO2 capture. Attempts to maintain the sorbent reactivity over multiple cycles using hydration have yielded encouraging results.
Nihar Phalak - One of the best experts on this subject based on the ideXlab platform.
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Class and Home Problems: Carbon Dioxide Capture from Coal-Fired Power Plants Using Calcium Looping.
Chemical engineering education, 2015Co-Authors: Niranjani Deshpande, Nihar Phalak, Sankaran SundaresanAbstract:Calcium Looping is based on the simple premise of the reversible reaction between CO 2 and CaO. This reaction can be used for separation of CO 2 from a mixture of gases; most notably the technology finds applications in CO 2 removal from gas streams in fossil fuel-based energy systems. This article gives a brief overview of the Calcium Looping Process and uses the example of a coal-fired power plant for discussing several aspects, including material balances and energy requirements. This article, which is based on an important topic of current research, is written in a format that can be directly adopted for a project in introductory chemical engineering courses.
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ca oh 2 based Calcium Looping Process development at the ohio state university
Chemical Engineering & Technology, 2013Co-Authors: Nihar Phalak, William WangAbstract:The cyclic Calcium oxide-Calcium carbonate (CaO-CaCO3) Process is a promising option for large-scale CO2 control. Important advantages include high-temperature operation, inexpensive sorbent feedstock, and high CO2 capture capacity of CaO. However, decreasing sorbent reactivity over multiple cycles, due to high-temperature sintering, presents a major challenge for further progress. The Ohio State University (OSU) has led the development of a novel three-step Calcium Looping (CaO-Ca(OH)2-CaCO3) Process for post- and precombustion CO2 capture. An overview of OSU's work is provided, highlighting the differences in this approach when compared to competing efforts in this field.
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Process simulation and economic analysis of the Calcium Looping Process clp for hydrogen and electricity production from coal and natural gas
Fuel, 2013Co-Authors: Daniel P. Connell, David A. Lewandowski, Nihar Phalak, Shwetha Ramkumar, Robert M. StatnickAbstract:Abstract The Calcium Looping Process (CLP) is being developed to facilitate carbon dioxide (CO 2 ) capture during the production of hydrogen (H 2 ) from syngas. The Process integrates CO 2 , sulfur, and halide removal with the water–gas shift (WGS) reaction in a single-stage reactor. In the CLP, a regenerable Calcium oxide (CaO) sorbent is used to chemically react with and remove CO 2 and other acid gases from syngas at high temperature (i.e., 550–700 °C). The removal of CO 2 drives the WGS reaction forward via Le Chatelier’s principle, obviating the need for a WGS catalyst and enabling the production of high-purity H 2 . The spent sorbent is heated in a calciner to regenerate CaO for reuse in the Process and to release a concentrated CO 2 stream, which can be dried and sequestered. The regenerated sorbent is then reactivated in a hydrator, to improve its recyclability, before being reintroduced into the H 2 production reactor. Techno-economic analyses were performed to evaluate the application of the CLP to a coal-to-H 2 plant, a steam methane reforming (SMR) plant, and an integrated gasification-combined cycle (IGCC) plant, all including ⩾90% CO 2 capture. In each case, use of the CLP resulted in a 9–12% reduction in the cost of H 2 or cost of electricity when compared with the use of conventional CO 2 capture and WGS technologies. The economic advantage afforded by the CLP is realized because of the large amount of high-quality heat produced in the Process, which is recovered to raise steam for electricity generation. This heat arises from the combustion of supplemental fuel in the CLP calciner and from the exothermic CO 2 removal, WGS, and hydration reactions, which are carried out at high temperature (i.e., ⩾500 °C) in the CLP. As a result of recovering this heat, the CLP-based coal-to-H 2 and SMR plants, which are designed to produce 26,000 kg/h H 2 , necessarily co-produce 320 MW e and 190 MW e of net electric power, respectively. Although the CLP can reduce the cost of producing H 2 from coal, the resulting cost is still about 26% greater than the cost of H 2 produced from natural gas using conventional WGS and CO 2 capture technologies, assuming coal and natural gas prices of $1.55/GJ and $6.21/GJ, respectively. The lowest cost of H 2 with CO 2 capture for these fuel prices is achieved by applying the CLP to an SMR plant.
