Patents Assigned to C-Green Technology AB
  • Method and system for hydrothermal carbonization and wet oxidation of sludge
    Patent number: 11724952
    Abstract: There is provided a method of hydrothermal carbonization of a sludge from a wastewater treatment plant, comprising the steps of: preheating the sludge with at least one first steam fraction to obtain a preheated sludge; further heating the preheated sludge with a second steam fraction to obtain a heated sludge; subjecting the heated sludge to hydrothermal carbonization (HTC) in a reactor to obtain a HTC-treated slurry; mixing the HTC-treated slurry with an oxidizing agent, such as oxygen gas, to obtain a wet-oxidized slurry; subjecting the wet-oxidized slurry to flashing to obtain the second steam fraction and a pre-cooled slurry; subjecting the pre-cooled slurry to flashing in at least one step to obtain the at least one first steam fraction and a cooled slurry; separating the cooled slurry into a liquid fraction and a solids fraction; and routing the liquid fraction to the wastewater treatment plant for further treatment, wherein the second steam fraction is used for heating preheated sludge to the temperat
    Type: Grant
    Filed: November 22, 2019
    Date of Patent: August 15, 2023
    Assignee: C-Green Technology AB
    Inventors: Fredrik Lundqvist, Erik Oden, Fredrik Ohman
  • Method for oxidation of a liquid phase in a hydrothermal carbonization process
    Patent number: 10836666
    Abstract: There is provided a method of treatment of sludge, such as municipal or industrial sludge from a wastewater treatment plant, comprising the steps of: —preheating an incoming sludge with at least one steam fraction, preferably by direct steam injection, to obtain a preheated sludge; —further heating the preheated sludge with a high-temperature steam fraction, preferably by direct steam injection, to obtain a heated sludge; —hydrothermal carbonization (HTC) of the heated sludge to obtain a HTC-treated sludge; —separating a particle-lean fraction from the HTC-treated sludge; —wet oxidation of the particle-lean fraction to obtain a heated particle-lean fraction; —subjecting the heated particle-lean fraction to a first flashing to obtain the high-temperature steam fraction used in the further heating step; —separating a particle-rich fraction from the HTC-treated sludge; —subjecting the particle-rich fraction to flashing to obtain at least one steam fraction that is used in the preheating step and a cooled particl
    Type: Grant
    Filed: June 21, 2017
    Date of Patent: November 17, 2020
    Assignee: C-Green Technology AB
    Inventors: Fredrik Lundqvist, Erik Odén, Fredrik Öhman