Abstract: Disclosed herein is a method for recovering a low sodium content lignin from spent kraft cooking liquor without the use a of strong mineral acid for acidulation.

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: There is disclosed a method for isolation and purification of phytosterols from tall oil pitch comprising the steps of: a) contacting the tall oil pitch with a solvent to form a tall oil solvent mixture; b) separating the tall oil pitch solvent mixture in at least two separate streams wherein one process stream is enriched in acidic pitch components and a second stream enriched in free- and bound sterols in the form of steryl esters; c) subjecting the stream enriched in free- and steryl esters to treatment with an alcohol under transesterification conditions wherein a reaction mixture is formed and sterols comprising the steryl esters are liberated as free sterols; and d) separating the free sterols from the reaction mixture of step c) by crystallization and extraction with one or more solvents. There are disclosed free fatty acids and resin acids separated from the tall oil pitch. Moreover, there is disclosed a manufacture and separation of fatty acid alkyl esters by the method.

Abstract: There is disclosed a method for conversion of crude tall oil into high-quality diesel fuels comprising the steps of: (a) removal of non-oil contaminants present in the crude tall oil and recovering valuable organic compounds present in the crude tall oil, thereby forming a refined tall oil stream; (b) removal of the volatile fraction of the refined tall oil stream from step a), thereby forming a volatiles free oil stream comprising organic components with boiling points, at atmospheric pressure, of 170 degrees C. or higher; (c) separation in a vacuum distillation column of the volatiles free oil stream of step b) into two process streams or phases wherein a first process stream or phase is substantially comprising components with boiling points, at atmospheric pressure, in the range of 170-400 degrees C. and a second process stream or phase is substantially comprising components with boiling points, at atmospheric pressure, over 400 degrees C.

Abstract: There is disclosed a method for recovering a low sodium content lignin from spent kraft cooking liquor without the use a of strong mineral acid for acidulation comprising the steps of acidulating a spent kraft cooking liquor with carbon dioxide gas to a pH below about 10.5, precipitating at least a portion of the lignin forming lignin agglomerates and lignin particles in the spent kraft cooking liquor and recovering a low water and low sodium content lignin product comprising calcium or magnesium compounds bound to said lignin.

Abstract: There is disclosed a method for manufacturing fatty acid alkyl esters from tall oil comprising the steps of a) esterifying tall oil in at least one esterification reactor in the presence of an acidic catalyst and an C1 to C8 alcohol to form a crude product stream comprising fatty acid alkyl esters and H2O, b) separating H2O and alcohol from the crude product stream formed in step a) to form a dehydrated fatty acid alkyl ester product stream, and c) separating dehydrated fatty acid alkyl ester product stream from step b) into at least two product streams wherein one product stream is enriched in fatty acid alkyl esters and one product stream is enriched in resin acid compounds. There are disclosed fatty acid alkyl esters and resin acids manufactured by the method. Moreover there is disclosed a fuel composition and its use as an automotive fuel, said fuel composition comprises the fatty acid alkyl esters produced according to the present invention.

Abstract: The invention relates to a process for providing tall oil or tall oil fuel from tall oil soap. In the process, tall oil soap, which may be neutralized with carbon dioxide, is treated with an alkaline earth metal compound to convert sodium soaps into alkaline earth metal soaps. The conversion reduces the sodium content and increases the heat value of the product. The converted product may be used to provide a low sodium fuel or it may be acidulated with a minimum of sulfur.

Abstract: A new and environmentally sound process for the manufacturing of a chemical pulp from lignocellulosic material with an integrated recovery system for recovery of pulping chemicals. The process is carried out in several stages involving a pre-treatment stage followed by one or more delignification stages using an alkaline buffer solution containing alkali metaborate and sodium carbonate as major components. The alkaline components of the pulping liquor are recovered from a chemicals recovery furnace and at least a portion of the alkali is recycled and used for delignification without any prior reactions with lime or calcium compounds for generation of alkali hydroxide. A quinone based delignification catalyst may be added to be present during delignification. In a preferred embodiment, the quinone pulping catalyst is added prior to alkaline delignification, the delignification being conducted in the substantial absence of sulphide.

Abstract: The present invention relates to a new and environmentally sound process for the manufacturing of a chemical pulp from lignocellulosic material with an integrated recovery system for recovery of pulping chemicals. The process is carried out in several stages involving a pre-treatment stage followed by one or more delignification stages using an alkaline buffer solution comprising alkali metaborate and sodium carbonate as major components. The alkaline components of the pulping liquor are recovered from a chemicals recovery furnace and at least a portion of the alkali is recycled and used for delignification without any prior reactions with lime or calcium compounds for generation of alkali hydroxide. A quinone based delignification catalyst may be added to be present during delignification.

Abstract: The present invention relates to a novel method for the production of a high yield chemical pulp from softwood in a pulp mill by the application of a delignification catalyst in a wood impregnation step and by using alkaline pulping liquors comprising boron compounds at a white liquor sulfidity level below about 25%. The method is practiced concurrently with a controlled sulfur chemicals management in the pulp mill thereby providing a pulping process which have low emission of odorous pollutants, low rate of corrosion in mill equipment and which has a rate of delignification and selectivity sufficient to produce softwood pulp in higher yield and at a quality at least on a par with a kraft pulping alternative.

