Abstract: A method of treating fly ash containing sodium sulfate from a recovery boiler of a chemical pulp mill. This method includes at least the following steps: a) ash is dissolved in an aqueous solution and the pH of the solution is adjusted with alkali for precipitating impurities, b) the solution is filtered for removing the impurities containing precipitate, c) sodium sulfate is crystallized from the solution and the crystals are separated from the solution by filtering or by centrifugation, and d) the crystallized sodium sulfate is used as initial material for producing sodium and sulfur containing chemicals or as process chemical.

Abstract: A deicing formulation, comprising a chemically degraded extract derived from biowaste; and a salt is provided. Methods for preventing ice formation or removing ice from a surface by applying the deicing formula made of chemically degraded extract derived from biowaste and a salt to the surface are also provided.

Abstract: 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.

Abstract: 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).

Abstract: The present invention relates to a method of making a foamed cellulosic fiber-thermoplastic composite article. The method includes the steps of providing a copolymer composition, combining the copolymer composition and cellulosic fibers, applying heat, mixing energy and pressure to form a foamable mixture, and forming the foamable article in a molding or extruding operation. The method is characterized in that at least 10% of the cellulosic fibers have been thermally modified prior to being combined with the copolymer composition.

Abstract: Provided is a solvent borne deicing composition which includes in a solvent, a blend of an inorganic salt, a low molecular weight lignin in an amount of at least 5 weight % (or 10 or 15 or 20 weight %) to 30 or 40 or 50 weight % of the solids, and hemicellulose in an amount of at least 0.1 weight % (or 0.2 or 0.5 or 1.0 or 2.0 or 5.0 weight %) to 20 weight % (or 10 or 15 or 18 or 25 or 30 weight %) of the solids.

Abstract: The invention relates to an improved method for generating clean steam in a digester plant of a chemical pulp mill. By feeding a steam-to-steam converter (SSC) with venting steam from a black liquor flash tank (FT) as well as venting steam from chip steaming (SV) could the volume of clean steam produced be increased by over 40-50%, and to such an extent that the volume of clean steam covers the needs for preheating of chips in the digester system also in severe operational conditions. The total consumption of clean steam from the steam net of the mill may be reduced and used for other purposes such as electricity production, which meets the requirements for converting the pulp mill to an environmental friendly pulp mill.

Abstract: The invention relates methods and processes for the separation and refining of lignin from spent cooking liquor, called black liquor, present in industrial chemical plants, and compositions thereof. A process is provided for separating black liquor into at least two, three, or four streams selected from: (i) a gaseous stream comprising volatile sulfur compounds; (ii) a lignin-comprising stream produced by extracting lignin into a limited solubility solvent S1; (iii) a salt stream, comprising solid sodium and sulfate salts; and (iv) a salt-depleted and lignin-depleted aqueous stream comprising hydrocarbons.

Abstract: A method for producing an aqueous equilibrium peroxylactic acid solution by reaction mixing lactic acid, hydrogen peroxide, water, one or more optional acid catalysts and one or more optional sequestering agents in a vessel over a period of time while maintaining the temperature of the solution at a temperature below about 100° C. The aqueous equilibrium peroxylactic acid solution can be used for reducing the bacterial count on a protein food product during processing.

Abstract: Provided are an abrasion resistance improver for inorganic filler-containing rubber composition capable of giving high abrasion resistance to a rubber composition containing an inorganic filler, a rubber composition containing the abrasion resistance improver for rubber composition, a tire using the rubber composition, and a method for producing the abrasion resistance improver for rubber composition.

Abstract: The invention relates to the use of biomethanol from the pulp industry in the production of biohydrogen. The preferred biomethanol comprises purified biomethanol derived from black liquor. The invention also relates to a process for the production of biohydrogen from crude biomethanol recovered from black liquor and to a process for producing hydrocarbon biofuel using such biohydrogen as a hydrogen source. The invention further relates to a biofuel production facility for producing fuel from biohydrogen and biohydrocarbon, and to biofuel so produced. The invention makes it possible to produce a biofuel, wherein 100% of the raw material stems from non-fossil sources.