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Design and Operation of a Fluidized Bed Hydrator for Steam Reactivation of Calcium Sorbent
Industrial & Engineering Chemistry Research, 2013Co-Authors: Alan Wang, Nihar Phalak, Niranjani Deshpande, Dawei Wang, William S Y WangAbstract:The decreasing CO2 capture capacity of Calcium sorbents over multiple reaction cycles poses a significant challenge to the large-scale cyclic carbonation-calcination Process. Several approaches, including intermediate hydration, have been suggested to overcome this limitation. Until this study, most hydration studies have been performed at laboratory-scale using thermogravimetric techniques at conditions that may not be feasible for Process scale-up. Moreover, data on the design of a steam hydrator suitable for the Calcium Looping Process is not available. For the first time, this study reports the design of a bench-scale high-temperature steam hydrator for Calcium sorbent reactivation. The hydrator, consisting of a fluidized-bed reactor with additional internals, was evaluated using cold-flow tests following which several reaction parameters were investigated in the hot unit. The results obtained from these high-temperature steam hydration tests (300–500 °C) are discussed here. Specifically, at an averag...
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Process simulation and economic analysis of the Calcium Looping Process (CLP) for hydrogen and electricity production from coal and natural gas
Fuel, 2013Co-Authors: Daniel P. Connell, David A. Lewandowski, Nihar Phalak, Robert M. Statnick, Shwetha Ramkumar, Liang-shih. FanAbstract:The Calcium Looping Process (CLP) is being developed to facilitate carbon dioxide (CO2) capture during the production of hydrogen (H 2) from syngas. The Process integrates CO2, sulfur, and halide removal with the water-gas shift (WGS) reaction in a single-stage reactor. In the CLP, a regenerable Calcium oxide (CaO) sorbent is used to chemically react with and remove CO2 and other acid gases from syngas at high temperature (i.e., 550-700 °C). The removal of CO2 drives the WGS reaction forward via Le Chatelier's principle, obviating the need for a WGS catalyst and enabling the production of high-purity H2. The spent sorbent is heated in a calciner to regenerate CaO for reuse in the Process and to release a concentrated CO2 stream, which can be dried and sequestered. The regenerated sorbent is then reactivated in a hydrator, to improve its recyclability, before being reintroduced into the H2 production reactor. Techno-economic analyses were performed to evaluate the application of the CLP to a coal-to-H2 plant, a steam methane reforming (SMR) plant, and an integrated gasification-combined cycle (IGCC) plant, all including ≥90% CO2 capture. In each case, use of the CLP resulted in a 9-12% reduction in the cost of H2 or cost of electricity when compared with the use of conventional CO2 capture and WGS technologies. The economic advantage afforded by the CLP is realized because of the large amount of high-quality heat produced in the Process, which is recovered to raise steam for electricity generation. This heat arises from the combustion of supplemental fuel in the CLP calciner and from the exothermic CO2 removal, WGS, and hydration reactions, which are carried out at high temperature (i.e., ≥500 °C) in the CLP. As a result of recovering this heat, the CLP-based coal-to-H2 and SMR plants, which are designed to produce 26,000 kg/h H2, necessarily co-produce 320 MWe and 190 MWe of net electric power, respectively. Although the CLP can reduce the cost of producing H2 from coal, the resulting cost is still about 26% greater than the cost of H2 produced from natural gas using conventional WGS and CO2 capture technologies, assuming coal and natural gas prices of $1.55/GJ and $6.21/GJ, respectively. The lowest cost of H2 with CO 2 capture for these fuel prices is achieved by applying the CLP to an SMR plant. © 2012 Elsevier Ltd. All rights reserved.
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Off-design model of concentrating solar power plant with thermochemical energy storage based on Calcium-Looping
SOLARPACES 2018: International Conference on Concentrating Solar Power and Chemical Energy Systems, 2019Co-Authors: C Ortiz, Jose Manuel Valverde, Matteo C Romano, Marco Binotti, Ricardo ChacarteguiAbstract:Dispatchability is a key issue to increase the competitiveness of concentrating solar power plants. Thermochemical energy storage systems are a promising alternative to molten salt-based storage because of the higher energy storage density and the possibility of increasing the storage period. Among possible thermochemical systems, the Calcium-Looping Process, based on the multicycle calcination-carbonation of CaCO3, is a main candidate to be integrated as energy storage system within a scenario of massive deployment of concentrating solar power plants. The present manuscript goes beyond previous works by developing an off-design model of the system that leads to a more accurate discussion on system size and plant efficiency. A capacity factor as high as 58% is calculated with lower mass of stored products than in commercial solar plants while the calculated solar-to-electric daily efficiency varies between 17.1% and 20.1%. Simulation results suggest an interesting attractive potential of the Calcium-Looping integration.Dispatchability is a key issue to increase the competitiveness of concentrating solar power plants. Thermochemical energy storage systems are a promising alternative to molten salt-based storage because of the higher energy storage density and the possibility of increasing the storage period. Among possible thermochemical systems, the Calcium-Looping Process, based on the multicycle calcination-carbonation of CaCO3, is a main candidate to be integrated as energy storage system within a scenario of massive deployment of concentrating solar power plants. The present manuscript goes beyond previous works by developing an off-design model of the system that leads to a more accurate discussion on system size and plant efficiency. A capacity factor as high as 58% is calculated with lower mass of stored products than in commercial solar plants while the calculated solar-to-electric daily efficiency varies between 17.1% and 20.1%. Simulation results suggest an interesting attractive potential of the Calcium-Loopi...
