Pulp bleaching production process technology of zero discharge of biological bleaching and bleaching water

Abstract

The invention relates to a biological bleaching and paper pulp bleaching production technique with bleaching used water zero discharging. It includes two times biological bleaching and once whitening, and makes the bleaching used water use circularly to realize its zero discharging. The paper pulp material includes straw, ditch reed, bamboo etc. The production technique has the advantages of no pollution, saving water, and low material consumption etc. And its cost is 40% of the chemical process. It is green high and new-technology industries with high economic benefit used to make food wrap paper, medicine wrap paper, and various papers.

Description

technical field [0001] The invention relates to a pulp bleaching production process, in particular to a pulp bleaching production process of biological bleaching and zero discharge of bleaching water. Background technique [0002] The invention of paper has greatly promoted the development of a civilized society. At present, the world's annual per capita paper consumption is 51.8 kg, and China's annual per capita paper consumption is 32 kg, ranking second in the world. China produced 43 million tons of paper in 2004, consumed 51 million tons of paper, and still needs to import a large amount of paper. [0003] The production process of pulp bleaching that is widely used now is mainly "calcium hypochlorite" and various chemical raw materials to bleach the lignin in wheat straw, straw, reed, bagasse, bamboo, wood and other raw materials to make it white, lignin It is the substance that binds cellulose in plants. The purpose of bleaching is to further decompose and bleach the ...

AI Technical Summary

Problems solved by technology

However, because lignin is an amorphous macromolecular structure and has strong stability, only a small amount of fungi can degrade lignin among the microorganisms existing in nature. The requirements for the environmental conditions are very strict. It must be humid and ventilated. At the same time, a large amount of oxygen must be supplied for the white rot fungus to decompose the bleached lignin. Because the bleached pulp must not invade the water, it is difficult to ensure uniform temperature, resulting in increased costs.

Nevertheless, it takes more than 30 days for white rot fungi to degrade lignin in 60% of paper-making materials, and the culture period of these white rot fungi is too long to be suitable for industrial production