Bio-preservative properties of technical lignins from South African pulp mills: An investigation towards a conceptualized development of natural compound-based wood preservatives

IRG/WP 18-30724

A Alade, L Tyhoda, M Meincken

The depletion of naturally durable timber and the risk posed by some of the conventional wood preservatives to human health and the environment continue to drive research efforts towards developing new formulations that are benign. Furthermore, the global concept of environmental sustainability aims at optimal use of resources and to comprehensively include conversion of waste to value added products. In view of these, it becomes a point of interest to utilize compounds from waste streams such as technical lignin obtainable from pulp black liquor by-products in the development of formulations to be used either as a sole material or component of wood preservatives. The incorporation of lignin into wood preservative formulations have only been previously achieved by means of a two-stage process involving fixation with metal salts, lignosulphonate copolymerisation and use of metal ammonia complexes as impregnants. However, the overall limitation of these processes is the inadaptability to industrial practice, owing to time factors, high cost of copolymerized lignins, and inability to use certain lignins. In view of the increasing global interest in green economy and environmental sustainability, the prospect of developing a natural compound-based wood preservative formulation using technical lignin alongside other natural compounds from biomaterial waste becomes invaluable. It is anticipated that the proposed preservative formulation would be suitable for a single-stage process adaptable to industrial practice. The suitability of lignin as a component in the development of the natural compound-based wood preservative depends on its properties. These properties vary with origin and isolation method. To this end, this study will investigate the bio preservative properties of technical lignin recovered from pulp black liquors (PBLs) obtained from different biomass origins and pulping processes commercially employed in the South African pulp industry.

Keywords: environmental sustainability, natural wood preservative, pulp black liquor, technical lignin

Conference: 18-04-29/05-03 Johannesburg, South Africa

Download document (219 kb)
free for the members of IRG. Available if purchased.

Purchase this document