キノン添加蒸解

Abstract

We found in 1974 for the first time in the world that the addition of a little amount of anthraquinone, anthrahydroquinone or 1, 4-dihydro- 9, 10-dihydroxyanthracene (DDA, products of Diels Alder reaction of naphthoquinone and butadiene) to various pulping process including sulfate, soda and sulfite process is effective in improving the cooking yield, the cooking rate and the pulp quality. And then we moved to a mill application. Now in Japan, many mills have started DDA additive sulfate and neutral sulfite cooking with the objective of cooking yield increase and cooking chemical saving as well as pulp production increase.In the sulfate process, by adding 0.02% DDA, we achieve the results of 1.5% cooking yield increase, and either the lowering of the cooking temperature by 5°C, the saving of 10% active alkali, or shortening the cooking time by 10 to 20%.There are no differences in the effect of DDA among wood species and this cooking method does not require any change of production facility.We have also thoroughly investigated the toxicity of DDA and confirmed the toxicity of DDA as negative.Applying 0.05% DDA to soda process, cooking yield, cooking rate and pulp quality reach the level of the conventional sulfate process.In the NSSC process, quinone additive works to promote uniformed softening of the chip and which in turn saves power consumption for refining decrease shive content and improves the bleachability and pulp quality.