149results about "Spent liquor concentration" patented technology

The present invention relates to a process tor the production of precipitated lignin from black liquor wherein the process comprises the steps of providing a black liquor stream treating the black liquor at an increased temperature and precipitating the lignin from the heat treated black liquor. The present invention further relates to precipitated lignin produced according to the process and use of the precipitated lignin produced.

Method of producing a process steam from a first black liquor derived in connection with the production of paper pulp, wherein the first black liquor is treated to give a second black liquor of a higher concentration than the first black liquor as well as a liquid of low concentration, whereafter said process steam is produced from the low concentration liquid.

The present disclosure describes a system for predicting explosions in a dissolving tank. The system includes acoustic emission sensors placed in or around the dissolving tank. By filtering the recorded frequencies to the range which is most sensitive for desired explosions “fingerprints,” it is possible to predict a smelt influx before the smelt influx occurs as well as program response actions to prevent compromising explosions.

In a method for the continuous precipitation of lignin from black liquor black liquor is provided so as to flow as a pressurized flow in a reactor (2) with a dwell time of less than 300s,—an acidifying agent selected from the group of carbon dioxide, acid and their combinations is led to the flow at one or more feeding sites (2a) to lower the pH of black liquor,—the pH is allowed to decrease by the effect of the acidifying agent in the pressurized flow to the precipitation point of lignin, the pressure of the pressurized flow is abruptly released, and lignin particles are separated from black liquor.

This invention provides an improved process for recovering chemicals from black liquor in alkaline pulping, which is achieved by introducing depuration treatments of green liquor and lime before causticization reaction and a two-step-causticization procedure in the causticization procedure of the conventional chemical recovery process. The process of this invention not only avoids the generation of the waste residue (lime mud) from the beginning and saves the recovery and treatment of lime mud, but also can directly produce a series of precipitated calcium carbonate products with various particle sizes by regulating process conditions while the alkali is recovered, said CaCO3 products including a CaCO3 suitable for making coated paper, wherein >=50% of the CaCO3 has a particle size below 2 mum; a CaCO3 suitable for making neutral sized paper, wherein >=90% of the CaCO3 have a particle size below 2 mum; a superfine CaCO3 having an average particle size <1 mum. The present invention can be used for treatment of pollution of black liquor in the alkaline pulping.

The invention discloses the agricultural and subsidiary products straw stalk resources clean production paper and the modified lignin new craft. The craft the black liquor took the precious resources, in steams and its concentrates two stages separately to join the modifier, steams the medicinal preparation, the molecular weight and the performance regulation medicinal preparation, fully uses in the straw stalk the textile fiber, the lignin equicomponent, always will pollute the traditional straw pulp juice the load approximately 90% elimination in the technological process. The craft suits the size middle and small scale straw pulp paper mill use, becomes paper pulp which delivers rate high, the viscosity is low, Yi Xiyi floats, more importantly the by-product lignin after the modification, has performance and so on good disperser caking conformity, widely uses in the cement sur- medicinal preparation, the water coal tar chemical additive, the agricultural chemicals dispersing agent and so on.

The invention discloses a method for reclaiming solvent in cellulose fiber preparation taking ionic liquid as the solvent, which comprises the following steps: filtering solution containing the ionic liquid to remove solid particle impurities; performing film condensation by a reverse osmosis membrane; and distilling the condensed solution containing the ionic liquid under reduced pressure to make the mass content of water in the solution containing the ionic liquid less than or equal to 2 percent, and obtaining the reclaimed ionic liquid. The method is suitable for reclaiming the solution containing the ionic liquid in wide concentration range, and has low energy consumption and easy implementation.

A method and an apparatus for preparing cellulose pulp, in which a lignin-containing raw material is impregnated with impregnation liquor and the impregnated raw material is cooked. The black liquor obtained by cooking is concentrated in an evaporation plant integrated in a chemical recovery plant. In the impregnation, the lignin-containing raw material is impregnated with a circulating alkaline impregnating liquor, which impregnating liquor is concentrated by evaporating water from it in at least one evaporator unit of the evaporation plant arranged in the chemical recovery plant of a pulp mill.

