Final Report: Microbial Solution: Application of Microorganisms for Biofuel Production and CO2 MitigationEPA Grant Number: SU833915
Title: Microbial Solution: Application of Microorganisms for Biofuel Production and CO2 Mitigation
Investigators: Markov, Sergei A. , Schiller, Joseph R.
Institution: Austin Peay State University
EPA Project Officer: Page, Angela
Project Period: August 15, 2008 through August 14, 2009
Project Amount: $10,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2008) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Air Quality , P3 Awards , Sustainable and Healthy Communities
These students contributed to this project: Dawn Danielson, Luke Holliday, Nimit Patel, Ryan Willingham, Tracy Bisaquera (Department of Biology), Matthew Murphy (Department of Engineering Technology), and Barbara Waldron (Department of Chemistry), Austin Peay State University
The purpose of this project is to convert solar energy and waste CO2 (carbon dioxide that is released in power plants by burning fossil fuels) into an array of biofuels by sequential use of microorganisms in bioreactors.
Summary/Accomplishments (Outputs/Outcomes):A 100 L photobioreactor for biodiesel generation from microalga Chlorella vulgaris was constructed from two parallel clear PVC 10 feet tubes (6’ diameter) with a small slope (10%). The gas mixture (5% CO2 and air) flowed up the top of the PVC tubes from the bottom as large gas bubbles. Photobioreactor was run in a batch mode for two weeks at room temperature. Continuous light was provided by cool white fluorescent lamps (136 - 186 μmol • m-2 • s-1 on the surface of the culture). Algal biomass was harvested at OD665 ~ 0.35 corresponding to a chlorophyll concentration of ~ 3 μg per ml, and concentrated by sedimentation with subsequent drying under 70◦C. Algal oil was extracted with hexane. The amount of oily material was expressed as a percentage of algal dry weight. Oil content in the algal cells in the bioreactor was found to be 10%. Algal oil was converted into biodiesel by transesterification with glycerol as a by-product. Next, glycerol was used as a substrate for making H2 and ethanol by bacterium Enterobacter aerogenes in batch culture (test tubes), and in hollow-fiber bioreactor. Highest H2 and ethanol production rates were observed under 2% glycerol, volume per volume (v/v), on a synthetic medium in test tubes. The yield of H2 from glycerol (0.9 mol/mol) was relatively high in batch culture (in test tubes). A lab-scale hollow-fiber bioreactor for conversion of glycerol into H2 and ethanol was constructed. The bioreactor was designed in a way that the glycerol diluted in growth medium was pumped from the outside of the fibers into the lumen (inside). Bacterial cells were readily adsorbed to the outer surface of the hollow fibers, and the cells consumed glycerol. Used growth medium was returned to the bioreactor medium reservoir, to create a close system in which it was possible to measure glycerol uptake and ethanol production by bacterial cells. The bioreactor was run under 30º C. Glycerol uptake efficiency by bacteria in the bioreactor was found to be 90% for 7 days. The assessment of H2 and ethanol-producing activity by bacteria in the hollow-fiber bioreactor in the presence of 2% glycerol (v/v) was made. Hydrogen production in the hollow-fiber bioreactor by E. aerogenes from glycerol was observed for 3 days at a maximum rate of 30 mL per hour (mL · h-1). Hydrogen from the hollow-fiber bioreactor was directly injected into a small fuel cell, and shown to be capable of generating enough electricity to power a small motor.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
|Other project views:||All 4 publications||1 publications in selected types||All 1 journal articles|
|| Markov SA. Potential of using microalgae for biofuel production and CO2 removal from atmosphere. International Scientific Journal of Alternative Energy and Ecology 2009;2:83-91.