Methods are provided for simple and efficient carbonization of cellulosic and/or lignin-containing materials to generate a char suitable for use as a pellet fuel. Cellulosic and/or lignin-containing waste materials can be suspended in water with a catalyst and, optionally, a carbonate and heated to generate a char. This char can be dried and formed into carbonized pellets suitable for use as fuel.

The invention relates to a hybrid power plant for autonomously supplying energy to buildings, in articular residential buildings, and industrial facilities which are arranged in an area that comprises a source of biomass. The hybrid power plant is preferably arranged in the vicinity of buildings and industrial facilities to be supplied in order to provide energy locally. The hybrid power plant comprises at least one system for generating power from renewable energy sources and a power-to-X device for thermochemically converting electricity from renewable energy sources and biomass into other energy carriers which are stored and converted back into electricity on demand. In order to supply energy to the buildings and industrial facilities to be supplied during dark doldrums, the hybrid power plant comprises one or more energy storage devices and at least one system for converting energy back into electricity. The supply of energy to buildings or industrial facilities by means of the hybrid power plant is climate and CO.sub.2 neutral.

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.

There is provided a method of hydrothermal carbonization of a sludge, comprising the steps of: a) preheating the sludge to obtain a preheated sludge; b) adding an oxidizing agent, such as oxygen gas, to the preheated sludge; and c) subjecting the sludge from step b) to hydrothermal carbonization (HTC) in a reactor to obtain a HTC-treated sludge.

The presently disclosed subject matter relates to torrefied biomass briquettes and methods for producing the same that make use of a mixture of lightly torrefied material (LTM) and highly torrefied material (HTM) and/or make use of torrefied materials that are subjected to a hydrolysis pretreatment prior to being torrefied.

A system and method for torrefying a combination of biomass and biochar colloidal dispersion is provided.

A hydrothermal liquefaction (HTL) system can comprise a biomass slurry source, a first pump in fluid communication with the slurry source and configured to pressurize a biomass slurry stream from the slurry source to a first pressure, a first heat exchanger in fluid communication with the first pump and configured to heat a slurry stream received from the first pump to a first temperature, a second pump in fluid communication with the first heat exchanger and configured to pressurize a slurry stream received from the first heat exchanger to a second pressure higher than the first pressure, a second heat exchanger in fluid communication with the second pump and configured to heat a slurry stream received from the second pump to a second temperature higher than the first temperature, and a HTL reactor configured to produce biocrude from a slurry stream received from the second heat exchanger.

A system and method for torrefying a combination of biomass and biochar colloidal dispersion is provided.

Commercially beneficial carbon-containing fractions can be recovered from hydrothermal liquefaction reactions in various types of processors. Feedstock slurry from waste solids is placed into a pressurized processor where it is maintained at temperature and pressure for a predetermined period. On discharge from the processor the processed discharge is separated into liquid and solid fractions. Gaseous fractions including carbon dioxide can also be removed or off-taken from the processor. New molecular structures are created in this reaction, resulting in fractions including biogas, biofuels, biosolids and biocrude. Silica, phosphates, potash and low concentration nitrogen based fertilizer, along with carbonaceous material can also be recovered.

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.