Simultaneous removal of SOx and NOx in flue gas at power stations over a Cu/Na-13X zeolite catalyst

Due to their significant impacts on the environment and health, there has been a growing environmental concern on sulfur oxide (SO_x), nitrogen oxides (NO_x) emissions to the atmosphere in the past two decades. Flue gas at coal-fired power stations is one of the main sources for the emissions of SO_x and NO_x. More and more stringent regulations on the emission of these pollutants come in force, which have put a high pressure on coal-fired power generators. Cost-effective and sustainable technologies for the reduction of such pollutants from flue gas have become increasingly important nowadays. However, even though numerous attempts have been made aiming at developing technologies for the removal of SO_x and NO_x, not much effort has been made on the simultaneous conversion of NO_x and SO_x in flue gas via selective catalytic reduction. This paper presents the study of simultaneous removal of SO₂ and NO over a synthesized Cu/Na-13X zeolite catalyst using carbon monoxide as a reducing agent. The characterization of fresh and spent catalysts was carried out using X-Ray Diffraction (XRD) and Brunauer-Emmett-Teller (BET) Surface Area Analyser. The experiments on the selective reduction of SO₂ and NO were carried out using a multi-functional catalyst testing rig with an online flue gas analyser. It has been found that zeolite has a good capability of SO₂ adsorption even under elevated temperatures. The removal efficiency was found to be 100% for SO₂ and 89% for NO over a Cu/Na-13X zeolite catalyst.