DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS

**Definition:** This place covers:

Retorts or coke ovens and details thereof, such as heating of coke ovens, doors or closures therefor, devices for charging or discharging coke ovens and mechanical treatments of coal charges, cooling or quenching coke, safety devices and other details.

Carbonising or coking processes, including pyrolysis and other methods of destructive distillation of solid carbonaceous materials, using direct heating (including the partial combustion of the material to be treated) and/or indirect heating (e.g. external combustion).

Destructive distillation specially adapted for particular types of solid raw material or for materials in special form (such as cellulose-containing materials, powdered coal, oil shale or bituminous rocks, synthetic polymeric materials e.g. tyres).

Coking mineral oils, bitumen, tar, etc. with solid carbonaceous materials.

**Limiting references (this place does not cover):** - Cracking oils -> C10G - Hydrothermal carbonisation -> C10L9/086 - Underground gasification of minerals -> E21B43/295

**Glossary:** - Retort: An airtight vessel in which substances are heated for a chemical reaction producing gaseous products to be collected in a collection vessel or for further processing - Coke oven: An airless oven for driving of volatile constituents from coal during carbonisation to produce coke. In "by-product" coke ovens, the gaseous and liquid by-products obtained during the carbonisation process are recovered, the principal by-products are coal tar and coke-oven gas. The coke oven gas is used to heat the ovens by combustion is external heating flues.In "non-recovery" or "heat recovery" coke ovens, the raw gas produced in the ovens is completely combusted and used to generate power. - Beehive oven: Earliest type of coke oven, developed in the 1850s; its main characteristic is that the heat necessary for coking is produced by burning the volatile constituents within the oven, whereby all the gaseous and liquid by-products are lost, together with large amounts of heat. - Destructive distillation: The process of pyrolysis conducted in a distillation apparatus to allow the volatile products to be collected. An example is tar making from pinewood slices (which are rich in terpenes), which are heated in an airless container causing the material to decompose, leaving charcoal and turpentine as by-products. - Coke: A solid, high in carbon content, and structurally in the non-graphitic state, derived from the pyrolysis of organic material (especially low-ash, low-sulphur bituminous coal) which has passed, at least in part, through a liquid or liquid-crystalline state during the carbonization process. The volatile constituents of the coal (including water, coal gas and coal-tar) are driven off by baking in an airless oven at temperatures as high as 2000 degrees C. - Coking: The transformation of coal or heavy oil into coke. - Carbonisation: The conversion of an organic substance into carbon or a carbon-containing residue through pyrolysis or destructive distillation. - Pyrolysis: The chemical decomposition of organic materials by heating in the absence of oxygen or any other reagents, except possibly steam. - Ablative pyrolysis: Fast pyrolysis by contacting feed with hot surface, e.g. hot plate or heated wall. - Torrefaction: Pyrolysis at temperatures below 320 degrees C.