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Juan Adanez - One of the best experts on this subject based on the ideXlab platform.
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double perovskite la2 xca bax nio4 oxygen carriers for Chemical Looping Reforming applications
International Journal of Hydrogen Energy, 2020Co-Authors: R A Medeiros, V R M Melo, D M A Melo, Heloisa P Macedo, Gustavo Torres Moure, Inaki Adanezrubio, M A F Melo, Juan AdanezAbstract:Abstract Double perovskites La2-xNiO4-δ doped with Ca and Ba were synthesized via microwave-assisted combustion method and studied as an alternative oxygen carrier (OC) for Chemical Looping Reforming processes (CLR). The OCs, La2NiO4, La1.8Ca0.2NiO4, La1.8Ba0.2NiO4 and La1.8Ca0.1Ba0.1NiO4 were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature-programmed reduction and oxidation (TPR/TPO) and cyclic thermogravimetric analysis (TGA). Rietveld's refinement, performed after each redox cycle, confirmed that doping allows smaller amounts of nickel to migrate from the perovskite structure. The double perovskites synthesized for the Chemical Looping Reforming process behave as simple nickel oxide and are considered as alternative oxygen carriers to solve the problems of deactivation due to the interaction of NiO with the support. The Ca-doped OC (La1.8Ca0.2NiO4) showed lower NiO concentration outside the structure and smaller crystallite size after the redox cycles, which was associated with a change in the crystal structure, presenting superior performance and stability. The results show that all perovskites have high reactivity in both reduction and oxidation reactions, however the perovskites were not able to uncouple oxygen, which is an unsual behavior for perovskites.
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syngas h2 production from bioethanol in a continuous Chemical Looping Reforming prototype
Fuel Processing Technology, 2015Co-Authors: F Garcialabiano, Pilar Sanz Gayan, A Serrano, E Garciadiez, Juan Adanez, L F De Diego, A Abad, Juan A C RuizAbstract:Abstract Chemical-Looping Reforming (CLR) allows H 2 production without CO 2 emissions into the atmosphere. The use of a renewable fuel, bioethanol, in an auto-thermal CLR process has the advantage to produce H 2 with negative CO 2 emissions. This work presents the experimental results obtained in a continuously operating CLR unit (1 kW th ) using ethanol as fuel. Two NiO-based oxygen carriers were used during more than 50 h of operation. The influence of variables such as temperature, water-to-fuel and oxygen-to-fuel molar ratios was analysed. Full conversion of ethanol was accomplished and carbon formation was easily avoided. A syngas composed of ≈ 61 vol.% H 2 , ≈ 32 vol.% CO, ≈ 5 vol.% CO 2 and ≈ 2 vol.% CH 4 was reached at auto-thermal conditions for both materials. Gas composition was closed to the given by the thermodynamic equilibrium. These results demonstrate the technical viability of H 2 /syngas production by using bioethanol in an auto-thermal CLR process.
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reduction and oxidation kinetics of nickel based oxygen carriers for Chemical Looping combustion and Chemical Looping Reforming
Chemical Engineering Journal, 2012Co-Authors: Cristina Dueso, Pilar Sanz Gayan, Alberto Abad, Luis F De Diego, Maria Ortiz, F Garcialabiano, Juan AdanezAbstract:Abstract The kinetics of reduction with CH 4 , H 2 and CO and oxidation with O 2 of two NiO-based oxygen-carriers for Chemical-Looping combustion (CLC) and Chemical-Looping Reforming (CLR) prepared by impregnation, NiO18-αAl and NiO21-γAl, have been determined in this work. In both solids, nickel was present as NiO and NiAl 2 O 4 in the oxidized state and the NiO/NiAl 2 O 4 ratio in the particles was a function of the solid conversion reached in the previous reduction process. Both nickel compounds were active for oxygen transfer although with very different reactivities. Therefore, kinetic parameters for NiO and NiAl 2 O 4 reduction were determined for each oxygen carrier and each reacting gas. The reaction rate of NiO reduction was the same in NiO18-αAl and NiO21-γAl particles. A model which assumed a linear relationship between time and conversion was used to describe NiO reduction. Nevertheless, differences in reactivity were observed during NiAl 2 O 4 reduction depending on the type of support, α-Al 2 O 3 or γ-Al 2 O 3 , probably due to a different crystalline structure of the alumina. The changing grain size model for spherical grain geometry was used to obtain the kinetic parameters of the NiAl 2 O 4 reduction working with both NiO-based oxygen-carriers. Chemical reaction control was assumed for NiO18-αAl whereas diffusion through the product layer was also considered when NiO21-γAl was used as oxygen-carrier. The oxidation reaction was very fast with both materials although small differences were observed again between NiO18-αAl and NiO21-γAl oxygen carriers, probably owing to the presence of a higher amount of NiAl 2 O 4 in the solid supported on γ-Al 2 O 3 . The combined model for consecutive reduction of NiO and NiAl 2 O 4 in the oxygen-carrier particles with the kinetic parameters obtained in this work predicted adequately the experimental results with both materials. These kinetic data could be used for the design of CLC and CLR systems.
