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

Abstract: Devices and methods for the high-pressure treatment of bulk material by extraction and/or impregnation. The bulk material is arranged in the interior volume of a pressure vessel device and is treated at a high pressure while sealed off from the surroundings. The high-pressure treatment is performed batchwise in a closed system in the pressure vessel device in a pressure-tight fashion. The bulk material is fed batchwise to the interior volume with the pressure vessel device closed and being arranged on at least one treatment level and, after the high-pressure treatment has occurred, being discharged batchwise from the interior volume with the pressure vessel device closed. The invention furthermore relates to the use of a supporting tray module with at least one treatment level for the high-pressure treatment in a closed system.

Abstract: Provided are a layer-separation method of a spent caustic solution, and a recycling method of an additive, and more particularly, a layer-separation method of a spent caustic solution including: injecting an additive and an acidic compound to the spent caustic solution occurring from a refinery process to break down a red oil emulsion and to perform layer-separation into an upper layer fraction and a lower layer fraction, wherein the additive is an aliphatic hydrocarbon compound having a water solubility of 0.1 to 10 g/L at 20° C.

Abstract: The disclosed solution relates to recovering thermal energy from the operation of a dissolver of a chemical recovery boiler used in pulp manufacturing. According to the solution, a primary fluid circuit conveys green liquor from the dissolver to an external process such as causticizing and solvent such as weak white liquor back to the dissolver, and from this circuit solvent is diverted into a secondary fluid passageway comprising a heat exchanger which cools the solvent by recovering heat from it and transfers the heat to a heat-consuming process. After heat recovery, solvent may be used for further processes before it is at least partly conveyed back to the dissolver.

Abstract: A novel chemical cycle for producing and capturing ammonia using nitrogen and hydrogen sulfide containing feedstocks is presented. An example of this cycle may start with the reaction between lithium nitride and hydrogen sulfide containing materials to form both lithium sulfide containing material and ammonia, where the produced ammonia is separated and captured. Metallic lithium may then be extracted high temperatures from said lithium sulfide containing material and then may or may not be separated from the said lithium sulfide containing material and other byproducts. The said extracted metallic lithium containing material may then be reacted with nitrogen containing feedstock to form lithium nitride containing material to complete the cycle.

Abstract: A method for treating a purge stream derived from a sodium carbonate, sesquicarbonate, wegsheiderite, or bicarbonate crystallizer, said purge stream comprising sodium carbonate and/or sodium bicarbonate and at least 1% by weight of sodium chloride and/or sodium sulfate, the method comprising: causticizing at least 50 mol.

Abstract: A method of treating waste liquors which comprise organic compounds, in order to recover chemical compounds or to recycle chemicals. In the present method, the sodium-based waste liquor, which comprises organic compounds that are sourced from lignocellulose, is subjected to partial wet oxidation, in order to produce organic sodium salts, in which case the partial wet oxidation is carried out in conditions where at least part of the lignin is simultaneously precipitated. The precipitated filtrate or lignin is subjected to further processing. Most suitably, the organic sodium salts, such as Na acetate, which are generated in the partial oxidation of the waste liquor, are also subjected to further processing, in which case it is possible, from the lignin and the organic sodium salts, to efficiently produce compounds which as such are already of sufficient quality as chemicals, or which as gases are suitable for further processing, for instance for production of fuels.

Abstract: A method for treating a purge stream derived from a sodium carbonate, sesquicarbonate, wegsheiderite, or bicarbonate crystallizer, said purge stream comprising sodium carbonate and/or sodium bicarbonate and at least 1% by weight of sodium chloride and/or sodium sulfate, the method comprising: causticizing at least 50 mol.

Abstract: A method for removing sulfide from an aqueous alkali solution in which hydrogen peroxide is introduced into a sulfide-containing aqueous alkali solution associated with an alkali mineral recovery operation. The method is particularly useful for the processing of sulfide-containing aqueous alkali solutions containing NaHCO3 and Na2CO3, where bicarbonate in the sulfide-depleted alkali solution is decomposed to form Na2CO3, with concurrent evolution of gaseous carbon dioxide byproduct but without formation of gaseous H2S as a pollutant, and where Na2CO3 values are subsequently recovered from the sulfide-depleted carbonate-rich alkali solution via a crystallization operation.

