TECHNOLOGY – CRUDE SULPHATE TURPENTINE
Crude sulphate turpentine is obtained as a by-product at sulphate cooking of cellulose. Volatile matters in wood of softwood species that are distilled off with water vapour are called “turpentinic”. Turpentines appear as a mixture of monoterpenic hydrocarbons having general formula C10H16 with a small sesquiterpens admixture that has hydrocarbons – from C15H24 up to C15H32. Turpentine dissolves genetically linked with terpens resin acids, giving them mobility. Thus the turpentine distribution in wood of softwood species is determined by distribution patterns of resin acids.
For example, for pine-tree the turpentine output depends on the part of trunk that goes for cooking. Aside from terpen hydrocarbons the sulphate terpentine has sulphur-containing compounds because it appears as a product of sulphate cooking. In the cooking process terpen hydrocarbons mixture evaporates and is in vaporized state.
The technology of sulphate terpentine obtaining includes feed-out and collection of terpen hydrocarbons vapors from a digester and evaporators, as well as condensing of collected vapors in a heat-exchanger with terpentine condensate formation and consecutive separation from under-terpentine water (which is condensing with vapors) in a separating flask. Ready crude sulphate turpentine is shipped to customers by railway or automotive transport.