Abstract: A method of utilizing lignin-containing material separated from spent kraft pulping liquor including: acidifying the liquor to a pH not less than seven thereby precipitating solid particles, separating precipitated solid particles from the accompanying liquid, and subjecting the separated precipitated solid particles to a washing process in which: the separated precipitated solid particles are washed with an aqueous medium or aqueous media in one or more washing steps, in each one of the washing steps, the aqueous washing medium contains, in a dissolved form, significant amounts of one or more added sodium salts, and a combined concentration of the added sodium salts in the washing medium in each of the washing step exceeds three percent by weight; and utilizing as fuel in a lime kiln at least part of the washed lignin-containing material is utilized as fuel in a lime kiln of a pulp mill.

Abstract: There is provided a fiberboard, such as a MDF fiberboard or a HDF fiberboard, comprising wood fibers, a binder, and a sludge such as a pulp and a paper sludge. The sludge can be, for example, chosen from a primary pulp and paper sludge, a secondary pulp and paper sludge, a de-inking sludge, and mixtures thereof.

Abstract: The present disclosure relates, at least in part, to compositions comprising lignocellulosic biomass and an organic solvent wherein the lignocellulosic biomass comprises 35% or greater of lignin material. The present disclosure relates, at least in part, to compositions comprising lignocellulosic biomass and an organic solvent wherein the lignocellulosic biomass comprises 50% or less of carbohydrate. In certain embodiments the present compositions may have a viscosity of 5000 cps or less.

Abstract: A process for recovery of lignin from black liquor that contains either soluble or dispersed lignin by generating a “liquid lignin” at high yield is disclosed. Soluble lignin at a high pH is precipitated by reducing the pH of the black liquor stream by countercurrent reaction with carbon dioxide, at elevated temperature and pressure, creating a dense liquid-lignin phase and a light lignin-depleted phase. The dense lignin-rich phase is separated and washed countercurrently with a non-sulfur containing acid, such as acetic acid or formic acid, to displace metal cations from the lignin, creating a low-salt lignin, which is then formed into a low-dust, high-bulk density lignin fuel pellet. If desired, an oxidation step may be used to eliminate odor for lignins having high value green chemistry applications.

Abstract: There is provided a method of producing a hydrolysate containing sugar from a lingocellulosic biomass, comprising the steps of: a) pretreating the lingocellulosic biomass in a pretreatment process to form a slurry comprising cellulosic particles; b) saccharification of the slurry obtained in step a) in the presence of hydrolytic enzymes in an enzymatic hydrolysis process to obtain a hydrolysate containing sugar; c) analyzing cellulosic particles present in the slurry obtained in step a) and/or cellulosic particles present in the enzymatic hydrolysis process during step b) using an image analysis method to obtain a data set; and d) controlling at least one process parameter of the pretreatment process in step a) and/or enzymatic hydrolysis process in step b) in response to the data set obtained in step c). A corresponding system is also provided.

Abstract: A process that directly converts carbohydrates, particularly biomass derived carbohydrates and more specifically biomass (e.g., lignocellulosic biomass), to furfural-/HMF-ketone adducts for liquid hydrocarbon production under mild conditions.

Abstract: The method is for separation of lignin from original black liquor (BLIN) and has the following phases in sequence. A first precipitation phase (PR1) for precipitation of lignin by a first acidification of the original black liquor by adding a first acid or mixture of acids (G1a) followed by a first storage phase wherein precipitated lignin particles are allowed to increase in size, followed by a second precipitation phase (PR2) for precipitation of lignin by a further acidification of the original black liquor by adding a second acid or mixture of acids (G1b). By retaining the acidified black liquor for at least 25 minutes in the storage phase are the precipitated lignin particles allowed to grow in size and the filterability is improved considerably.

Abstract: The present invention relates to an environmentally friendly, simple and economic process for producing xylose. The process comprises the steps of: a) countercurrently extracting tropical fruit biomass by hydrolysis with sulfuric acid to obtain a high-concentration xylose extract; b) adjusting the extract to a pH of 1.5-2.5 and decolorizing and filtering the pH-adjusted extract; c) desalting the filtrate in an electrodialysis device; and d) recycling a waste sulfuric acid solution recovered from step c), to step a), and concentrating and directly recovering the desalted filtrate to obtain xylose crystals.