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catalytic activity of ni based oxygen carriers for steam methane Reforming in Chemical Looping processes
Energy & Fuels, 2012Co-Authors: Maria Ortiz, Pilar Sanz Gayan, Alberto Abad, Luis F De Diego, F Garcialabiano, Juan AdanezAbstract:Chemical-Looping technology has been suggested as one of the most promising technologies for reducing the cost of CO2 capture using fossil fuels. This technology involves the use of an oxygen-carrier, which transfers oxygen from air to the fuel avoiding the direct contact between them. Oxygen carriers based on nickel have been the most extensively analyzed in the literature because of their good performance working at high temperatures (900–1100 °C). It is well-known that Ni catalyzes steam methane Reforming (SMR) and water–gas shift (WGS) reactions, which are produced both in Chemical-Looping combustion (CLC) and Chemical-Looping Reforming (CLR) processes. In this work, the catalytic activity of two Ni-based oxygen-carriers prepared by impregnation, NiO18-αAl2O3 and NiO21-γAl2O3, with respect to SMR and WGS reactions, have been determined in a fixed-bed reactor at different operating conditions. The catalytic activity was similar for both oxygen-carriers but lower than that exhibited by conventional Ni c...
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hydrogen production by auto thermal Chemical Looping Reforming in a pressurized fluidized bed reactor using ni based oxygen carriers
International Journal of Hydrogen Energy, 2010Co-Authors: Maria Ortiz, Pilar Sanz Gayan, Alberto Abad, Luis F De Diego, F Garcialabiano, Juan AdanezAbstract:Abstract This work presents the experimental results obtained during auto-thermal Chemical-Looping Reforming (CLRa) in a semicontinuous pressurized fluidized bed reactor working with two Ni-based oxygen carriers and using methane as fuel. During operation the effect of the total pressure, reduction reaction temperature, and oxygen carrier-to-fuel molar ratio on CH4 conversion, gas outlet concentrations, and carbon formation was analyzed. In the range of pressures analyzed (up to 10 bars), it was found that an increase in the total operating pressure did not produce a negative effect on the gas product distribution obtained in the process. At all operating pressures the CH4 conversion was very high (>98%) and no carbon formation was detected. The most important variable affecting the gas product distribution was the solid circulation rate, that is, the oxygen carrier-to-fuel molar ratio (NiO/CH4). The oxygen carriers were physically and Chemically characterized by several techniques before and after using in the pressurized fluidized bed reactor. Important changes in the surface texture and the solid structure of the oxygen carrier particles were not detected. These results suggest that these oxygen carriers could have a high durability, being suitable for use in a pressurized CLRa system.
Pilar Sanz Gayan - One of the best experts on this subject based on the ideXlab platform.
