The Corrosion Debacle in Extracting Furfural with Chloroform

The extract of tower 6 entered a distillation column 7 recovering the amine/hydro-carbon mixture as the sump fraction, to be recycled into the extractor 6, white the head fraction of column 7, a mixture of acetic acid and formic acid, was separated in the distillation column 8. 

This reaction falls into the category of autoxidation defined as the slow low-temperature oxidation of organic compounds by O2 via a radical chain mechanism, based on the fact that the oxygen molecule is a diradical 

Step (A) represents the liberation of atomic hydrogen and the formation of peroxy radicals. In step (B), two peroxy radicals combine to form a tetroxide, and in step (C) the tetroxide decomposes to form phosgene, oxygen, and atomic chlorine. Finally, in step (D), the atomic chlorine of (C) reacts with the atomic hydrogen of (A) to form hydrochloric acid. 

Combination of these reactions shows that in the presence of water each oxidized chloroform molecule yields three molecules of HCl. 

3 where an elevated temperature accelerated the corrosion process. In view of these gruesome facts, the plant had to be abandoned. 

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