Application of mass transfer in the pulp and paper Industry- overview, processing, challenges, and prospects

This study reviews the mass transfer with a focus on the challenges, benefits, processing and prospects in the pulp and paper industry with a scope limited to Kraft pulping which is the dominant pulping process worldwide. The mass transfer usually occurs in various processes that deal with reactions, separation, and heat transfer. All these aforementioned processes occur in the production of pulp and paper from their raw materials. The application of mass transfer to these processes is of great importance in setting target yields, and specifications and improving efficiency. The major processes where mass transfer principles are applied are drying, chemical washing, pulp digestion and pulp bleaching respectively. Understanding the requirements and targets of each of these processes in combination with the mass transfer principles helps in the development of models and design of equipment that operate based on the developed models in meeting the required targets. Studies have indicated that mass and energy balances cannot be done independently in meeting the required targets and equipment design. The drying and stripping of lignocellulosic components of the feed-in paper manufacture constitute a large part of the challenges faced by the industry. Drying techniques have been considered to be inefficient, and lignocellulosic by-products are known to contain toxic components. Green chemistry production processes and newer drying techniques were indicated as possible solutions. It is expected that researchers and investors would find this article useful.