The cell performance and temperature gradient of a tubular solid oxide fuel cell with indirect internal reformer (IIR-SOFC) fuelled by natural gas, containing a typical catalytic packed-bed reformer, a catalytic coa...The cell performance and temperature gradient of a tubular solid oxide fuel cell with indirect internal reformer (IIR-SOFC) fuelled by natural gas, containing a typical catalytic packed-bed reformer, a catalytic coated wall reformer, a catalytic annular reformer, and a novel catalytic annular-coated wall reformer were investigated with an aim to determine the most efficient internal reformer system. Among the four reformer designs, IIR-SOFC containing an annular-coated wall reformer exhibited the highest performance in terms of cell power density (0.67 W.cm 2) and electrical efficiency (68%) with an acceptable temperature gradient and a moderate pressure drop across the reformer (3.53 × 10 5 kPa). IIR-SOFC with an annular-coated wall reformer was then studied over a range of operating conditions: inlet fuel temperature, operating pressure, steam to carbon (S : C) ratio, gas flow pattern (co-flow and counter-flow pattern), and natural gas compositions. The simulation results showed that the temperature gradient across the reformer could not be decreased using a lower fuel inlet temperature (1223 K-1173 K) and both the power density and electrical efficiency of the cell also decreased by lowering fuel inlet temperature. Operating in higher pressure mode (1-10 bar) improved the temperature gradient and cell performance. Increasing the S : C ratio from 2 : 1 to 4:1 could decrease the temperature drop across the reformer but also decrease the cell performance. The average temperature gradient was higher and smoother in IIR-SOFC under a co-flow pattern than that under a counter-flow pattern, leading to lower overpotential and higher cell performance. Natural gas compositions significantly affected the cell performance and temperature gradient. Natural gas containing lower methane content provided smoother temperature gradient in the system but showed lower power density and electrical efficiency.展开更多
The Alkaline Thermal Treatment(ATT)of biomass is one of the few biomass conversion processes that has a potential for BECCS(bio-energy with carbon capture and storage).Combining in-situ carbon capture withcreates a ca...The Alkaline Thermal Treatment(ATT)of biomass is one of the few biomass conversion processes that has a potential for BECCS(bio-energy with carbon capture and storage).Combining in-situ carbon capture withcreates a carbon-neutral process that has the potential to be carbon-negative.This study has shown that the conversion of cellulose tosuppressedcan be achieved through the reforming of gaseous intermediates in a fixed bed of 10%Ni/ZrO2.Reforming occurs at low temperatures≤773 K,which could allow for improved sustainability.展开更多
An approach for the simulation and optimization of continuous catalyst-regenerative process of reforming is proposed in this paper.Compared to traditional method such as finite difference method,the orthogonal colloca...An approach for the simulation and optimization of continuous catalyst-regenerative process of reforming is proposed in this paper.Compared to traditional method such as finite difference method,the orthogonal collocation method is less time-consuming and more accurate,which can meet the requirement of real-time optimization(RTO).In this paper,the equation-oriented method combined with the orthogonal collocation method and the finite difference method is adopted to build the RTO model for catalytic reforming regenerator.The orthogonal collocation method was adopted to discretize the differential equations and sequential quadratic programming(SQP)algorithm was used to solve the algebraic equations.The rate constants,active energy and reaction order were estimated,with the sum of relative errors between actual value and simulated value serving as optimization objective function.The model can quickly predict the fields of component concentration,temperature and pressure inside the regenerator under different conditions,as well as the real-time optimized conditions for industrial reforming regenerator.展开更多
