Chlorine Bleach Wood Pulp

For example the use of elemental chlorine in the bleaching of wood pulp produces organochlorines and persistent organic pollutants including dioxins.

Chlorine bleach wood pulp.

Chlorine dioxide serves as a bleaching agent for wood pulp and it is used because chlorine dioxide minimizes the amount of organochlorine compound that are produced in the process. As a core component of best available technique bat for production of pulp paper and board ecf bleaching will likely continue to dominate. Elemental chlorine free ecf is a technique that uses chlorine dioxide for the bleaching of wood pulp. Ecf is a pollution prevention technology recognized and accepted globally by such organizations as the united nations environment.

Two part bleach changes the actual color of wood and the other three remove stains. Traditionally the paper industry used chlorine gas to bleach pulp. These are toxic carcinogenic and recalcitrant to degradation. Chlorine is commonly used as a bleach.

Recently paper makers have begun using chlorine dioxide to bleach paper. According to an industry group the use of chlorine dioxide in these processes has reduced the dioxin generation to under detectable levels. In this process the wood pulp s color is enlightened and whiten. Bleaching wood subtract color to add life.

Although preliminary surveys have detected dioxin in pulp mill wastes the scope of the problem is not yet known. Chlorine dioxide ecf technology currently is the most important bleaching method worldwide. About 95 of all bleached kraft pulp is made using chlorine dioxide in ecf bleaching sequences. For over four decades we have helped the industry navigate the changing landscape of bleaching technologies.

In the production of paper residual lignin from wood pulp is chemically liberated by using chlorine bleaching forming chlorinated lignin derivates such as chlorolignols. The process of doing it is called bleaching of wood pulp which is a chemical process. There are four types of bleach that woodworkers commonly use. Elemental chlorine free ecf.

Read on to find out what each one does and how to use them safely. Bleaching is done to whiten the paper which makes text on it easier to read the chlorine produces several by products including dioxins and furans. Chlorine two part wood bleach oxalic acid and peroxide. Biobleaching is an important alternative to reduce the use of chlorine.

It is used at moderately acidic ph 3 5 to 6. It has been found that bleaching can result in the formation of dioxin in the pulp when chlorine reacts with organic constituents of wood. Pulp and paper industry currently uses chlorine dioxide bleaching also known as elemental chlorine free or ecf.