FIBROUS CHEMISORBENT OF SULFUR DIOXIDE BASED ON THE COMPLEX COMPOUNDS OF COOPER (II) SULPHATE AND POLYETHYLENEPOLYAMINE

Abstract

The principal possibility of using the copper (II) sulfate complex with polyethylenepolyamine (PEPA) as a reagent for the creation of impregnated fibrous chemisorbents (IFCS) has been investigated. The sorption of water vapor by IFCS–Cu–PEPA, obtained by impregnating a fibrous material with aqueous solutions of copper (II) sulfate complexes with PEPA at different molar ratio Cu: N (1/k) was determined under static conditions, the nature of the effect of the preabsorbed water on this process was stated. Sorption isotherms have been analyzed according to Brunauer-Emmett-Teller theory of polymolecular sorption, the monolayer capacity and the heat of sorption of water molecules in the first layer have been determined. Under static and dynamic conditions the absorption of sulfur dioxide by the obtained IFCS–Cu–PEPA samples was studied. It is shown the SO2 uptake process, flogoing predominantly through the chemisorption mechanism, occurs only in the presence of «free» water formed after the formation of the monolayer, with the formation of «onium» sulfites on the carrier fibers surface. It has been established the values of the SO2·H2O static chemisorption increase with increasing PEPA content in IFCS–Cu–PEPA samples. The binding of amine nitrogen atoms during the chemisorption of sulfur dioxide occurs only at »50% of the expected S : N = 1,0 : 2,0. It is assumed the complete hydrolytic breakdown of the Cu (II) complex with Am and the copper (II) partially prevents the more complete «triggering» of the N atoms with respect to SO2. It was shown the obtained IFCS-Cu-PEPA can be used to absorb acidic gases at the ratio Cu: N = 1 : 5 ¸ 1 : 6, and ammonia at the ratio 1 : 1 ¸ 1 : 2. With a ratio of 1 : 3 ¸ 1 : 4, IFCS–Cu–PEPA performs combined air purification from both sulfur dioxide and ammonia. IFCS–Cu–PEPA is recommended for use in equipping respiratory protection devices – lightweight gas-dust respirators.