Desirable chemicals are recovered from a raw material that is formed in substantial amounts during the production of cellulose pulp from renewable lingo-cellulose material. An ammonia / ammonium-containing methanol / water mixture is acidified with an acid that has the ability of forming ammonium salt with the ammonium. The mixture is circulated and passed through an apparatus that has an indirect heat exchanger combined with an storage volume fitted with a gas collection device.

A device and a method for recovering alkali from black liquid of papermaking by using fluidized bed relates to a fluidized bed alkali recovery device and a process thereof. The invention solves the problems of the prior art such as bed material sintering during burning black liquid of papermaking. The device comprises a fluidized bed alkali recovery furnace communicated with a cyclone with a bottom dipleg communicated with the fluidized bed alkali recovery furnace, and an air blower respectively communicated with a burner, the dipleg, a lance and an air preheater through pipes. The method comprises the following step of pumping the black liquid to the fluidized bed alkali recovery furnace through a multi-effect evaporator, a disk evaporator and a concentrated black liquid tank by a black liquid pump, burning the black liquid at a furnace temperature of 700 to 900 DEG C by using sodium-based zeolite as the bed material to produce an inorganic sodium salt, and precipitating and separating the inorganic sodium salt and the bed material in a dissolving tank. The invention solves the problems of pellet coagulation and sintering of bed material of the fluidized bed, and the bed material can be repeatedly used, thus effectively solving pollution of papermaking industry.

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.

In a tall oil refining operating plant, a warm water loop is disclosed for cooling the tall oil heads fraction extracted from the crude tall oil, rather than the conventional use of cold water. This avoids condensation and the subsequent solidification of athraquinone pulping aid remaining in the crude tall oil; thus, avoiding fouling of the cooling towers. The temperature of the warm-water is controlled automatically by tempering the cold water entering the warm water "cooling" loop, while removing excessively warm water from said loop to the cooling tower system, as needed.

The invention discloses a five-coproduction process for comprehensively utilizing biological straw, aiming at solving the technical problem of expanding the straw utilization scale. The process consists of three lines: the first line is used for producing xylooligosaccharide: smashing biological straw, introducing steam for boiling, passing through an ultrafiltration membrane-1 after filter pressing, passing through an ultrafiltration membrane-2 after enzymatic hydrolysis reaction, enabling penetrating fluid to be subjected to nanofiltration concentration so as to be concentrated by 3-5 timesto obtain the xylooligosaccharide; the second line is used for producing straw pulp and sodium lignosulfonate: smashing the biological straw, enabling the smashed biological straw and waste residue tobe subjected to pressurized high temperature boiling together, enabling obtained serous liquid to be subjected to filter pressing separation, and enabling solid matter obtained after separation to besubjected to adverse current cleaning to obtain wheat straw pulp; enabling black liquor and washing black water obtained after separation to evaporate and concentrate, then performing heat exchange via hot-blast air to obtain sodium lignosulphonate powder; and the third line produces biochar and combustible pyrolysis gas. On the premise of generating remarkable economical benefit, the five-coproduction process is friendly to environment and does not generate waste water so as to achieve zero discharging, solid waste does not exist, and the exhaust gas reaches the standard and is emitted.

The invention relates to a process for concentrating straw pulp black liquor. When the production process is used for evaporating and concentrating the black liquor, the energy resource consumption is little, the efficiency is high, the produced solid in the concentrated black liquor mainly comprises alkali lignin which has wide application; and the alkali lignin can be used as raw materials of various products with extremely high economic value and for preparing excellent water reducing agent, and can be added by little crosslinking agent so as to prepare lignin sand solidification agent.

In a digester, wood chips and white liquor are combined and cooked under pressure to pulp the wood. This produces black liquor which is concentrated and burned in a recovery boiler. The recovery boiler produces ash that contains sodium, sulphur, potassium and chloride. The ash is dissolved and subjected to a process that recovers sodium sulfate and burkeite. The concentration of potassium and chloride is reduced, in part at least, by subjecting the ash to adiabatic cooling in a crystallizer which produces glaserite and a purge stream rich in chloride. By leaching the glaserite, sodium sulfate is removed from the glaserite, leaving potassium sulfate. The recovered sodium sulfate and burkeite can be recycled and used as pulping chemicals. The removed potassium and chloride can be further treated or appropriately discarded.