Abstract: A method was developed for: a) improving the filterability of acid-precipitated lignin from kraft black liquors, b) increasing the dry solids content of the final lignin product, c) reducing the acid requirements and d) minimizing or eliminating TRS emissions during the acidification of black liquor to produce lignin and/or the subsequent suspension of the lignin in acid and/or the washing of the lignin with acid. No major difference in the chemical composition, MWD and main functional groups was found in the lignin of the present invention compared with lignins produced by conventional methods.

Abstract: The present invention provides a process for fractionating lignocellulosic biomass, comprising: digesting a biomass feedstock in the presence of a solvent for lignin, an acid, and water, to produce cellulose-rich solids; separating and washing the cellulose-rich solids with a wash solvent; washing the cellulose-rich solids with water, to generate washed cellulose-rich solids and a wash liquor comprising fines, wherein the wash liquor is introduced to or in contact with a classifier to remove the fines; and separating the fines and recycling the remaining water. The classifier may include a screen with mesh size in the range of 10 to 500, such as 200. The washed cellulose-rich solids will typically have a lower Kappa number (lignin content) and ash content compared to cellulose-rich solids from a process without a classifier that removes fines.

Abstract: A method was developed for: a) improving the filterability of acid-precipitated lignin from kraft black liquors, b) increasing the dry solids content of the final lignin product, c) reducing the acid requirements and d) minimizing or eliminating TRS emissions during the acidification of black liquor to produce lignin and/or the subsequent suspension of the lignin in acid and/or the washing of the lignin with acid. No major difference in the chemical composition, MWD and main functional groups was found in the lignin of the present invention compared with lignins produced by conventional methods.

Abstract: The method is for separation of lignin from original black liquor (BLIN) and has the following phases in sequence. A first precipitation phase (PR1) for precipitation of lignin by a first acidification of the original black liquor by adding a first acid or mixture of acids (G1a) followed by a first storage phase wherein precipitated lignin particles are allowed to increase in size, followed by a second precipitation phase (PR2) for precipitation of lignin by a further acidification of the original black liquor by adding a second acid or mixture of acids (G1b). By retaining the acidified black liquor for at least 25 minutes in the storage phase are the precipitated lignin particles allowed to grow in size and the filterability is improved considerably.

Abstract: One exemplary embodiment can be a process for reducing one or more insoluble solids in a black liquor. The process may include hydrothermal processing the black liquor to a temperature of about 250-less than about 300° C. for an effective time to reduce the one or more insoluble solids by more than about 40%, by weight, based on a weight of the one or more insoluble solids prior to hydrothermal processing.

Abstract: A method was developed for: a) improving the filterability of acid-precipitated lignin from kraft black liquors, b) increasing the dry solids content of the final lignin product, c) reducing the acid requirements and d) minimizing or eliminating TRS emissions during the acidification of black liquor to produce lignin and/or the subsequent suspension of the lignin in acid and/or the washing of the lignin with acid. No major difference in the chemical composition, MWD and main functional groups was found in the lignin of the present invention compared with lignins produced by conventional methods.

Abstract: A process for converting a starting material to a purified pulp material, comprising removing lignin from a starting material to form a wet pulp comprising at least 5 wt. % water, extracting hemicellulose from the wet pulp with an extractant, and separating the extracted hemicellulose from the extraction mixture to form a cellulosic product comprising less hemicellulose than the wet pulp. The extractant comprises a cellulose solvent and a co-solvent. The cellulosic product advantageously retains its cellulosic fiber morphology. The process involves separating and recovering hemicellulose and separating and recycling various process streams employed in the process.

Abstract: A method for precipitating (separation) of lignin, using small amounts of acidifying agents, whereby a lignin product or an intermediate lignin product is obtained which can be used as fuel or chemical feed stock (or as a chemical or a raw material for further refining), from a lignin containing liquid/slurry, such as black liquor. A method for separation of lignin from a lignin containing liquid/slurry, such as black liquor, whereby a more pure lignin is obtained, a lignin product or an intermediate lignin product obtainable by the above methods, and use, preferably for the production of heat or for use as chemical, of the lignin product or intermediate lignin product are also disclosed.

