IMPREGNATED FIBROUS CHEMOSORBENTS OF ACID GASES FOR RESPIRATORY PURPOSE

Abstract

The present review is dedicated to the analysis of scientific works carried out in Physico- Chemical Institute of Environment and Human Protection (Odessa, Ukrainie) and directed to the development of import-substituting sorption-filtering materials for respiratory purposes – impregnated fibrous chemisorbents (IFCS) of acid gases, which are manufactured using standard equipment, as well as affordable and inexpensive chemical reagents and carriers of domestic origin. The process of chemisorption of sulphur dioxide by hexamethylenetetramine (HMTA) modified nonwoven fibrous material resulted acid-catalyzed hydrolysis of HMTA to form aminomethanesulfonic acid and toxic formaldehyde. The IFCS with HMTA carried was recommended to use for air purification only from SiF4, HF, HCl and Cl2. Chemisorption of sulphur dioxide by fibrous materials impregnated by ethanolamines (monoethanolamine, diethanomamine, triethanomamine and N-methylethanolamine) and polyethylenepolyamine (PEPA) occurs only in the presence of “free” water with formation of “onium” sulphites, hydrosulphites and pyrosulphites. IFCS-PEPA (dynamic activity is 1,38 mmol(SO2)/g) are not inferior to the protective characteristics of IFCS with Na2CO3, HMTA, ethanolamines and the best foreign ionexchange fibrous chemisorbents brand VION and FIBAN (dynamic activity is 0,263 ÷0,422 mmol(SO2)/g) under conditions of respirators actual use (jAGM = 60 ÷ 90 %, TAGM = 297 K, VAGM = 2,0 sm/s, СSO2 = 20 ÷ 1000 mg/g3, QPEPA = 3,45 mmol/g). It is recommended to use the condensation products of primary alkylamines with formaldehyde (with large molar masses than the bases), complex compounds of amines with 3d-metals (Ni(II) and Cu(II)), salts of amine with aminoacids (glycine) and polybasic acids (orthophosphoric acid (pKa1 = 2,12) and citric acid (pKa1 = 3,13)) for manufacturing of IFCS of acid gases The IFCS with indication of dynamic absorptive capacity “wearing” (IVKS-I) was developed.