Recovery Act - Electromechanical Dewatering of Paper Pulp for Increased Energy Efficiency

Paper production is an energy intensive business. Dewatering alone accounts for a significant portion of the energy cost of paper production; 4-5 million Btu are required per ton of pulp processed. Dewatering is carried out first by mechanical dewatering, and then by evaporation, which occurs when the paper web is rolled over multiple heated rollers. Reducing evaporative dewatering energy requirements with more energy efficient dewatering methods can be an important step in making paper production more energy efficient and cost competitive. Eltron Research & Development Inc. proposes a new dewatering approach to increase the amount of water currently removed mechanically, lowering the drying load placed on evaporation. The goal of this technology is to increase the solid content of the paper web to 60-65% solids prior to the evaporative process, by employing electroosmotic-assisted mechanical dewatering. This increased level of solids loading prior to evaporative drying is enough to reduce the energy requirements of the drying process by nearly 40%. Adoption of the technology by the entire U.S. paper industry could lead to an estimated energy savings of 131 TBtu/year. In the proposed Phase I program, a bench-scale apparatus will be used to demonstrate this novel dewatering method and determine the effects of pulp chemistry and additives on the dewatering rate and efficiency. A preliminary techno-economic model for scale-up of the technology will be developed. Commercial Applications and Other Benefits: Dewatering technology is cross-cutting research, with potential applications in a variety of fields. Dewatering is an energy intensive step in many industrial processes, such as food processing. In addition to paper production, which is a large industry and is interested in new energy saving technologies, the pulp production market could benefit, although the demand for market pulp is expected to decline over time as the industry transitions to integrated plants.