APPLICATION OF LIGNOLYTIC ENZYMES IN THE PAPER AND PULP INDUSTRY - RECENT RESULTS

The basis of this work was expounded by H.-P. Call, A. v. Raven and H. Leyerer at the Annual Meeting of ZELLCHEMING. Building upon this, the application of lignolytic enzymes was analysed and optimised in mainly four areas: Deinking of waste paper, pre-bleaching of sulphate pulps, pre-bleaching of mechanical pulps and treatment (lignin removal) of effluents from grinding and TMP plants. After laboratory-scale research and initial experiments with a pilot scale flotation cell, the trials were continued on an industrial scale. This showed that the same results as with conventional deinking could be achieved with a definitely reduced input of chemicals, independently of the quality of the waste paper input. Processes for pre-bleaching of sulphate and mechanical pulps are at the proving stage. The results indicate that the application of chlorine will no longer be required during the bleaching of sulphate pulps. During the pre-bleaching of mechanical pulps the lignin is degraded to a greater or lesser extent depending upon the progress of the treatment. A clear reduction of COD occurs when grinding and TMP effluents are treated with enzymes. The investigations are continuing on an industrial scale. All these methods use Laccases, which could be mass-produced commencing at the end of 1992.