The invention discloses a zero discharge process of pulping waste liquid of all-cotton straw pulp. The process includes firstly performing front-end high concentration extraction of pulping waste liquid, then performing evaporation and concentration of the high concentration pulping waste liquid, recycling evaporation and condensation water, and recycling evaporation residue fluid, so as to realize the zero discharge of the pulping waste liquid finally. The front-end high concentration extraction of the pulping waste liquid includes cotton stalk raw material pigment decomposition, pigment extraction and reverse washing, and front-end extraction.

Methods for producing chemical pulp from lignocellulose-containing material in processes for kraft pulp production are disclosed including charging the lignocellulose-containing material to a digester, initially treating the lignocellulose-containing material with an impregnation liquor, and then treating the impregnated lignocellulose-containing material with hot liquor and displacing calcium-containing spent liquor from the digester during that treatment, heating and cooking the heated lignocellulose-containing material to produce cooked lignocellulose-containing material and cooking liquor and displacing the cooking liquor from the digester using at least a portion of the displaced calcium-containing spent liquor.

Methods for facilitating sugar release from lignocellulosic biomass and for utilizing the sugars for microbial lipid (e.g. biofuel) production are provided. The methods involve pretreating lignocellulosic biomass using various oxidizing agents (ozone, peroxone, etc.) at a temperature not higher than 50° C. and pressure no higher than 1.5 atm to render the biomass more accessible to enzymatic hydrolytic degradation into sugars and utilizing soluble sugars for fermenting oleaginous microorganism to produce microbial lipids.

The invention relates to a paper making pulping black liquid crystallization and evaporation method which comprises the following steps of: sending a black liquid from a first effect evaporator into a black liquid mixing tank, adding alkali ash and / or mirabilite, mixing with the black liquid to generate a mixed black liquid, and enabling the mixed black liquid to contain excess sulfate to become a sulfate supersaturated liquid; sending one part of the obtained mixed black liquid to a crystallization and densification evaporator for evaporation, and sending the evaporated black liquid to a pressure black liquid tank for storage; mixing one part of the black liquid with the black liquid from a second effect evaporator to sequentially enter three chambers of the first effect evaporator for evaporation, and sending into the black liquid mixing tank after evaporation. The invention can effectively avoid the scale formation of the black liquid in the evaporation process, obtains higher concentration of the black liquid, is beneficial to alkali reclamation and has lower energy consumption.

The invention provides an evaporation pretreatment process method for alkaline peroxide mechanical pulp, which comprises a waste liquor recovery process and an alkali recovery process, wherein in the waste liquor recovery process, filter water in the production process of the alkaline peroxide mechanical pulp is collected to a waste liquor intermediate pond, and in the alkali recovery process, collected waste liquor in the waste liquor intermediate pond is subjected to alkali recovery treatment. Before the alkali recovery treatment, the method also comprises the following evaporation pretreatment steps of: (a) performing pressure filtering on waste liquor, namely filtering the waste liquor in the waste liquor intermediate pond by a pressure sieve, discharging dregs formed during filtering to a dreg sieving pond, and discharging the filtered waste liquor to a waste liquor tower to enter the step (b); and (b) performing evaporation grading treatment on the filtered waste liquor by an evaporator, wherein heavily-polluted concentrated solution is discharged to a concentrated solution pond for alkali recovery treatment, mildly-polluted concentrated solution is discharged to a wood chip washing water tank to clean wood chips, and after being mixed with disk mill dilution water in a white water tower, white water generated during evaporation is discharged to a hot white water tank and enters a pulping system of the alkaline peroxide mechanical pulp. The evaporation pretreatment process method has the advantages of high alkali recovery efficiency and environment friendliness.

A flash tank including: an interior chamber having a interior surface formed by a sidewall of the flash tank; a vapor exhaust port coupled to an upper portion of the chamber; a liquid discharge port coupled to a lower portion of the chamber; an insert inlet tube having an insert outlet and inserted into an inlet port of the chamber, wherein the insert inlet tube extends inward of the sidewall and the insert outlet has an elongated cross-sectional shape oriented substantially parallel to a center vertical axis of the flash tank and substantially perpendicular to a radial line of the flash tank, such that the insert outlet is substantially tangential to the sidewall.

