Kraft process

The kraft process (also known as kraft pulping or sulfate process) is a process for conversion of <a href="/facts/Wood/z13NpHPl">wood</a> into <a href="/facts/Wood_pulp/wIlq5nWm">wood pulp</a>, which consists of almost pure <a href="/facts/Cellulose/wYPafTU0">cellulose</a> fibres, the main component of <a href="/facts/Paper/FUETwwKV">paper</a>. The kraft process involves treatment of wood chips with a hot mixture of water, <a href="/facts/Sodium_hydroxide/xjtdYtq7">sodium hydroxide</a> (NaOH), and <a href="/facts/Sodium_sulfide/DKu0s158">sodium sulfide</a> (Na2S), known as <a href="/facts/White_liquor/Pc8bseyH">white liquor</a>, that breaks the bonds that link <a href="/facts/Lignin/CdaxpB3b">lignin</a>, <a href="/facts/Hemicellulose/s7wg6TEP">hemicellulose</a>, and <a href="/facts/Cellulose/wYPafTU0">cellulose</a>. The technology entails several steps, both mechanical and chemical. It is the dominant method for producing paper. In some situations, the process has been controversial because kraft plants can release odorous products and in some situations produce substantial liquid <a href="/facts/Waste/qLmtkUQ4">wastes</a>.
The process name is derived from the German word Kraft, meaning "strength" in this context, due to the strength of the <a href="/facts/Kraft_paper/WgsmnFUn">kraft paper</a> produced using this process.

Kraft process open-in-new

Kraft process