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Combustion and Reforming of Liquid Fossil Fuels through Chemical Looping Processes: Integration of Chemical Looping Processes in a Refinery
Energy Procedia, 2017Co-Authors: Francisco García-labiano, E. García-díez, Pilar Sanz Gayan, Luis Francisco De Diego, Alberto Abad, A Serrano, Juan Elorza AdanezAbstract:Oil refining processes demand and use vast quantities of energy and thus are responsible for the emission of a great deal of CO2. In addition, hydrogen is used in oil refineries for hydrodesulfurization and hydrocraking processes. In this sense, the integration of Chemical Looping technology in an oil refinery using vacuum residues as fuel could drive to significant reductions in CO2 emissions. In this work, Chemical Looping Combustion (CLC) and Chemical Looping Reforming (CLR) experiments have been carried out in a continuously operated 1 kWth unit using a Cu- and Ni-based oxygen carrier, respectively. Diesel, synthetic and mineral lubricant oil were used as fuels as a previous step to the use of low grade residues. Regarding Chemical Looping Combustion conditions, almost 100% of combustion efficiency and full carbon capture were obtained at low oxygen carrier-to-fuel molar ratios (ø≥1.6). Regarding Chemical Looping Reforming conditions, a syngas containing a H2 concentration over 50 vol.% in dry basis was obtained with the additional advantage of reaching 100% CO2 capture efficiency in the process. In all cases, syngas composition obtained was close to the given by the thermodynamic equilibrium. These results provide a basis for concluding that the integration of Chemical Looping processes for heat/steam and hydrogen production in an oil refinery is feasible and could lead to significant environmental advantages.
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Autothermal Chemical Looping Reforming process of different fossil liquid fuels
International Journal of Hydrogen Energy, 2017Co-Authors: E. García-díez, Alberto Secades Abad, Pilar Sanz Gayan, Juan Elorza Adanez, Luis Francisco De Diego, Francisco García-labiano, Alberto AbadAbstract:The autothermal Chemical-Looping Reforming (a-CLR) is a process where syngas is produced with two main advantages; there are captured CO2 emissions and the heat required for the syngas production is generated by the process itself. A Ni-based material is used as oxygen carrier circulating between two fluidized bed reactors: the fuel and air reactors. In this work, the auto-thermal conditions in a global H2 production process, integrated by the a-CLR process and a Water Gas Shift reactor, using different liquid fossil fuels were theoretically determined. The hydrogen production per mol of carbon in the fuel was similar for all fossil fuels, taking a value of 2.2 at the optimal operating temperature (700 °C). In addition, the possibility of working at low temperature for a maximum H2 production was experimentally demonstrated in a continuous 1 kWth a-CLR unit.
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Steam, dry, and steam-dry Chemical Looping Reforming of diesel fuel in a 1 kWth unit
Chemical Engineering Journal, 2017Co-Authors: E. García-díez, Alberto Secades Abad, Pilar Sanz Gayan, Juan Elorza Adanez, Luis Francisco De Diego, Francisco García-labiano, Alberto Abad, J. A.c. RuízAbstract:Chemical Looping Reforming (CLR) is a process that enables the production of syngas/H2 with CO2 capture by using oxygen carriers that prevent direct contact between the fuel and air. This work presents the experimental results obtained in a 1 kWth CLR unit using a Ni-based oxygen carrier and diesel as fuel, as a first trial for further advancement with heavier liquid fuels. The influence of the main operating conditions, such as oxygen-to-diesel molar ratio and the H2O and/or CO2 feed into the system, was analysed in both steam and dry CLR processes. In addition, the combined steam-dry CLR process enabled the production of syngas with any H2/CO molar ratio between 0.2 and 3, which resulted in a wide variety of final products during its use in Fischer-Tropsch processes. In all cases, the syngas composition was close to that given by the thermodynamic equilibrium. These results demonstrate the technical feasibility of steam, dry, and combined steam-dry Reforming processes for liquid fossil fuels in a Chemical Looping system.
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Optimization of hydrogen production with CO2 capture by autothermal Chemical-Looping Reforming using different bioethanol purities
Applied Energy, 2016Co-Authors: E. García-díez, Alberto Secades Abad, Pilar Sanz Gayan, Juan Elorza Adanez, Luis Francisco De Diego, Francisco García-labiano, Alberto Abad, J. A.c. RuízAbstract:Autothermal Chemical-Looping Reforming (a-CLR) is a process which allows hydrogen production avoiding the environmental penalty of CO2 emission typically produced in other processes. The major advantage of this technology is that the heat needed for syngas production is generated by the process itself. The heat necessary for the endothermic reactions is supplied by a Ni-based oxygen-carrier (OC) circulating between two reactors: the air reactor (AR), where the OC is oxidized by air, and the fuel reactor (FR), where the fuel is converted to syngas. Other important advantage is that this process also allows the production of pure N2 in the AR outlet stream. A renewable fuel such as bioethanol was chosen in this work due to their increasing worldwide production and the current excess of this fuel presented by different countries.In this work, mass and heat balances were done to determine the auto-thermal conditions that maximize H2 production, assuming that the product gas was in thermodynamic equilibrium. Three different types of bioethanol has been considered according to their ethanol purity; Dehydrated ethanol (≈100 vol.%), hydrated ethanol (≈96 vol.%), and diluted ethanol (≈52 vol.%). It has been observed that the higher H2 production (4.62 mol of H2 per mol of EtOH) has been obtained with the use of diluted ethanol and the surplus energy needed could be compensated by the energy save achieved during the purification of ethanol in the production process.
