Experimental Demonstration of Two-Stage Packed Bed Chemical-Looping Combustion Using Syngas with CuO/Al₂O₃ and NiO/CaAl₂O₄ as Oxygen Carriers

Abstract

Recently, a novel two-stage reactor configuration for packed bed chemical-looping combustion (CLC) has been proposed and studied by numerical simulations. This two-stage CLC consists of two pressurized packed bed reactors connected in series, where the first bed contains an oxygen carrier material which is reactive at relatively low temperatures (450 °C) such as CuO/Cu, while the second bed contains an oxygen carrier which is resistant to relatively high temperatures (typically 1200 °C) such as NiO/Ni. In this work, this two-stage CLC concept has been experimentally demonstrated using CuO/Al2O3 and NiO/CaAl2O4 as bed materials in a high-pressure, high-temperature packed bed reactor. The influence of the operating conditions has been examined, and a validated reactor model has been used to scale up the process to industrial scale. The two-stage CLC concept is successfully demonstrated with a maximum temperature of 839 °C in the second bed. The operating pressure, the throughput during the reduction cycle, and the fuel concentrations have been found to result in small or negligible influences on the maximum temperature rise. This means that they do not affect the TS-CLC performance as long as the cycle time is adopted such that the heat produced in the first reactor bed is exactly transferred to the second bed. It has also been demonstrated that operation at higher pressures (to reach a higher overall process efficiency) does not affect the performance of the TS-CLC reactor. However, the fuel type (H2, syngas, CO, or CH4) strongly influences the temperature increase in the reactor, since it influences to what extent the oxygen carriers can be reduced. The experimental results could be well described by a one-dimensional packed bed reactor model provided that the extent of heat losses and the response time of the thermocouples are properly taken into account. The validated reactor model shows that the desired gas flow rate at 1200 °C can indeed be produced after some small changes in the operating conditions and the active weight content of the oxygen carriers. Therefore, TS-CLC can be regarded as a feasible technology for power production with inherent CO2 capture with high LHV efficiency.

Pre-combustion packed bed chemical looping (PCCL) technology for efficient H2-rich gas production processes

“…These results confirm that the expected temperature rise of the PCCL concept is in between the CLC and steam-iron processes. This conclusion is also confirmed by the theoretical temperature rise presented by Noorman et al [62] and discussed from numerical and experimental point of view in other works [27,29,63]. Photographs and SEM images of the fresh solid OC material and the materials after the tests in the packed bed reactor are shown in Fig.…”

Technoeconomic Analysis of a Fixed Bed System for Single/Two–Stage Chemical Looping Combustion

“…In their work, they investigated the performance of a CLC plant coupled with an integrated gasification combined cycle, in which the first OC is based on Cu and the second OC is based on Mn. Subsequent experimental studies were also performed by Kooiman et al [31] using CuO/Al 2 O 3 and NiO/ CaAl 2 O 4 in series, confirming the viability of this approach. More recently, Mancusi et al [32] analyzed CLC of methane and compared the performance of a single fixed bed reactor in a configuration embodying either one or two in-series OCs.…”

Gas Switching as a Practical Alternative for Scaleup of Chemical Looping Combustion

“…Another interesting PBCLC configuration recently proposed is the two‐stage CLC (TS‐CLC) concept . This concept has also recently been demonstrated experimentally . Here, two different oxygen carrier materials were employed: one specialized for low‐temperature operation (≈400–800 °C) and another for high‐temperature operation (≈800–1200 °C).…”

“…[35] This concept has also recently been demonstrated experimentally. [36] Here,t wo different oxygen carrier materials were employed: one specialized for low-temperature operation ( % 400-800 8C) and another for high-temperature operation ( % 800-1200 8C). Thel ow-temperature material (e.g.,C u-based) can be selected to displayf ast kinetics at low temperatures, whereas the high-temperature material (e.g., Mn-or Febased)c an be selected for good stability and selectivity at high temperatures.…”