Determination of the oxidation kinetics of high loaded CuO-based materials under suitable conditions for the Ca/Cu H2 production process

Abstract

In this work, the oxidation reaction of high loaded CuO-based materials was investigated under atmospheric and pressurized conditions. The oxygen transport capacity of the materials was firstly tested in the TGA and no losses greater than 5% were observed along 100 oxidation/reduction cycles. The kinetic parameters governing the oxidation reactions of the selected CuO-based materials were determined using a shrinking core model with chemical reaction control. The experimental results suggested that a SCM with chemical reaction control is able to predict the oxidation conversion of high loaded CuO-based materials in powder and pellet form. On the other hand, the effect of total pressure on materials reactivity was analyzed. The kinetic parameters obtained under atmospheric conditions were applied to fit the experimental data obtained under pressurized conditions. The results confirmed that the pressure has not an important effect on the oxidation kinetics of high loaded CuO-based materials and the parameters obtained at atmospheric pressure can be applied to study the oxidation under pressurized conditions.

A calcium zirconate based combined material for calcium-copper chemical looping technology

“…The peaks located around 300°C could also be attributed to CuO reduction, as the profile overlap between the reference H2-TPR CuO powder match well with the TPR 2 / TPR 3 profile shape. The reference H2-TPR CuO pattern is in line with that reported for CuO in literature (L. Díez-Martín et al, 2018a) (Laura Díez-Martín et al, 2018. It is of note that a significant portion of copper present in the combined material is seemingly more easily reduced than the CuO reference powder.…”

“…Common choices for improving copper based oxygen carriers are other pure or mixed metal oxides, e.g. Al2O3 (Chuang et al, 2008) (L. Díez-Martín et al, 2018a, MgAl2O4 (Arjmand et al, 2012) or ZrO2. Of special interest for this work are the reported Cu/Zr systems.…”

Complete Ca/Cu cycle for H2 production via CH4 sorption enhanced reforming in a Lab-Scale fixed bed reactor

“…The material was pelletized and the final particle size was in a range 0.6-2 mm to form a homogeneous bed with the sorbent and catalyst. A detailed kinetic study has been also performed elsewhere to determine oxidation and reduction kinetics of the Cu-based material under suitable conditions for the process [41,42]. It was determined that the evolution of material conversion with time can be successfully predicted by a shrinking core model under chemical reaction control and cylindrical geometry.…”

“…Momentum balance, Ergun equation [41,42] The wall-bed heat transfer coefficient (h w ) has been experimentally determined as described in the description of the rig. It has been determined as 9.5 W/m 2 K and allowed for an accurate fitting of the energy balance in the model.…”

Experimental investigation of the Ca-Cu process for H2 production: Evaluation of reduction/calcination strategies

“…According to a recent study carried out with this material by our research group [17], the HiFUEL catalytic activity for the steam methane reforming reaction was maintained after multiple redox cycles as the operation limits determined for the fresh catalyst were still valid for a mixture catalyst sorbent that had experienced hundred redox cycles. A detailed study has been performed to determine the materials kinetic parameters those govern the oxidation and reduction reactions of the Cu-based material [18,19], the carbonation reaction of the CO 2 sorbent [16], and the reforming kinetics of the catalyst. According to the results obtained during the materials testing, they presented sufficient reactivity and stability to be used for the process proof of concept that took place within the project.…”