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syngas h2 production from bioethanol in a continuous Chemical Looping Reforming prototype
Fuel Processing Technology, 2015Co-Authors: F Garcialabiano, Pilar Sanz Gayan, A Serrano, E Garciadiez, Juan Adanez, L F De Diego, A Abad, Juan A C RuizAbstract:Abstract Chemical-Looping Reforming (CLR) allows H 2 production without CO 2 emissions into the atmosphere. The use of a renewable fuel, bioethanol, in an auto-thermal CLR process has the advantage to produce H 2 with negative CO 2 emissions. This work presents the experimental results obtained in a continuously operating CLR unit (1 kW th ) using ethanol as fuel. Two NiO-based oxygen carriers were used during more than 50 h of operation. The influence of variables such as temperature, water-to-fuel and oxygen-to-fuel molar ratios was analysed. Full conversion of ethanol was accomplished and carbon formation was easily avoided. A syngas composed of ≈ 61 vol.% H 2 , ≈ 32 vol.% CO, ≈ 5 vol.% CO 2 and ≈ 2 vol.% CH 4 was reached at auto-thermal conditions for both materials. Gas composition was closed to the given by the thermodynamic equilibrium. These results demonstrate the technical viability of H 2 /syngas production by using bioethanol in an auto-thermal CLR process.
Alberto Abad - One of the best experts on this subject based on the ideXlab platform.
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Combustion and Reforming of Liquid Fossil Fuels through Chemical Looping Processes: Integration of Chemical Looping Processes in a Refinery
Energy Procedia, 2017Co-Authors: Francisco García-labiano, E. García-díez, Pilar Sanz Gayan, Luis Francisco De Diego, Alberto Abad, A Serrano, Juan Elorza AdanezAbstract:Oil refining processes demand and use vast quantities of energy and thus are responsible for the emission of a great deal of CO2. In addition, hydrogen is used in oil refineries for hydrodesulfurization and hydrocraking processes. In this sense, the integration of Chemical Looping technology in an oil refinery using vacuum residues as fuel could drive to significant reductions in CO2 emissions. In this work, Chemical Looping Combustion (CLC) and Chemical Looping Reforming (CLR) experiments have been carried out in a continuously operated 1 kWth unit using a Cu- and Ni-based oxygen carrier, respectively. Diesel, synthetic and mineral lubricant oil were used as fuels as a previous step to the use of low grade residues. Regarding Chemical Looping Combustion conditions, almost 100% of combustion efficiency and full carbon capture were obtained at low oxygen carrier-to-fuel molar ratios (ø≥1.6). Regarding Chemical Looping Reforming conditions, a syngas containing a H2 concentration over 50 vol.% in dry basis was obtained with the additional advantage of reaching 100% CO2 capture efficiency in the process. In all cases, syngas composition obtained was close to the given by the thermodynamic equilibrium. These results provide a basis for concluding that the integration of Chemical Looping processes for heat/steam and hydrogen production in an oil refinery is feasible and could lead to significant environmental advantages.
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Autothermal Chemical Looping Reforming process of different fossil liquid fuels
International Journal of Hydrogen Energy, 2017Co-Authors: E. García-díez, Alberto Secades Abad, Pilar Sanz Gayan, Juan Elorza Adanez, Luis Francisco De Diego, Francisco García-labiano, Alberto AbadAbstract:The autothermal Chemical-Looping Reforming (a-CLR) is a process where syngas is produced with two main advantages; there are captured CO2 emissions and the heat required for the syngas production is generated by the process itself. A Ni-based material is used as oxygen carrier circulating between two fluidized bed reactors: the fuel and air reactors. In this work, the auto-thermal conditions in a global H2 production process, integrated by the a-CLR process and a Water Gas Shift reactor, using different liquid fossil fuels were theoretically determined. The hydrogen production per mol of carbon in the fuel was similar for all fossil fuels, taking a value of 2.2 at the optimal operating temperature (700 °C). In addition, the possibility of working at low temperature for a maximum H2 production was experimentally demonstrated in a continuous 1 kWth a-CLR unit.
