The invention relates to a method for producing an oil rich fraction (OF) from primary feedstock (FS) that comprises water, first salt, second salt, and biomass. The feedstock (FS) is provided to a first reaction zone (Z1) of a conversion reactor (100), where it is allowed to react at a temperature of at least 350° C. in a pressure of at least 160 bar to form converted primary feedstock. The method comprises separating from the converted primary feedstock a first salt rich fraction (SF1), a second salt rich fraction (SF2), and an oil rich fraction (OF). The method comprises withdrawing the oil rich fraction (OF) from the first reaction zone (Z1) and withdrawing the first salt rich fraction (SF1) and the second salt rich fraction (SF2) from the conversion reactor (100). In the method the first salt rich fraction (SF1) comprises at least some of the first salt dissolved in the water, the second salt rich fraction (SF2) comprises at least some of the second salt in solid form, and at least one of the first salt and the second salt is a salt capable of catalysing the reaction of the biomass of the primary feedstock (FS) with the water of the primary feedstock (FS) to produce the oil rich fraction (OF). A device for the same.

The disclosed technology includes a membrane-based device configured to concentrate black liquor, which results from papermaking. Certain embodiments may comprise a nanofiltration membrane configured to remove lignin from black liquor, and the nanofiltration membrane may include a first macroporous polymer substrate and a first graphene oxide membrane covering the first macroporous polymer substrate. Some embodiments may comprise a reverse osmosis membrane, which may include a second macroporous polymer substrate and a second graphene oxide membrane covering the second macroporous polymer substrate.

The present invention relates to novel lignin-derived compounds and compositions comprising the same and their use as redox flow battery electrolytes. The invention further provides a method for preparing said compounds and compositions as well as a redox flow battery comprising said compounds and compositions. Additionally, an assembly for carrying out the inventive method is provided.

Methods of dewatering viscous materials are provided. The method comprises contacting the viscous material with pressurized carbon dioxide at a temperature and for a time wherein at least a fraction of water is expressed from the viscous material. Then the pressure is released, and the water expressed from the viscous material is removed to yield a dewatered product. Exemplary viscous materials that can be dewatered by the method include black liquor from wood pulping operations, wet lignin, wet super water absorbent polymers and sugar solutions. The pressurized carbon dioxide is present in subcritical or supercritical form. The method provides dewatering at reduced cost.

The method is for separation of lignin from original black liquor (BL.sub.IN) that has a first precipitation stage (PR) for precipitation of lignin by a first acidification using acidifier AC.sub.1, preferably using CO.sub.2, at alkaline conditions, then separating a lignin cake with subsequent suspension of the lignin cake in a strong acid in order to leach our metals from the lignin followed by dewatering and obtaining a clean lignin product LP. The process further is improved by intensified hydrolysis of lignin cake such that most of the carbohydrates are broken down to dissolvable monomers that could be separated from the lignin in the filtrate from a filtering stage subsequent to the hydrolysis. The improved hydrolysis could reduce as much as 90% of the carbohydrate content using a moderately increased temperature and increased charge of acidifier while avoiding any larger lignin yield losses.

The invention is directed to compositions and processes concerning efficient downstream processing of products derived from organic acids pretreatment of plant materials.

The invention is characterised in the steps of a) performing a first separation of the mixture in a first centrifugal separator, resulting in a first heavy fraction comprised of the heavy phase with only small amounts of impurities in the form of the light phase and a first light fraction comprising of the light phase with impurities in form of the heavy phase; and b) performing a second separation of the first light fraction in a second hermetic centrifugal separator of purificator type, resulting in a second heavy fraction comprised of the heavy phase with impurities in the form of the light phase and a second light fraction comprised of the light phase with only small amounts of impurities in the form of the heavy phase. The invention also relates to a device.

Process for upgrading effluent treatment plants for pulp and paper production processes, where salts are removed from the effluent for water reuse and chemical recovery. The process comprises a first dialysis system for salt removal, a second treatment system for recovery or re-concentration, and optionally a post-treatment of the re-concentrate preventing liquid discharges to the environment. In the first system, a reversible electrodialysis or reversible pulsed step is carried out, separating the salts from the effluent, which are sent to the second treatment system to concentrate the salts (re-concentrate) or transform them into useful chemicals for the same process (recovery). Chemical recovery is achieved by electrodialysis with bipolar membranes or metathesis, to reduce the re-concentrate stream, which cannot be reused in the same plant. Lastly, this stream may be treated by spray drying, crystallization or evaporation.

The invention relates to a method for treating biomass (2). In a step (S10), biomass (2) and an impregnation liquid are fed into a first reactor unit (10) such that the biomass (2) is impregnated with the impregnation liquid while the biomass (2) is transferred through the first reactor unit (10) by a conveyor means (11). In another step (S20), the impregnated biomass (2a) is transferred from the first reactor unit (10) to a separation unit (25), wherein at least a part of the impregnation liquid is separated from the impregnated biomass (2a) within the separation unit. In a step (S30), the separated impregnation liquid is discharged from the separation unit (25), such that a first part (26a) of the impregnation liquid is recirculated back to the first reactor unit (10). The invention further relates to a system for treating biomass (2).

Methods and systems for reducing the loss of usable fibers from whitewater while simultaneously increasing paper making machine performance and paper quality are provided. The methods and systems utilize a fractionating saveall to separate whitewater into a dilute wastewater fraction that contains unwanted fine particles and a thicker consistency reusable fraction containing paper-forming fibers. The reusable fraction is recirculated back into the whitewater stream, while the wastewater is routed away from the whitewater stream.