Reengineering the paper mill waste management

There are thousands of pulp and paper mills worldwide. The utilization of the waste they produce is a problem of particular importance. Many methods have already been put forward for the management of the mixture of lime mud and cellulose fibre residues. The chemical nature of its management presents a challenge because it requires costly catalysts and long retention times or raises criticisms about its environmental impacts. Several techno-economic analyses (including various modifications to anaerobic fermentation; combustion; pyrolysis and composting) have been carried out on an almost commercial scale to holistically assess the wide portfolio of management issues. The data obtained indicate that it cannot be clearly concluded that one particular method is the best for dealing with all management issues. However, the conclusions do provide an insight into how processing technologies can be adapted in specific cases.