Noun
dry distillation (countable and uncountable, plural dry distillations)
The heating of solid materials to produce gaseous products (which may condense into liquids or solids).
Baltic amber yields on dry distillation succinic acid, the proportion varying from about 3% to 8%, and being greatest in the pale opaque or bony varieties. Source: Internet
For example, acetone could be formed by the dry distillation of metal acetates, so acetone was the syndesmide of two acetate ions. Source: Internet
For this reason, benzoic acid for human consumption was obtained by dry distillation of gum benzoin. Source: Internet