Abstract: The present invention relates to separation of lignin from an aqueous slurry containing lignocellulosic biomass material comprising providing the aqueous slurry having an initial pH level to at least one precipitation phase for precipitating lignin, performing said precipitation phase during a reaction time including adding at least one acidifier, wherein a decrease in the pH value of the aqueous slurry to a lower ph level is created, separating the lignin in a first separation phase, performing an acidification phase including, performing a re-slurry step including mixing lignin from the first separation phase with an acidifier to form an acidic slurry, establishing a reaction temperature in a range of 65-95 degrees Celsius. and performing a retention step including maintaining the acidic slurry at the reaction temperature for a reaction time period of 30-60 minutes, and separating the treated lignin content from the acidic slurry in a second separation phase.

Abstract: The invention relates to separation of lignin from an aqueous slurry containing lignocellulosic biomass material, such as black liquor, comprising the steps of providing an aqueous slurry having an initial pH level to a first precipitation phase, where the first precipitation phase is performed during a first time duration including adding a first acidifier. Thereby, a decrease in the pH value of the aqueous slurry from the initial pH level to a first pH level above 11 is created. Thereafter, processed aqueous slurry is fed from the first precipitation phase to a second precipitation phase. The second precipitation phase is performed during a second time duration. The second precipitation phase includes adding of a second acidifier, wherein a decrease in the first pH value from said first pH level to a second pH level above 9 is created.

Abstract: The present invention relates to a method of producing lignin with reduced amount of guaiacoland etylguaiacol in order to reduce the content of odorous substances by subjecting the ligninto a heating processing order to remove guaiacol.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.