Determination of Acidic Degradation Products in Aqueous Ethylene Glycol and Propylnene Glycol Solutions Using Ion Chromatography.
Determination of Acidic Degradation Products in Aqueous
Ethylene Glycol and Propylnene Glycol Solutions Using
Rossiter, W. J., Jr.; Brown, P. W.; Godette, M.
Solar Energy Materials, Vol. 9, 267-279, 1983.
ethylene glycol; propylene glycol; chromatography;
degradation; antifreeze; heat transfer fluids; solar
collectors; thermal oxidation; glycolic acid; copper;
Aqueous ethylene glycol and propylene glycol solutions
are the principal antifrcczcs used as heat
transfer fluids in flat-plate solar collector systems.
Acidic degradation produces formed in the
thermal oxidation of these solutions have been analyzed
using ion chromatography (IC) and the
ion-chromatography exclusion (ICE) method of analysis.
The primary acidic degradation product
found in the case of ethylene glycol solutions was
glycolic acid. Propylene glycol solutions yielded
mainly lactic acid. The presence of metallic copper
significantly increased the amount of degradation
products over that produced in the absence of metal.
Solutions heated in the presence of
metallic aluminum were only slightly more degraded than
those heated without metal, but
contained relatively large amounts of formic acid. Only
traces of formic acid were observed when
the glycol solutions were heated in the absence of metal
or in the presence of metallic copper.