Finding means to improve the conversion and expand the beneficial use of biomass fuels constitutes the primary research effort for the Biomass Laboratory. Much of the current biomass conversion research is targeted at understanding the role of inorganic materials found in biomass during thermal conversion to heat and power via combustion and gasification. Boilers burning biomass are subject to fouling and corrosion from alkali metals, chlorine, and other constituents of biomass released during combustion. These phenomena contribute to lower system efficiency, reduced availability, and higher costs. They are also critical inhibitors to the wider use of agricultural residues, such as straw, in existing and advanced power generation systems. Mitigating fouling and corrosion from such fuels would yield significant benefits in providing alternatives to open burning and higher cost cultural practices for straw management.
One possibility is to reduce the input of undesirable constituents. Recent work has shown that alkali metals and chlorine are removed in large amounts from biomass via simple wet extraction, or leaching. Techniques to enable the large scale use of leached fuel in existing and future conversion facilities are under investigation. Other possibilities include modifying the operating conditions to reduce gas temperatures in critical areas of the boiler. Laboratory studies and full-scale experiments in operating
power plants are currently under way. Many of these studies are joint with industry and national laboratories.
Coupling biological conversion, such as fermentation or anaerobic digestion, with thermal conversion also provides a means to control the partitioning and fate of elements through the conversion process. Research exploring the thermal conversion of ligneous co-products from biological conversions is underway.
Costs of using biomass are heavily dependent on the acquisition cost. Research is conducted on technologies to improve the harvest of agricultural residues for use not only as fuel, but for manufactured products as well. Currently under investigation are designs of improved acquisition systems for rice straw, including the development of GIS models to assess the potential optimization of the delivery system.
Materials production from biomass and agricultural wastes has taken on more importance to help solve certain environmental problems. Sequential evaporation of drainage water through crops, trees, halophytes, and solar evaporators has been developed as a way to allow sustained farming in parts of the San Joaquin Valley of California. The process generates salt as the final product, and disposing of the salt in a practical manner is critical to the eventual success of such systems. Vitrification of salt to make commercial glass products is now being investigated. Included are studies of rice straw and other biomass as the source of silica.
Research also includes investigations into the fundamental combustion behavior of biomass and the characterization of important fuel properties, small scale gasification systems for remote power applications, and energy utilization in controlled environments, such as greenhouses.