This paper presents a novel quasi-autothermal hydrogen production process. The proposed layout couples a Chemical Looping Combustion (CLC) section and a Steam Methane Reforming (SMR) one. In CLC section, four packed-beds are operated using Ni as oxygen carrier and CH4 as fuel to continuously produce a hot gaseous mixture of H2O and CO2. In SMR section, two fixed-beds filled with Ni-based catalyst convert CH4 and H2O into a H2-rich syngas. Four heat exchangers were employed to recover residual heat content of all the exhaust gas currents. By means of a previously developed 1D numerical model, a dynamic simulation study was carried out to evaluate feasibility of the proposed system in terms of methane conversion (100% circa), hydrogen yield (about 0.65 molH2/molCH4) and selectivity (about 70%), and syngas ratio (about 2.3 molH2/molCO). Energetic and environmental analyses of the system performed with respect to conventional steam methane reforming, highlights an energy saving of about 98% and avoided CO2 emission of about 99%.

Novel quasi -autothermal hydrogen production process in a fixed-bed using a chemical looping approach: A numerical study

Diglio G;Bareschino P;Mancusi E
;
Pepe F
2017

Abstract

This paper presents a novel quasi-autothermal hydrogen production process. The proposed layout couples a Chemical Looping Combustion (CLC) section and a Steam Methane Reforming (SMR) one. In CLC section, four packed-beds are operated using Ni as oxygen carrier and CH4 as fuel to continuously produce a hot gaseous mixture of H2O and CO2. In SMR section, two fixed-beds filled with Ni-based catalyst convert CH4 and H2O into a H2-rich syngas. Four heat exchangers were employed to recover residual heat content of all the exhaust gas currents. By means of a previously developed 1D numerical model, a dynamic simulation study was carried out to evaluate feasibility of the proposed system in terms of methane conversion (100% circa), hydrogen yield (about 0.65 molH2/molCH4) and selectivity (about 70%), and syngas ratio (about 2.3 molH2/molCO). Energetic and environmental analyses of the system performed with respect to conventional steam methane reforming, highlights an energy saving of about 98% and avoided CO2 emission of about 99%.
Steam methane reforming Chemical looping; Near zero-CO2 emissions; Fixed-bed reactors network
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/20.500.12070/4587
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