Abstract: An embodiment of the present invention relates to a method for treating spent caustic soda generated from an oil refinery process, a petrochemical process, etc. through a process in which a series of treatment steps are integrated, wherein the method can constitute a process under mild conditions excluding high temperature and/or high pressure conditions and can be advantageous to a post treatment process since the amount of by-products is small.

Abstract: The method and arrangement is for cleaning at least one of filter sheets and filter cakes in a pressurized white liquor filter with spray nozzles and driving fluid. The white liquor filter is used in a causticizing process in which green liquor is causticized before the white liquor filter by the addition of lime and in which it forms during the process a lime mud slurry. The white liquor filter 101 is used to separate white liquor from the lime mud. The driving fluid for the spray nozzle is constituted principally by the filtrate that is obtained from the filter.

Abstract: A separation process for separating two or more immiscible liquids using contactors utilizing high surface area vertical hanging fibers is disclosed. This separation process is especially useful in the separation of disulfide oil formed during the oxidation of spent caustic solution that was used to remove sulfur contaminates from light hydrocarbons.

Abstract: A method for purifying an aqueous alkaline solution, which comprises: bringing a fibrous activated carbon into contact with an aqueous alkaline solution to remove a metal component other than alkali metals and alkaline earth metals from the aqueous alkaline solution.

Abstract: A method of treating alkaline industrial by-products, such as red mud generated by Bayer process bauxite refining, is described. Embodiments of the method comprise treating the alkaline industrial by-products with salts of divalent and/or polyvalent cations, thereby lowering pH of the alkaline industrial by-products. The method involves replacement reactions in which relatively insoluble hydroxide salts form precipitates, thereby removing hydroxide ions from solution.

Abstract: A separation process for separating two or more immiscible liquids using fiber-film technology is disclosed. This separation process is especially useful in the separation of disulfide oil formed during the oxidation of spent caustic solution that was used to remove sulfur contaminates from light hydrocarbons.

Abstract: A caustic recovery system comprising an oxygen source adapted to provide a gas stream comprising at least 30% oxygen. A method of regenerating caustic comprising intermingling spent caustic with a gas stream comprising at least 30% oxygen.

Abstract: A process to regenerate wet flue gas scrubber purge liquid into NaOH caustic suitable for make-up caustic for the scrubber is disclosed. Further, sulfur is removed from waste effluent in the form of gypsum with the process described herein. Lime is added to the spent, sodium sulfate-containing purge liquid to result in the formation of gypsum and sodium hydroxide.

Abstract: In the methods for treatment of caustic effluents described in the specification, a spent caustic refinery effluent is supplied to a submerged combustion gas evaporator in which hot combustion gas containing carbon dioxide is injected into the caustic liquid to concentrate the liquid and convert a hydroxide constituent to a carbonate. Where the caustic effluent is from a petroleum refinery, oil in the waste liquid is separated from the aqueous constituent before, during or after concentration.

Abstract: Feeding device for feeding burned lime to a reaction vessel for causticizing a soda liquor to caustic soda. The feeding device, in its upper part, comprises an inlet for a slurry of the burned lime and the soda liquor for formation of said slurry inside said feeding device. The system further comprises a tall and slender feed vessel having a lower part having an outlet defined therein for the slurry. The outlet, via a pump, is operatively connected to the reaction vessel. The process and the feeding system utilize the feeding device, in which process the slurry is created of the burned lime and a first part of the soda liquor, a second part being preheated before addition to the slurry, whereafter slaking and causticizing reactions are completed under elevated temperature and pressure.

Abstract: The invention relates to a composition and method for treating liquid hydrocarbons in order to remove acidic impurities, such as mercaptans, particularly mercaptans having a molecular weight of about C4 (C4H10S=90 g/mole) and higher, such as recombinant mercaptans.

