C-green Technology Ab

C-green Ab

Fredrik Lundqvist

Fredrik Öhman

Erik Oden

Fredrik Ohman

Erik Odén

Fredrik ÖHman

Erik ODÉN

There is provided a method of hydrothermal carbonization of a sludge, comprising the steps of: preheating the sludge to obtain a preheated sludge; mixing the preheated sludge with a wet-oxidized fraction to obtain a reaction mixture; subjecting the reaction mixture to hydrothermal carbonization (HTC) in a reactor to obtain a HTC-treated sludge; separating a fraction from the HTC-treated sludge; and mixing the fraction with an oxidizing agent, such as oxygen gas, to obtain the wet-oxidized fraction, wherein the temperature of the fraction before the wet oxidation is at least 15° C. higher than the temperature of the preheated sludge. A corresponding system is also provided.

Hydrothermal carbonization of sludge including recycling of a wet-oxidized fraction

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 temperature of the HTC reaction. A corresponding system is also provided.

Method and system for hydrothermal carbonization and wet oxidation of sludge

There is provided a method of treatment of sludge, such as municipal or industrial sludge from a wastewater treatment plant, comprising the steps of: &#x2014;preheating an incoming sludge with at least one steam fraction, preferably by direct steam injection, to obtain a preheated sludge; &#x2014;further heating the preheated sludge with a high-temperature steam fraction, preferably by direct steam injection, to obtain a heated sludge; &#x2014;hydrothermal carbonization (HTC) of the heated sludge to obtain a HTC-treated sludge; &#x2014;separating a particle-lean fraction from the HTC-treated sludge; &#x2014;wet oxidation of the particle-lean fraction to obtain a heated particle-lean fraction; &#x2014;subjecting the heated particle-lean fraction to a first flashing to obtain the high-temperature steam fraction used in the further heating step; &#x2014;separating a particle-rich fraction from the HTC-treated sludge; &#x2014;subjecting the particle-rich fraction to flashing to obtain at least one steam fraction that is used in the preheating step and a cooled particle-rich fraction.

Method for oxidation of a liquid phase in a hydrothermal carbonization process

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Ekerö, Sweden

Fredrik Lundqvist