A technique, method and system for drying a solid waste stream in a pyrolysis recycling installation, including drying the waste stream in a first dryer, feeding the partially dried waste stream from the first dryer to a second dryer, further drying the waste stream in the second dryer to produce a dried waste stream, and feeding the dried waste stream from the second dryer to a pyrolysis unit, wherein the first and second dryers dry the waste stream primarily, or exclusively, using heat generated from the pyrolysis unit.

A technique, method and system for drying a solid waste stream in a pyrolysis recycling installation, including drying the waste stream in a first dryer, feeding the partially dried waste stream from the first dryer to a second dryer, further drying the waste stream in the second dryer to produce a dried waste stream, and feeding the dried waste stream from the second dryer to a pyrolysis unit, wherein the first and second dryers dry the waste stream primarily, or exclusively, using heat generated from the pyrolysis unit.

The specification describes a system and process for treating a sludge or slurry to produce biochar. The sludge or in slurry may be digestate produced by an anaerobic digester that receives waste activated sludge from a wastewater treatment plant. In a process, digestate is dosed with metal ions, dewatered, and pyrolized. A corresponding system includes a reactor, a dewatering unit and a pyrolysis unit. In an example, the digestate is air stripped in the reactor and a metal salt is added to it. The metal ions form precipitates in the digestate that remain in the biochar. In some cases, a precipitate such as struvite is formed that also increases the phosphorous content of the biochar. The biochar may be used as a soil amendment, wherein the metal and phosphorous are beneficial to the soil.

The specification describes a system and process for treating a sludge or slurry to produce biochar. The sludge or in slurry may be digestate produced by an anaerobic digester that receives waste activated sludge from a wastewater treatment plant. In a process, digestate is dosed with metal ions, dewatered, and pyrolized. A corresponding system includes a reactor, a dewatering unit and a pyrolysis unit. In an example, the digestate is air stripped in the reactor and a metal salt is added to it. The metal ions form precipitates in the digestate that remain in the biochar. In some cases, a precipitate such as struvite is formed that also increases the phosphorous content of the biochar. The biochar may be used as a soil amendment, wherein the metal and phosphorous are beneficial to the soil.

A waste management system, primarily intended to be for waste floating in water, though it can also be used on land. A shredding device will reduce the size of the particles of waste. Ocean water is removed by a drying device. The dried waste material is cryogenically frozen using liquid nitrogen or other suitable means. The frozen waste material is then pulverized and ground into a powder. The powder may then be sprayed into a gas-filled chamber and heated. Temperature, pressure and humidity are maintained within the chamber for more than one minute. Microwave or other radiation and catalysts may be used to enhance the process of extraction. The processed material is then removed from the chamber. Carbon and water may be recycled. The carbon may be used as fuel by the ship. Water may also be used by the ship or returned to the ocean in a non-toxic condition.

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.

Methods and systems for calcining dewatered tailings and/or mine waste are disclosed herein. In some embodiments, the method comprises (i) processing dewatered tailings comprising clay minerals, (ii) calcining the processed tailings to produced calcined tailings, and (iii) altering a composition and/or one or more characteristics of the calcined tailings to produce a cementitious product. Altering the composition can include blending the calcined tailings with one or more additives, such as lime, dolomitic lime, lime kiln dust, argillaceous limestone, limestone, pulverized quicklime, ground calcium carbonate, quicklime, gypsum, natural pozzolans, artificial pozzolans, water, flow aids, or the like.

The invention relates to a co-pyrolyzed sludge biochar modified by lanthanum carbonate, a preparation method and a use thereof. The method comprises: adding a co-pyrolyzed sludge biochar into a metal salt solution of lanthanum ions, heating and adding a carbonate solution until the pH is 8 to 9, and standing still at a constant temperature, and separating to obtain a co-pyrolyzed sludge biochar modified by lanthanum carbonate, the sludge biochar is prepared by co-pyrolysis of sludge and bamboo. The co-pyrolyzed sludge biochar modified by lanthanum carbonate prepared by the present invention can effectively adsorb and remove phosphate in water due to containing the lanthanum carbonate with strong affinity for anions and a larger specific surface area.

The invention relates to a co-pyrolyzed sludge biochar modified by lanthanum carbonate, a preparation method and a use thereof. The method comprises: adding a co-pyrolyzed sludge biochar into a metal salt solution of lanthanum ions, heating and adding a carbonate solution until the pH is 8 to 9, and standing still at a constant temperature, and separating to obtain a co-pyrolyzed sludge biochar modified by lanthanum carbonate, the sludge biochar is prepared by co-pyrolysis of sludge and bamboo. The co-pyrolyzed sludge biochar modified by lanthanum carbonate prepared by the present invention can effectively adsorb and remove phosphate in water due to containing the lanthanum carbonate with strong affinity for anions and a larger specific surface area.

Apparatus and associated methods relate to drying a wet coated seed material stream comprising an incoming wet granular biosolids stream mixed with a controlled size dried seed material recycling stream to produce a moist air and pellet stream, separating an uncontrolled size dried pellet stream from the moist air and pellet stream, diverting a recycle portion of the uncontrolled size dried pellet stream to be recycled, diverting the remainder of the uncontrolled size dried pellet stream to an outlet, resizing oversized pellets from the recycle portion of the uncontrolled size dried pellet stream to produce the controlled size dried seed material recycling stream, and mixing the controlled size dried seed material recycling stream with the incoming wet granular biosolids stream to produce the wet coated seed material stream. Oversized pellets may be selected using a screen. The oversized pellets may be resized using a crusher inline with the recycle stream.