24results about "Multistage pulping process" patented technology

A piece of natural plant material is subjected to one or more chemical treatments to remove substantially all lignin therefrom, thereby allowing the extraction of delignified, cellulose-based fibers. For example, the natural plant material can be a grass, such as bamboo or gladiolus. Subsequent drying of the extracted fiber densifies the structure, yielding improved mechanical properties. In some embodiments, the extracted fibers can be used, either alone or in combination with other materials, as a structural material. For example, the extracted fibers can be embedded within, infiltrated with, coated by, or otherwise combined with a polymer or concrete to form a composite material.

Disclosed are improved non-woody slurries, in particular non-woody slurries prepared from plants of the family Aspartate, and more particularly one or more plants of the genus Yucca, and methods of making the same. The method of manufacture generally includes at least one mechanical processing stage, such as mechanical refinement, without adding chemicals to the biomass. In some cases, the biomass may be subjected to two stages of refinement where the consistency of the biomass differs between the stages such that the first refinement stage may be performed at a consistency in the range of about 8% to about 12% and the second stage may be performed at a consistency in the range of about 3% to about 4%. The resulting non-wood slurry has a high degree of freeness, such as freeness in the range of 500 mL to 600 mL, and a relatively moderate degree of tensile strength, such as a tensile index of about 50 or less.

This invention provides a low-cost and environmentally friendly papermaking pulping process, comprising the following steps: S1. Pretreatment of papermaking fiber plant raw materials. S2. Oxy-alkali cooking: The pretreated papermaking fiber plant raw materials are mixed with an aqueous sodium carbonate solution, and cooked for 0.5–5 hours using oxygen as an oxidant. Then, sodium hydroxide is added, and cooking continues for 0.3–2 hours. Finally, the pulp and black liquor are separated by pressing. S3. Black liquor treatment: The black liquor is mixed with fiber waste, pressed, and burned as biomass fuel. S4. Recovery and causticization. This papermaking pulping process uses sodium carbonate and a small amount of sodium hydroxide for staged oxy-alkali pulping, and the generated black liquor is mixed with fiber waste and burned to recover sodium carbonate and heat, reducing the causticization rate and pulping costs.

The invention discloses a paper or paper pulp molded product with high lignin content as well as a preparation method and application of the paper or paper pulp molded product. The paper is paper or a paperboard, the paper or paper pulp molded product further contains cellulose and hemicellulose, the mass of lignin accounts for 25%-45% of the dry weight of the paper or paper pulp molded product, the mass of cellulose accounts for 50%-70% of the dry weight of the paper or paper pulp molded product, and the mass of hemicellulose accounts for 5%-25% of the dry weight of the paper or paper pulp molded product. The paper or paper pulp molded product is prepared through first-stage pulping, second-stage pulping, pulping and forming. The paper or pulp molded product has excellent physical properties. The paper can be used for preparing packaging paper, mulching films and release paper; the paper pulp molded product can be used for household appliance industrial packaging, egg supporting plates, inner liners and paper corner protectors.

The present application relates to the technical field of chemical fibers, and discloses a process for preparing lyocell pulp by mixing bamboo and wood pulp, comprising the following steps: bamboo pretreatment: cutting and shaping the bamboo, and then sequentially performing steam explosion defibration, acid treatment directional silicon removal and biological enzyme assisted delignification; wood pulp pretreatment: sequentially performing airflow sorting impurity removal, low-temperature alkali refining degreasing and biological enzyme deep purification; through the step-by-step directional pretreatment strategy, steam explosion causes microcracks in the cell wall of the short-cut bamboo fibers, and the high selectivity of the oxalic acid-ammonium fluoride composite acid liquid to silicate is used to achieve deep silicon removal of the short-cut bamboo fibers without damaging the cellulose skeleton; at the same time, the biological enzyme system step-by-step dissociates the hemicellulose side chain and the lignin aromatic ring structure, and removes the soluble oligomers, so that the risk of spinning blockage caused by silicon residues is eliminated under the premise of retaining the high polymerization degree cellulose of the bamboo, and the solubility of the pulp in the NMMO solvent is ensured.

