Dry distillation is the
heating of
solid materials to produce
liquid or
gaseous products (which may condense into solids). The method may or may not involve pyrolysis/thermolysis. The products are
condensed and collected. This method usually requires higher temperatures than classical
distillation. The method has been used to obtain liquid
fuels from
coal and
wood. It can also be used to break down mineral
salts such as
sulfates through
thermolysis, in this case producing
sulfur dioxide/
sulfur trioxide gas which can be dissolved in water to obtain
sulfuric acid. By this method sulfuric acid was first
produced.
See also