Application of Catalyst Technology in Pulping Process

—Application Development to “Catalyzer-type Cooking Accelerator”—

Abstract

Recycling of waste paper is an important issue for environmental protection. In recent years, decreasing of demand for recycled pulp and shortage of waste paper as raw material have become serious problem due to decrease in the subscription volume of printed materials such as newspapers and magazines. The paper industry needs to consolidate recycled pulp equipment to adjust production volume. Among them, many efforts have been made to close the gap between the used paper collection rate and the used paper utilization rate. Therefore, there are now situations where even poor quality used paper must be used.

There are two significant quality problems in the deinking process of used paper. One is the problem of UV curable ink printed matter. In 2016, we combined surface science and catalyst science, and we proposed a “catalyzer-type deinking agent” that was excellent in miniaturization of the ink.

The other is a problem called pitch （dust, dirt） generated during the paper manufacturing process using used paper. There are many origins of pitch, such as the adhesive for postal slip, back glue and resins in coating agents.

In particular, used paper recycling plants are facing this pitch problem as often as UV curable ink problems. Thus, as the solution of pitch problem, the development of a new generation of pitch control agents has been required for many years in the paper industry.

This time, we have developed the “hydrolyze-type pitch control agent” that can accelerate the dissolution of pitch and prevent it from becoming huge by decomposing the resin by applying the catalytic technology used in the “catalyzer-type deinking agent”.

On the other hand, in order to produce pulp from plant lignocellulosic materials such as wood, it is generally treated with alkali or sulfites for cooking. Pulp is produced by the cooking method, which remove lignin or natural resin components from lignocellulose material by dissolving, dispersing, decomposing, and filtering.

However, at present, reckless deforestation of natural resources such as timber is regulated due to environmental problems, and the price of timber is rising. Therefore, increasing pulp production per unit of raw wood and producing high quality pulp products have become more and more important.

As a method for solving these problems, a method using a cooking accelerator that enhances cooking efficiency is known. Furthermore, in recent years, a safer cooking accelerator has been demanded. This time, we have found that this catalyst technology can be applied not only to deinking agents and pitch control agents, but also to pulping processes from lignocellulosic materials.

In this paper, we introduce newly developed “Catalyzer-type cooking accelerator” that has the potential of pitch control effect as well as the cooking promotion effect in the cooking process.