Abstract: This invention discloses improvements on previous inventions for catalytic conversion of coal and steam to methane. The disclosed improvements permit conversion of petroleum residua or heavy crude petroleum to methane and carbon dioxide such that nearly all of the heating value of the converted hydrocarbons is recovered as heating value of the product methane. The liquid feed is distributed over a fluidized solid particulate catalyst containing alkali metal and carbon as petroleum coke at elevated temperature and pressure from the lower stage and transported to the upper stage of a two-stage reactor. Particulate solids containing carbon and alkali metal are circulated between the two stages. Superheated steam and recycled hydrogen and carbon monoxide are fed to the lower stage, fluidizing the particulate solids and gasifying some of the carbon. The gas phase from the lower stage passes through the upper stage, completing the reaction of the gas phase.

Abstract: Sulfur compounds present as sulfides and mercaptans in spent caustic streams from refinery and petrochemical processes are oxidized by contacting them with an oxygen-containing gas in a packed column recycle reactor.

Abstract: A process for pre-treating a spent caustic stream prior to oxidation which includes countercurrent multi-stage elevated temperature solvent extraction of dissolved organic material from the spent caustic using a solvent to yield a spent caustic raffinate containing only residual amounts of organic solute and steam distilling the spent caustic raffinate to remove the residual organic solutes, yielding a pretreated spent caustic stream substantially free of organic material which is then subjected to wet air oxidation and thereafter to ozonolysis to yield a wastewater stream having a low COD and BOD, which is neutralized to a pH of 8.5 to 9.0.

Abstract: An alkaline solution containing dissolved sodium sulfides, mercaptides and phenolates is treated with a carbon dioxide-containing solvent in a reaction zone under mass transfer conditions to neutralize effluent alkaline solution and recover processable hydrocarbon values.

Abstract: A process for pretreating a spent caustic stream prior to oxidation includes countercurrent multi-stage elevated temperature solvent extraction of dissolved organic material from the spent caustic using a solvent to yield a spent caustic raffinate containing only residual amounts of organic solute. The raffinate is steam distilled to remove the residual organic solutes, yielding a pretreated spent caustic stream substantially free of organic material. The pretreated spent caustic is suitable for use in a Kraft paper process or for oxidation prior to recycle or disposal. Solvent extract from the extractor is regenerated in a solvent regenerator having an overhead stream for purging light ends, a bottom stream for purging heavy ends, and a heart-cut side stream for recycling solvent to the extractor.

Abstract: A method of producing white liquor having enhanced and/or reduced sulphidity in the recovery of chemicals in a sulphate pulp process is described. In the method one starts from a calcium sulphide rich smelt of inorganic chemicals, which has been obtained by simultaneous combustion of black liquor and processing of lime sludge. This smelt is treated with an aqueous solution, whereupon the calcium sulphide in the smelt is present in a solid form and the rest of the chemicals are in solution. Thereupon the solid calcium sulphide is separated and the obtained solution is processed as a green liquor in per se known manner to a white liquor having reduced sulphidity, whereupon optionally the separated solid calcium sulphide is mixed with the required amount of white liquor to a white liquor having enhanced sulphidity.

Abstract: A method for manufacturing Li.sub.2 Mn.sub.2 O.sub.4 which comprises the steps of providing LiMn.sub.2 O.sub.4 ; providing a lithium salt; forming a solution or suspension of the LiMn.sub.2 O.sub.4 and lithium salt in a liquid medium; and adding a reducing agent to the solution or suspension.

Abstract: The specification describes a process for recovering alkali metal hydroxides from an organic liquor such as black liquors derived from pulping wood chips. The organic liquor is burned in a fluidised bed combustion furnace containing fluidised particles of an iron rich mixed oxide of an alkali metal and iron. Particles of alkali metal ferrite are extracted from the furnace and dissolved in a solution of alkali metal hydroxide to form a more concentrated solution of alkali metal hydroxide and a precipitate of the iron rich mixed oxides of alkali metal and iron. A mixed oxide disclosed in the specification generally has the following formula: NaFe.sub.5 O.sub.8.4H.sub.2 O.