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Steam, dry, and steam-dry Chemical Looping Reforming of diesel fuel in a 1 kWth unit
Chemical Engineering Journal, 2017Co-Authors: E. García-díez, Alberto Secades Abad, Pilar Sanz Gayan, Juan Elorza Adanez, Luis Francisco De Diego, Francisco García-labiano, Alberto Abad, J. A.c. RuízAbstract:Chemical Looping Reforming (CLR) is a process that enables the production of syngas/H2 with CO2 capture by using oxygen carriers that prevent direct contact between the fuel and air. This work presents the experimental results obtained in a 1 kWth CLR unit using a Ni-based oxygen carrier and diesel as fuel, as a first trial for further advancement with heavier liquid fuels. The influence of the main operating conditions, such as oxygen-to-diesel molar ratio and the H2O and/or CO2 feed into the system, was analysed in both steam and dry CLR processes. In addition, the combined steam-dry CLR process enabled the production of syngas with any H2/CO molar ratio between 0.2 and 3, which resulted in a wide variety of final products during its use in Fischer-Tropsch processes. In all cases, the syngas composition was close to that given by the thermodynamic equilibrium. These results demonstrate the technical feasibility of steam, dry, and combined steam-dry Reforming processes for liquid fossil fuels in a Chemical Looping system.
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optimization of hydrogen production with co2 capture by autothermal Chemical Looping Reforming using different bioethanol purities
Applied Energy, 2016Co-Authors: E Garciadiez, Juan Elorza Adanez, Luis Francisco De Diego, Alberto Abad, P Gaya, J. A.c. RuízAbstract:Autothermal Chemical-Looping Reforming (a-CLR) is a process which allows hydrogen production avoiding the environmental penalty of CO2 emission typically produced in other processes. The major advantage of this technology is that the heat needed for syngas production is generated by the process itself. The heat necessary for the endothermic reactions is supplied by a Ni-based oxygen-carrier (OC) circulating between two reactors: the air reactor (AR), where the OC is oxidized by air, and the fuel reactor (FR), where the fuel is converted to syngas. Other important advantage is that this process also allows the production of pure N2 in the AR outlet stream. A renewable fuel such as bioethanol was chosen in this work due to their increasing worldwide production and the current excess of this fuel presented by different countries.
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Optimization of hydrogen production with CO2 capture by autothermal Chemical-Looping Reforming using different bioethanol purities
Applied Energy, 2016Co-Authors: E. García-díez, Alberto Secades Abad, Pilar Sanz Gayan, Juan Elorza Adanez, Luis Francisco De Diego, Francisco García-labiano, Alberto Abad, J. A.c. RuízAbstract:Autothermal Chemical-Looping Reforming (a-CLR) is a process which allows hydrogen production avoiding the environmental penalty of CO2 emission typically produced in other processes. The major advantage of this technology is that the heat needed for syngas production is generated by the process itself. The heat necessary for the endothermic reactions is supplied by a Ni-based oxygen-carrier (OC) circulating between two reactors: the air reactor (AR), where the OC is oxidized by air, and the fuel reactor (FR), where the fuel is converted to syngas. Other important advantage is that this process also allows the production of pure N2 in the AR outlet stream. A renewable fuel such as bioethanol was chosen in this work due to their increasing worldwide production and the current excess of this fuel presented by different countries.In this work, mass and heat balances were done to determine the auto-thermal conditions that maximize H2 production, assuming that the product gas was in thermodynamic equilibrium. Three different types of bioethanol has been considered according to their ethanol purity; Dehydrated ethanol (≈100 vol.%), hydrated ethanol (≈96 vol.%), and diluted ethanol (≈52 vol.%). It has been observed that the higher H2 production (4.62 mol of H2 per mol of EtOH) has been obtained with the use of diluted ethanol and the surplus energy needed could be compensated by the energy save achieved during the purification of ethanol in the production process.
