IMPROVEMENT OF PROCESS FOR PRODUCTION OF CARBON CHEMICAL ABSORBER FOR AMMONIA

Abstract

The present work is devoted to the study of the dependence of ammonia chemical absorber properties on the conditions of the absorber synthesis. As a chemical absorber carrier the granulated active carbon of AG type with sorption space maximum volume of 0.512 cm3/g and with micropore volume of 0.414 cm3/g was used. The copper sulfate (II) salt was taken as an ammonia-reactive additive. Samples of the chemical absorber were obtained by impregnating the carbon carrier with a hot solution of the active component. The impregnating solution was prepared by two methods: traditional one, with dissolving the salt sample in hot water and the second one, with the use of ultrasonic treatment. It was found that with an increase in CuSO4 total content in the absorber to 9% by weight the proportion of bound (inactive) copper decreased; however, at the content above this value the share of bound (inactive) copper (II) form in the chemical absorber practically did not change. The presence of oxygen-containing functional groups with basic character on the active carbon surface leads to their interaction with copper (II) ions of the impregnating solution and deactivates them as related to ammonia. The change in the nature of the chemical absorber porous structure when adding a copper sulfate (II) active additive onto the surface of the active AG coal depending on conditions of impregnating solution preparation and the semi-product drying rate is shown. Studies on the use of ultrasound in the preparation of copper sulfate solution have been conducted. Such use leads to the formation of active additive crystallites on the carrier surface. These crystallites are of much smaller size (1–5 nm) in comparison with ones formed by the thermal method of solution preparation (8–12 nm). Herewith, the capacity of the chemical absorber as related to ammonia increases by 3.5–4.5 times.