The present disclosure relates to a process for treatment of biomass, specifically for pulping and biorefinery applications. The process relates to an organosolv process using high boiling organic solvents for the extraction of high molecular weight lignin and other products from the solution of pulping liquor, by using recycled liquor as the white liquor for pulping. The disclosure also relates to byproducts of pulp & paper industry such as lignin. C5 & C6 sugars.

The invention relates to the technical field of chemical fibers, and discloses a process for preparing lyocell pulp by mixing bamboo wood and wood cotton and carrying out directional treatment, which comprises the following steps: bamboo wood pretreatment: sequentially carrying out steam explosion splitting, acid treatment directional silicon removal and biological enzyme assisted delignification on the cut and formed bamboo wood; the raw material wood cotton is sequentially subjected to airflow separation and impurity removal, low-temperature alkali refining and degreasing and biological enzyme deep purification; through a step-by-step directional pretreatment strategy, micro cracks are generated on cell walls of the chopped bamboo fibers through steam explosion, and deep silicon removal of the chopped bamboo fibers is realized without damaging a cellulose skeleton in cooperation with the high-selectivity dissolving capacity of oxalic acid-ammonium fluoride composite acid liquor to silicate; meanwhile, a hemicellulose side chain and a lignin aromatic ring structure are dissociated step by step by a biological enzyme system, and soluble oligomers are removed, so that the spinning blockage risk caused by silicon residues is eliminated on the premise that high-polymerization-degree cellulose of bamboo wood is reserved, and the dissolution smoothness of pulp in an NMMO solvent is guaranteed.

The application provides a bamboo filament continuous cooking method, which comprises a bamboo filament pretreatment step and a continuous cooking step. In the bamboo filament pretreatment step, the bamboo filament is treated with hot water containing NaOH and alkali such as guanidine hydrochloride for 1-2 hours. The continuous cooking step is carried out by using a horizontal tube continuous digester. Through in-depth study of the chemical and physical changes in the cooking process, the application uses suitable cooking parameters and treatment methods to ensure that the pretreatment process reduces the damage to the papermaking required holocellulose while dissolving the lipid substances and lignin; and improves the silicon retention effect of CaO in the cooking process, so that a small amount of CaO can be used to effectively retain silicon in the cooking process, thereby reducing the difficulty of black liquor treatment and the reactor fouling rate.

The invention discloses a paper pulp raw material with high lignin content as well as a preparation method and application thereof. The paper pulp raw material contains lignin, cellulose and hemicellulose; the water content is 60%-80%; the mass of the lignin accounts for 25%-45% of the dry weight of the paper pulp raw material, the mass of the cellulose accounts for 50%-70% of the dry weight of the paper pulp raw material, the mass of the hemicellulose accounts for 5%-25% of the dry weight of the paper pulp raw material, and the dry weight of the paper pulp raw material refers to the weight of the paper pulp raw material except water; the paper pulp raw material is prepared by cooking plant log with black liquor and grinding, the black liquor is liquid obtained by cooking the pulping raw material with alkali liquor, grinding and performing solid-liquid separation, or liquid obtained by adding alkali into washing liquid obtained by washing solids obtained by performing solid-liquid separation after cooking the pulping raw material with alkali liquor, grinding and performing solid-liquid separation; the pulping raw material is selected from coniferous wood, broadleaf wood or bamboo. The pulp raw material can be used for preparing paper, paperboards or pulp molded products.

