Patent ID: 11866456
Assignee: LIQUID LIGNIN COMPANY
Field: Biotechnology (Chemistry)
Classification: CPC C  D | IPC C  D

Claim 18:
19. A method for producing a lignin product from black liquor, said method comprising:
in a first carbonation step, carbonating said black liquor with CO2 to reduce a pH of said black liquor and form a partially carbonated black liquor;
transferring an entire volume of said partially carbonated black liquor to a second carbonation step;
in said second carbonation step, carbonating said partially carbonated black liquor with CO2 to reduce a pH of said partially carbonated black liquor and form a carbonated black liquor;
phase separating said carbonated black liquor into a dense liquid-lignin phase and a light lignin-depleted liquid phase;
acidifying said dense liquid-lignin phase to neutralize basic components from said dense liquid-lignin phase and evolve gaseous CO2;
generating a porous, solid lignin in response to evolving said gaseous CO2 during acidifying; and
washing said porous, solid lignin to remove ash.