Tall oil

For other uses, see Tall oil (disambiguation).

Overview

Tall oil processing plant in Rauma, Finland

Tall oil is a viscous yellow-black odorous liquid obtained as a byproduct of the kraft process of wood pulp production. The name "tall oil" comes from the Swedish word "tallolja," which means "pine oil," as it is derived from the resins of pine trees. Tall oil is a complex mixture of resin acids, fatty acids, and neutral compounds.

Production

Tall oil is produced during the kraft process, which is a method for converting wood into wood pulp, consisting of almost pure cellulose fibers. The process involves the treatment of wood chips with a mixture of sodium hydroxide and sodium sulfide, which breaks down the lignin and releases the cellulose fibers. During this process, the black liquor is formed, which contains the dissolved lignin and other wood components, including tall oil.

The black liquor is concentrated and then acidified to precipitate the tall oil soap, which is then skimmed off and acidified to produce crude tall oil. This crude tall oil can be further refined into various fractions, including tall oil fatty acids (TOFA), tall oil rosin (TOR), and distilled tall oil (DTO).

Applications

Tall oil has a wide range of applications due to its chemical properties. It is used in the production of adhesives, inks, and coatings. Tall oil fatty acids are used in the manufacture of soaps, detergents, and lubricants. Tall oil rosin is used in the production of rubber, paper, and paints.

Environmental Impact

The use of tall oil as a renewable resource contributes to the sustainability of the pulp and paper industry. By utilizing a byproduct of the kraft process, the industry can reduce waste and improve the overall efficiency of wood processing. Additionally, tall oil can be used as a biofuel, providing an alternative to fossil fuels and reducing carbon emissions.

Related pages

• Kraft process
• Pulp and paper industry
• Biofuel
• Resin