According to an example aspect of the present invention, there is provided a method of treating a fibrous raw-material containing cellulosic fibres and polyester fibres, comprising the steps of subjecting the raw-material to acid treatment and to a washing operation, subjecting the washed first modified fibrous raw-material to an alkaline treatment to dissolve at least a portion of the polyester fibres and to form a second modified fibrous raw-material that is subjected to separation to separate solid matter from an aqueous liquid phase comprising dissolved material, recovering the solid matter of the separation, subjecting the recovered second modified raw-material to a washing, subjecting the liquid phase to a first filtration step using a micromembrane to obtain a first aqueous permeate, subjecting the first permeate to a second filtration step using a nanomembrane to obtain a second permeate, recovering the second aqueous permeate and recycling it to an alkaline treatment step.

A piece of natural plant material is subjected to one or more chemical treatments to remove substantially all lignin therefrom, thereby allowing the extraction of delignified, cellulose-based fibers. For example, the natural plant material can be a grass, such as bamboo or gladiolus. Subsequent drying of the extracted fiber densifies the structure, yielding improved mechanical properties. In some embodiments, the extracted fibers can be used, either alone or in combination with other materials, as a structural material. For example, the extracted fibers can be embedded within, infiltrated with, coated by, or otherwise combined with a polymer or concrete to form a composite material.

The invention relates to an energy-saving and environment-friendly intermittent pulping and cooking process which comprises the following steps: performing stepped heating type cooking on wood chips and cooking liquor to prepare slurry; after cooking is finished, reverse heat exchange is conducted on the dilute black liquor and the pulp, and hot black liquor is replaced; then, dilute black liquor is introduced again, and warm black liquor is replaced; the warm black liquor can be used as a material for preparing the cooking liquor; the hot black liquor is subjected to flash evaporation to remove 10-15% of moisture, the concentration of the hot black liquor is increased to 18-21 Be degrees, and the flash-evaporated hot black liquor firstly enters a quadruple-effect down-flow multi-effect evaporator to be concentrated to 28-30 Be degrees and then enters a sextuple-effect falling film evaporator to be concentrated to 65% or above; wherein secondary steam generated by flash evaporation is used as a first-effect heat source of the quadruple-effect down-flow multi-effect evaporator after liquid drops are removed through the steam-water separator. According to the method, flash secondary steam is combined to drive the first effect of the multi-effect evaporator, hot black liquor pretreatment concentration optimization alkali recovery and the like, so that energy gradient utilization is sufficient, comprehensive energy consumption is greatly reduced, and the win-win situation of environmental protection and resource recycling is achieved.

Disclosed are improved non-wood pulps, particularly non-wood pulps prepared from plants of the family Asparagaceae and more particularly one or more plants of the genus Hesperaloe, and methods of producing the same. The manufacturing processes generally comprise at least one mechanical treatment stage, such as mechanical refining, without the addition of chemicals to the biomass. In certain instances, the biomass may be subjected to two stages of refining where the consistency of the biomass differs between the stages, such that the first refining stage may be performed at a consistency ranging from about 8% to about 12% and the second stage may be performed at a consistency ranging from about 3% to about 4%. The resulting non-wood pulps have a high degree of Freeness, such as Freeness ranging from 500 mL to 600 mL and a relatively modest degree of tensile strength, such as a Tensile Index of about 50 or less.

An evaporative device has a piece of at least partially-delignified plant material. The at least partially-delignified plant material has a modified microstructure including a plurality of vessels, a plurality of fibers, and a plurality of engineered micropores. Each vessel can define a first lumen having a maximum cross-sectional dimension of at least 100 μm. Each fiber can define a second lumen having a maximum cross-sectional dimension less than or equal to 20 μm. The engineered micropores can extend through walls of the vessels or fibers so as to fluidically interconnect the first and second lumina. In some embodiments, the plant material is reed or bamboo.

A process to perform a controlled exothermic delignification of biomass comprises providing a system having a first vessel and a second vessel, providing a biomass comprising lignin, hemicellulose and cellulose fibers placed into the first vessel, providing an aqueous acidic composition comprising a sulfuric acid component, providing a modifier component and providing a peroxide component. The biomass is exposed to the sulfuric acid component and peroxide component, thereby creating a reaction mass. The reaction mass is mixed and the sulfuric acid, modifier and peroxide components are allowed to come into contact with the biomass for a period of time sufficient for a delignification reaction to occur and to remove a predetermined amount of the lignin from the biomass. The predetermined amount is assessed by testing a first kappa number of the biomass. When the first kappa number of the biomass is reached, the biomass is transferred to the second vessel.

