Evaluation of various additives on the preparation of rice husk ash (RHA)/CaO-based sorbent for flue gas desulfurization (FGD) at low temperature

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

“…This FTIR spectrum (Fig. 2(c)) was similar to previous study [25]. In addition, a slight/weak band around 850 and 1384 cm −1 are detected for nitrate (NO 3 − ) species [37,39].…”

“…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.…”

The effect of hydrogen peroxide solution on SO2 removal in the semidry flue gas desulfurization process

“…Ca(OH) 2 in the slurry droplets also dissolves into ion form: Ca(OH) 2 ⇔ Ca 2+ + 2OH − . Thus, calcium species reacts with SO 3 2− to form calcium sulfite in the liquid film. Therefore, the product in the conventional semidry FGD processes is primarily consisted of unreacted Ca(OH) 2 dissolution into liquid film will almost not be affected by the liquid side equilibrium.…”

“…The semidry flue gas desulfurization (FGD) processes are effective in reducing SO 2 emission from medium-and small-scale coal-fired power stations with the advantages of small space requirement, low water consumption and low investment and operation costs [1][2][3]. Thus, these processes are very attractive for the desulfurization retrofits in the old units.…”

Review on the physicochemical treatments of rice husk for production of advanced materials

“…Acid washing lowered the ash pH and enhanced lutein adsorption by the ash. In the case of gas adsorption it was reported that absorbent prepared from rice husk ash such asRHA/CaO/CeO 2 , RHA/CaO, RHA doped with copper and RHAlithium based have a high capacity in sulfur dioxide (SO 2 ), NO and CO 2 absorption [32][33][34][35][36].In additionwith the aim of lowering manufacturing cost and green synthesis for CO 2 absorbant, a series of polyethyleneim-immobilized uni model and/or biolodal porous silicas were prepared from rice husk ash with biopolymer of chitosan as a pore structure-directing agent [37]. Zeng and Bai reported that TEPA-impregnated mesoporous silica from rice husk treated at 400ºC exihibits agood CO 2 adsorptioen capacity of 173 mg/g adsorbent under 10%CO 2 at 75ºC.…”