Welcome! Project H2-Photobioreactor (PBR)

Outline Motivation H2 Photosynthesis Photobioreactors Project PBR!

Human activities and global warming Keeling curve shows trend of increasing [CO 2 ] occurring over 4 decades seasonal variation in northern hemisphere due to vegetation amount of CO 2 increase from 280 ppm (pre-1860) to 370 ppm, at present increase of 30 ppm in last 20 years alone see Carbon Cycle Greenhouse Gasses Group at NOAA (

Human activities and global warming ice core measurments of atmospheric [CO 2 ] cycles correlate with ice ages average temperature deviation over last 150 years

CO2, NOx, and CH4 are effective “greenhouse” gases

Worldwide demand for energy current consumption: 12.8 TW/year 3.3 TW consumed by the United States 10.2 TW from coal, oil, methane conservative model predicts TW annual consumption within 50 years 1.2 x 10 5 TW/year reaches earth from Sun (Hoffert et al. (1998) Nature)

H 2 - an ideal energy carrier can be stored, shipped, and used multiple sources sustainable if renewable source is used +∆G -∆G

merchant market ~$7 billion specialty chemicals manufacture metallurgy food laboratory transport captive-use market ~$20 billion petroleum refining (59%) ammonia synthesis (fertilizer) Current H 2 markets

OriginAmount in billionsPercent Nm 3 /year Natural gas Oil Coal Electrolysis 20 4 Total Used mostly in the production of ammonia-based fertilizers and oil refining Current global H 2 production release of CO 2 as H 2 is produced

Provided by the SeaWiFS ProjASA/Goddard Space Flight Center and ORBIMAGE Photosynthesis- the true power of the planet

Photosynthesis & biological production of H2 production of proton gradients used to generate ATP energized electrons used to reduce electron transport compounds- NADP + chemical energy used to fix inorganic C, N, and S for metabolism energy and hydrogen stored in chemical compounds- carbohydrates 2H 2 O  4H + + 4e - + O 2 4H + + 4e -  2H 2 2H 2 O  2H 2 + O 2 light, photosynthetic apparatus enzymes

Outline of electron and proton movement in photosynthetic architecture

Hydrogenases Diverse and large family of multisubunit enzyme complexes Structurally divided into three classes: Fe-only Fe-Nickel Iron free Functionally divided into two categories Uptake hydrogenase Bi-directional hydrogenase 2H + + 2e -  H 2

Photosynthesis

Biological pathways for H 2 production direct photobiolysis indirect photobiolysis photofermentation dark fermentation biological water-gas shift reaction biomass gasification

Direct biophotolysis reducing power generated by photosynthetic apparatus used to reduce protons to H 2 continuous production of H 2 in the light hydrogenase is inhibited by O 2 produced by PSII

Indirect biophotolysis reducing power is used to first fix inorganic carbon; carbohydrates act as storage medium for hydrogen (C 6 H 12 O 6 with H 2 O theoretically yields 12 H 2 ) reducing energy and hydrogen are released by fermentation O 2 generating and O 2 sensitive processes are temporally separated

Reported outputs of biohydrogen schemes from Resnick, R. J. (2004) The economics of biological methods of hydrogen production. M.S. Thesis, Management of Technology, MIT-Sloan

cost for steam methane reformation is $19.08/GJ costs listed above underestimated (labor cost not factored in) from Resnick, R. J. (2004) The economics of biological methods of hydrogen production. M.S. Thesis, Management of Technology, MIT-Sloan Cost ($/GJ) of biologically produced hydrogen

Energy prices (in £ per GJ) for Great Britain bottom line: coal and natural gas cost ≤ $10/GJ (from Energy Systems and Sustainability Oxford Press)

Bioreactors- real world parameters biological process engineering capital costs operating costs gas separation, culture mixing, aerobic/anaerobic primary resource is area light and climate

“Simple”schematic for biological hydrogen production circulating pumps gas collection sun transparent tubes filled with hydrogen releasing algae and nutrient medium other examples include open ponds for the accumulation and harvesting of algal biomass

from Photosynthetic Prokaryotes, Mann and Carr, eds. Real world photobioreactor

Hillbilly photobioreactor

Project PBR- Scale up proven technology Design and Build Working Photobioreactor! Design phase- Summer 2005 Assembly- Summer/Fall 2005 Run/Experiment- through Spring 2006 Background:

Laboratory scale PBR from Kosourov et al. (2002)

Project PBR- basic considerations Vessel materials- H2, O2 impermeable Mixing- mechanical v.s. gas driven Organism- eukaryotic v.s. prokaryotic Ports- culture injection, sterility Sensors- monitoring, pH, O2, H2 Fuel cell- gas mixture, transit time

Basic PBR schematic pump fuel cell battery

PBR- Greenfuel design gas diffuser clear tubing

Project PBR model #1

Project PBR model #2

Resources Edgerton Center- workspace, Bridgeport machines, $, truck Printed materials to: Biological Energy Interest Group c/o Edgerton Center 77 Massachusetts Ave, Bldg Cambridge, MA Packages: Biological Energy Interest Group c/o Edgerton Center 32 Vassar Street, Cambridge, MA Steve Banzaert, Ed Moriarty, Sandy Lipnoski,

What we need! $$$ (Edgerton Matching Funds) PBR site location Storage/assembly space

Tasks for next meeting… Preliminary sketches for subsystem Find supplier for clear tubing Approach departments for funding, space Web development- Athena locker, downloadables, blog?