New insights in the optimization of sulfur dioxide flue gas desulfurization (FGD) using porous materials in a semi-dryer system

The reduction of sulfur dioxide emissions has led to significant research into gas desulfurization methods. Techniques for reducing sulfur dioxide emissions can be classified into dry, semi-dry, and wet flue gas desulfurization (FGD). Limestone is widely used in FGD due to its availability and cost-effectiveness, but its reactivity is often insufficient for effectively removing sulfur dioxide. Lime, a byproduct material, is an environmentally friendly option due to its abundance and low cost. Zeolites, microporous crystalline materials with thermal and chemical stability, catalytic properties, and a high specific surface area, are commonly used for gas separation and as catalysts. The study aims to investigate a semi-dry system operating at low concentrations that is designed to address challenges in practical gas desulfurization. Porous materials, specifically slaked lime and a selected synthetic 13X zeolite are evaluated as adsorbents. The efficiency of the adsorbents is evaluated using microgas chromatography. A model calculation detailing gas mobility, X-ray powder diffraction, thermal analysis, and scanning electron microscopy are used in the integrated approach to elucidate the mechanisms governing gas desulfurization and propose an experimental prototype setup for the absorption of SO2 in semi-dry and low concentrated systems.