The effect of quaternary ammonium compounds on pulping

The conventional delignification processes (Kraft and Sulfite) are working with sulfur containing pulping liqueors. Inspite of nearly closed process systems and the thorough recycling of the chemicals , these processes are connected with water and air pollution. Recently a new pulping process called Quatam process was developed [1] which uses an aqueous solution of tetramethyl-ammoniumhydroxid (TMAH) as reacitve agent. Except of tetrabutylammonium hydroxide [2] quaternary ammonium compounds have not been earlier tried in delignification processes. The aim of the present work was to compare the pulping effect of different quaternary ammonium hydroxides as well as that of TMAH and natrium hyroxid in the pulping of softwood and hardwood species. Experiments were carried out also with mixtures of TMAH and natrium hydroxid, as pulping liquors.