New technology for papermaking : biopulping economics

Fungal pretreatment of wood chips prior to mechanical pulping (biopulping) reduces the electrical energy requirements during refining, potentially increases mill throughput, and improves paper strength. An economic analysis of a 600 tons/day thermo-mechanical pulp (TMP) mill indicates that, based on energy savings alone, the process is economically feasible, and results in an overall savings of about US$ 10 per ton of pulp. Increasing the mill throughput by 20% achieves additional savings of more than US$ 40 per ton of pulp. Replacement of TMP for kraft pulp results in additional savings. For any particular mill, the savings realized will depend on the specific conditions of the mill, utility costs, and current operations. The conclusion is that biopulping is feasible from both an engineering and economic standpoint Application : biopulping, the treatment of wood chips with a lignin-degrading fungus, reduces the electrical energy requirement for refining while producing a stronger pulp. We quantify the economic benefit of the energy savings, throughput increase, and stronger paper through an analysis of a 600 tons/day mill.