III. B.1. Introduction

The long-term objective of the ASP was to develop microalgae liquid fuel production processes. Since its inception, the ASP supported laboratory R&D projects (Section II) and algal mass culture projects. However, for the most part, the laboratory and outdoor projects were not integrated into a strongly unified program. This reflects in large part the difficulty of such integration. Also, during the early stages of the ASP, too close an integration would have been restrictive, as it was not yet clear at the time which research approaches, production systems or algal strains would be best.

The extensive work on strain isolation, selection, characterization, etc., carried out by the ASP was used to a significant extent by the field projects, through the testing of a number of the isolates in algal mass cultures, specifically in the projects reviewed in this section. Unfortunately, the laboratory-level screening protocols had, in hindsight, relatively little predictive power for the ability of the strains to dominate and perform in outdoor ponds. Similarly, the laboratory work on the biochemistry, genetics and physiology of lipid biosynthesis, was difficult to apply to the goal of increasing lipid productivities in outdoor systems. Greater integration of laboratory and outdoor R&D is a challenge for any future microalgae R&D program.

The ASP initiated two outdoor projects in 1980, one in California using a paddle wheel-mixed raceway pond design (“high rate pond,” [HRP]), and another in Hawaii. The Hawaii project was to demonstrate a patented algal culture system, invented by then-ASP program manager, Dr. Larry Raymond (1981). This “Algal Raceway Production System” (ARPS) used very shallow flumes (<10 cm), rapid mixing by air lifts, covers with CuSO4 filters to screen out harmful infrared radiation, and harvesting of the biomass by foam fractionation, among many other claimed attributes (Figure III. B. 1.). Very high productivities were claimed. But a review of the work (Raymond 1979), in which P. tricornutum was grown in a 0.5-m2 system, revealed that this projection derived from a single batch culture, and in fact, the last data point showed biomass density actually decreasing. Benemann et al. (1982a, b, see Section III. D.5.), carried out a comparative analysis of the ARPS and the HRP designs, concluding that the ARPS would be too expensive and energy intensive, compared to the HRP design. These two projects in California and Hawaii, carried out for more than 6 years each, are reviewed in this section, followed by descriptions of the ASP projects in Israel, New Mexico, and related projects.