Furan from Furfural Vapour and Steam over Zinc-Iron Chromite (Whitman, du Pont, US 2,374,149)

Furfural carries one aldehyde group too many for most uses. Whitman passed its vapour with plenty of steam over a hot mixed zinc-iron chromite; the aldehyde group leaves and furan, a very volatile ring liquid, is caught in cold condensers. Result: furan boiling at 31-32 C, 85 % of the furfural converted. Source: Whitman, US 2,374,149 (du Pont, 1945), Example I. Picture drawn by Youblob.