The kraft process (also known as kraft pulping or sulfate process) is a process for conversion of wood into wood pulp, which consists of almost pure cellulose fibres, the main component of paper. The kraft process involves treatment of wood chips with a hot mixture of water, sodium hydroxide (NaOH), and sodium sulfide (Na2S), known as white liquor, that breaks the bonds that link lignin, hemicellulose, and cellulose. 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 wastes.[1][2][3]
The process name is derived from the German word Kraft, meaning "strength" in this context, due to the strength of the kraft paper produced using this process.[4]
- ^ Hoffman, E., Lyons, J., Boxall, J., Robertson, C., Lake, C. B., & Walker, T. R. (2017). Spatiotemporal assessment (quarter century) of pulp mill metal (loid) contaminated sediment to inform remediation decisions. Environmental Monitoring and Assessment, 189(6), 257.
- ^ Hoffman, E., Bernier, M., Blotnicky, B., Golden, P. G., Janes, J., Kader, A., ... & Walker, T. R. (2015). Assessment of public perception and environmental compliance at a pulp and paper facility: a Canadian case study. Environmental Monitoring and Assessment, 187(12), 766.
- ^ Rudolf Patt et al. "Paper and Pulp" in Ullmann's Encyclopedia of Industrial Chemistry 2002 Wiley-VCH, Weinheim. doi:10.1002/14356007.a18_545.pub4
- ^ Both capitalized and lowercase spelling ("Kraft process" and "kraft process") appear in the literature, but "kraft" is most commonly used in the pulp and paper industry.