The purpose of this study is to explore a method for the high-yield production of hydrogen by pyrolysis and steam reforming of polymer plastics.The developed Fe-based catalyst supported on activated carbon was applied...The purpose of this study is to explore a method for the high-yield production of hydrogen by pyrolysis and steam reforming of polymer plastics.The developed Fe-based catalyst supported on activated carbon was applied to reactions with polypropylene for hydrogen production.The effects of iron loading(%)in the catalyst,the total catalyst amount,and the water content in the reaction atmosphere on the performance of hydrogen and gas production were investigated.Under the optimal conditions,the hydrogen yield without water added reached 38.73 mmol/gPP,and this yield was significantly improved by adding water into the reaction atmosphere.By optimizing the amount of water added,the hydrogen yield reached 112.71 mmol/gPP.The surface morphology and structural components of the fresh and used catalysts were characterized,and the morphology and quantity of carbon deposition on the catalyst were analysed.The catalytic stability of the 15Fe/AC catalyst was determined by repeating the test 10 times under the optimal reaction conditions.As the reaction time increased,the selectivity of the catalyst for hydrogen decreased and that for hydrocarbons increased.Moreover,the experimental method used in this study had excellent hydrogen production capacity.Thus,this study provided a novel method for the high-efficiency production of hydrogen by pyrolysis and steam reforming of polymer plastics.展开更多
Catalytic steam reforming is a promising route for tar conversion to high energy syngas in the process of biomass gasification. However, the catalyst deactivation caused by the deposition of residual carbon is still a...Catalytic steam reforming is a promising route for tar conversion to high energy syngas in the process of biomass gasification. However, the catalyst deactivation caused by the deposition of residual carbon is still a major challenge. In this paper, a modified Ni-based Ni-Co/Al2O3-CaO (Ni-Co/AC) catalyst and a conventional Ni/Al2O3 (Ni/A) catalyst were prepared and tested for tar catalytic removal in which toluene was selected as the model component. Experiments were conducted to reveal the influences of the reaction temperature and the ratio between steam to carbon on the toluene conversion and the hydrogen yield. The physicochemical properties of the modified Ni-based catalyst were determined by a series of characterization methods. The results indicated that the Ni-Co alloy was determined over the Ni-Co/AC catalyst. The doping of CaO and the presence of Ni-Co alloy promoted the performance of toluene catalytic dissociation over Ni-Co/AC catalyst compared with that over Ni/A catalyst. After testing in steam for 40 h, the carbon conversion over Ni-Co/AC maintained above 86% and its resistance to carbon deposition was superior to Ni/A catalyst.展开更多
基金supported by the Cultivation Project of Major Achievements Transformation of Sichuan Provincial Education Department(#14CZ0005)supported by the Natural Science Foundation of China(#21406184)
基金supported by the Thailand Research Fund(TRG 5680051)
文摘The cell performance and temperature gradient of a tubular solid oxide fuel cell with indirect internal reformer (IIR-SOFC) fuelled by natural gas, containing a typical catalytic packed-bed reformer, a catalytic coated wall reformer, a catalytic annular reformer, and a novel catalytic annular-coated wall reformer were investigated with an aim to determine the most efficient internal reformer system. Among the four reformer designs, IIR-SOFC containing an annular-coated wall reformer exhibited the highest performance in terms of cell power density (0.67 W.cm 2) and electrical efficiency (68%) with an acceptable temperature gradient and a moderate pressure drop across the reformer (3.53 × 10 5 kPa). IIR-SOFC with an annular-coated wall reformer was then studied over a range of operating conditions: inlet fuel temperature, operating pressure, steam to carbon (S : C) ratio, gas flow pattern (co-flow and counter-flow pattern), and natural gas compositions. The simulation results showed that the temperature gradient across the reformer could not be decreased using a lower fuel inlet temperature (1223 K-1173 K) and both the power density and electrical efficiency of the cell also decreased by lowering fuel inlet temperature. Operating in higher pressure mode (1-10 bar) improved the temperature gradient and cell performance. Increasing the S : C ratio from 2 : 1 to 4:1 could decrease the temperature drop across the reformer but also decrease the cell performance. The average temperature gradient was higher and smoother in IIR-SOFC under a co-flow pattern than that under a counter-flow pattern, leading to lower overpotential and higher cell performance. Natural gas compositions significantly affected the cell performance and temperature gradient. Natural gas containing lower methane content provided smoother temperature gradient in the system but showed lower power density and electrical efficiency.
