Petroleum naphtha
Petroleum naphtha is an intermediate hydrocarbon liquid stream derived from the refining of crude oil with CAS-no 64742-48-9. It is most usually desulfurized and then catalytically reformed, which rearranges or restructures the hydrocarbon molecules in the naphtha as well as breaking some of the molecules into smaller molecules to produce a high-octane component of gasoline.
There are hundreds of different petroleum crude oil sources worldwide and each crude oil has its own unique composition or assay. There are also hundreds of petroleum refineries worldwide and each of them is designed to process either a specific crude oil or specific types of crude oils. Naphtha is a general term as each refinery produces its own naphthas with their own unique initial and final boiling points and other physical and compositional characteristics.
Naphthas may also be produced from other material such as coal tar, shale deposits, tar sands, and the destructive distillation of wood.
Types of virgin naphthas
The table below lists some typical virgin heavy naphthas, available for catalytic reforming, derived from various crude oils. It can be seen that they differ significantly in their content of paraffins, naphthenes and aromatics:| Crude oil name Location | Barrow Island Australia | Mutineer-Exeter Australia | CPC Blend Kazakhstan | Draugen North Sea |
| Initial boiling point, °C | 150 | 140 | 149 | 150 |
| Final boiling point, °C | 200 | 190 | 204 | 180 |
| Paraffins, liquid volume % | 46 | 62 | 57 | 38 |
| Naphthenes, liquid volume % | 42 | 32 | 27 | 45 |
| Aromatics, liquid volume % | 12 | 6 | 16 | 17 |
Cracked naphthas
Some refinery naphthas also contain some olefinic hydrocarbons, such as naphthas derived from the fluid catalytic cracking, visbreakers and coking processes used in many refineries. Those olefin-containing naphthas are often referred to as cracked naphthas.In some petroleum refineries, the cracked naphthas are desulfurized and catalytically reformed to produce additional high-octane gasoline components.
Other uses
Some petroleum refineries also produce small amounts of specialty naphthas for use as solvents, cleaning fluids and dry-cleaning agents, paint and varnish diluents, asphalt diluents, rubber industry solvents, recycling products, and cigarette-lighter, portable-camping-stove and lantern fuels. Those specialty naphthas are subjected to various purification processes which adjusts chemical characteristics to suit specific needs.On a much larger scale, petroleum naphtha is also used in the petrochemicals industry as feedstock to steam reformers and steam crackers for the production of hydrogen, ethylene, and other olefins.