4 results about "Kraft process" patented technology

The present invention is directed to fractionation of crude tall oil, which originates from the Kraft process black liquor. In the method according to the present invention, at least two strongly basic anion exchange resins are used to efficiently separate fractions from the crude tall oil.

The present invention provides a biobased and biodegradable cooking enhancement formulation for kraft pulping and a process for preparing the same. The formulation comprises lauryl alcohol ethoxylate, alpha olefin sulphonate, polysorbate-20, lactic acid, and water as essential components. The synergistic combination of these ingredients enhances delignification efficiency in kraft cooking by improving liquor impregnation, promoting oxidation through in situ peracid generation, and stabilizing oxidized lignin fragments through emulsification. The formulation enables efficient delignification at reduced active alkali concentration and lower cooking severity, thereby improving pulp brightness and yield while reducing rejects and pitch content. The biobased composition provides a non-toxic and environmentally safe alternative to conventional anthraquinone-based cooking aids and is completely biodegradable. The invention thus offers an effective and sustainable solution for improving kraft pulping performance and process efficiency.

This invention belongs to the field of pulping and papermaking technology, and provides a method for constructing a model of component leaching in acacia wood pretreated with microwave-assisted hydrothermal treatment and a method for pulping it. The model was constructed using the component leaching content as a parameter after microwave-assisted hydrothermal pretreatment of acacia wood. The F-value was 161.6355, P < 0.05, reaching a significant level, indicating a very good fit. The R-value of the model is... 2 The value was 0.9728, and the mean square error was 0.0318, indicating a reliable prediction result. The treated acacia wood chips were then subjected to sulfate pulping. The pulp was screened, beaten, defatted, and then processed into paper. The prepared paper exhibited excellent properties, with a tear index of 2.76–7.36 mN·m. 2 / g, tensile index is 44.4-102 N·m / g, burst index is 1.91-6.12 kPa·m 2 The ring compression index is 9.77–14.67 N·m / g. This invention provides a powerful tool for evaluating pretreatment effects and optimizing process parameters, further enhancing the scientific rigor and practicality of the research.

A method for separating water and at least one lignin fraction, lignin derivatives, low-molecular carboxylic acids, sodium sulfate, or a mixture thereof from filtrates originating from a black liquor of a kraft process. Black liquor is concentrated to a solids content between 25 and 55 wt. %. A first separation step, polymer lignin with a number average of the molecular mass distribution of >6 kDa is precipitated and filtered out by lowering the pH value of the black liquor, a first filtrate is obtained which is acidified with sulfuric acid; a formed precipitate consisting of lignin is separated by means of filtration; a second acid filtrate is obtained, cooled to a temperature less than 10° C., a fraction consisting substantially of inorganic salts is crystallized out; the formed precipitate is filtered off, a third filtrate is obtained which contains low-molecular carboxylic acid-soluble lignin and groups of the inorganic salts.