Solving soap and turpentine related process problems in softwood draft mills

Abstract Effective separation of soap and turpentine is an important, but mill-specific aspect, regarding the entire softwood kraft process performance. This paper describes a systematic approach to evaluate and solve various extractives-related process problems. In a mill “audit”, the soap and extractives potential of the mill’s wood raw material is first estimated, the key process streams are tested and the…

Towards complete impregnation of wood chips with aqueous solutions. Part 5: improving uniformity of kraft displacement batch pulping.

ABSTRACT Pulping uniformity is critical for improving the performances of cooking and downstream operations such as bleaching and papermaking. In spite of certain success of recent modifications of batch and continuous kraft cooking systems, there is still a lot of room for improving the contemporary cooking systems in order to address problem of heterogeneous pulping. Incomplete penetration and inadequate diffusion…

Towards complete impregnation of wood chips – new research enables effective processes.

ABSTRACT The important role of impregnation prior to chemical pulping has been long recognized qualitatively but not fully realized quantitatively. Cost effective production of uniform, high quality pulp can only be achieved by efficient mass transfer of pulping chemicals that must start with complete impregnation of wood chips. The present paper describes the main results of an in-depth research project…