Abstract: The present invention relates to a process for the production of bleached wood particles and a process for the production of pale to white wood-base materials which are produced from the bleached wood particles.

Abstract: A method was developed for: a) improving the filterability of acid-precipitated lignin from kraft black liquors, b) increasing the dry solids content of the final lignin product, c) reducing the acid requirements and d) minimizing or eliminating TRS emissions during the acidification of black liquor to produce lignin and/or the subsequent suspension of the lignin in acid and/or the washing of the lignin with acid. No major difference in the chemical composition, MWD and main functional groups was found in the lignin of the present invention compared with lignins produced by conventional methods.

Abstract: Provided is a process for manufacturing shaped cellulose materials from lignocellulose where a dissolving grade pulp is manufactured and dissolved in an aqueous alkaline or acidic solvent system forming a solution suitable for shaping new cellulose structures including fibers, films and cellulose derivatives. At least a part of the spent cellulose dissolving or cellulose shaping chemicals are recovered in one or more unit operations in a pulp mill chemical recovery cycle.

Abstract: A lignin plastics solids mass containing lignin solids and liquids with up to 85% liquids can be partially dewatered by heating the lignin plastics solids mass to above a critical temperature at which time the lignin plastics solids agglomerate into lower moisture granular solids with between about 45% to 55% liquids releasing excess liquid which can be easily removed from the solids. The process is particularly useful for lignin plastics solids removed from black liquor from paper mills, or for similar lignin plastics solids masses, which can contain up to 85% liquids and which need to be dried to form useful lignin solids, which can be used for example for fuel. The dewatering process can be combined with the process for separating the lignin from the black liquor to separate the dewatered lignin directly from the black liquor.

Abstract: Method for separating lignin from black liquor includes the following steps: a) precipitating lignin by acidifying black liquor and thereupon dewatering, b) suspending the lignin filter cake obtained in step a) to obtain a second lignin suspension and adjusting the pH level to approximately that of the washing water of step d) below, c) dewatering of the second lignin suspension, d) adding washing water and performing a displacement washing at substantially constant conditions without any dramatic gradients in the pH, and e) dewatering the lignin cake produced in step d) into a high dryness and displacing the remaining washing liquid in the filter cake, whereby a lignin product is obtained which has an even higher dryness after the displacement washing of step d). The lignin product or an intermediate lignin product obtained by the method, and its use, preferably for the production of heat or chemicals is also disclosed.

Abstract: The system is for the reception and transport of dry lime mud from a continuously operating pressurized filter in a causticization process. A tube valve is used as an outlet from the pressurized process. The tube valve has a minimum length that is twice a diameter of the tube. A column of lime mud can be held within it as a pressure lock. The column of lime mud can be caused to descend through the tube valve by controlling a difference in pressure between an inner surface and an outer surface of the tube such that the diameter of the tube expands essentially uniformly along its length by 5-10% or by at least 4-6 millimeters.

Abstract: A method for producing crude tall oil from black liquor soap while removing calcium carbonate and lignates is disclosed. Black liquor soap is first combined with an alkaline ash medium having a lower concentration of lignates and inorganic solids than the black liquor soap, to form washed tall oil soap, fortified brine, lignates, and calcium carbonate. The washed tall oil soap is then separated from the fortified brine, lignates, and calcium carbonate, by centrifugation, decantation, filtration, settling, or a combination of these techniques. Acidification of the washed tall oil soap gives crude tall oil and a spent acid mixture. The crude tall oil is separated from the spent acid. The spent acid is made alkaline, and at least a portion of it is returned for use as alkaline wash medium. The method avoids accumulation of calcium sulfate in acidulation units.

Abstract: One exemplary embodiment can be a process for reducing one or more insoluble solids in a black liquor. The process may include hydrothermal processing the black liquor to a temperature of about 250-less than about 300° C. for an effective time to reduce the one or more insoluble solids by more than about 40%, by weight, based on a weight of the one or more insoluble solids prior to hydrothermal processing.

Abstract: A method for controlling the sodium and sulphur balance of a pulp mill while separating lignin from black liquor, and also a lignin product or an intermediate lignin product obtainable by the method. The present invention also provides use of a lignin product or an intermediate lignin product for the production of fuel (solid, gaseous or liquid) or materials.