The invention discloses a treatment method of papermaking black liquid. The treatment method comprises the following steps: concentrating the papermaking black liquid, and separating to obtain a first solid matter and a first supernatant; neutralizing the first supernatant with an acid, and separating to obtain a second solid matter and a second supernatant; concentrating the second supernatant, and separating to obtain a third solid matter and a third supernatant. By adopting the treatment method disclosed by the invention, the CODCr of the waste liquid can be reduced, the wastewater treatment load can be reduced, different solid matters can be recycled respectively, and the economic benefit of enterprises can be increased.

The invention relates to a mixture of dried grain of alkali and ammonium sulfite black straw liquor as well as relevant preparation method. The invention is mainly a product by mixing alkali method black straw liquor with ammonium sulfite black straw liquor before performing condensation and drying, as well as relevant products that are produced. Evaporating and condensing black liquor with the production technique needs less energy consumption, and main dried grains include sodium lignin and ammonium lignin sulfonate as well as fulvic acid like substances. Therefore, the invention has broad application and can be used as raw materials for many products with high economic value. Moreover, the invention can also be utilized in preparation of an excellent water reducer, or be added with some crosslinkers to prepare lignin sand-fixing solvent.

The invention provides a method for extracting lignose with zero discharge of paper making black liquors and a device thereof. The method is mainly applicable to wood such as wheat straws, rice straws, sugar cane waste, cotton straws, eulaliopsis binata, reeds and bamboos; the wood after being selected is put in a spherical digester, a sauce pan or a continuous digester, sprayed in a spraying bin after the manganese value is obtained and sent to a twin screw squeezing pulp machine or other squeezing pulp equipment for squeezing by a screw discharging machine, and the high consistency black liquors are extracted by steam-boiling, and dilute liquors left in fibers are sent back to a boiler for recycling use; in the system adopting the low temperature condensation negative pressure principle, black liquors are automatically sucked in a reaction kettle for condensation reaction due to vacuum; after instant contact drying, grain-sized dry powder by products are generated. The method of the invention has the advantages of completely resolving the problem of back liquor pollution in the paper making industry because of clearing away the very root, improving the transfer ratio of resource reutilization and protecting the environment, along with low equipment cost, low cost and good economic benefits.

A descaling method for plate-type falling-film evaporators is provided, which belongs to the technology field of pulp and paper industry. The method includes the following steps: immersing a heat exchange plate of a plate-type falling-film evaporator in a white liquor containing 70-90 g / L of NaOH, boiling under such conditions that the temperature is 110-130 DEG C and the pressure is 0.1-0.15 MPa until the fiber scale is loose; and purging the fibrous scale from the surface of the heat exchange plate by using a high-pressure water gun at a pressure of 400-500 Kg / cm<2>. The method can remove fiber scale efficiently and completely. Compared with the prior art, the method lengthens the descaling period from one month to three months, shorten the descaling time by a half, removes the scale completely, increases the efficiency of the plate-type falling-film evaporator and improves the production capacity of the equipment.

The invention discloses an optimizing process for alkali recovery of papermaking waste liquid, the optimizing process comprises black liquor extraction, evaporation concentration, high-temperature calcining and causticization, the black liquor extraction section is used for extracting dilute black liquor from pulping cooked liquor, the evaporation concentration section is used for heating the black liquor of the black liquor extraction section by virtue of steam from the high-temperature calcining section; the high-temperature calcining working section is used for first concentrating the blackliquor with the concentration of 50% obtained by the evaporation concentration section further to the concentration of 65%, the obtained black liquor is sent to an alkali furnace for high-temperaturecalcining, a melt is formed by the calcined black liquor, and the melt is dissolved into water obtain green liquor; and the causticization section is used for reacting the green liquor with limestoneto obtain a sodium hydroxide solution. According to the optimizing process, the process is simple and feasible, the recycling efficiency of the black liquor is high, and the quality is guaranteed.

A method for inhibiting the formation, deposition and adherence of calcium salt scale to metallic and other surfaces in the equipment, vessels and / or piping of a chemical pulp process facility comprising adding an effective scale inhibiting amount of a composition to the alkaline aqueous mixture in the digester of said chemical pulping process. Said composition consists of at least one phosphonate component (I) and at least one component (II) consisting of at least one carboxylated fructan compound.