Microalgae Energy Technologies; Renewable Biomass Production for Biofuels, Bioenergy, and Bioproducts

Summary

Algae can produce biomass at rates more than twice that of terrestrial plants, and can be converted to a variety of energy forms such as liquid fuels (biodiesel and green-gasoline), biogas (methane), or liquid alcohol fuel (butanol or ethanol). We are developing technology for producing algae on agricultural, industrial and municipal wastewaters and converting the biomass to fuels.

Situation

Georgia and the US face many challenges in the 21st century including developing a reliable and stable source of energy that is locally generated, addressing the need to revitalize rural economies, and providing a solution to environmental issues such as urban air quality and waste management. Biodiesel, Green diesel or gasoline, bioethanol, and biomethane are promising alternatives to the petroleum-based energy production. There are two steps that would need to be taken for producing biofuels on a large scale; growing the feedstock, and processing them into fuels. The main issue that is often contested is whether or not we would be able to grow enough crops to provide the amount of energy that would be required to completely replace petroleum or other fossil fuels as an energy source. The more efficient a particular plant is at converting solar energy into chemical energy, the more efficient it is from a biofuels perspective. Among the most photosynthetically efficient plants are various types of algae, abundantly available in many ecosystems. Microalgae can use sunlight, nutrients in wastewater, and CO2 from waste flue gases and fermentation off gases to produce biomass rapidly and efficiently. As the potential benefits are enormous, research on algal production using waste streams and CO2 emissions is a high priority. Oil yield per acre per year by algae is over 2,000 gallons whereas crops like corn and soybeans only produce 18 and 48 gallons, respectively. Microalgae offer great promise to contribute a significant portion of the renewable fuels that will be required to meet the U.S. biofuel production target of 36 billion gallons by 2022, as mandated in the Energy Independence and Security Act of 2007 under the Renewable Fuels Standard.

Response

Our response has been to establish a research and development program in the area of algae-biorefinery. The program includes laboratory capabilities such as photobioreactors, climate controlled growth chambers, outdoor race-way ponds, temperature controlled green house for scale-up studies, and analytical facilities to quantify biomass, pigments, lipids, carbohydrates and proteins, and monitor water quality. We have 2 graduate students, 2 undergraduate student, 4 research staff and 3 faculty members working on: 1. Development of cost effective large-scale microalgae cultivation system using industrial, agricultural and municipal wastewaters 2. Increasing renewable biomass feedstock productivity on a per land area basis 3. Utilization of land and water (saline/brackish/wastewater) which otherwise cannot be used for conventional agriculture 4. Algae biomass/biofuel feedstock production process coupled with waste stream treatment to recycle waste nutrients and improving water conservation 5. Use of algae as carbon dioxide sink for carbon cycling

Impact

In the past 5 years, we have begun developing a combined biotechnological system for processing and treating industrial, agricultural and municipal waste streams. We have completed two major projects on utilizing carpet industry wastewater with sewage mix for cultivation of algae to produce biofuels. We developed a novel approach of using robust consortium of native algal isolates for biofuel applications which is totally different from the conventional approach of using monocultures. We made biodiesel from consortium of native algal isolates cultivated in treated carpet industrial wastewater and established the proof of concept for their biofuel production and nutrient removal potential. We also isolated 3 robust mixotrophic strains of algae from carpet industry wastewater which can utilize both CO2 and organic carbon sources simultaneously. Encouraged by the outcome of this project, Dalton Utilities, our industry partner who sponsored this research study, is presently piloting this technology in collaboration with UGA and Hydromentia Inc. This technology for biofuel production is coupled with phosphorus removal a benefit to Dalton Utilities. In 2001, significant removal of phosphorus (>75%) were achieved in the 2000-square feet pilot reactors located in Dalton GA. Currently we are developing algal biomat production technology on solid surfaces using the principles of attached growth, to reduce harvesting costs and enhance biomass productivity. Our work has also gained the recognition of federal government, as our research group was one among the two algae research groups in the country which received the DOE award for producing advanced biofuels from algae in 2008. Our work has had impacts far beyond Georgia when we were successful in obtaining grant funds from the US Department of Defense to establish a research program in partnership with the University of Puerto Rico. This effort, with $1.2 million funding from the US DOD will help train undergraduate and graduate students on algae biomass production and conversion to liquid fuels. In 2011 we applied for an international grant to establish at US-INDIA Algae-Biorefinery R&D Center. This application is presently under review by the US DOE. Our work related to algae biofuels technology in the past 5 years has resulted in 6 patent-pending technologies covering various aspects of cultivation and harvesting. We have trained over 25 students and staff in this area and our work has resulted in 15 peer-reviewed journal articles. Considering the future potential of algae biofuel technology, we are currently developing novel reactor configurations and advanced conversion technologies for nutrients and CO2 delivery, harvesting and cost effective production of biodiesel, biomethane, and bioethanol from algal biomass which will reduce the cost of production leading to more rapid commercialization.

State Issue

Conservation & Management of Natural Resources

Details

• Year: 2011
• Geographic Scope: County
• County: Clarke
• Program Areas:
  • Agriculture & Natural Resources