title: Kinetic study of the reaction between sulfur dioxide and calcium hydroxide at low temperature in a fixed-bed reactor.
abstract: A quantitative study of the influence of inlet sulfur dioxide concentration (600-3000 ppm), relative humidity (20-60%), reactor temperature (56-86 degrees C) and different amounts (0-30 wt.%) of inorganic additives (NaCl, CaCl(2) and NaOH) on gas desulfurization has been carried out in a continuous downflow fixed-bed reactor containing calcium hydroxide diluted with silica sand. Results show that the reaction rate does not depend on sulfur dioxide partial pressure (zero-order kinetics) and that the temperature and the relative humidity have a positive influence on reaction rate. An apparent activation energy of 32 kJ/mol Ca(OH)(2) has been estimated for the reaction. An empirical reaction rate equation at 71.5 degrees C and 36.7% relative humidity that includes the type and amount of additive is proposed. It has been found that calcium chloride is the best additive studied because it allows for a higher degree of sulfur dioxide removal.
authors.affiliation: Chemical Engineering Department, Faculty of Chemistry, University of Barcelona, C/ Martí i Franqués 1, 08028, Barcelona, Spain. felipe@angel.qui.ub.es
authors.forename: J F
authors.initials: JF
authors.lastname: Izquierdo
authors.forename: C
authors.initials: C
authors.lastname: Fité
authors.forename: F
authors.initials: F
authors.lastname: Cunill
authors.forename: M
authors.initials: M
authors.lastname: Iborra
authors.forename: J
authors.initials: J
authors.lastname: Tejero
mesh_terms: D000397:Air Pollution / Q000517:prevention & control; D002126:Calcium Hydroxide / Q000378:metabolism*; D005740:Gases; D006813:Humidity; D007287:Inorganic Chemicals / Q000378:metabolism; D007700:Kinetics; D011210:Power Plants; D013458:Sulfur Dioxide / Q000378:metabolism*; D013696:Temperature
chemical_list: D005740:Gases; D007287:Inorganic Chemicals; D013458:Sulfur Dioxide; D002126:Calcium Hydroxide