Novel Algae Technology for CO₂ Utilization

Technical Report · Fri Dec 01 00:00:00 EST 2017

OSTI ID:1410799

Prasad, Ravi ^[1]

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1. Helios-NRG, LLC, Amherst, NY (United States)

Non-Confidential The United States, the world’s largest energy user and second largest CO₂ emitter, is heavily dependent on fossil energy. In 2014, CO₂ emissions from US coal burning power plants was ~ 1562 MM tons/yr, accounting for 76% of the total US power sector emission1. Hence, reducing the CO₂ emission footprint from coal plants is widely viewed as a key element in mitigating global warming. Despite significant interest, implementation of CO₂ capture technologies have been hamstrung by high capture costs which significantly increases the cost of electricity. In this project, supported by a SBIR grant from the US DOE, Helios-NRG in collaboration with the State University of New York at Buffalo (UB) aims to develop a novel, algae based technology to capture CO₂ from coal based power plants and convert it to renewable bio-fuels and other higher value co-products. The use of algae to capture CO₂ and subsequently utilize it to produce products has the promise to enable substantial reductions in the net cost of carbon capture. The Phase 1 project was aimed at demonstrating technical feasibility of critical components of the proposed concept in the presence of some key flue gas contaminants and advancing the technology. The project is now complete and all the project objectives were met or exceeded. The contaminants in typical flue gas streams post-FGD, including heavy metals, were quantified. The CO₂ levels in this stream is ~12% which is much hgher than the ambient concentrations that all algae have evolved on. In addition this stream contains ~75ppm SO_x, 75ppm NO_x and small amounts of a large number of heavy metals. Phase 1 demonstrated the ability of two preferred strains of algae to survive and grow in simulated flue (CO₂, SO_x, NO_x) as well as three of the most toxic heavy metals.These strains were selected based on their suitability for the flue gas enviroment and potential for high carbon capture. These species were then used in carbon capture tests using existing photo bireactors to simulate a new process. The target CO₂ capture efficiency of 70% was exceeded in these tests and stable operation demonstrated. Technology for a new dewatering technology called DeAqua was advanced. This can potentially reduce both the cost and energy for the critical dewatering step. The algae used in the carbon capture tests were shown to contain a number of valuable co-products. Data obtained in the tests were used to simulate operation of the new process at high carbon capture efficiency. A reasonable set of design and operating conditions were identified that can achieve 90% CO₂ capture from the post FGD flue gas stream. Preliminary economic analysis was performed for CO₂ capture from a 550MW supercritical power plant burning sub-bituminous coal. The results showed the potential of the proposed technology to significantly reduce the cost of CO₂ capture compared to current options. The results showed that the utilization of the CO₂ captured to generate high value products can make a step change in the cost of carbon capture. Plans to advance the technology in Phase II were developed and potential partners identified.

• Research Organization: Helios-NRG, LLC, Amherst, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: SC0017077
• OSTI ID: 1410799
• Type / Phase: SBIR (Phase I)
• Report Number(s): DOE-Helios-NRG-DE-SC0017077
• Country of Publication: United States
• Language: English

Related Subjects

29 ENERGY PLANNING, POLICY, AND ECONOMY
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
Microalgae
CO2 capture
hydrothermal liquefaction
low cost
bio-fuels
high value chemicals
water recycle