Methods and systems for treatment of organic waste by means of hydrothermal carbonization include a mixing tank for receiving organic waste. A first batch of mixed wet waste is fed from the mixing tank to a first thermal reactor to undergo thermal hydrolysis. A second batch of mixed wet waste is fed from the mixing tank to a second thermal reactor to undergo thermal hydrolysis. Bio-char sludge is fed in an alternating manner from the first and second thermal reactors to a bio-char cooler. To save energy, hot and pressurized water from the first thermal reactor is subsequently supplied to the second thermal reactor or from the second thermal reactor to the first thermal reactor in an alternating manner for the respective hydrolysis processes.

The present invention relates to a process for reduction of energy consumption during the pretreatment of biomass.

During hydrothermal carbonization, biomass is converted to biocoal. The reaction yield depends on the reaction conditions, including duration of the carbonization reaction or time period within which the slurry composed of water and biomass remains in the reaction tank and is exposed to pressure and temperature. These conditions should be selected so that the greatest possible dry residue of carbonized material remains in the slurry. It has been shown that the dry residue amount changes during the carbonization reaction with a curve that is similar, to a great extent, to that of the slurry pH value. Because determining the dry residue is difficult during the ongoing reaction, but determining the pH value can be easy during the entire reaction period, the reaction is terminated at a maximum of the pH value corresponding to a maximum of the biocoal dry residue, to the greatest possible extent.

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 particle-rich fraction.

The present invention provides a method and system for preparing fuel gas by utilizing an organic waste with high water content. The method comprises the following steps: 1) providing an organic waste with high water content; 2) performing hydrothermal reaction by using the organic waste with high water content as a reactant to obtain a hydrothermal reaction product; 3) enabling the hydrothermal reaction product to generate steam, and separating a solid product and an oily liquid product in the hydrothermal reaction product; 4) performing gasification reaction by using the solid product, the oily liquid product and the steam as reactants to obtain a gasification reaction product; and 5) purifying the gasification reaction product to obtain clean fuel gas. The present invention further provides a system for preparing fuel gas. The method can be used for preparing clean fuel gas from the organic waste with water content of 60% or more.

A system for the hydrothermal carbonization of a flowable biomass comprises a pump, a heat exchanger and a tubular reactor. The pump is connected to the heat exchanger via a delivery conduit for the flowable biomass, and the heat exchanger is connected to the tubular reactor via a connecting conduit. The heat exchanger contains an insert element and the tubular reactor contains no insert element.

A combined hydrothermal liquefaction (HTL) and catalytic hydrothermal gasification (CHG) system and process are described that convert various biomass-containing sources into separable bio-oils and aqueous effluents that contain residual organics. Bio-oils may be converted to useful bio-based fuels and other chemical feedstocks. Residual organics in HTL aqueous effluents may be gasified and converted into medium-BTU product gases and directly used for process heating or to provide energy.

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.

Disclosed is a method for heating a biomass moving along an industrial treatment line including an inlet (1) for the incoming biomass, a heating unit (4), and a treatment station (5). A fraction of the biomass heated by the heating unit (4) is returned along a return branch (R) to a mixing station (2) upstream of the heating unit (4) so as to form, together with the incoming biomass, a mixture having a temperature above the temperature of the incoming biomass, the heated biomass fraction being removed at an outlet (51) of the treatment station (5).

Solvent consumption in supercritical ethanol, propanol or butanol treatment of either refined pre-extracted lignin or comparatively impure lignin-rich solid residual from hydrothermally pretreated lignocellulosic biomass can be minimized by conducting the reaction at very high loading of lignin to solvent. Comparatively impure, crude lignin-rich solid residual can be directly converted by supercritical alcohol treatment to significantly diesel-soluble lignin oil without requirement for pre-extraction or pre-solubilization of lignin or for added reaction promoters such as catalysts, hydrogen donor co-solvents, acids, based or H2 gas. O:C ratio of product oil can readily be obtained using crude lignin residual in such a process at levels 0.20 or lower.