Dry SO₂ Removal Process Using Calcium/Siliceous‐Based Sorbents: Deactivation Kinetics Based on Breakthrough Curves

Abstract

The removal of sulfur dioxide (SO 2 ) from simulated flue gas was investigated in a laboratory-scale stainless steel fixed-bed reactor using sorbents prepared from various siliceous materials, i.e., coal fly ash (CFA), oil palm ash (OPA) and rice husk ash (RHA) mixed with lime (CaO) by means of the water hydration method. Experiments were carried out with a flue gas flow rate of 150 mL/min, reaction temperature of 100°C, and SO 2 concentration of 1000 ppm. It was found that sorbents prepared from RHA have high BET surface areas and high SO 2 sorption capacities, based on breakthrough curve analysis. In addition, the SO 2 breakthrough curves were also described in terms of a simple first-order deactivation model containing only two rate constants, one of which, k s , describes the surface reaction rate constant while the other, k d , describes the deactivation rate constant. The values of k s and k d obtained from the deactivation kinetics model were in good agreement with the experimental breakthrough curves and were also compared with those available in the literature.

Selection of metal oxides in the preparation of rice husk ash (RHA)/CaO sorbent for simultaneous SO2 and NO removal

“…Previously, we had reported the sorption characteristics of SO 2 by RHA/CaO sorbent [21][22][23][24][25]. However, this sorbent was unable to remove NO gases.…”

Value-added utilization of oil palm ash: A superior recycling of the industrial agricultural waste

“…Simultaneously, oil palm ash, an abundantly available throwaway waste from the fired-boiler furnaces, has currently emerged to be an ideal adsorbent in the wastewater treatment processes and as air purifier in cleaning of atmosphere contaminants [27]. Table 2 lists previous researches in the utilization of oil palm ash as novel adsorbents for different applications.…”

“…In the perspective, gas sulfur dioxide has been identified as a major air pollutant, mainly hinges of its accumulative and detrimental effect to the survival of aquatic life, ecology and food chains, by imposing a significant influence on the mobilization and attenuation towards the formation of acid rain and urban smog, resulting in visibility impairment, buildings damages, silicosis syndrome, fatigue, bronchitis, shortness of breath, smell sense alteration, loss of appetite (respiratory failure) and even death [7,27]. A substantial amount of adsorption studies have been abounded, reporting a 100% gas removal, equivalent to a 5.06 mg/g adsorption capacity [9,27,29,35]. Under the co-treatment process, pozzolanic phenomenon begins with the elution of silica and alumina from ash particles by alkaline water (rate-limiting step), succeeding by the reaction with calcium oxide and hydroxide in the formation of calcium aluminium silicate hydrate compounds.…”

Recovery of Acrylic Acid Using Calcium Peroxide Nanoparticles: Thermodynamics and Continuous Column Study

“…The deactivation kinetic model involving a single activity term denoting a combined effect of active surface area, pore structure, and activity per unit area of solid reactant, was developed primarily for gas-solid adsorption. The model neglects axial dispersion and mass transfer resistance, and assumes isothermal and pseudo-steady-state conditions 46,47 . The deactivation kinetic model is expressed as follows 48 : where k 0 and k d are initial adsorption rate constant (mL g -1 min -1 ) and deactivation rate constant (min -1 ), respectively.…”