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In this article, a process for sorption-enhanced steam methane reforming in an adiabatic fixed-bed reactor coupled with a solid oxide fuel cell (SOFC) is evaluated using a 1D numerical reactor model combined with a simplified fuel cell simulation. A novel material comprising CaO/CuO/Al2O3(NiO) pellets is considered. Three operating stages are considered in the proposed system, namely (i) CaO carbonation/reforming, (ii) Cu and Ni oxidation, and (iii) CaCO3 calcination/CuO and NiO reduction. The operating conditions that enable cyclic operation of these stages and the strategy needed to switch between each stage are evaluated. Under the adopted control strategy, methane conversion was about 95%, whilst H2 yield and purity were around 3.2 molH2 molCH4−1 and 90%, respectively. Moreover, a concentrated CO2 stream ready for storage was obtained. By using a portion of the produced H2 to make the process self-sufficient from an energy standpoint, an equivalent H2 yield and a reforming efficiency of about 2.8 molH2 molCH4−1 and 84% were achieved, respectively. With respect to SOFC integration, net power and thermal energy generation of around 11 kW and 6 kW, respectively, can be achieved. With respect to the chemical energy of the inlet methane, the net electrical and thermal efficiencies of the considered process are 56% and 30%, respectively, i.e., the overall efficiency of the entire system is 86%. The proposed cogeneration system showed better thermodynamic, environmental and economic performances than those of conventional systems, with an investment pay-back period of 2.2 years in the worst-case scenario. The levelised cost of electricity, of heat and total power were about 0.096 € kW h−1, 0.19 € kW h−1, and 0.065 € kW h−1, respectively, while the CO2 emissions were avoided at no cost.

In this study sorption-enhanced steam methane reforming (SE-SMR) in fixed beds is investigated by means of 1D numerical modelling, and the model is validated with the data reported in the literature. Isothermal conditions (973 K) are considered, and the equilibrium between the carbonation and calcination stages is shifted by a pressure swing: 3.5 · 106 Pa and 1013 Pa, respectively. The results showed that under these operating conditions at least 8 reactors in parallel are required to continuously produce a high-purity stream of H2, and a separated stream of concentrated CO2. The average H2 purity is 0.92, whilst the average H2 yield and selectivity are 2.9 molH2 molCH4−1 and 90%, respectively. A thermodynamic analysis was performed, which highlighted that, by using a portion of the produced H2 (about 0.4 molH2 molCH4−1), it is possible to fully cover heat and power demands of the process, making it completely energy self-sufficient. In the case when the proposed SE-SMR is integrated with a solid oxide fuel cell, net power generation at the scale of ∼950 kWel can be achieved with a net efficiency of the entire system of 51%, with the important feature that CO2 is concentrated.

Sorption-enhanced steam methane reforming (SE-SMR) is a promising alternative for H 2 production with inherent CO 2 capture. This study evaluates the techno-economic performance of SE-SMR in a network of fixed beds and its integration with a solid oxide fuel cell (SE-SMR-SOFC) for power generation. The analysis revealed that both proposed systems are characterised by better economic performance than the reference systems. In particular, for SE-SMR the levelised cost of hydrogen is 1.6 €⋅kg −1 and the cost of CO 2 avoided is 29.9 €⋅t CO2 −1 (2.4 €⋅kg −1 and 50 €⋅t CO2 −1 , respectively, for SMR with CO 2 capture) while for SE-SMR-SOFC the levelised cost of electricity is 0.078 €⋅kWh −1 and the cost of CO 2 avoided is 36.9 €⋅t CO2 −1 (0.080 €⋅kWh −1 and 80 €⋅t CO2 −1 , respectively, for natural gas-fired power plant with carbon capture). The sensitivity analysis showed that the specific cost of fuel and the capital cost of fuel cell mainly affect the economic performance of SE-SMR and SE-SMR-SOFC, respectively. The daily revenue of the SE-SMR-SOFC system is higher than that of the natural gas-fired power plant if the difference between the carbon tax and the CO 2 transport and storage cost is > 6 €⋅t CO2 −1 .

Although exploitation of Dual Fluidized Bed systems (DFB) is currently being explored in various fields, DFBs present some criticalities, mainly related to effective control of solids recirculation and to avoidance of gas leakage between the beds, extremely critical in Chemical Looping Reforming (CLR) for hydrogen production. For the latter, the choice of the degree of oxygen carrier oxidation/reduction, operation temperature and loop design makes the design even more challenging. This paper aims at the quantitative assessment of the influence of design variables by means of the numerical simulation of a DFB-CLR process operated at steady state conditions. The model couples a simple hydrodynamic simulation of a DFB system equipped with non-mechanical valves for bed solids circulation with a 1D, dynamic and non-isothermal CLR model developed to determine temperature and oxidation degree of solids and gaseous species concentration at the exit of both Air and Fuel Reactors. The DFB, consisting of a riser and of a bubbling fluidized bed (BFB) as Air and Fuel Reactors respectively, was modeled as a combination of interconnected blocks (riser, cyclone, L-valve, BFB, loop-seal) after selection of constitutive equations. Methane and Nickel (II) oxide were selected as fuel and oxygen carrier. Results corresponding to steady state operation are presented and the effects of operating conditions on the expected process performance are assessed. It is concluded that an appropriate choice of both operating temperature and amount of oxygen transported by oxygen carrier from AR to FR is an essential prerequisite in order to ensure process feasibility and good performances in terms of CH4 conversion and H2 selectivity.