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.

A system and process of producing pulp from lignocellulosic material after the lignocellulosic material has undergone compression (pressurization), maceration and removal of extractives produced during compression and maceration followed by chemical addition, fiberization, digestion (cooking) and further mechanical refining.

An oxygen bleaching method of pulp includes the steps of: adding a solution formulated by a magnesium salt and an activator to an unbleached chemical pulp, stirring to be mixed well, and bleaching by introducing oxygen. The activators are nano zero-valent metals that are conventional, low-cost, and recyclable. These activators can activate low-concentration oxygen at low-temperature in neutral aqueous solution to efficiently generate peroxide anion radicals, so as to promote the generation of hydroperoxide anions and peroxide ions, achieving high efficient delignification. The whole process does not generate waste water, the oxygen consumption is only 50-85% of the original process, the yield is increased by 1.5-2.8% compared with the original system, the pulp brightness is increased to 28-32° SR, and the magnesium salt can be recycled and reused.

An oxygen bleaching method of pulp includes the steps of: adding a solution formulated by a magnesium salt and an activator to an unbleached chemical pulp, stirring to be mixed well, and bleaching by introducing oxygen. The activators are nano zero-valent metals that are conventional, low-cost, and recyclable. These activators can activate low-concentration oxygen at low-temperature in neutral aqueous solution to efficiently generate peroxide anion radicals, so as to promote the generation of hydroperoxide anions and peroxide ions, achieving high efficient delignification. The whole process does not generate waste water, the oxygen consumption is only 50-85% of the original process, the yield is increased by 1.5-2.8% compared with the original system, the pulp brightness is increased to 28-32° SR, and the magnesium salt can be recycled and reused.

This disclosure relates to methods of making novel dissolving wood pulps by processes comprising acid prehydrolysis, pulping, and a multi-stage bleaching process comprising oxidation with a catalyst and peroxide under acidic conditions, as well as to products made therefrom having a combination of medium-purity, low viscosity, and improved reactivity, filterability, and/or clogging that can be used as a substitute for traditional high-purity dissolving pulps in a wide variety of applications.

This disclosure relates to methods of making novel dissolving wood pulps by processes comprising acid prehydrolysis, pulping, and a multi-stage bleaching process comprising oxidation with a catalyst and peroxide under acidic conditions, as well as to products made therefrom having a combination of medium-purity, low viscosity, and improved reactivity, filterability, and/or clogging that can be used as a substitute for traditional high-purity dissolving pulps in a wide variety of applications.

The invention relates to a method for treating biomass (1). In a step (S10) of the method, the biomass (1) and an amount of water (2) is fed into a first reactor unit (10) such that the biomass (1) is impregnated using the amount of water (2) while the biomass (1) is transferred through the first reactor unit (10) by a conveyor means (11). In another step (S20), the impregnated biomass (22) is transferred from the first reactor unit (10) to a separation unit (20) in which at least a part (21) of the amount of water (2) used for impregnation can be separated from the impregnated biomass (22). In another step (S30), the impregnated biomass (22) is transferred from the separation unit (20) into a second reactor unit (30) in which the impregnated biomass (22) is subjected to a predetermined pressure (S30). The invention further relates to the use of the method for treating non-wood material as well as to a device for treating biomass (1).

The invention relates to a method for treating biomass (1). In a step (S10) of the method, the biomass (1) and an amount of water (2) is fed into a first reactor unit (10) such that the biomass (1) is impregnated using the amount of water (2) while the biomass (1) is transferred through the first reactor unit (10) by a conveyor means (11). In another step (S20), the impregnated biomass (22) is transferred from the first reactor unit (10) to a separation unit (20) in which at least a part (21) of the amount of water (2) used for impregnation can be separated from the impregnated biomass (22). In another step (S30), the impregnated biomass (22) is transferred from the separation unit (20) into a second reactor unit (30) in which the impregnated biomass (22) is subjected to a predetermined pressure (S30). The invention further relates to the use of the method for treating non-wood material as well as to a device for treating biomass (1).

The multi-stage modular horizontal digester is primarily comprised of a single auger in a horizontal orientation. The single auger includes sections of lesser and greater inner diameter, thus creating sections of that allow for mixing and time to operate on the contents, and sections where the liquids are squeezed out. As compared to the known processing methodology, the multi-stage modular horizontal digester creates numerous benefits. For example, by maintaining elevation of the pulp, it can be directly expelled into the hydrapulper without the need for an additional pump. Processes can be changed quickly by altering the rotation speed, auger sections, or chemical inputs and outputs without the need to move heavy tanks or adjust pumps. In other words, there is no need for the standard cascade-style system where the pulp descends through a step, is raised to the next step, and so forth.

The multi-stage modular horizontal digester is primarily comprised of a single auger in a horizontal orientation. The single auger includes sections of lesser and greater inner diameter, thus creating sections of that allow for mixing and time to operate on the contents, and sections where the liquids are squeezed out. As compared to the known processing methodology, the multi-stage modular horizontal digester creates numerous benefits. For example, by maintaining elevation of the pulp, it can be directly expelled into the hydrapulper without the need for an additional pump. Processes can be changed quickly by altering the rotation speed, auger sections, or chemical inputs and outputs without the need to move heavy tanks or adjust pumps. In other words, there is no need for the standard cascade-style system where the pulp descends through a step, is raised to the next step, and so forth.