Unit process data for lignin extraction in a softwood kraft pulp mill

This unit process represents the gate-to-gate production of 1 air-dried metric tonne of kraft lignin, coproduced with southern bleached softwood kraft pulp (SBSK), high voltage electricity and unrefined tall oil soap. The pulp is derived from pine or loblolly pine in a kraft pulping process at a mill in the southern United States (U.S.). Lignin is extracted via precipitation and acid washing. All flows are production weighted to kraft lignin. The SBSK pulp production technologies are an aggregation of those applied in the southern U.S. in 2013.