Abstract: The present invention relates to a new and environmentally sound process for the manufacturing of a chemical pulp from lignocellulosic material with an integrated recovery system for recovery of pulping chemicals. The process is carried out in several stages involving a pre-treatment stage followed by one or more delignification stages using an alkaline buffer solution comprising alkali metaborate and sodium carbonate as major components. The alkaline components of the pulping liquor are recovered from a chemicals recovery furnace and at least a portion of the alkali is recycled and used for delignification without any prior reactions with lime or calcium compounds for generation of alkali hydroxide. A quinone based delignification catalyst may be added to be present during delignification.

Abstract: The present invention relate to a two-stage gasification process using a gas generator for the recovery of strongly alkaline chemicals and energy value from a cellulose spent liquor. The temperature in the first reaction zone of the gas generator is maintained between 1000 C. and 1400 C. by the controlled addition of an oxygen containing gas. A strongly alkaline smelt comprising alkali oxide, alkali hydroxide, alkali carbonate and alkali borate's corresponding to at least 75% by weight of the smelt is recovered from below the first reaction zone of the gas generator. A gaseous components stream formed by exothermal reactions in the first reaction zone are directed to a second reaction or gas transfer zone of substantially of updraft or up-flow design, wherein the gaseous stream is cooled to a temperature below about 1000 C, said cooling preferably achieved by endothermal decomposition of cellulose spent liquor injected into the gaseous stream.

Abstract: A substantially sulfur free process for the manufacturing of a chemical pulp with an integrated recovery system for recovery of pulping chemicals is carried out on in several stages involving physical and chemical treatment of lignocellulosic material in order to increase accessibility of the lignocellulosic material to reactions with an oxygen-based delignification agent. Spent cellulose liquor comprising lignin components and spent chemical reagents is fully or partially oxidized in a gas generator wherein a stream of hot raw gas and a stream of alkaline chemicals and chemical reagents is formed for subsequent recycle and reuse in the pulp manufacturing process.

Abstract: The present invention relates to a process for producing pulp which is cooked under alkaline conditions and which is bleached without using chlorine-containing bleaching chemicals, in which process used cooking chemicals are recovered in a first recovery installation and used bleaching chemicals are recovered in a second recovery installation. The used cooking and bleaching chemicals can be regenerated and reused.

Abstract: A method for impregnation and chemical digestion of lignocellulosic material and recovery of pulping liquors. A spent impregnating or cooking liquor is withdrawn and sulphurous compounds are recovered therefrom in a partial oxidation reactor. These sulphurous compounds are converted into hot liquid elemental sulphur which thereafter is mixed with a hot sulphide containing liquor to provide a polysulphide liquor with a concentration greater than 10 g/l and which is essentially free from thiosulphate. This polysulphide liquor is used for carbohydrate stabilising impregnation and/or for cooking at a relatively low temperature.

Abstract: Provided is a novel process for the preparation of an aqueous solution of alkaline compounds from a generator gas, containing carbon monoxide, carbon dioxide, hydrogen and entrained alkaline compounds, which gas has been formed during partial combustion of cellulose spent liquors in a gas generator connected to a quench vessel.

Abstract: The present invention relates to a method for producing pulp cooked under alkaline conditions, in which method cellulose-containing material is brought into contact, in a digester, with an alkaline cooking liquor containing dissolved potassium and sodium compounds, with used spent cooking liquor being separated off from the cellulose-containing material and withdrawn for the recovery of energy and chemicals, wherein:a) The molar ratio, calculated as K/K+Na, between potassium and sodium in a withdrawn spent cooking liquor exceeds 0.25.b) The withdrawn spent cooking liquor is concentrated with respect to its content of solid material and is subjected to partial oxidation in a reactor, resulting in the formation of a, combustible gas which is withdrawn from the reactor.c) oxygen-containing gas is supplied to the reactor in order to support the partial oxidation.d) The operating temperature in the reactor is adjusted to between 400.degree.-1200.degree. C.

Abstract: The present invention is directed to a process for efficient combustion of cellulose spent liquors using a burner connected to a reactor, while supplying an oxygen containing gas, which invention is characterized in that more than 80% of the oxygen which is required for the partial combustion of the spent liquor is supplied through the lance of the burner to the reactor as an oxygen containing gas at a stoichiometric ratio of between 0.3 and 0.6 relative to complete combustion of the spent liquor.

Abstract: The process for producing hydrogen peroxide, used in the bleaching of pulp, uses the hydrogen generated wholly or partly by the gasification or partial combustion of cellulose spent liquors used in digesting cellulose material to produce the hydrogen peroxide.

Abstract: A method of separating sulphur compounds out of a gas containing carbon dioxide and hydrogen sulphide, in a gas washing system, said gas being obtained by gasification of spent cellulose liquor. According to the invention the gas washing system has a gas-liquid contact zone (5) operating at a pressure exceeding atmospheric pressure as well as a regeneration zone (8) operating at a pressure substantially less than the pressure in the gas-liquid contact zone (5). The carbon dioxide partial pressure in the gas prior to entering the gas-liquid contact zone exceeds 0.2 atm. Furthermore the gas comes into contact with an alkaline absorption liquid in the gas-liquid contact zone, and alkaline liquid containing alkali hydrogen sulphide is withdrawn from the gas-liquid contact zone and transferred to the regeneration zone, in which zone hydrogen sulphide is expelled from said liquid containing alkali hydrogen sulphide and withdrawn in the form of a gas.