Towards a more cost-efficient paper and board making using microfibrillated cellulose

The economic potential in terms of variable cost needed for production of fine paper has been evaluated for a case where microfibrillated cellulose (MFC) was added in order to increase the filler content at maintained grammage and tensile index. MFC production was based on a mechanical enzymatic pretreatment procedure prior to high-pressure homogenisation. Two different scenarios were studied: without and with wet end starch. For cost evaluation, it was assumed that the cost for production MFC had been calculated from the pulp and enzyme price and energy needed for refining and homogenisation. Although the pulp used was a never-dried bleached softwood sulphite pulp, the price was assumed to be equal to that for bleached kraft pulp. Techno-economic analysis was based on a pilot scale trial using a mobile demonstration plant with a capacity to produce 100kg MFC. The plant consisted of a three-stage process: enzyme treatment, refining and homogenisation. It has been concluded that the use of MFC as a strength additive had a positive impact on the variable costs for a fine paper case when increasing the filler content