Study on mercury adsorption by modified calcium-based sorbent

The large amount of fossil fuel consumption has increased Hg emission into atmosphere and the related Hg emission has attracted more and more attention. Based on the disadvantages of active carbon sorbent injection, this research has proposed using low-cost calcium-based sorbent which prepared by Ca(OH)₂ and fly ash to capture mercury in flue gas. Experiments were carried out in a fixed-bed facility with gaseous elemental mercury which produced by a permeation tube and other simulated flue gas composition. The experiment results indicated that the adsorption performance of hydrated lime is relatively poor. The presence of SO₂ in the simulated flue gas can enhance the Hg⁰ removal efficiency. The Hg⁰ removal efficiency of modified calcium-based sorbent which have additive is higher than hydrated lime. The Hg⁰ removal efficiency of modified calcium-based sorbent decreased when SO₂ exist in the simulated flue gas. The use of modified calcium-based sorbent can achieve simultaneous removal of SO₂ and Hg⁰ by relatively low cost.