Shahriar Amini - One of the best experts on this subject based on the ideXlab platform.
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Techno-economic assessment of Chemical Looping Reforming of natural gas for hydrogen production and power generation with integrated CO2 capture
International Journal of Greenhouse Gas Control, 2018Co-Authors: Shareq Mohd Nazir, Joana Francisco Morgado, Rosa M. Quinta-ferreira, Olav Bolland, Shahriar AminiAbstract:The current study presents the techno-economic analysis of the CLR-CC process. The CLR-CC process comprises of Chemical Looping Reforming (CLR) of Natural Gas, water gas shift, CO2 capture and compression, and combined cycle power plant. A 1-D phenomenological model was developed using MATLAB and is used to study the performance of CLR, whereas the remaining part of the process was analysed using commercial software tools like Aspen and Thermoflow. The effect of design conditions in CLR, mainly the air flowrate to the oxidation reactor, oxidation reactor outlet temperature and the steam flowrate to the fuel reactor of CLR, on the overall techno-economic performance of the CLR-CC process is reported. The CH4 conversion in CLR, net electrical efficiency, CO2 avoidance rate and the Levelised Cost of Electricity (LCOE) have been identified as techno-economic performance indicators. For the sensitivity study carried out in this study through 12 cases, the net electrical efficiency of the CLR-CC process varies between 40.0 and 43.4%, whereas the LCOE varies between 75.3 and 144.8 $/MWh, which is highly dependent on the fuel cost and process contingency rates.
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Analysis of combined cycle power plants with Chemical Looping Reforming of natural gas and pre-combustion CO2 capture
Energies, 2018Co-Authors: Shareq Mohd Nazir, Olav Bolland, Shahriar AminiAbstract:In this paper, a gas-fired combined cycle power plant subjected to a pre-combustion CO2 capture method has been analysed under different design conditions and different heat integration options. The power plant configuration includes the Chemical Looping Reforming (CLR) of natural gas (NG), water gas shift (WGS) process, CO2 capture and compression, and a hydrogen fuelled combined cycle to produce power. The process is denoted as a CLR-CC process. One of the main parameters that affects the performance of the process is the pressure for the CLR. The process is analysed at different design pressures for the CLR, i.e., 5, 10, 15, 18, 25 and 30 bar. It is observed that the net electrical efficiency increases with an increase in the design pressure in the CLR. Secondly, the type of steam generated from the cooling of process streams also effects the net electrical efficiency of the process. Out of the five different cases including the base case presented in this study, it is observed that the net electrical efficiency of CLR-CCs can be improved to 46.5% (lower heating value of NG basis) by producing high-pressure steam through heat recovery from the pre-combustion process streams and sending it to the Heat Recovery Steam Generator in the power plant.
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Modelling study of two Chemical Looping Reforming reactor configurations: Looping vs. switching
Powder Technology, 2017Co-Authors: Joana Francisco Morgado, Thomas Gurker, John Morud, Schalk Cloete, Shahriar AminiAbstract:Autothermal Chemical Looping Reforming (CLR) is a promising technology for hydrogen production with integrated CO2separation. However, the interconnected CLR reactor configuration is expected to present significant scale up challenges, especially under the pressurized conditions required for high process efficiency. These challenges can be circumvented by carrying out the reduction/oxidation reactions in a single bubbling/turbulent fluidized bed alternatively fed with fuel and air, henceforth called gas switching Reforming (GSR). The primary drawbacks of the GSR concept are the undesired mixing between fuel and nitrogen after the gas feed switch and the need for high temperature valves at the reactor outlet. The performance of the CLR and GSR concepts are compared using a generic phenomenological model, applicable over different fluidization regimes. Results showed that the GSR process is best operated by separating the reduction and Reforming reactions, whereas these reactions occur simultaneously in the CLR fuel reactor. This fundamental difference led to lower fuel conversion, but a higher heating value syngas in the GSR process. Separation of reduction and Reforming steps in the GSR concept also allows for the efficient utilization of the off-gas fuel from a PSA unit for high purity pressurized hydrogen production. This makes the GSR process more applicable to hydrogen production with integrated CO2capture, whereas the CLR concept is better suited to power production with pre-combustion CO2capture.
