Influence of input variables over the wood digestion in a sulfite pulp mill for biorefinery purposes

Abstract

Eucalyptus globulus is the most profitable specie in Europe for pulping. However, in recent years some diseases and pests have caused its defoliation, affecting the available quantity of wood. In this sense, the mills are studying how to avoid the loss of pulp yield as well as the optimization of byproducts in order to take advantage of every component present in the wood using biorefinery processes. One of the possible options is to complete the consumption of E. globulus with other species such as Eucalyptus nitens. The objective of this paper is to study the behavior of both species related to the dissolving pulp manufacturing process as well as the characteristics of the resulting products. Parameters that can be very useful for the evaluation of the raw material, such as the growing data or density of both species, have been compared. Major attention has been focused on the composition of both species and how it affects the characteristics of the possible final products. E. nitens presents good results of forestry characteristics, being better than E. globulus in terms of growing and resistance to frosts. The cellulose content of both species is similar, however the digestion process in the case of E. nitens needs to be improved in order to optimize the involved energy and the obtained products.