CRACKING HYDROCARBON OILS

**Definition:** This place covers:

Production of liquid hydrocarbon mixtures from oil-shale, oil-sand or non-melting solid carbonaceous materials (e.g. wood, coal), from oxides of carbon (e.g. Fischer-Tropsch processes), from oxygen-containing organic materials (e.g. fatty acids or fatty oils) or from gases (e.g. natural gas).

Distillation, dewatering or demulsification of hydrocarbon oils.

Catalytic or non-catalytic cracking of hydrocarbon oils in the absence of hydrogen.

Refining of hydrocarbon oils in the absence of hydrogen.

Reforming naphtha.

Hydrotreatment processes involving refining, cracking or other treatment of hydrocarbon oils in the presence of hydrogen or hydrogen generating compounds.

Production of liquid hydrocarbon mixtures from lower carbon number hydrocarbons, e.g. oligomerisation or polymerisation to make longer carbon chains. Multi-step processes for treating hydrocarbon oils in the presence or absence of hydrogen.

Working up of normally gaseous mixtures of undefined composition obtained from cracking processes.

Treatment of hydrocarbon oils or fatty oils for lubricating purposes, including thickening by voltolisation. Recovery of refining of mineral waxes, e.g. montan wax.

**Limiting references (this place does not cover):** - Cracking mainly to hydrogen or synthesis gas -> C01B - Preparation of individual hydrocarbons or mixtures thereof of definite or specified constitution, including by cracking or pyrolysis of hydrocarbon gases -> C07C

**Glossary:** - Cracking: Cracking is the process whereby complex organic molecules such as heavy hydrocarbons are broken down into simpler molecules (e.g. light hydrocarbons) by the breaking of carbon-carbon bonds in the precursors. the rate of cracking and the end products are strongly dependent on the temperature and the presence of any catalysts. - Refining: Refining is the process of purification of a substance. The term is usually used of a natural resource that is almost in a usable form, but which is more useful in a purer form. For instance, most types of natural petroleum will burn straight from the ground, but they will burn poorly and quickly clog an engine with residues and byproducts. the Term "refining" is broad and may include more drastic transformations. the refining of liquids is often accomplished by distillation or fractionation. - Reforming (catalytic): Thermal or catalytic reforming is a chemical process used to convert naphtha boiling range feedstocks, typically having low octane ratings, into high-octane liquid products called reformates which are components of high-octane gasoline (also known as petrol). The process represents the total effect of numerous simultaneous reactions, such as dehydrogenation, isomerisation, cracking and polymerisation. - Destructive hydrogenation: Splitting of molecules of the raw material with addition of hydrogen to them, also called direct liquefaction, liquefaction of coal by reacting it with hydrogen at high temperature and pressure. - Voltolising: Subjecting oils to treatment with an electric discharge.