US 12,385,184 B2
Method and system for continuously treating biomass material
Francois Lambert, Sundsvall (SE); Patrik Pettersson, Alnö (SE); and Peter Björklund, Umeå (SE)
Assigned to VALMET AB, Sundsvall (SE)
Appl. No. 18/558,642
Filed by VALMET AB, Sundsvall (SE)
PCT Filed May 3, 2022, PCT No. PCT/SE2022/050425
§ 371(c)(1), (2) Date Nov. 2, 2023,
PCT Pub. No. WO2023/282815, PCT Pub. Date Jan. 12, 2023.
Claims priority of application No. 2150878-3 (SE), filed on Jul. 5, 2021.
Prior Publication US 2024/0229353 A1, Jul. 11, 2024
Int. Cl. D21C 1/02 (2006.01); D21B 1/36 (2006.01); D21C 7/08 (2006.01); D21C 7/12 (2006.01)
CPC D21C 7/08 (2013.01) [D21B 1/36 (2013.01); D21C 1/02 (2013.01); D21C 7/12 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method for continuously treating biomass material comprising:
feeding the biomass material into a substantially vertically arranged pressurized vessel;
adding steam to said pressurized vessel for hydrothermal treatment of the biomass material, wherein said adding steam comprises adding steam at a lower portion of the pressurized vessel;
discharging the biomass material from a bottom portion of the pressurized vessel using a discharge device;
withdrawing vapor from a top portion of the pressurized vessel, and adding said vapor to the discharge device;
controlling differential pressure between said top portion of the pressurized vessel and said discharge device by controlling a flow of said vapor; and
determining a minimum flow of steam needed to heat the biomass material in the pressurized vessel to a predetermined temperature, wherein said adding steam comprises adding steam at a flow that is higher than said minimum flow.
 
12. A system for continuous hydrothermal steam treatment of biomass material, said system comprising:
a substantially vertically arranged pressurized vessel;
a discharge device configured to discharge the biomass material from a bottom portion of the pressurized vessel;
a conduit connecting a top portion of the pressurized vessel with said discharge device, said conduit comprising a control valve for controlling a flow of vapor from said top portion to said discharge device;
a pressure measurement device configured to measure differential pressure between said top portion of the pressurized vessel and said discharge device,
at least one steam injection nozzle configured to inject steam into said pressurized vessel, each injection nozzle comprising a corresponding valve to control the steam flow, wherein at least one of said at least one steam injection nozzle is arranged at a lower portion of said pressurized vessel, and
a control unit configured to control said control valve in response to differential pressure measurement data from said pressure measurement device, the control unit further being configured to determine a minimum flow of steam needed to heat the biomass material in the pressurized vessel to a predetermined temperature, and to control each valve of the at least one steam injection nozzle such that the total flow of steam into the pressurized vessel is higher than said minimum flow.