文摘The Alkaline Thermal Treatment(ATT)of biomass is one of the few biomass conversion processes that has a potential for BECCS(bio-energy with carbon capture and storage).Combining in-situ carbon capture withcreates a carbon-neutral process that has the potential to be carbon-negative.This study has shown that the conversion of cellulose tosuppressedcan be achieved through the reforming of gaseous intermediates in a fixed bed of 10%Ni/ZrO2.Reforming occurs at low temperatures≤773 K,which could allow for improved sustainability.
基金This work was supported by the Science and Technology Development Project of SINOPEC,China(No.319026).
文摘An approach for the simulation and optimization of continuous catalyst-regenerative process of reforming is proposed in this paper.Compared to traditional method such as finite difference method,the orthogonal collocation method is less time-consuming and more accurate,which can meet the requirement of real-time optimization(RTO).In this paper,the equation-oriented method combined with the orthogonal collocation method and the finite difference method is adopted to build the RTO model for catalytic reforming regenerator.The orthogonal collocation method was adopted to discretize the differential equations and sequential quadratic programming(SQP)algorithm was used to solve the algebraic equations.The rate constants,active energy and reaction order were estimated,with the sum of relative errors between actual value and simulated value serving as optimization objective function.The model can quickly predict the fields of component concentration,temperature and pressure inside the regenerator under different conditions,as well as the real-time optimized conditions for industrial reforming regenerator.
基金supported by National Key R&D Program of China(2019YFC1906803)CAS Project for Young Scientists in Basic Research(YSBR-044).
文摘The purpose of this study is to explore a method for the high-yield production of hydrogen by pyrolysis and steam reforming of polymer plastics.The developed Fe-based catalyst supported on activated carbon was applied to reactions with polypropylene for hydrogen production.The effects of iron loading(%)in the catalyst,the total catalyst amount,and the water content in the reaction atmosphere on the performance of hydrogen and gas production were investigated.Under the optimal conditions,the hydrogen yield without water added reached 38.73 mmol/gPP,and this yield was significantly improved by adding water into the reaction atmosphere.By optimizing the amount of water added,the hydrogen yield reached 112.71 mmol/gPP.The surface morphology and structural components of the fresh and used catalysts were characterized,and the morphology and quantity of carbon deposition on the catalyst were analysed.The catalytic stability of the 15Fe/AC catalyst was determined by repeating the test 10 times under the optimal reaction conditions.As the reaction time increased,the selectivity of the catalyst for hydrogen decreased and that for hydrocarbons increased.Moreover,the experimental method used in this study had excellent hydrogen production capacity.Thus,this study provided a novel method for the high-efficiency production of hydrogen by pyrolysis and steam reforming of polymer plastics.
基金This work was financially supported by the National Nature Science Foundation of China(Grant Nos.51922040 and 51821004)the Fok Ying Tung Education Foundation(Grant No.161051)the Fundamental Research Funds for the Central Universities(Nos.2018ZD08 and 2020DF01).
文摘Catalytic steam reforming is a promising route for tar conversion to high energy syngas in the process of biomass gasification. However, the catalyst deactivation caused by the deposition of residual carbon is still a major challenge. In this paper, a modified Ni-based Ni-Co/Al2O3-CaO (Ni-Co/AC) catalyst and a conventional Ni/Al2O3 (Ni/A) catalyst were prepared and tested for tar catalytic removal in which toluene was selected as the model component. Experiments were conducted to reveal the influences of the reaction temperature and the ratio between steam to carbon on the toluene conversion and the hydrogen yield. The physicochemical properties of the modified Ni-based catalyst were determined by a series of characterization methods. The results indicated that the Ni-Co alloy was determined over the Ni-Co/AC catalyst. The doping of CaO and the presence of Ni-Co alloy promoted the performance of toluene catalytic dissociation over Ni-Co/AC catalyst compared with that over Ni/A catalyst. After testing in steam for 40 h, the carbon conversion over Ni-Co/AC maintained above 86% and its resistance to carbon deposition was superior to Ni/A catalyst.