Valmet Technologies Oy

Valmet Power Ab

Valmet Ab

Valmet Aktiebolag

Anders Littorin

Henrik Wallmo

Tobias Wittmann

Panu Tikka

Martin Wimby

Eric Enqvist

Ville Tarvo

Hanna Kristina Karlsson

Anders Uhlin

Lars-Erik Åkerlund

Hanna Norberg

Hanna Karlsson

Lignin-rich starting material is suspended in a first medium, which is acidic and aqueous, to form a aqueous acidic suspension, which is heated and allowed to form two continuous phases, a thermoplastic lignin phase and an aqueous phase. The thermoplastic lignin phase is separated from the aqueous phase and passed through a shape giving process into a second medium which is at a temperature lower than that of the thermoplastic lignin phase and in which the thermoplastic lignin phase is essentially insoluble. Solid lignin formed in the second medium is recovered.

Method for producing solid lignin

The method is for separation of lignin from original black liquor. Lignin is precipitated in a first acidification stage followed by dewatering a first lignin suspension while forming a first filter cake. The first lignin filter cake is suspended in a second acidification stage whereupon a second lignin suspension is obtained. The second lignin suspension is dewatered to form a second filter cake. The second filter cake is washed and the washed second lignin cake is dewatered to obtain a lignin product. Waste gases from the second acidification stage is recirculated back to the first acidification stage and mixed with the original black liquor.

Method for precipitating lignin from black liquor by utilizing waste gases

Growing community of inventors

Hisings Kärra, Sweden

Anders Littorin