公开(公告)号：WO2023287396A1

公开(公告)日：2023-01-19

申请号：PCT/US2021/041350

申请日：2021-07-13

Applicant: LIQUID LIGNIN COMPANY ,  LAKE, Michael, A. ,  BLACKBURN, John, C. ,  HAYDEN, J., George

Inventor： LAKE, Michael, A. ,  BLACKBURN, John, C. ,  HAYDEN, J., George

IPC: C07G1/00 ,  C08H8/00 ,  C08L97/00

Abstract: This invention provides improvements to processes for making granular lignin from black liquor. One of the improvements is that the use of a pre-carbonation column reduces the CO2 flow into the sparger of a carbonation column. The pre-carbonation column is used to reduce the pH of the black liquor to about 12. Another improvement is that it has been found that coalescing droplets into a bulk liquid-lignin phase can be enhanced by placing the exit of the carbonation column at or slightly beneath carbonated black liquor/liquid-lignin interface. It has also been found that operating the carbonation settler at a low pressure and pumping the liquid- lignin from the carbonation settler to the acidification reactor operating at a higher pressure allows recycling the vent gas from the acidification reactor to the pre-carbonation column. The invention also provides for a vent gas absorber.