A novel continuous reactor for catalytic reduction of NO_x—fixed bed simulations

Abstract

A novel dual-zone fluidized bed reactor was proposed for the continuous adsorption and reduction of NO x from combustion flue gases. The adsorption and reaction behaviour of such a reactor has been simulated in a fixed bed reactor using Fe/ZSM-5 catalyst and propylene reductant with model flue gases. Fe/ZSM-5 exhibited acceptable activity at T = 350 • C and GHSV = 5000 h −1 when O 2 concentration was controlled at levels lower than 1% with a HC to NO molar ratio of about 2:1. XPS and BET surface area measurement revealed the nature of the deactivation of the catalyst. Those performance data demonstrated the feasibility of a continuous dual-zone fluidized bed reactor for catalytic reduction of NO x under lean operating conditions.

NOx adsorption and reduction with C3H6 over Fe/zeolite catalysts: Effect of catalyst support

“…NH 4 -form zeolites were first transformed to their H-form by calcination at 550 °C in air for 4 h. Fe/zeolites with an iron content of 5% were prepared via wet impregnation method by using a solution of Fe(AA) 3 (iron(III) acetylacetonate) in toluene, with details reported previously [11]. 4 2.2 Adsorption and reaction tests NO x adsorption and reduction were performed in a fixed bed reaction system, typically with 3.4 g of catalyst.…”

“…To overcome this problem, an internal circulating fluidized bed (ICFB) reactor with integrated NO x adsorption-reduction has been proposed to mitigate the negative impact of excess O 2 in the flue gas [11,12]. The SCR catalysts with good adsorption capacity and reduction of NO x are important for ICFB reactor.…”

Hydrodynamic Study of Gas–Solid Internally Circulating Fluidized Bed Using Multiphase CFD Model

“…Gas-solid fluidization by novel internally circulating fluidized beds (ICFB) are the second-generation fluidized beds adopted in various industrial operations such as coal combustion and gasification, catalyst regeneration, thermal cracking, specific nanoparticle synthesis and drying operations (Burugupalli 1988;Kim et al 2000;Kim et al 1997;Yang et al 2008). The ICFB is a compact modified spouted fluidized bed with a draft tube inside the column to avoid problem of gas bypassing and external solids recirculation.…”

Experimental investigation of hydrodynamics of gas‐solid flow in an internally circulating fluidized bed

“…The internally circulating fluidized bed with a draft tube (ICFB), a second‐generation fluidized device having combined properties of both modified spouted and circulating fluidized beds, is widely applied in physical and chemical processes such as coal combustion and gasification, catalyst regeneration, thermal cracking, specific nano‐particle synthesis, drying, coating, and granulation operations . The ICFB is a compact modified spouted fluidized bed with a draft tube inside the column to avoid the problem of gas bypassing and external solids recirculation found in conventional circulating fluidized beds (CFB).…”

“…Further, most past studies have utilized either mono‐size or narrow‐size particles. A few studies have also measured the fraction of bypassing gas using online gas chromatography and a few estimated gas bypassing using equal mass flux equations …”