(215e) Evaluation and Comparison of the Scale-up Potential for Autotropic and Heterotrophic Algal Oil Production
In this study, a group of senior chemical engineering students developed preliminary designs and then performed an economic analysis for algal oil production utilizing both autotropic and heterotrophic growth strategies. Both proposed systems utilizes the strain of microalgae Chlorella Vulgaris as the raw material. Chlorella Vulgaris has a lipid content ranging between 15-35 wt%.
The study involved the development of Input/output diagrams, block flow diagrams, and process flow diagrams for compete processes starting from lab algae inoculation through to final lipid oil product purification. Preliminary equipment sizing was performed. The capital costs were estimated using a factored broad cost estimation method based on vendor quotes for the largest equipment and cost chart data for the rest of the equipment. Revenues and operating costs for a 20 year project life were also estimated.
The heterotrophic option will yield a higher lipid content which will generate a larger amount of oil when compared to the autotrophic strain but will require a higher quantity of inputs. The production throughput was comparable to a small scale oilseed production facility. Neither option is currently economically competitive with a commercial soybean oil processing facility. However, the heterotrophic option had significant advantages over the autotropic design. The key barriers to commercialization were identified so that future R&D activities can focus in these areas.