Hydrolysis of Urea for Ammonia-Based Wet Flue Gas Desulfurization

Abstract

Nowadays, the ammonia-based wet flue gas desulfurization is gaining more popularity. In this study, the ammonia-based wet flue gas desulfurization obtained ammonia resource from urea hydrolysis instead of anhydrous ammonia and aqueous ammonia, which was beneficial for the development of circular economy. An electric-heating reactor was employed as the hydrolysis reactor instead of traditional ones using hot air or water vapor as the heat carrier. The effects of temperature, pressure, urea solution concentration, and time on urea hydrolysis were investigated, and the optimum hydrolysis condition was estimated to be 30 (wt, %) urea solution hydrolyzing for 4 h at 140 °C, 0.4 MPa. The desulfurization experiment was conducted in a bubbling reactor. The effects of SO2 concentration and liquid–gas ratio on desulfurization were investigated. The ammonia-based absorbent for desulfurization was prepared by the ammonia produced from the 30 (wt, %) urea solution hydrolyzing for 4 h at 140 °C, 0.4 MPa. The experiment...