Abstract: Disclosed is a process for making orthorhombic Na.sub.2 SO.sub.4 containing less than 0.1 ppm chromium from a solution of Na.sub.2 SO.sub.4 containing 0.1 to 100 ppm Cr(III). The Cr(III) is oxidized to Cr(VI) at a pH greater than 7, water is evaporated from the solution to precipitate the orthorhombic Na.sub.2 SO.sub.4, and the precipitated orthorhombic Na.sub.2 SO.sub.4 is separated from the solution.

Abstract: The present invention is directed toward a process for regenerating sodium hydroxide (NaOH) from aqueous solutions of sodium sulfide (Na.sub.2 S) comprising heating aqueous sodium sulfide in the presence of a metal selected from the group consisting of iron and cobalt, for a time and at a temperature sufficient to form a metal sulfide, sodium hydroxide and molecular hydrogen.

Abstract: Process for disposing of insoluble tailings that remain when solubilizing uncalcined or calcined trona in the process of producing soda ash, in which the tailings are slurried with water or waste solutions of sodium carbonate and/or sodium bicarbonate, adding an alkali metal hydroxide or alkaline earth metal hydroxide in effective amounts up to about 10% by weight of the aqueous slurrying solution, pumping the slurry into a well connected to an underground mined-out cavity with sufficient pressure to prevent build-up of tailings from plugging the bottom of the well opening, dispersing and settling said tailings in the cavity, removing a liquor from said cavity whose concentration of sodium carbonate and/or sodium bicarbonate has been increased and recovering such enriched liquor for use in the manufacture of sodium-containing chemicals such as soda ash.

Abstract: A system and method of concentrating spent caustic at a refinery has a multi-stage flash drum for separating a spent caustic stream into an overhead output stream including vaporized water and volatile organic compounds, and a concentrated spent caustic output stream. The system also has a condenser for condensing the overhead output stream, and a separator for separating the condensed overhead output stream into a volatile organic compound stream, a liquid hydrocarbon stream and a water stream. The system further has an ejector for applying a vacuum to the flash drum to vaporize the spent caustic stream at a reduced temperature, and to the separator to remove the volatile organic compound stream. The volatile organic compounds are removed from the overhead of the separator through the ejector to a burner of a fired heater.

Abstract: Lithium metatungstate as a new composition of matter and the production thereof are disclosed. A solution of lithium monotungstate is treated with an extractant to remove sufficient lithium ions to produce a dilute solution of lithium metatungstate and the dilute solution is then concentrated. Lithium metatungstate solutions are more dense than other alkali metal metatungstates and have lower viscosities which properties make the solutions highly useful for heavy media separations.

Abstract: Method is described for the low temperature preparation of the spinel LiMn.sub.2 O.sub.4 phase which is an intercalable compound of interest for use in lithium secondary batteries. This phase can be prepared in bulk or thick film form at temperatures less than 400.degree. C. using acetate precursors.

Abstract: A method for treating caustic solutions to remove colorants, including iron, therefrom comprises: contacting the solution with a substance comprising a calcined product of a compound having the formula: A.sub.w B.sub.x (OH).sub.y C.sub.z.nH.sub.2 O, wherein A represents a divalent metal cation; B a trivalent metal cation; C a mono- to tetravalent anion; and w, x, y, z and n satisfying the following: 0<z.ltoreq.x.ltoreq.4.ltoreq.w.ltoreq.1/2y and 12.gtoreq.n.gtoreq.1/2(w-x). On a preferred basis, the contacted substance is a hydrotalcite derivative made by reacting activated magnesia with an aqueous solution of aluminate, carbonate, and hydroxyl anions before calcining at one or more temperatures between about 400.degree.-650.degree. C. There is further disclosed a method for producing an aluminum hydroxide having improved whiteness according to the invention.

Abstract: An improved method for causticizing the green liquor formed in a kraft paper plant by contacting the green liquor with lime to thereby form white liquor followed by clarifying the white liquor by removing the lime mud therefrom in a clarifier is disclosed wherein the improvement lies in removing the lime mud from the clarifier at a predetermined rate.

