Methods for producing corrugated paper, natural gas and organic fertilizer from straws

Abstract

The invention discloses methods for producing corrugated paper, natural gas and organic fertilizer from straws. The method for producing the corrugated paper includes: (1) cutting the straws; (2) dedusting by a dry method; (3) dedusting by a water membrane; (4) extracting and washing with hot water to remove sand; (5) hydrolyzing by continuous steaming; (6) sprinkling and collecting; (7) backwashing in multiple stages; (8) grinding into high-concentration liquid firstly; (9) ripening; (10) grinding into high-concentration liquid and low-concentration liquid; (11) producing the corrugated paper. The method for producing the natural gas includes the steps of: (1) subjecting high-concentration wastewater to anaerobic treatment; (2) subjecting the treated wastewater to aerobic treatment; (3) purifying marsh gas obtained from anaerobic treatment to obtain the natural gas. The method for producing the organic fertilizer is also provided. The methods for producing the corrugated paper, the natural gas and the organic fertilizer from straws are environmentally friendly, the wastewater obtained in the processes can be recycled, self-producing capability of pulp for industrial packing paperincluding the corrugated paper and the like can be improved, the difficulty of fibrous material shortage in our country can be alleviated, and reliance on imported waste paper can be reduced.

Description

technical field [0001] The invention relates to the technical field of pulping and papermaking, in particular to a method for producing corrugated paper, natural gas and organic fertilizer by utilizing straw. Background technique [0002] my country lacks timber resources, and the main raw material of corrugated paper and other industrial packaging paper is recycled waste containerboard, which mainly comes from domestic recycled waste paper and imported waste paper. [0003] In 2017, my country's total output of corrugated boxboard and other industrial packaging paper was 47.2 million tons, accounting for 42% of China's total paper output of 111.3 million tons; my country is the world's largest importer of waste paper, with 25.72 million tons of waste paper imported in 2017; More than 20% of paper products are lost with the export of goods and one-time consumer paper; another 20% are stored as books and materials, and the domestic waste paper recycling has exceeded 50 million...

AI Technical Summary

Problems solved by technology

[0003] In 2017, my country's total output of corrugated boxboard and other industrial packaging paper was 47.2 million tons, accounting for 42% of China's total paper output of 111.3 million tons; my country is the world's largest importer of waste paper, with 25.72 million tons of waste paper imported in 2017; More than 20% of paper products are lost with the export of goods and one-time consumer paper; another 20% are stored as books and materials, and the domestic waste paper recycling has exceeded 50 million tons, which is close to the recycling limit; especially Industrial packaging paper (waste carton) products, due to repeated recycling and reuse, lead to a decrease in fiber strength and yield, and fiber quality is getting worse and worse, resulting in an increase in the amount of chemical additives and increased sewage treatment costs; they can only rely on imports OCC (waste containerboard) to increase the addition of fresh fiber to improve fiber strength and yield

[0011] As raw material of plant straw, pulp used for producing corrugated paper, if chemicals such as sodium hydroxide are added, most of the 1% sodium hydroxide extract components will enter the cooking liquor, and a large part of the higher ash content is mainly silicate Inorganic substances also enter the cooking liquid in a colloidal state, so that the cooking liquid not only has a high content of dissolved substances, but also has a high viscosity, poor drainage, and increased washing water, resulting in a low concentration and large amount of wastewater. Due to the biochemical degradation of alkaline degradation products Poor sex, average BOD 5 / COD does not exceed 0.35, which is refractory wastewater. The investment and operation costs of wastewater treatment facilities are extremely high, and it is difficult to meet the standards. This is the main reason why a large number of such factories in history have not survived to today

[0012] In addition, steam blasting is used to process straw materials, and then they are used as corrugated pulp ingredients after refining. Due to the lack of sufficient washing and fiber swelling process, the blasting direction is poorly selected, resulting in a large number of fiber fragments, most of which are crushed by blasting shock waves. The radial fracture fragments are not axial tears formed from each swelling point of the internal fibers, so that the fibrillation form mainly longitudinal tearing cannot be formed; the material is not microfibrillated, and hydrogen bonded positions are produced. Strictly speaking, the material produced by this method cannot be counted as pulp, does not have the technical characteristics required for pulp, and cannot be used alone to produce paper, but is only used as an ingredient, or mixed with waste paper pulp, Or mix it into chemical pulp to produce paper products; the products to be mixed include corrugated paper or fiber pressed products such as lunch boxes and dinner plates; there is another method, which is to cut and impregnate the straw raw materials, and directly use a high-consistency refiner or double Combination of screw pulper and high-consistency refiner for refining, the quality of this product is the same as the above-mentioned method, and the use and function are basically the same; the prepared "pulp" does not have the technical characteristics of pulp, so it cannot produce corrugated paper Such as paper products, can only be used as a small amount of ingredients

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