Carbonaceous materials modified catalysts for simultaneous SO2/NOx removal from flue gas: A review

Globally, considerable effort and resources are being channeled toward controlling the rising threat from pollution and other related impacts from man-made activities, which have detrimental effects on human health and the environment. The presence of some associated gases such as nitrogen oxides and sulfur oxides in the flue gas interfering with the carbon capture processes are responsible for acid rain and ground-layer ozone formation. The wet flue gas desulfurization and the selective catalytic reduction technologies are associated with high investment, production of secondary pollution, poor catalyst durability, and high temperature requirements. In response to these limitations, the development of a hybrid environmental catalyst, especially using activated carbon, carbon-coated monolith, and metal oxides, is desirable. For a catalyst to be competitive, it must be cost-effective with enhanced sorption capacity, regenerability, and be safe for disposal. Some of the recent methods for dispersing the metal oxides on the supports and the simultaneous removal of sulfur oxides and nitrogen oxides were enumerated in this review and the possible ways for improvement have been presented.