Energy Efficiency - A Particular Challenge for the Cellulose-based Products Industries

Wood-processing facilities, including pulp, paper, lumber, and engineered wood facilities, use large amounts of energy for such purposes as evaporative drying and the curing of adhesives. Much of that energy is already being supplied by the incineration of biomass, and there is opportunity to increase the proportion of renewable energy that is used. Specific changes can be made within such factories that allow them to come closer to what is thermodynamically possible in terms of avoiding the wastage of exergy, which can be defined as useful energy. Savings in exergy are often obtained by optimization of a network of heat exchangers within an integrated system. No steam should be allowed to leak to the atmosphere; rather the latent heat (due to phase transitions) and sensible heat (due to temperature changes) are recovered during the heating up of incoming air and water, ideally at a similar range of temperatures. Thus, by a combination of process integration and full utilization of cellulosic residues generated from the process, even biobased industries can be made greener.