Other Microalgae Projects During the ERDA/DOE Period
During the 1975-1979 period, several other proj ects on microalgae fuels production were funded by ERDA/DOE, including the biophotolysis projects using heterocystous cyanobacteria, discussed earlier (see review by Benemann et al. 1980). Another biophotolysis project tested an optical fiber system for diffusing solar light into algal cultures, thereby overcoming the light saturation limitation to photosynthetic efficiencies (Manley 1979). This was shown to be impractical and was abandoned after only some very initial work. However, optical fiber photobioreactors are today the centerpiece of the 10-year, very large Japanese R&D program for microalgae CO2 utilization (Section IV. B.1.c.).
In 1976, Lawrence Livermore National Laboratory (LLNL) established a well funded in-house project that was very similar to the University of California-Berkeley project, including the use of microstrainers for harvesting filamentous microalgae, biomass recycle, and even a biophotolysis component using heterocystous cyanobacteria (Jeffries et al. 1977; Timourian et al. 1997). This project failed to receive support from ERDA, and was disbanded in 1977.
Professor Harry Gregor at Columbia University was funded for 2 years to develop membrane systems for cross-flow filtration harvesting of microalgae. However, the membranes available at the time, the pressure drops required, and the fouling problems encountered made this approach impractical (Gregor and Gregor 1978).
At Woods Hole Oceanographic Institutions, Drs. John Ryther and Joel Goldman carried out extensive research on microalgae cultivation in outdoor ponds on mixtures of seawater-secondary sewage effluent. When Dr. Ryther relocated to the Harbor Branch Oceanographic Foundation in Florida in the late 1970s, he was supported by DOE and later the ASP for the production of freshwater plants (water hyacinths, etc.) and seaweeds (Ryther 1981; 1982; 1983), as well as for microalgae culture collection work (See Part II. A.2.). Dr. Goldman also wrote a review on the theoretical and practical aspects of microalgae cultivation under contract with DOE (Goldman 1979a, b). One conclusion was that the productivity of microalgae systems would be limited, because of the light saturation effect and other factors, to below 50 mt/ha/yr. Although the analysis was correct, it was a very conservative conclusion, making no allowance for productivity improvements caused by fundamental and applied R&D advances, as discussed in the remainder of this report.