Sorption-enhanced Reforming Process Research Articles

Modelling of methane sorption enhanced reforming for blue hydrogen production in an adiabatic fixed bed reactor: unravelling the role of the reactor's thermal behavior

Methane sorption enhanced reforming (SER) is investigated in this work as a promising route for blue H2 production. A 1-D dynamic heterogeneous model is developed to evaluate the thermal behavior of a fixed bed reactor under adiabatic conditions. The heterogeneous model allows to decouple the feed gas temperature from the initial solid one in order to investigate the behavior of the reforming step in a temperature swing reforming/regeneration process. The effects of the feed gas temperature, the initial bed temperature, and the bed thermal capacity are studied by evaluating the global impact of each parameter through a set of key performance indices (CH4 conversion, H2 yield and purity, carbon capture ratio) calculated as integrals over the duration of the reforming step. The results highlight the minor effect of the initial bed temperature on the process performances showing the potential of minimizing the extent of a cooling step between regeneration and reforming stages. Besides, due to the endothermic nature of the methane sorption enhanced reforming process at high temperatures, thermal energy must be provided to the SER process to achieve high CH4 conversion and high carbon capture ratio. This can be made either in the form of high feed temperature or by utilizing the energy stored in the bed benefiting from the bed thermal capacity.

Experimental study of the application of a NiO/NiAl2O4 catalyst and a CaO-based synthetic sorbent on the Sorption Enhanced Reforming process

A CaO-based synthetic sorbent and a NiO/NiAl2O4 catalyst are synthesized and tested under Sorption Enhanced Reforming (SER) conditions in a fixed bed reactor. The effect of temperature, steam-to-methane ratio (S/C) and sorbent-to-catalyst proportion (Z) are studied. A SER based plant simulation model is implemented to evaluate if the operating conditions chosen allow for a self-sustained plant from a thermal energy consumption standpoint.The most appropriate temperature for SER test is 650 °C. At 600 °C the catalyst seems to be not sufficiently active, while at 700 °C, a longer breakthrough period results. SER equilibrium is reached even at the lowest S/C ratio of 1.6, obtaining H2 purity of 82 vol.% (dry basis). For the SER based plant simulation developed, the low S/C ratio of 1.6 allows a self-sustained plant where the energy required in the calciner for CaCO3 decomposition is supplied by burning the off-gas from the H2 purification unit.

Sorption-enhanced reforming with limestone from iron production

In this work, the experimental performance of sorption-enhanced reforming using limestone as bed material, which is used in raw iron production, is presented. Steam gasification of solid biomass by sorption-enhanced reforming process (SER) leads to product gas with high hydrogen content and low tar content. The product gas can be used for a wide range of applications. This includes heat and electricity production, synthetic fuels, and other downstream processes. On the basis of dual fluidized bed steam gasification of biomass (dual fluid gasification), a reactive bed material is used to enhance the formation of hydrogen. Blast furnaces in iron production operate on the principle of chemical reduction, whereby carbon monoxide and hydrogen reduce the iron to its elemental form. The present paper summarizes the results of an experimental investigation into SER with limestone usually used as a part of iron production. The illustrated results reflect the operation of sorption-enhanced reforming within an experimental facility at the Vienna University of Technology.

Study of nickel catalysts for hydrogen production in sorption enhanced reforming process

The performance of Ni based catalysts to be used in Sorption Enhanced Reforming (SER) is assessed. For this aim, both their activity at low temperature and their behavior during multiple oxidation–reduction cycles in steam methane reforming are studied. Ni catalysts supported on α-Al2O3, Si3N4 and NiAl2O4, with different amounts of Ni (0–50% NiO), are compared by testing their activity in a fixed bed micro-reactor. While Ni/Si3N4 catalysts do not show an appropriate performance at low temperature, Ni/α-Al2O3 and Ni/NiAl2O4 present a significant activity, close to equilibrium data, at the typical SER conditions. The best experimental results are attained for 20% NiO/α-Al2O3 and 10% NiO/NiAl2O4 catalysts that show an activity close to the equilibrium for steam to methane ratio of 4.5. Higher amounts of NiO in both catalysts do not reveal an improvement in conversion results. In addition, both 20% NiO/α-Al2O3 and 10% NiO/NiAl2O4 catalysts show a good reforming activity after oxidation–reduction cycles at typical SER temperatures. The observed trend to carbon deposition on the catalyst surface for the studied supports is Si3N4 > Al2O3 > NiAl2O4, being negligible when NiAl2O4 support is used. These results suggested that 10% NiO/NiAl2O4 and 20% NiO/Al2O3 catalysts could be perfect candidates to be used in SER process.

Design of a hydrogen production process for power generation based on a Ca-Cu chemical loop

This work proposes the integration into a NGCC of a novel H2 production process based on a double chemical Ca-Cu loop. This H2 production process is based on the Sorption Enhanced Reforming process including a CaO-based solid as a high temperature CO2 sorbent. The addition of a second CuO/Cu loop provides the energy required to carry out sorbent regeneration. The coupling between this process and a combined cycle is discussed in this paper, and an efficiency assessment of the whole plant is accomplished. 9.5 percentage points of efficiency penalty has resulted from the integration proposed in this work, which is in the range of those penalties reported for the ATR, POX or SEWGS integrated with a combined cycle. Ca-Cu looping performance is prone to be improved if less exigent conditions were chosen, which added to the inherent advantages of cheaper reactor design, feasible solid materials and less process units make the Ca-Cu looping process emerge as a potential pre-combustion CO2 capture technology.

National Baby Congress and Health Exposition

This work proposes the integration into a NGCC of a novel H2 production process based on a double chemical Ca-Cu loop. This H2 production process is based on the Sorption Enhanced Reforming process including a CaO-based solid as a high temperature CO2 sorbent. The addition of a second CuO/Cu loop provides the energy required to carry out sorbent regeneration. The coupling between this process and a combined cycle is discussed in this paper, and an efficiency assessment of the whole plant is accomplished. 9.5 percentage points of efficiency penalty has resulted from the integration proposed in this work, which is in the range of those penalties reported for the ATR, POX or SEWGS integrated with a combined cycle. Ca-Cu looping performance is prone to be improved if less exigent conditions were chosen, which added to the inherent advantages of cheaper reactor design, feasible solid materials and less process units make the Ca-Cu looping process emerge as a potential pre-combustion CO2 capture technology.