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Full Plant Scale Analysis of Natural Gas Fired Power Plants with Pre-Combustion CO2 Capture and Chemical Looping Reforming (CLR)
Energy Procedia, 2017Co-Authors: Shareq Mohd Nazir, Olav Bolland, Shahriar AminiAbstract:In this study, first of its kind complete plant scale integration of pre-combustion CO2 capture method with Chemical Looping Reforming (CLR) of Natural Gas (NG), Water Gas Shift (WGS) process, CO2 capture and CO2 compression in a combined cycle power plant has been presented. The CLR consisted of oxidation and fuel reactor. The oxidation reactor oxidizes the metal oxygen carrier with compressed air and produces an oxygen depleted air stream (N2 stream) as by-product. The fuel reactor reforms the NG with the metal oxide in presence of steam to produce syngas. The syngas is further subjected to WGS and CO2 capture using a-MDEA, to prepare a H2-rich fuel, which is combusted in the Gas Turbine (GT) system. The heat from cooling of process streams in the pre-combustion CO2 capture method, is used to prepare saturated low pressure steam, fraction of which is used in reboiler to regenerate the amine for CO2 capture, and the remainder is expanded in Steam Turbine (ST) to generate power. The power plant is a combined cycle with two GT, two Heat Recovery Steam Generators (HRSG) and one ST. 12% of air entering the GT is used in the oxidation reactor of CLR, and equivalent amount of N2 stream is compressed and added as diluent in the GT. The overall process was integrated and analysed at full load conditions. The current process has also been compared with Natural Gas Combined Cycle (NGCC) plant without CO2 capture. The net electric efficiency of the power plant with pre-combustion CO2 capture in this study is 43.1%, which is 15.3%-points less than the NGCC plant without capture. Major energy penalty in the process comes from air compressor, the diluent N2 stream compressor and due to low degree of process integration to avoid complexity.
Juan Elorza Adanez - One of the best experts on this subject based on the ideXlab platform.
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Combustion and Reforming of Liquid Fossil Fuels through Chemical Looping Processes: Integration of Chemical Looping Processes in a Refinery
Energy Procedia, 2017Co-Authors: Francisco García-labiano, E. García-díez, Pilar Sanz Gayan, Luis Francisco De Diego, Alberto Abad, A Serrano, Juan Elorza AdanezAbstract:Oil refining processes demand and use vast quantities of energy and thus are responsible for the emission of a great deal of CO2. In addition, hydrogen is used in oil refineries for hydrodesulfurization and hydrocraking processes. In this sense, the integration of Chemical Looping technology in an oil refinery using vacuum residues as fuel could drive to significant reductions in CO2 emissions. In this work, Chemical Looping Combustion (CLC) and Chemical Looping Reforming (CLR) experiments have been carried out in a continuously operated 1 kWth unit using a Cu- and Ni-based oxygen carrier, respectively. Diesel, synthetic and mineral lubricant oil were used as fuels as a previous step to the use of low grade residues. Regarding Chemical Looping Combustion conditions, almost 100% of combustion efficiency and full carbon capture were obtained at low oxygen carrier-to-fuel molar ratios (ø≥1.6). Regarding Chemical Looping Reforming conditions, a syngas containing a H2 concentration over 50 vol.% in dry basis was obtained with the additional advantage of reaching 100% CO2 capture efficiency in the process. In all cases, syngas composition obtained was close to the given by the thermodynamic equilibrium. These results provide a basis for concluding that the integration of Chemical Looping processes for heat/steam and hydrogen production in an oil refinery is feasible and could lead to significant environmental advantages.
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Autothermal Chemical Looping Reforming process of different fossil liquid fuels
International Journal of Hydrogen Energy, 2017Co-Authors: E. García-díez, Alberto Secades Abad, Pilar Sanz Gayan, Juan Elorza Adanez, Luis Francisco De Diego, Francisco García-labiano, Alberto AbadAbstract:The autothermal Chemical-Looping Reforming (a-CLR) is a process where syngas is produced with two main advantages; there are captured CO2 emissions and the heat required for the syngas production is generated by the process itself. A Ni-based material is used as oxygen carrier circulating between two fluidized bed reactors: the fuel and air reactors. In this work, the auto-thermal conditions in a global H2 production process, integrated by the a-CLR process and a Water Gas Shift reactor, using different liquid fossil fuels were theoretically determined. The hydrogen production per mol of carbon in the fuel was similar for all fossil fuels, taking a value of 2.2 at the optimal operating temperature (700 °C). In addition, the possibility of working at low temperature for a maximum H2 production was experimentally demonstrated in a continuous 1 kWth a-CLR unit.
