Abstract
Chemical looping combustion of natural gas is one of the most promising technologies for power production with inherent CO2 capture. Pressurized chemical looping systems promise the potential for increasing the power plant efficiency compared to atmospheric process, hence gas turbine can be used in a combined cycle operation. However, there are many challenges facing the pressurized operation of the conventional dual fluidized-bed reactor.
This study provides the prospects and opportunities that exist for novel application of the internally circulating reactor (ICR) to be used for pressurized chemical looping combustion.
A novel reactor design, the ICR, is proposed which incorporates many of the operational capabilities of the circulating fluidized-bed, while eliminating the complex separation systems (i.e., cyclone and loop seals). The unit consists of a single reactor that combines two sections, (i.e., the fuel and air sections) with internal physical separations. Specifically, the concept aims to simplify the design, ease the solid circulation, operate at high pressure easily in a single pressurized vessel and eventually bring the chemical looping technology a step closer to commercialization [1,2]. The aim of this study is to experimentally study the feasibility of chemical looping combustion using ICR concept, as well as to obtain some insights about this type of reactor in terms of configuration and operation conditions.
The ICR unit has been constructed and currently being commissioned. The reactor placed in a cylindrical shell to accommodate a maximum pressure of 10 bar. Cold flow experiments revealed the operating conditions required for achieving steady solids circulation and minimum gas leakage between the two sections.
The primary aim of the reactive experiments is to demonstrate autothermal operation of the CLC process in the ICR under pressurized conditions. Experiments are being carried out using NiO/Al2O3 as oxygen carrier under different temperatures, pressures and air/fuel ratios to gain a complete understanding of reactor behaviour. Reactor performance is quantified in terms of the fuel and air conversion achieved as well as the degree of undesired gas leakage between the two reactor sections. Gas leaking with the circulating solids through the interconnecting ports will decrease CO2 capture and purity, and must be minimized. Previous work has shown that CO2 capture and purity of ~95% can be achieved when reactor operation is optimized [2].
References
[1] Zaabout, S. Cloete, S. Amini, Chemical Engineering & Technology, 39 (2016) 1413-1424.
[2] S. Cloete, A. Zaabout, S. Amini, Energy Procedia, 114 (2017) 446-457.
This study provides the prospects and opportunities that exist for novel application of the internally circulating reactor (ICR) to be used for pressurized chemical looping combustion.
A novel reactor design, the ICR, is proposed which incorporates many of the operational capabilities of the circulating fluidized-bed, while eliminating the complex separation systems (i.e., cyclone and loop seals). The unit consists of a single reactor that combines two sections, (i.e., the fuel and air sections) with internal physical separations. Specifically, the concept aims to simplify the design, ease the solid circulation, operate at high pressure easily in a single pressurized vessel and eventually bring the chemical looping technology a step closer to commercialization [1,2]. The aim of this study is to experimentally study the feasibility of chemical looping combustion using ICR concept, as well as to obtain some insights about this type of reactor in terms of configuration and operation conditions.
The ICR unit has been constructed and currently being commissioned. The reactor placed in a cylindrical shell to accommodate a maximum pressure of 10 bar. Cold flow experiments revealed the operating conditions required for achieving steady solids circulation and minimum gas leakage between the two sections.
The primary aim of the reactive experiments is to demonstrate autothermal operation of the CLC process in the ICR under pressurized conditions. Experiments are being carried out using NiO/Al2O3 as oxygen carrier under different temperatures, pressures and air/fuel ratios to gain a complete understanding of reactor behaviour. Reactor performance is quantified in terms of the fuel and air conversion achieved as well as the degree of undesired gas leakage between the two reactor sections. Gas leaking with the circulating solids through the interconnecting ports will decrease CO2 capture and purity, and must be minimized. Previous work has shown that CO2 capture and purity of ~95% can be achieved when reactor operation is optimized [2].
References
[1] Zaabout, S. Cloete, S. Amini, Chemical Engineering & Technology, 39 (2016) 1413-1424.
[2] S. Cloete, A. Zaabout, S. Amini, Energy Procedia, 114 (2017) 446-457.