Abstract: A method was developed for: a) improving the filterability of acid-precipitated lignin from kraft black liquors, b) increasing the dry solids content of the final lignin product, c) reducing the acid requirements and d) minimizing or eliminating TRS emissions during the acidification of black liquor to produce lignin and/or the subsequent suspension of the lignin in acid and/or the washing of the lignin with acid. No major difference in the chemical composition, MWD and main functional groups was found in the lignin of the present invention compared with lignins produced by conventional methods.

Abstract: A process for refining and producing cellulose, lignin and xylose from biomass material comprises the following steps: pulverizing and screening the biomass material; and then dipping the biomass material in organic acid with lower boiling point and decomposing it into xylose, xylo-oligosaccharide, cellulose and lignin to make the biomass material fluidify; cooling the fluidified biomass material after finishing the reaction, adding organic solvent, and mixing uniformly and standing; separating, washing and drying the precipitation to obtain amorphous cellulose after precipitating; distilling the mother solution of precipitation of cellulose and recovering the organic acid and the resulting volatile organic substance; standing the distilled mother solution after cooling, and then separating, washing and drying the precipitation to obtain xylose and xylo-oligosaccharide after precipitating; distilling and recovering the organic solvent in the mother solution of precipitation of xylose and xylo-oligosaccharide,

Abstract: A process for refining and producing cellulose, lignin and xylose from biomass material comprises the following steps: pulverizing and screening the biomass material; and then dipping the biomass material in organic acid with lower boiling point and decomposing it into xylose, xylo-oligosaccharide, cellulose and lignin to make the biomass material fluidify; cooling the fluidified biomass material after finishing the reaction, adding organic solvent, and mixing uniformly and standing; separating, washing and drying the precipitation to obtain amorphous cellulose after precipitating; distilling the mother solution of precipitation of cellulose and recovering the organic acid and the resulting volatile organic substance; standing the distilled mother solution after cooling, and then separating, washing and drying the precipitation to obtain xylose and xylo-oligosaccharide after precipitating; distilling and recovering the organic solvent in the mother solution of precipitation of xylose and xylo-oligosaccharide,

Abstract: A method for separating carbohydrates from pulping liquors includes the steps of providing a wood pulping or wood or biomass hydrolysis pulping liquor having lignin therein, and mixing the liquor with an acid or a gas which forms an acid upon contact with water to initiate precipitation of carbohydrate to begin formation of a precipitate. During precipitation, at least one long chain carboxylated carbohydrate and at least one cationic polymer, such as a polyamine or polyimine are added, wherein the precipitate aggregates into larger precipitate structures. Carbohydrate gel precipitates are then selectively removed from the larger precipitate structures. The method process yields both a carbohydrate precipitate and a high purity lignin.

Abstract: The method and an arrangement are for dewatering and washing lime slurry before the dewatered lime mud is passed to a lime mud kiln. The lime slurry is dewatered in a pressurized lime mud filter of disc or drum type. The pressurized lime mud filter is pressurized through a compressor drawing on its suction side (s) gas phase from the filtrate tank and pressurizing on the pressurized side (p) of the compressor the pressure vessel on the lime mud side of the filter. A certain pre-determined amount of gas phase in the gas circulation system is vented and an equivalent pre-determined amount of fresh air is added to the recycled gas phase with the aim of maintaining the partial pressure of oxygen gas above a certain minimum level.

Abstract: The invention proposes an installation (10) in which the impregnation and fractionation of the raw material (MP) are conducted at atmospheric pressure, characterized in that it comprises means (18, 20) for transferring the raw material (MP) successively to a first treatment station (PT1) and a second treatment station (PT2), each comprising means (G1, G2) for temporarily combining, at the first station (PT1), the raw material (MP) with a quantity of a first mixture of organic acids and, at the second station (PT2), for temporarily combining the raw material (MP) with a quantity of a second mixture; and means, after impregnation, for at least partially recovering the quantity of second mixture after impregnation and for recycling at least a portion of the second recovered mixture to form at least partially said first impregnation mixture used at the first station (PT1).

