The problem of deck channel rewetting that occurs when a drainage chamber in a roll upwardly approaches a horizontal line extending past the horizontal diameter of the roll is solved by using a comb plate comprising at least one comb tooth engaging the perforated plate and extending through a deck channel to a drainage channel such that the at least one comb tooth has a slope configured to direct a slurry suspension from the perforated plate into the drainage channel.

The problem of deck channel rewetting that occurs when a drainage chamber in a roll upwardly approaches a horizontal line extending past the horizontal diameter of the roll is solved by using a comb plate comprising at least one comb tooth engaging the perforated plate and extending through a deck channel to a drainage channel such that the at least one comb tooth has a slope configured to direct a slurry suspension from the perforated plate into the drainage channel.

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.

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.

The invention relates to pretreating of native cellulose pulp in the manufacture of nanofibrillated cellulose, and to a nanofibrillated cellulose product obtainable by the method.

The invention relates to pretreating of native cellulose pulp in the manufacture of nanofibrillated cellulose, and to a nanofibrillated cellulose product obtainable by the method.

Bleaching methods and formulations for bleaching/delignification processes for chemical pulp are provided. The bleaching methods utilize peroxide and an organomanganese complex under aqueous caustic conditions, increasing bleaching efficiency of the overall bleaching/delignification process. Chemical pulp having increased brightness can be obtained at decreased temperatures and with reduced stage time, resulting in reduced chemical consumption and improved energy efficiency.

The disclosure belongs to the technical field of papermaking technology and waste comprehensive utilization, and specifically relates to a method for preparing biomechanical unbleached pulp from wheat straw and full utilization of by-products thereof. In the present disclosure, wheat straw is used as raw materials for pulping, and treated by hot water, then a trace of KOH is added, the temperature of the wheat straw after heat saturation and softening is adjusted, alkaline compound enzymes is added for biological treatment, and refining of wheat straw is performed at last. The mechanical pulp meets the production requirements for unbleached packaging paper and paper-based materials, meanwhile, the by-products are recycled to prepare a biomass compound fertilizer, turning solid waste into treasures, and realizing a high value full utilization of wheat straw. Thus a good practical application value and a broad application prospect are performed.

The disclosure belongs to the technical field of papermaking technology and waste comprehensive utilization, and specifically relates to a method for preparing biomechanical unbleached pulp from wheat straw and full utilization of by-products thereof. In the present disclosure, wheat straw is used as raw materials for pulping, and treated by hot water, then a trace of KOH is added, the temperature of the wheat straw after heat saturation and softening is adjusted, alkaline compound enzymes is added for biological treatment, and refining of wheat straw is performed at last. The mechanical pulp meets the production requirements for unbleached packaging paper and paper-based materials, meanwhile, the by-products are recycled to prepare a biomass compound fertilizer, turning solid waste into treasures, and realizing a high value full utilization of wheat straw. Thus a good practical application value and a broad application prospect are performed.

The present disclosure relates to a method for preparing an unbleached biomechanical pulp from straws and full utilization of by-products, which belongs to the technical field of papermaking technology and waste comprehensive utilization. In the present disclosure, straw as raw material for pulping is treated with steam, then a small amount of KOH is added, the straw is softened by hydrothermal saturation, then the temperature of the straw is adjusted, alkaline compound enzymes are added for biological treatment, and finally the straw is refined, where the prepared mechanical pulp can meet the requirements of producing unbleached packaging paper and paper-based materials. At the same time, the by-products are recycled to prepare biomass compound fertilizer, which turns solid waste into treasure and realizes the high-value full utilization of wheat straw. Therefore, it has good practical application value and broad application prospects.