Abstract: A method of cleaning green liquor of solid particulate impurities by adding caustic lime corresponding to 0.5 to 10% of the amount of caustic lime needed for complete causticizing of the green liquor to the green liquor in a soda dissolving tank or in a separate mixing tank to which the liquor is led directly from the dissolving tank. Calcium carbonate precipitates and forms, with the impurities, particles having better settling and filtration properties than particles in green liquor which has not been treated with caustic lime.

Abstract: Process for causticizing a water solution containing alkali carbonate with calcium oxide and hydroxide by bringing the water solution containing alkali carbonate into contact with the calcium oxide or hydroxide and by separating the alkali hydroxide solution arisen in the causticizing from the calcium carbonate precipitate. The water solution containing alkali carbonate is conducted through a bed which has been formed by mixing calcium oxide and calcium carbonate in the causticized alkali solution and by removing the excess alkali solution.

Abstract: Method and apparatus for controlling the reactivity of lime produced in a lime cycle process that includes the steps of forming burnt lime in a kiln, washing and filtering of lime sludge, and causticizing of green liquor, which lime cycle process steps are carried out under variable operating conditions. At least one mechanical property of the burnt lime is measured, and at least one operating condition of the time cycle process is adjusted, based on the measured mechanical property of the burnt lime, so as to thereby control the reactivity of lime produced in the lime cycle process.

Abstract: A process for treating hydrocarbons containing mercaptans comprising the steps of contacting a first mercaptan-containing hydrocarbon stream with a first aqueous alkaline solution stream to form a mercaptide-rich aqueous alkaline solution stream and a reduced-mercaptan hydrocarbon stream; combining said mercaptide-rich aqueous alkaline solution stream with a second mercaptan-containing hydrocarbon stream and with oxygen to form a first mixture; oxidizing said mixture to form a second mixture of hydrocarbon, disulfides and aqueous alkaline solution; and separating said second mixture into a disulfide-containing hydrocarbon stream and a regenerated aqueous alkaline solution stream; whereby said second hydrocarbon stream is sweetened and said mercaptide-rich aqueous alkaline solution is regenerated simultaneously in the same step.

Abstract: Chlorate is removed from aqueous caustic soda by reducing with iron pentacarbonyl and separating off the resulting iron oxide containing precipitate.

Abstract: A soluble salt (sodium sulfate or sodium borate (Na.sub.2 SO.sub.4 or Na.sub.2 B.sub.4 O.sub.7) contained as the main component in a concentrated radioactive waste liquid generated in the BWR power plant or the PWR power plant is insolubilized and precipitated, sodium hydroxide (NaOH formed in the insolubilization is separated from the precipitate and the radioactive waste liquid slurry containing the precipitate is solidified with a hydraulic solidifying material. Since the separated caustic soda (NaOH) is free of radioactive substances, it can be easily utilized again, and since the radioactive substances are stably fixed in the solidified body, leakage of radioactivity from the solidified body can be greatly reduced.

Abstract: A volume-reducing solidification treatment method for radioactive waste liquid containing boron primarily in the form of boric acid or borates is disclosed.After an alkali is added to the waste water to adjust pH thereof, and optionally after evaporation concentration is carried out, soluble calcium compounds such as Ca(OH).sub.2 are added, the waste water is stirred at a specific temperature to form insoluble calcium borate aged at a lower temperature than that of forming borate, and evaporation and concentration is carried out, which raises the concentration of the solid component. The concentrated liquid obtained is solidified with cement.The concentrated liquid may also be dried into a powder using a thin film evaporator.