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Steam, dry, and steam-dry Chemical Looping Reforming of diesel fuel in a 1 kWth unit
Chemical Engineering Journal, 2017Co-Authors: E. García-díez, Alberto Secades Abad, Pilar Sanz Gayan, Juan Elorza Adanez, Luis Francisco De Diego, Francisco García-labiano, Alberto Abad, J. A.c. RuízAbstract:Chemical Looping Reforming (CLR) is a process that enables the production of syngas/H2 with CO2 capture by using oxygen carriers that prevent direct contact between the fuel and air. This work presents the experimental results obtained in a 1 kWth CLR unit using a Ni-based oxygen carrier and diesel as fuel, as a first trial for further advancement with heavier liquid fuels. The influence of the main operating conditions, such as oxygen-to-diesel molar ratio and the H2O and/or CO2 feed into the system, was analysed in both steam and dry CLR processes. In addition, the combined steam-dry CLR process enabled the production of syngas with any H2/CO molar ratio between 0.2 and 3, which resulted in a wide variety of final products during its use in Fischer-Tropsch processes. In all cases, the syngas composition was close to that given by the thermodynamic equilibrium. These results demonstrate the technical feasibility of steam, dry, and combined steam-dry Reforming processes for liquid fossil fuels in a Chemical Looping system.
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optimization of hydrogen production with co2 capture by autothermal Chemical Looping Reforming using different bioethanol purities
Applied Energy, 2016Co-Authors: E Garciadiez, Juan Elorza Adanez, Luis Francisco De Diego, Alberto Abad, P Gaya, J. A.c. RuízAbstract:Autothermal Chemical-Looping Reforming (a-CLR) is a process which allows hydrogen production avoiding the environmental penalty of CO2 emission typically produced in other processes. The major advantage of this technology is that the heat needed for syngas production is generated by the process itself. The heat necessary for the endothermic reactions is supplied by a Ni-based oxygen-carrier (OC) circulating between two reactors: the air reactor (AR), where the OC is oxidized by air, and the fuel reactor (FR), where the fuel is converted to syngas. Other important advantage is that this process also allows the production of pure N2 in the AR outlet stream. A renewable fuel such as bioethanol was chosen in this work due to their increasing worldwide production and the current excess of this fuel presented by different countries.
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Optimization of hydrogen production with CO2 capture by autothermal Chemical-Looping Reforming using different bioethanol purities
Applied Energy, 2016Co-Authors: E. García-díez, Alberto Secades Abad, Pilar Sanz Gayan, Juan Elorza Adanez, Luis Francisco De Diego, Francisco García-labiano, Alberto Abad, J. A.c. RuízAbstract:Autothermal Chemical-Looping Reforming (a-CLR) is a process which allows hydrogen production avoiding the environmental penalty of CO2 emission typically produced in other processes. The major advantage of this technology is that the heat needed for syngas production is generated by the process itself. The heat necessary for the endothermic reactions is supplied by a Ni-based oxygen-carrier (OC) circulating between two reactors: the air reactor (AR), where the OC is oxidized by air, and the fuel reactor (FR), where the fuel is converted to syngas. Other important advantage is that this process also allows the production of pure N2 in the AR outlet stream. A renewable fuel such as bioethanol was chosen in this work due to their increasing worldwide production and the current excess of this fuel presented by different countries.In this work, mass and heat balances were done to determine the auto-thermal conditions that maximize H2 production, assuming that the product gas was in thermodynamic equilibrium. Three different types of bioethanol has been considered according to their ethanol purity; Dehydrated ethanol (≈100 vol.%), hydrated ethanol (≈96 vol.%), and diluted ethanol (≈52 vol.%). It has been observed that the higher H2 production (4.62 mol of H2 per mol of EtOH) has been obtained with the use of diluted ethanol and the surplus energy needed could be compensated by the energy save achieved during the purification of ethanol in the production process.