What is "destructive distillation"

Distillation \Dis`til*la"tion\ (d[i^]s`t[i^]l*l[=a]"sh[u^]n), n.

1. The act of falling in drops, or the act of pouring out in drops.

2. That which falls in drops. [R.]
   --Johnson

3. (Chem.) The separation of the volatile parts of a substance from the more fixed; specifically, the operation of driving off gas or vapor from volatile liquids or solids, by heat in a retort or still, and the condensation of the products as far as possible by a cool receiver, alembic, or condenser; rectification; vaporization; condensation; as, the distillation of illuminating gas and coal, of alcohol from sour mash, or of boric acid in steam.

   Note: The evaporation of water, its condensation into clouds, and its precipitation as rain, dew, frost, snow, or hail, is an illustration of natural distillation.

4. The substance extracted by distilling.
   --Shak.

   Destructive distillation (Chem.), the distillation, especially of complex solid substances, so that the ultimate constituents are separated or evolved in new compounds, -- usually requiring a high degree of heat; as, the destructive distillation of soft coal or of wood.

   Dry distillation, the distillation of substances by themselves, or without the addition of water or of other volatile solvent; as, the dry distillation of citric acid.

   Fractional distillation. (Chem.) See under Fractional.

Destructive \De*struc"tive\, a. [L. destructivus: cf. F. destructif.] Causing destruction; tending to bring about ruin, death, or devastation; ruinous; fatal; productive of serious evil; mischievous; pernicious; -- often with of or to; as, intemperance is destructive of health; evil examples are destructive to the morals of youth.

Time's destructive power.
--Wordsworth.

Destructive distillation. See Distillation.

Destructive sorties(Logic), a process of reasoning which involves the denial of the first of a series of dependent propositions as a consequence of the denial of the last; a species of reductio ad absurdum.
--Whately.

Syn: Mortal; deadly; poisonous; fatal; ruinous; malignant; baleful; pernicious; mischievous.

n. (context chemistry English) The heating of a material, such as coal or wood, in an inert atmosphere, at a high temperature such as to cause decomposition; the principal products include oils and tars from which many useful organic compounds may be obtained; town gas and coke were obtained in this way.

n. heating a solid substance in a closed container and collecting the volatile products

Destructive distillation is the chemical process involving the decomposition of feedstock by heating it to a high temperature; the term generally applies to processing of organic material in the absence of air or in the presence of limited amounts of oxygen or other reagents, catalysts, or solvents, such as steam or phenols. It is an application of pyrolysis. The process breaks up or 'cracks' large molecules. Coke, coal gas, gas carbon, coal tar, Buckminsterfullerene, ammonia liquor, and " coal oil" historically, are examples of commercial products of the destructive distillation of coal.

Destructive distillation of any particular inorganic feedstock produces only a small range of products as a rule, but destructive distillation of organic materials commonly produces very many compounds, often hundreds, though not all chemical products of any particular process are of commercial importance. The distilled molecules are generally smaller and more volatile than the feedstock molecules, but some reactions polymerise or condense small molecules into larger molecules, including heat-stable tarry substances and chars. Cracking into liquid and volatile compounds, and polymerisation or the formation of chars and solids may all occur in the same process, and any class of the products might be of commercial interest.

Currently the major industrial application of destructive distillation is to coal.

Historically the process of destructive distillation and other forms of pyrolysis led to the discovery of many chemical compounds or elucidation of their structures before contemporary organic chemists had developed the processes to synthesise or specifically investigate the parent molecules. It was especially in early days that investigation of the products of destructive distillation, like those of other destructive processes, played parts in enabling chemists to deduce the chemical nature of many natural materials. Well known examples include the deduction of the structures of pyranoses and furanoses.