Reactive Condensation of Cr Vapor on Aluminosilicates Containing Alkaline Oxides

Abstract

This research aims to improve fundamental understanding of the reactive condensation of Chromium (Cr) vapors, which are generated in many high-temperature (>500℃) process environments and can form potentially problematic condensed hexavalent (Cr(VI)) species downstream. . This study focuses on the effects of alkaline oxide additives in aluminosilicate fibers on Cr condensation and speciation. Cr vapors were generated by flowing humid, high-temperature air over chromia (Cr 2 O 3 ) powder, with aluminosilicate fiber samples positioned downstream. Results indicate presence of hexavalent chromium (Cr(VI)) species condensed on all samples investigated, with significantly more on those containing alkaline oxides (CaO and MgO) additions. Comparative results and analyses are discussed to help inform mechanistic understanding and future related research and engineering efforts.