Chemical-looping combustion - an overview and application of the recirculating fluidized bed reactor for improvement

Abstract

SUMMARYThis paper propose recirculating fluidized bed (RCFB) reactor for chemical-looping combustion (CLC) to overcome some of the issues associated with the existing interconnected reactors arrangements like low residence time of bed material in the air reactor, high attrition of bed material in the cyclone separator, cluster formation in the air reactor, complex operation involving loop seals and high heat losses. RCFB has high solid circulation rate, long residence time, efficient fuel-oxygen carrier contact, low heat losses and low gas leak in between the reactors, as compared to the existing reactor configurations. A cold model study was performed on a Perspex made, semicircular, transparent RCFB reactor. A single RCFB reactor was operated in the alternate oxidation and fuel burning cycles to simulate the interconnected reactors arrangement for CLC. The generated experimental data has been used to predict the optimal RCFB reactor configuration for a RCFB-based CLC power plant.

Energy and exergy analysis of chemical looping combustion technology and comparison with pre-combustion and oxy-fuel combustion technologies for CO2 capture

“…OC particles recovered in cyclone are recycled to the fuel reactor. The CLC reactor models are validated with experimental results available in literature [32][33][34]. Steam generation/reheat for Case 4 follows the same approach as discussed in Case 3.…”

Redox reactivity of titania‐doped YSZ‐promoted iron‐based oxygen carrier over multiple redox cycles for chemical looping reforming of methane and hydrogen production

“…This process takes advantages of lower energy requirement in separation steps for CO 2 capture or air separation unit (ASU) . The metal oxides are used as oxygen carrier that transfers pure oxygen from the oxidizing gases to fuel in a separate reactor, leading to enhancing the exergy efficiency due to reduction of parasitic energy in separation steps . The oxygen carrier is mainly composed of the active metal oxide and the supporting material for mechanical strength and redox properties .…”

“…[1][2][3][4][5] The metal oxides are used as oxygen carrier that transfers pure oxygen from the oxidizing gases to fuel in a separate reactor, leading to enhancing the exergy efficiency due to reduction of parasitic energy in separation steps. [6][7][8] The oxygen carrier is mainly composed of the active metal oxide and the supporting material for mechanical strength and redox properties. 9 The overall process efficiency and the heat/ mass balance largely depend on the selection of the metal oxide redox pairs (ie, Fe 2 O 3 $ Fe, NiO $ Ni, and CuO $ Cu).…”

On the accuracy of Landweber and Tikhonov reconstruction techniques in gas‐solid fluidized bed applications

“…Polymerization, drying, and granulation are a few examples of their applications. [1][2][3][4][5][6] Due to the importance of these contactors, a wide range of experimental techniques has become available to capture their hydrodynamic behavior. [7][8][9][10][11][12][13][14][15] Each experimental technique has its own advantages and disadvantages.…”