In a system and process, sludge is treated by two stages of anaerobic digestion in series separated by intermediate thickening and hydrolysis. The hydrolysis product is transferred to the second digester essentially without dilution.

In a system and process, sludge is treated by two stages of anaerobic digestion in series separated by intermediate thickening and hydrolysis. The hydrolysis product is transferred to the second digester essentially without dilution.

A method of continuous hydrothermal carbonization of sludge containing organic matter, involving a stage of hydrothermal reaction carried out in a reactor (4), includes: a step of introduction of sludge in which the sludge is introduced into the reactor (4) by a first inlet (11), a step of endogenous injection of steam in which steam is injected into the reactor (4) by a second inlet (15) distinct from the first inlet (11), a step of extraction in which at least a portion of the sludge contained in the reactor (4) is extracted continuously by a sludge outlet (16), a step of preheating in which the temperature of the sludge is raised prior to its introduction into the reactor (4) up to a temperature of preheating greater than 70 C. Also disclosed is a device making it possible to carry out such a method.

An apparatus, method and system is provided for treating sewage sludge by dewatering the sewage sludge, heating the sewage sludge being treated to destroy pathogens, and then reducing volatile solids in the sewage sludge being treated through biochemical decomposition to produce a treated biosolids product that meets government regulations for pathogen reduction and vector attraction reduction.

Products from a high pressure processing system are separated and purified. The processing system is adapted for pressurizing and heating a feed mixture comprising carbonaceous material(-s) in the presence of homogeneous catalysts and liquid organic compounds to produce a converted feed mixture. The converted feed mixture is cooled and depressurized, and then separated into: a gas phase, an oil phase, and a water phase comprising liquid organic compounds and dissolved homogeneous catalysts comprising potassium and/or sodium. The liquid organic compounds and dissolved homogenous catalysts are at least partly recovered from said water phase, thereby producing a first water phase stream enriched in liquid organic compounds and homogeneous catalysts and a second water phase stream depleted in liquid organic compounds and homogeneous catalysts. The first water phase is at least partly recycled to the feed mixture, with a bleed stream being withdrawn therefrom prior to recycling.

Method and installation of thermal hydrolysis of sludges implementing a group of thermal hydrolysis reactors (71,72,73,74) characterized in that it comprises successions of cycles, each of these successions of cycles being dedicated to one of said thermal hydrolysis reactors, each cycle comprising: a step a) for conveying a batch of non-preheated sludges to be treated into a thermal hydrolysis reactor (71,72,73,74), said step for conveying comprising the continuous passage of the sludges of said batch of sludges into a dynamic mixer (3) into which recovery steam is injected; a step b) for injecting live steam into said thermal hydrolysis reactor (71,72,73,74) containing said batch of sludges so as to increase the temperature and the pressure prevailing in this reactor; a step c) of thermal hydrolysis of the batch of sludges in the thermal hydrolysis reactor; a step d) for emptying the content of the batch of hydrolyzed sludges of said thermal hydrolysis reactor towards a recovery vessel (13), and for concomitant de-pressurizing of said reactor prompting the emission of recovery steam from the recovery vessel (13); the cycle starting points of the successions of cycles being staggered in time so that the steps a) of a succession of cycles are concomitant with the steps d) of another succession of cycles, the recovery steam emitted during the steps d) of a succession of cycles constituting the recovery steam injected during the steps a) of another succession of cycles.

Method and installation of thermal hydrolysis of sludges implementing a group of thermal hydrolysis reactors (71,72,73,74) characterized in that it comprises successions of cycles, each of these successions of cycles being dedicated to one of said thermal hydrolysis reactors, each cycle comprising: a step a) for conveying a batch of non-preheated sludges to be treated into a thermal hydrolysis reactor (71,72,73,74), said step for conveying comprising the continuous passage of the sludges of said batch of sludges into a dynamic mixer (3) into which recovery steam is injected; a step b) for injecting live steam into said thermal hydrolysis reactor (71,72,73,74) containing said batch of sludges so as to increase the temperature and the pressure prevailing in this reactor; a step c) of thermal hydrolysis of the batch of sludges in the thermal hydrolysis reactor; a step d) for emptying the content of the batch of hydrolyzed sludges of said thermal hydrolysis reactor towards a recovery vessel (13), and for concomitant de-pressurizing of said reactor prompting the emission of recovery steam from the recovery vessel (13); the cycle starting points of the successions of cycles being staggered in time so that the steps a) of a succession of cycles are concomitant with the steps d) of another succession of cycles, the recovery steam emitted during the steps d) of a succession of cycles constituting the recovery steam injected during the steps a) of another succession of cycles.

A biogas collection and purification system that includes a plurality of sources of biogas and a network of conduits configured to convey the biogas from the sources to a central processing facility for processing the biogas into methane. The central processing facility removes impurities to convert biogas to biomethane and may include an H.sub.2S removal stage; an activated carbon scrubber; a gas drier; and a carbon dioxide removal stage. The facility also has a biomethane gas compressor configured to deliver the biomethane for use in power plants, for CNG production. Ancillaries to the system include fuel cells for direct electricity generation from biogas/biomethane.

The present invention relates to methods for biological wastewater treatment for Se control in Se-laden wastewater. The Se contaminants in the wastewater include the Se oxyanions selenate (SeO.sub.4.sup.2-) and selenite (HSeO.sub.3.sup.?), which are biochemically reduced and transformed to elemental selenium (Se.sup.0) by microorganisms through anaerobic biological reduction. The resulting Se.sup.0 is entrained in the biomass, which is further processed to enable the efficient recovery of concentrated Se.sup.0.

A method and system for converting an aqueous salt containing sludge into gases and a solid residue is described. The sludge is pyrolyzed and gasified with the assistance of microwave radiation.