A process for isolating lignin from an alkaline process stream of thickened black liquor which is introduced continuously into a lower region of at least one circulation reactor having two reactor zones in concentric arrangement, liquid level of the alkaline process stream in the interior of the reactor is at a level with an upper end of an inner tubular reactor zone, a CO.sub.2-containing gas is blown continuously from the bottom into the inner tubular reactor zone of the reactor, wherein the CO.sub.2-containing gas is absorbed by the alkaline process stream in the inner circulation reactor zone and offgas is drawn off with residual amounts of the CO.sub.2 at the top of the reactor, the process is run at 1 atm, and thickened black liquor with a reduced lignin content together with precipitated lignin present are drawn off optionally after settling at the base of the reactor.

An oleophilic and hydrophobic nanocellulose material is disclosed herein, for nanocellulose sponges and other applications. The oleophilic and hydrophobic nanocellulose material comprises lignin-coated cellulose nanofibrils and/or lignin-coated cellulose nanocrystals. In various embodiments, the nanocellulose material is in the form of a 2D coating or layer, or a 3D object (e.g., foam or aerogel). The nanocellulose material may be disposed onto a scaffold. A process is provided for producing an oleophilic and hydrophobic nanocellulose object, comprising fractionating a biomass feedstock with an acid, a solvent for lignin, and water, to generate cellulose-rich solids and a lignin-containing liquor; mechanically treating the cellulose-rich solids to form cellulose fibrils and/or cellulose crystals; generating a nanocellulose object from the intermediate nanocellulose material; exposing the nanocellulose object to the lignin-containing liquor to allow lignin to deposit onto a surface of the nanocellulose object; and recovering the oleophilic and hydrophobic nanocellulose object.

The present invention relates generally to the generation of bio-products from organic matter feedstocks. More specifically, the present invention relates to the use of pulping liquors in the hydrothermal/thermochemical conversion of lignocellulosic and/or fossilised organic feedstocks into biofuels (e.g. bio-oils) and/or chemical products (e.g. platform chemicals).

The present invention relates to a process for manufacturing an upgraded bio-oil derived from black liquor, comprising the following steps: —Providing black liquor, which comes from the pulp and paper manufacturing industry; —Subjecting black liquor to a pyrolysis treatment with formation of a pyrolyzed black liquor gas and a solid mass, which comprises char and salts; —Catalytic conversion of said pyrolyzed black liquor gas by contacting at least part of the latter with a bi-metallic modified zeolite catalyst with formation of the upgraded bio-oil, which comprises benzene, toluene, xylene (BTX), naphthalene and non-BTX products.

Methods and systems for controlling operation of a smelt dissolving tank receiving a flow of smelt and having a vent stack in fluid communication are provided. A dissolving liquid is injected into the smelt dissolving tank at a predetermined injection rate. A temperature of a flow of vapour in the vent stack is measured with a sensor. The injection rate of the dissolving liquid is controlled based on the temperature of the flow of vapour.

Methods and systems for controlling operation of a smelt dissolving tank receiving a flow of smelt and having a vent stack in fluid communication are provided. A dissolving liquid is injected into the smelt dissolving tank at a predetermined injection rate. A temperature of a flow of vapour in the vent stack is measured with a sensor. The injection rate of the dissolving liquid is controlled based on the temperature of the flow of vapour.

The specification relates to a method and a system for adjusting pH of green liquor dregs. The method comprises contacting a slurry containing green liquor dregs (100, 200, 300, 400, 500) with flue gas (101, 201, 301, 401, 501). The system comprises a recovery boiler (105) configured to burn black liquor to produce smelt, a smelt dissolving tank (107) configured to dissolve the smelt to produce green liquor comprising green liquor dregs, and a green liquor clarifier/filter (103) and/or a dregs filter (104) configured to separate a slurry containing green liquor dregs (100, 200, 300, 400, 500) from the green liquor. The system further comprises a vessel (102, 202, 302, 402) configured to receive a slurry containing green liquor dregs (100, 200, 300, 400, 500) and a gas inlet (210, 310, 410, 510) configured to convey flue gas (101, 201, 301, 401, 501) to be contacted with the slurry containing green liquor dregs (100, 200, 300, 400, 500).

The present invention describes a process for continuous fractionation of CTO (crude tall oil) to RTD (refined tall diesel), said process comprising:—when removing a stream of TOP (tall oil pitch) the CTO is fed through at least two evaporation zones arranged in series so that one stream of CTO is fed from a first evaporation zone to a second evaporation zone, wherein a TOP stream is produced and fed from the second evaporation zone, wherein a first vapor stream is produced within the first evaporation zone and a second vapor stream is produced within the second evaporation zone and wherein there is a temperature difference of at least 10° C. between the first vapor stream and the second vapor stream; and—feeding the first vapor stream and the second vapor stream into a subsequent fractionation column to produce a stream of RTD from the fractionation column, wherein the first vapor stream and the second vapor stream are being fed to different positions, relative to the column height, in the fractionation column, where different conditions are applied to ensure suitable fractionations of a more fatty acid rich material and a more rosin rich material, respectively, and which different positions in the fractionation column are separated by packing means.

In a method and an apparatus for recovering chemicals from an alkaline lignin material, the alkaline lignin material (3) which comprises NaOH or KOH is precipitated in presence of an acid in a precipitation stage (6) for forming a precipitated lignin (7), the precipitated lignin (7) is supplied to a separation stage (8) in which a purified lignin (9) is recovered and from which at least one fraction (10) which comprises Na or K is supplied to a crystallization stage (11), and the fraction (10) which comprises Na or K is treated by crystallization in the crystallization stage (11) for forming a crystallized compound (12). Further, the invention relates to use of the purified lignin, and lignin and chemical products.

Provided herein are compositions and processes concerning efficient downstream processing of products derived from organic acids pretreatment of plant materials.