Thermogravimetric Analysis of Copper Oxide for Chemical-Looping Hydrogen Generation

Abstract

The chemical-looping hydrogen generation (CLH) system consists of reduction of metal oxide and water decomposition by oxidizing reduced metal oxide. In the present study, water decomposition by the reduction and oxidation of metal oxide (CuO) was conducted in a thermogravimetric analysis (TGA) system for the CLH process. The particles are reduced completely in an atmosphere of synthesis gas (H2 + CO), and the fully reduced particles decompose water to produce 3.7 L of H2 per kilogram of metal oxide. The particles prepared by the impregnation exhibits better reactivity than those by coprecipitation and the solid phase method, and the particles supported on Al2O3 exhibit better reactivity than those on SiO2. Based on the TGA, the reduction and oxidation of CuO/Al2O3 prepared via impregnation are characterized by the kinetic equations from the solid-state reaction rate models. The phase-controlled-boundary model was successfully applied to predict the initial stages of reduction and oxidation of the metal oxide, and the activation energies for reduction and oxidation are determined to be 4.13−19.5 and −55.8 kJ/mol, respectively.

Advancements in Development of Chemical-Looping Combustion: A Review

“…In the 20-cycle test neither performance decay nor mechanical degradation of the oxygen carrier has been observed. Son et al [49] found that the oxygen particles supported on SiO 2 exhibit worse reactivity than those on Al 2 O 3 . In addition, ZrO 2 , TiO 2 , and bentonite were also studied as the inert support for copper-based oxygen carrier [50][51][52].…”

“…The outlet gas stream from the fuel reactor contains only CO 2 and H 2 O at complete conversion of the fuel, while the exit gas from the steam reactor is just H 2 with excess H 2 O. Therefore, pure H 2 and CO 2 can be obtained with H 2 O condensation without any further separation process [95]. The work in [95] reported that 3.7 L of H 2 was generated through reaction between per kilogram fully reduced copper-based oxide and steam.…”

“…Therefore, pure H 2 and CO 2 can be obtained with H 2 O condensation without any further separation process [95]. The work in [95] reported that 3.7 L of H 2 was generated through reaction between per kilogram fully reduced copper-based oxide and steam. Go et al [96] investigated hydrogen production by chemical-looping of methane in a fluidized-bed reactor using iron-based oxygen carrier.…”

Kinetics of mixed copper–iron based oxygen carriers for hydrogen production by chemical looping water splitting

“…The reduced carrier is then transported to an air reactor where it is reconstituted to its original state with air. The CLWS process is based on two reactors, similar to those used in the CLC [11] with the difference that the desired product is hydrogen, not energy. A fuel (natural gas/syngas/ coal and even biomass) reacts with an oxygen carrier in the fuel reactor to produce both H 2 O and CO 2 .…”

“…Copper was recently proposed by Son et al as an active metal for H 2 generation [11]. The reaction occurs at low temperatures and involves the Cu/Cu 2 O redox couple Iron has probably been the most studied metal oxide (together with Zn/ZnO) regarding water hydrolysis.…”