The high yield potential and attractive chemical composition of Typha make it a particularly viable energy crop. The Minnesota research effort has demonstrated that total annual biomass yields equivalent to 30 dry tonnes/ha (13 tons/acre) are possible in planted stands. This compares with yields of total plant material between 9 and 16 dry tonnes/ha (4 to 7 tons/acre) in a typical Minnesota corn field. At least 50% of the Typha plant is comprised of a belowground rhizome system containing 40% starch and sugar. This high level of easily fermentable carbohydrate makes rhizomes an attractive feedstock for alcohol production. The aboveground portion of the plant is largely cellulose, and although it is not easily fermentable, it can be gasified or burned. This report is organized in a manner that focuses on the evaluation of the management options task. Results from stand management research performed at the University of Minnesota during 1982 and 1983 are integrated with findings from an extensive survey of relevant emergent aquatic plant research and utilization. These results and findings are then arranged in sections dealing with key steps and issues that need to be dealt with in the development of a managed emergent aquatic bio-energy system. A …

Research on the mass culturing of microalgae has been carried out over the past 30 years in many parts of the world. Today there are numerous potential applications for algal mass cultures including protein production, wastewater treatment, water renovation, closed life-support systems, production of commercial chemicals, aquaculture, and bioconversion of energy. Photosynthetic yields over 30 gr dry wt m/sup -2/ day/sup -1/ have been attained on occasion in many locations for short periods and yields between 15 to 25 gr dry wt m/sup -2/ day/sup -1/ for longer periods are now common. This apparent upper limit in productivity is not coincidental. Under outdoor conditions peak yields are possible only under conditions of light limitation. Photosynthetic algae absorb light energy and convert it to stored chemical energy under rigid adherence to the laws of thermodynamics. By examining the basic physics of photosynthesis, it is possible to clearly demonstrate that under conditions of full sunlight in the most ideal locations maximum yields of 30 to 40 gr m/sup -2/ day/sup -1/ can be expected. For long-term operation of large-scale outdoor cultures, many bioengineering factors are involved and realistic yields considerably less than the maximum potential can be anticipated. Manipulation of the two …