1. A2MA2M Experimental and modeling approaches to optimize an algae-to-methane coupled bioreactor system Ruby An – 2015 SURF Metcalf Student Principal Investigators : Joe Vallino & Zoe Cardon The University of Chicago – Chicago – IL – MA – Woods Hole – Marine Biological Laboratory

2. Algae-to-methane (A2M) has potential as an efficient and practical renewable energy strategy Algal biomass: minimal land & water usage Methane: efficiently stored & energy on demand www.prx.orgwww.wageningenur.nl

3. A2M Research Aims 1.Experimental – Develop closed system with 100% nutrient recycling – Maximize methane production 2.Modeling – Develop accurate description of system – Predict system performance to achieve experimental objectives

4. A2 M Design Temperature: 25 °C

5. A2 M Design Aerobic Algal Reactor Inputs: Air CO 2 Light – Diel 12h Cycle Temperature: 25 °C

6. Chlamydomonas rienhardtii CW15 25 μm Green algae mutant lacking a cell wall

7. A2 M Design Temperature: 25 °C Anaerobic Microbial Digester Output: CO 2 and methane gas Digested algae as nutrients & detritus

8. Aim 1: Experimental Set-up A2M IRL

9. Liquid Volume: pH Dissolved oxygen (DO) Headspace: Oxygen (O 2 ) Carbon Dioxide (CO 2 ) Methane (CH 4 ) Data Monitoring in both reactors

10. Key Features of the Data

11. Lights onLights off

12. Lights onLights off CO 2 + H 2 O CH 2 O + O 2 light algae

13. Key Features of Data Installed spargers Doubled light levels Elevated CO 2 input 0.039% => 2%

14. Key Features of Data Day 1Yesterday

15. Aim 2a: Algal Reactor Mass Balance Model rate of change = gain - loss State Variables: 1.C Algae 2.C DIC(aq) 3.C O2(aq) 4.p CO2(g) 5.p O2(g)

17. Inflow & Outflow

18. Mass Transfer

19. Inflow & Outflow Mass Transfer Algal Growth & Respiration

20. CO 2 + H 2 O CH 2 O + O 2 light algae Algal Growth Equation Light Limitation CO 2 Limitation

21. Adjustable Parameters

22. Model & Data Comparison Model fit to days 57-60 Model Data

23. Model & Data Comparison Model predictions for days 30-33 Data Model

24. In Summary: Experimentally - achieved high algal growth Accurately modeled algal reactor dynamics Establish and maximize methane production Develop the full coupled bioreactor model to simulate methanogenisis Next Steps:

25. Acknowledgements Joe Vallino Zoe Cardon Suzanne Thomas Anonymous Donor Ken Foreman & Wyntin Goodman Zeiss Microscopy Staff Jim & Joey

26. Questions/Discussion

28. Supplementary Info

29. Anaerobic Microbial Community www.oceanscience.com Inoculated Day 71

30. Methane

31. Microscopic analysis of algal cellular disintegration Jumpstart methanogenic pathway : new inoculum Genomic analysis of microbial community? Methane Production Strategies