Development of Sorbent Compositions from TPP Water-Treatment Facility Waste for Gaseous Fuel Desulfurization

Abstract

Development of sorbent compositions from industrial waste is a promising and economically feasible method for solving environmental problems. Power industry enterprises experience an acute need for the development of new environmentally friendly and cheap sorbents for gaseous fuel desulfurization purposes. Owing to removal of sulfur compounds from the fuel, the latter becomes less corrosive in nature, due to which it becomes possible to increase the equipment’s service life and also to decrease the deposits of sulfides on the surfaces of power installations. Based on a review of literature sources, the most important developments for sorbents consisting of industrial waste were determined. The waste of a thermal power plant (TPP) water-treatment facility (WTF) in the form of sludge water is of the greatest interest for removing sulfur compounds from fuel. Sludge water has a complex composition, which depends directly on the source water quality and water-treatment technology. Sludge water is produced at the natural water pretreatment stage, during which suspended matter is removed from source water by adding coagulants, flocculants, and other chemical agents that are specified by the process regulation. The article presents the composition of a sorbent produced from the WTF sludge at one of the Kazan combined heat and power plants (CHPP) for gaseous fuel desulfurization. Laboratory experiments were carried out with this sorbent, as a result of which the sulfur compound absorption efficiency and the strength characteristics of the prepared and formed sorbent were determined. A new method for indicating the extent to which the adsorbent absorption efficiency is decreased by using an indicating sorbent is also proposed. It is very difficult to monitor the level of sulfur compounds in purified gas by means of automatic sensors in view of a high measurement error, due to which an inaccurate result is obtained. An indicating sorbent composition that makes it possible to detect nonadsorbed sulfuric compositions by showing a color change from light to deep yellow is proposed. A method for using this indicating sorbent is described, and experimental data on its ability to absorb sulfur compounds are given.