 of agriculture, including soil and nutrient loss to natural waterways, are seldom included in agricultural economic analyses, so that a true comparison is difficult. In addition, in parallel with human experience over millennia of agricultural development, monocultural algal solutions, and more recently genetically modified solutions, have been sought. There is little question that this can be done, since algal isolates have been cultured in the laboratory for many decades. However, the complexity of achieving agricultural levels and methods of algal production over decades, when the processes for higher plants took millennia, provides a serious economic test.
The ATS system has overcome most of the large scale algal culture problems by using algal “weeds” that are available, year-round in the waters being treated. Moreover in moving to non-point-source treatment, it has become clear that an enormous diversity of “weedy” species is readily available in natural environments, and disease and competition are not issues of concern. Pests and excessive chemical pollution provide minor concerns, as we noted above. However, the economics of constructed systems as opposed to open field agriculture remains the primary issue in the production of algal products. As shown below, if value is achieved for water clean- up, ATS provides a very cogent economic scenario.
Table 3 presents an economic model for treatment of the Susquehanna River at or near its confluence with Chesapeake Bay. The 3000 acre model is employed because at this dimension ATS will remove the amount of phosphorus independently assessed as necessary to return the upper Bay to nutrient health; at this dimension, ATS will also inject enough oxygen into the water column to securely remove the hypoxia (dead) zone that has come to characterize the upper Bay. In addition, an engineering design, with economic analysis, for the Suwannee River in Florida has been completed by Hydromentia and provides the basic accounting to develop such a large scale model.
Currently efforts are underway to join the stack gas CO 2 of a Constellation coal-fired power plant, as well as warm water effluent to ease winter operation, with the more-than- adequate area potentially available at the Aberdeen Proving Ground, at the confluence of the Susquehanna River and the Chesapeake Bay. This base is presently being reviewed for base closure. Whether or not this action is completed, there is a large area on this base that could be considered for co-use. The economic model presented in Table 3, is based on this situation, although other sites are also possible.
As the economic model demonstrates, given a nutrient trading or banking scenario, cost is not a significant factor in Bay clean-up. Indeed, it is likely that utilized in this manner, ATS clean-up of Chesapeake Bay is a green economic engine. Similar operations could be developed on the Potomac and James Rivers, potentially using available military land. This would not only provide a return of Chesapeake Bay to health, but would provide an economic boost to the Bay in greatly improving the fisheries of these waters that have been so long under environmental stress.
from 2004. Based on current anecdotal information this provides about a 27% discount on the current values (approximately $200/kg P $10/kgN). However, as we shall show, allowing for the value of by-products, ATS systems operated by a public, non-profit entity solely to reduce nutrient removal costs, could remove nutrients (and carbon) at about 50% of current costs.
The analysis of Table 3 is written to be carried out by a quasi government agency, with 30-year construction bonds at 5%. Carried out by a private engineering firm the difference between ATS nutrient removal costs and the market price, minus the cost of capital, would have to be negotiated. Given a functioning nutrient banking system, a significant return on investment could be available to drive clean-up efforts.
Omega-3 oils, 3.4 gals./dry ton, 490K gals @$100 gals. whsl.
The refining process for by-products needs to be expanded to pilot scale and then financially re-analyzed. Also, life cycle analysis needs to be carried out, especially for the refining process. It seems likely that the hydrogen produced in butanol fermentation would be most efficiently utilized on site to provide power for refinery operation. Also, CO 2 injection into ATS systems has not been performed at large scale, although the technology exists to do so using the All Terrain system, and application does not appear to be difficult. This aspect of project economics would have to be linked to carbon trading. Rivers in the Chesapeake Watershed have moderate alkalinity and in-water CO 2 supply is not a serious problem. The considerable rise in the pH of test systems shows that CO 2 stress is being placed on productivity. CO 2 injection, spread-out on floways can significantly increase algal productivity. On the other hand, this will delay phosphorus precipitation down the floway. These two opposing needs will have to be worked out in pilot operations. ATS has already been constructed and routinely operated for several years at multi-acre scale at a half-dozen sites. It is certainly time to expand to a 25-50 acre dimension pilot with a similarly scaled-up refining plant.
Now that it has been established that ATS remediation (nutrient removal and oxygen injection) is technically and economically feasible for non-point source waters (rivers and bays) at least up to mid latitudes, it is essential that this endeavor expand to multi-acre pilot demonstration scale. Since the Chesapeake Bay has demonstrated significant environmental problems, and the Federal Government has committed itself to solving this long-standing issue, it is here that our efforts will be concentrated.
A coalition of interested parties, convened and managed by Blackrock Energy, including the partner universities of this study plus the Universities of Virginia and Penn State University and the energy companies Exelon and Constellation Energy, have indicated a strong interest in forming a consortium to move ATS to pilot scale. This coalition has developed a project for both water-cleaning and by-products, including butanol, on the upper Chesapeake Bay. The Constellation coal-fired plant adjacent to the Army‟s Aberdeen Proving Ground will provide the land, heated effluent water and stack gases from its plant to expand to the next phase. Scientists at the Universities of W. Michigan and Arkansas are prepared to ramp up over one year, first to algae shipped “by the barrel” and then to a mobile refinery hauled to the Constellation site by year‟s end.
Exelon and Constellation plan to work together to support this endeavor with the goal of sourcing both funding and the necessary political support. Once fully successful at pilot scale (1- 3 acres), the intent is to expand to a 25-50 acre industrial pilot and within a few years to full acreage necessary for upper Bay clean-up. Tentatively, land area on the Aberdeen Proving Ground is being considered for this scale up. Additional efforts will also be initiated to develop similar facilities on the Potomac and James Rivers, thus looking to ameliorate the entire Bay as well as to provide significant quantities of by-products, including biofuels. A series of meetings are planned by all parties during early 2010 to bring this effort to fruition.
A recent proposal, developed by Blackrock Energy to the U. S. Department of Energy, in support of the Algae Consortium effort, is included in the Appendix. Constellation Energy and Exelon Corporation are the lead organizations in this proposal.
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