Abstract: A method for increasing the efficiency of the caustizing process which comprises: (a) adding to a green liquor between 78 and 82% of the stoichiometric amount of lime necessary to react with the amount of Na.sub.2 CO.sub.3 present in the green liquor to obtain a white liquor containing NaOH and lime mud. The white liquor is then clarified by extracting the lime mud present to obtain a white liquor having a total solid concentration of about 10-60 grams/liter. The supernatant liquid of the white liquor is treated with an additional amount of lime to increase the causticity to about 87%, then allowing further causticizing reaction between the lime and Na.sub.2 CO.sub.3. The remaining lime mud present is removed to obtain a white liquor which has the causticity of about 87%. One is thus able to raise the causticity of partially clarified white liquor following the normal causticizing process, the mud present being sufficient to increase causticity without substantially decreasing settling rate.

Abstract: The invention concerns a causticizing procedure by which from soda liquor derived from a sulphate cellulose digesting process and from unslaked lime is produced white liquor for reuse in the digesting process, over lime slaking and a subsequent causticizing reaction proper. It is essential in the invention that the lime slaking is carried out using white liquor, whereafter the causticizing reaction proper is allowed to take place between the slaked lime and soda liquor combined therewith. The requisite white liquor is obtained by recirculating part of the white liquor produced by the causticizing process, to the slaking step, where it either completely or partially replaces the soda liquor employed in prior art. By using white liquor, one avoids the foaming, interfering with the process, which is encountered in the slaking step.

Abstract: A method is disclosed for reducing alkali metal chlorate impurities in an aqueous alkali metal hydroxide solution by heating a mixture of the alkali metal hydroxide solution with a hydroxycarboxylic acid or a salt thereof at temperature above about 125.degree. C. and for a period of time sufficient to substantially eliminate the chlorate, the hydroxycarboxylic acid or salt thereof being substantially non-volatile at the heating temperature.

Abstract: A process of recausticizing kraft green liquor in which the green liquor containing sodium carbonate is passed in a stream in admixture with particles comprising slaked lime, in which stream the liquid phase becomes progressively weaker in sodium carbonate and stronger in sodium hydroxide. Lime is added in order to provide a continuous supply of slaked lime for reaction with the sodium carbonate, and the stream is passed to a solids/liquid separator which recovers liquid phase from said stream, strong in NaOH, continuously and separately from the solid phase of the stream, as white liquor. The rate of the recausticizing reaction is limited by the rate of diffusion of carbonate ion into the solid particles, and of hydroxyl ion out of the solid particles. Typically, these rates limit the amount of causticizing achieved to less than the equilibrium value.

Abstract: An alkaline solution containing mercaptides is regenerated in an improved process wherein the alkaline solution to be regenerated containing a suitable oxidation catalyst is contacted with an oxygen-containing solvent which is immiscible with said alkaline solution in a reaction zone comprising a plurality of fibers positioned longitudinally within a conduit, whereby the two liquids are in contact while concurrently flowing through said reaction zone during which the mercaptides contained in the alkaline solution are oxidized to disulfides and are simultaneously extracted from the alkaline solution into the solvent solution.

Abstract: A process for the removal of essentially chromium-free sulfate from a chromate and sulfate-containing chlorate liquor which includes mixing the chlorate liquor having a pH of between about 2.0 and 6.0 with a calcium-containing material at a temperature and for a time sufficient to form a sulfate-containing precipitate predominantly of glauberite, Na.sub.2 Ca(SO.sub.4).sub.2, and separating the substantially chromium-free glauberite from the chlorate liquor.

Abstract: A novel process for the recovery of alumina and potassium sulfate from alunite is provided comprising leaching the alunite with potassium hydroxide to which no sodium materials have been added, said leach solution being saturated with potassium sulfate. Aluminum values are solubilized into the leachate, and potassium and sulfur values are rendered soluble, but remain in the residue. The leachate is desilicated if necessary, preferably with lime, and aluminum trihydroxide is precipitated therefrom, followed by calcining to alumina product. The residue is leached to solubilize potassium sulfate in a secondary leach and the potassium sulfate product crystallized therefrom. Potassium hydroxide is regenerated from a portion of the potassium sulfate secondary leachate by several methods.Novel procedures for regenerating alkali metal hydroxides from the corresponding sulfates are also provided including routes involving formates and carbonates as intermediates and pyrohydrolysis.