This study presents the findings of an investigation involving the absorption of SO₂ from flue gases, using three different sorbents, in a spray dryer. Experimentation involved the evaluation of three sorbents, i.e., hydrated lime (Ca[OH]₂), limestone (CaCO₃), and trona (Na₂CO₃·NaHCO₃·2H₂O), and their relevant properties, for flue gas desulfurization by spray dry scrubbing. Experiments were conducted to explore the effects of spray characteristics in the spray drying scrubber on SO₂ removal efficiency using the selected sorbents. The ranges of various operating parameters were considered, including the stoichiometric molar ratio of (1.0-2.5), the inlet gas phase temperature of (120-180 °C), and an inlet SO₂ concentration of 1000 ppm. The use of trona gave better SO₂ removal characteristics; a high SO₂ removal efficiency of 94% was recorded at an inlet gas phase temperature of 120 °C and a stoichiometric molar ratio of 1.5. Under the same operating conditions, Ca[OH]₂ and CaCO₃ gave 82 and 76% SO₂ removal efficiency, respectively. Analysis of the desulfurization products by X-ray fluorescence (XRF) and Fourier transform infrared (FTIR) spectroscopy revealed the presence of CaSO₃/Na₂SO₃, a product of the semidry desulfurization reaction. A significant proportion of unreacted sorbent was observed when Ca[OH]₂ and CaCO₃ sorbents were used at a stoichiometric ratio of 2.0. Trona also gave the highest degree of conversion (96%) at a stoichiometric molar ratio of 1.0. Ca[OH]₂ and CaCO₃ gave 63 and 59%, respectively, under the same operating conditions.

This work reports on the structural modification of cellulosic materials with magnetic iron oxide nanoparticles through the co-precipitation method. Cellulose is one of the most abundant natural polymers with chemical variability brought about by the presence of several hydroxyl groups, allowing its surface modifications through the insertion of several chemical groups to impact its cellulosic characteristics. Thus, the objective of this study was to synthesize magnetic iron oxide nanoparticles (MNPs) through co-precipitation, followed by in situ incorporation of MNPs onto chemically purified cellulose (CPC) and cellulose nanocrystals (CNC). The composites were characterized for thermal properties using TGA, molecular structure using FTIR, surface morphology using SEM, elemental composition using electron dispersion spectroscopy (EDS), and crystallinity using XRD. The prepared composites presented improved crystal, thermal, and surface properties. CNC-MNPs and CPC-MNPs bore particle sizes of 26.94 and 37.72 nm, respectively, whereas MNPs’ particle size was 10.3 nm. EDS analysis indicated that Fe, C, and Cl were the main elements present in the composites. Surface modification of the cellulosic materials presented excellent sorption surface properties and can be used in several industrial processes, such as wastewater purification, air filtration, and various environmental remediation processes.