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one dimensional model of entrained flow carbonator for co2 capture in cement kilns by Calcium Looping Process
Chemical Engineering Science, 2018Co-Authors: Maurizio Spinelli, I Martinez, Matteo C RomanoAbstract:Abstract In this work, a 1D model of an entrained-flow carbonator of a Calcium Looping Process for cement plants is presented and the results of a sensitivity analysis on the main governing Process parameters is discussed. Several design and operating parameters have been investigated through a wide sensitivity analysis, namely: adiabatic vs. cooled reactor, high gas velocity gooseneck reactor vs. low velocity downflow reactor, solid-to-gas ratio, sorbent capacity, reactor inlet temperature and solids recirculation. The effect of these design and Process parameters on the CO2 capture efficiency and on Calcium Looping Process heat consumption is assessed. The results of the calculations showed that with a proper combination of solid-to-gas ratio in the carbonator and sorbent carbonation capacity (e.g. ∼10 kg/Nm3 and ∼20% respectively), carbonator CO2 capture efficiencies of about 80% (i.e. total cement kiln CO2 capture efficiencies higher than 90%) can be obtained in a gooseneck-type carbonator with a length compatible with industrial applications in cement kilns (∼120 to 140 m). Further experimental investigations on this reactor concept, especially about fluid-dynamic behavior and the chemical properties of raw meal as CO2 sorbent, are needed to demonstrate the technical feasibility of the proposed Process.
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co2 capture in cement plants by tail end Calcium Looping Process
Energy Procedia, 2018Co-Authors: E De Lena, Maurizio Spinelli, Matteo C RomanoAbstract:Abstract In this work the integration of the Calcium-Looping (CaL) Process, used as a post-combustion CO2 capture system, into a cement kiln was analyzed by means of Process simulations. The results show that capture efficiencies of about 90% can be achieved with operating conditions of CaL reactors similar to those for power generation applications. The integration of the CaL Process increases the fuel consumption of the cement kiln, but the additional primary energy introduced for sustaining this CO2 capture Process can be efficiently exploited for raising HP steam and producing electricity in a Rankine cycle.
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Process integration of Calcium Looping thermochemical energy storage system in concentrating solar power plants
Energy, 2018Co-Authors: C Ortiz, Matteo C Romano, J M Valverde, Marco Binotti, Ricardo ChacarteguiAbstract:Abstract The Calcium-Looping Process is a promising thermochemical energy storage method based on the multicycle calcination-carbonation of CaCO3-CaO to be used in concentrated solar power plants. When solar energy is available, the CaCO3 solids are calcined at high temperature to produce CaO and CO2, which are stored for subsequent utilization. When power is needed, these reaction by-products are fed into a carbonator reactor where energy is released from the exothermic carbonation reaction. In comparison with currently commercial energy storage systems, such as solar salts, the Calcium-Looping Process presents several benefits such as the feasibility to work at significantly higher power cycle temperatures, a higher energy storage density and the possibility to store energy in the medium-long term. The present manuscript analyzes a number of novel Calcium-Looping configurations for energy storage combined with CO2 cycles in a solar tower plant. The high overall efficiencies achieved (32–44%, defined as the ratio of net electric power production to net solar thermal power entering the calciner) indicate a potential interest for the integration of the Calcium-Looping Process in Concentrating Solar Power Plants, although major technological challenges related to the design of the solar receiver and of the high temperature solids handling devices remain to be faced.
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the Calcium Looping Process for low co2 emission cement plants
Energy Procedia, 2014Co-Authors: Matteo C Romano, Maurizio Spinelli, Stefano Campanari, Stefano Consonni, Maurizio Marchi, Natale Pimpinelli, Giovanni CintiAbstract:Abstract The aim of this work is investigating the application of the Calcium Looping Process in cement plants with CO 2 capture. A novel configuration with oxyfuel calciner and a carbonator integrated in the raw meal suspension preheater has been assessed by means of Process simulations. The results obtained show a high potential of the proposed Process, with equivalent avoided CO 2 emissions (i.e. accounting for credits associated to electric power export) of about 94%, vs. 76% obtained for a competitive oxyfuel cement plant.