Abstract: A lignin plastics solids mass containing lignin solids and liquids with up to 85% liquids can be partially dewatered by heating the lignin plastics solids mass to above a critical temperature at which time the lignin plastics solids agglomerate into lower moisture granular solids with between about 45% to 55% liquids releasing excess liquid which can be easily removed from the solids. The process is particularly useful for lignin plastics solids removed from black liquor from paper mills, or for similar lignin plastics solids masses, which can contain up to 85% liquids and which need to be dried to form useful lignin solids, which can be used for example for fuel. The dewatering process can be combined with the process for separating the lignin from the black liquor to separate the dewatered lignin directly from the black liquor.

Abstract: A method for controlling the sodium and sulphur balance of a pulp mill while separating lignin from black liquor, and also a lignin product or an intermediate lignin product obtainable by the method. The present invention also provides use of a lignin product or an intermediate lignin product for the production of fuel (solid, gaseous or liquid) or materials.

Abstract: A continuous and batch system to produce cellulose, native lignin and unicellular protein from any form of vegetation in a closed process. The biomass is mixed in the impregnate solution of nitric acid and/or ammonium hydroxide and water. After a period of time at room temperature and atmospheric pressure the chemical solution is recycled. The biomass is moved to the reactor and heated. Evaporated impregnate is recovered via absorption tower and recycled back to chemical solution. The biomass is moved to an alkaline solution, then cooled to separate pulp from black liquor. The black liquor is pumped to a separation tank and is treated to precipitate lignin. The solution is filtered to separate sweet liquor and lignin. The lignin is dried and the sweet liquor is fermented to produce unicellular protein.

Abstract: A method for the preparation of pulp by means of alkaline cooking, in which method spent liquor is transferred to pressurized tanks, and at least one liquor is expanded corresponding to a temperature difference of 1 to 5° C. The generated steam is led to turpentine recovery. Thus, the removal of turpentine and gases dissolved in said liquor is effective, the amount of recovered turpentine increases, and pulp of better washability and higher quality is obtained.

Abstract: A method for separating carbohydrates from pulping liquors includes the steps of providing a wood pulping or wood or biomass hydrolysis pulping liquor having lignin therein, and mixing the liquor with an acid or a gas which forms an acid upon contact with water to initiate precipitation of carbohydrate to begin formation of a precipitate. During precipitation, at least one long chain carboxylated carbohydrate and at least one cationic polymer, such as a polyamine or polyimine are added, wherein the precipitate aggregates into larger precipitate structures. Carbohydrate gel precipitates are then selectively removed from the larger precipitate structures. The method process yields both a carbohydrate precipitate and a high purity lignin.

Abstract: A process (44) for the production of pulp and paper (28), recycling of cooking chemicals (3, 29), combustion of biomass (30, 37) and generation of heat and electric energy (27, 40) comprising a pulp and paper mill (28), in that the part of the process which is recycling cooking chemicals is adjusted from combustion (29) to gasification (3) to generate synthesis gas (14); and that biomass is added (33, 39) in an amount sufficient for compensating of the decrease in heat and electricity generation as a consequence of the generation of synthesis gas (14).

Abstract: This invention relates to a process of treating a lignocellulosic material to produce bio-ethanol. The process includes the steps of: (a) exposing the lignocellulosic material to conditions including a pH not less than about 8, and steam at a first pressure, to produce a step (a) product; (b) explosively discharging the step (a) product to a second pressure less than the first pressure to produce a step (b) product; and (c) further processing the step (b) product to produce bio-ethanol and other co-products. In another embodiment, the invention relates to a conical auger fractionation column. The fractionation column includes a column body having an input and an output. A conical filter is positioned inside the column body, the filter having a larger diameter end directed toward the input and a smaller diameter end directed toward the output.

Abstract: The invention relates to a process for recovering and producing chemicals in a pulp production process where organic chemicals, such as formic acid and acetic acid, are used as cooking chemicals. The process of the invention is based on regeneration of cooking acids and formation of additional cooking acids and furfural by evaporating the cooking liquor and then separating acetic acid, formic acid, furfural and water. The separation is preferably carried out by distillation using the furfural formed in the process as a distilling aid in the distillation.