SBIR-STTR Award

Mechanical pulping accounts for about 25% of the wood pulp production in the world today. This volume is expected to increase in the future. Mechanical pulping, with its high yield, is viewed as a way to extend these resources. However, mechanical pulping is electrical energy-intensive (a mill processing 300 tons of pulp/day spends about $10 million in electricity cost) and yields paper with less strength. Biopulping, defined as the fungal treatment of wood chips prior to mechanical pulping, overcomes both of these problems. Unfortunately, the process reduces the brightness and opacity of resulting biofibers. High brightness and high opacity are highly desirable for the production of high quality papers. Fiber loading is a technology in which calcium carbonate is deposited onto the surface and inside the fibers, which increases the brightness and opacity of papers significantly and thus has the potential of solving both problems associated with biopulping. Therefore, the proposed research is directed at demonstrating the technical and scientific feasibility of combining the two newly-developed technologies. Both mechanical (control and biofibers), and softwood bleached kraft pulps will be subjected to fiber loading to produce high quality papers. ANTICIPATED RESULTS & POTENTIAL COMMERCIAL APPLICATIONS OF RESEARCH The proposed research will result into an innovative technology that will save electrical energy (at least 30%); improve paper strength and optical properties; reduce the environmental impact of pulping, particularly reduction in greenhouse gas emissions; enhance economic competitiveness by lowering the production cost significantly ($7-8 million/year anticipated savings); and create jobs in rural areas. Thus the proposed research will also satisfy the public interest by developing a sustainable agricultural system; protecting the environment; developing value-added non-food products from agricultural materials; and enhancing global competitiveness, and economic opportunity and quality of life, especially for people in rural areas.

The overall goal of the proposed program is to demonstrate the technical and scientific feasibility of combining the biopulping and fiber loading technologies at a pilot-scale simulating industrial conditions to minimize the initial research and development costs. The combined technology will save electrical energy, improve paper quality (strength and optical properties), and reduce the environmental impact of pulping cost-effectively compared to the present process of producing the same products. Biopulping, defined as the treatment of wood chips with a lignin-degrading fungus prior to mechanical pulping, is a new technology for papermaking. In this process, at least 30% electrical energy is saved and paper strength properties are improved. Unfortunately, the process reduces the brightness and opacity of the resulting paper. High brightness and high opacity are critical for the production of high quality papers, particularly when the trend in the pulp and paper industry is towards producing lightweight papers. We have also developed another new technology called fiber loading. In this technology, calcium carbonate is deposited as filler within, on the surface of, and outside the fibers. The process improves brightness, opacity, and bonding strength, and reduces energy consumption during drying. Thus, this fiber loading technology has the potential of overcoming both the problems associated with biopulping. During Phase I, the technical feasibility of combining the two newly developed technologies was established at a laboratory scale.