A cost-effective biorefining process has been developed to produce multiple products, including mono-saccharomate syrup, poly-phenolic precursor, and cellulosic derivatives such as (R)-cellulose, (µ)-cellulose and (n)-cellulose, from surplus crop residues. This process involves several steps, including saccharomate recovery, solid-liquid separation, poly-phenol extraction, blanching, density separation, depolymerization, and drying. Furthermore, the by-products generated at each stage of the biorefining process can be utilized to increase the value of the overall process by incorporating a photosynthetic resource recovery strategy. The methods used for extraction and treatment vary depending on the composition and type of the feedstock biomass.

The invention relates to the technical field of paper, in particular to softwood pulp and bamboo pulp synergistically enhanced white kraft paper and a preparation method thereof. The method comprises the following steps: carrying out enzyme pretreatment and high-pressure homogenization on bamboo pulp to prepare bamboo-based nano cellulose, and then carrying out carboxymethylation; the preparation method comprises the following steps: carrying out double graft polymerization on chitosan, 2-acrylamide-2-methylpropanesulfonic acid and dodecyl methacrylate; carboxymethylated bamboo-based nanocellulose is divided into two parts for use, one part is compounded with the double-grafted chitosan, and the other part is added into the mixed slurry to construct a first enhanced network; adding cationic starch, AKD (alkyl ketene dimer) and other wet end assistants; and finally forming the paper sheet. Through a synergistic enhancement mechanism, the tensile strength, bursting strength and sizing degree of the paper are remarkably improved, meanwhile, good whiteness and opacity are kept, and the problem that the strength is insufficient under the high bamboo pulp proportion is solved.

The invention relates to a method for feeding a slurry of chips and liquid to a prehydrolysis reactor in the production of dissolving pulp. The slurry is pumped by using at least one pump to the reactor, and alkali is fed into the at least one pump 5 for adjusting the pH of the slurry to a range of 7-10.

A method for extracting hydrolysate in a batch cooking process for producing pulp, said method comprising the steps of: - providing lignocellulose raw material to a batch cooking vessel; - performing acid hydrolysis of the lignocellulose raw material in the batch cooking vessel; - displacing a first part of a hydrolysate from the batch cooking vessel by adding to the batch cooking vessel at least one first displacement liquid comprising recycled hydrolysate from a hydrolysate recirculation tank, wherein said recycled hydrolysate has been transferred to the hydrolysate recirculation tank from the batch cooking vessel during a previous batch cooking process; - receiving the first part of the hydrolysate in at least one hydrolysate extraction tank; - displacing a second part of the hydrolysate from the batch cooking vessel by adding to the batch cooking vessel at least one second displacement liquid comprising alkaline neutralization liquor; and - receiving the second part of the hydrolysate in a hydrolysate recirculation tank.

Some variations provide a process for impregnating a biomass feedstock with a reaction solution, comprising: providing a biomass feedstock that contains non-condensable gases within biomass pores; introducing a condensable vapor into the biomass pores to remove non-condensable gases out of the biomass pores, thereby generating an intermediate biomass material, wherein at least a portion of the condensable vapor remains within the biomass pores; exposing the intermediate biomass material to a liquid solution to infiltrate the liquid solution into the biomass pores and condense the vapor to form a condensed liquid contained within the biomass pores, thereby generating an impregnated biomass material containing a reaction solution; and recovering or further processing the impregnated biomass material. The non-condensable gases may be oxygen, nitrogen, or carbon dioxide, for example. The condensable vapor may be steam, for example. The reaction solution may contain a pretreatment chemical, such as a catalyst and / or a solvent.