Straw comprehensive utilization method

Abstract

The invention discloses a straw comprehensive utilization method comprising the following steps: 1, paper product production: (1) straw cutting off; (2) dry dedusting; (3) hot water extraction, countercurrent washing and sand removal; (4) cooking and hydrolyzing; (5) spraying and receiving; (6) multistage countercurrent washing; (7) high-concentration pulping; (8) low-concentration pulping; and (9) papermaking; 2, natural gas production: (1) anaerobic treatment; (2) aerobic treatment; and (3) biogas purification; 3, production of an organic fertilizer: (1) extracting chippings generated by drydedusting in the step 1, plant chippings filtered by hot water extraction countercurrent washing water in the step 1, and solids obtained by solid-liquid separation of multi-stage countercurrent washing water for fermentation production of the organic fertilizer; and (2) mixing the concentrated sludge produced by anaerobic treatment and aerobic treatment in the step 2 with air flotation dross andplant debris, and fermenting to produce the organic fertilizer. The straw comprehensive utilization method provided by the invention is environment-friendly, realizes process wastewater resource utilization, can improve the slurry self-production capability in China, alleviates the problem of lack of fiber raw materials in China, can effectively utilize crop straws, and increases agricultural income.

Description

technical field [0001] The invention relates to the technical field of pulping and papermaking, in particular to a method for comprehensive utilization of straw. Background technique [0002] Since modern times, due to the relative scarcity of wood resources in my country, plant straw raw materials have occupied a large proportion in the production of self-made pulp, mainly using alkaline pulping or sulfite pulping, including bleaching technology, basically in the It was developed on the basis of wood pulping and papermaking technology; compared with wood, straw has a large difference in tissue structure and chemical composition, and the cooking black liquor of straw raw materials has high ash content and high viscosity. Poor performance, black liquor extraction rate and evaporation efficiency are far inferior to wood raw materials, resulting in low alkali recovery rate, high water treatment cost, and low overall benefit. Since the 1990s, most of them have been gradually shut ...

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Problems solved by technology

[0002] Since modern times, due to the relative scarcity of wood resources in my country, plant straw raw materials have occupied a large proportion in the production of self-made pulp, mainly using alkaline pulping or sulfite pulping, including bleaching technology, basically in the It was developed on the basis of wood pulping and papermaking technology; compared with wood, straw has a large difference in tissue structure and chemical composition, and the cooking black liquor of straw raw materials has high ash content and high viscosity. Poor performance, black liquor extraction rate and evaporation efficiency are far inferior to wood raw materials, resulting in low alkali recovery rate, high water treatment cost, and low overall benefit. Since the 1990s, most of them have been gradually shut down; at present, pulping enterprises basically use Wood chips are the raw material, the technology is mature, and the benefits are good. However, due to the lack of mature forests that can be harvested in my country, large-scale pulp mills basically rely on imports of wood chips, and my country is also the largest importer of wood pulp and the largest net importer of waste paper in the world.

[0003] Taking industrial packaging paper as an example, in 2017, the total output of industrial packaging paper such as corrugated boxboard in my country was 47.2 million tons, accounting for 42% of China's total paper production of 111.3 million tons; the main raw material is waste paper, and the import volume was 25.72 million tons. Make my country the world's largest importer of waste paper; more than 20% of paper products are lost with the export of goods and disposable consumer paper; another 20% are stored as books and materials, and the amount of domestic waste paper recycling has reached More than 50 million tons, close to the recycling limit; especially for industrial packaging paper (waste carton) products, due to repeated recycling and reuse, the fiber strength and yield decrease, and the fiber quality is getting worse and worse, resulting in the consumption of chemical additives. Increase, the cost of sewage treatment increases; can only rely on imported OCC (waste container board) to increase the addition of fresh fiber to improve fiber strength and yield

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