general update
DESCRIPTION
General Update. Bojan Tamburic. Investigating the pO 2 /pH 2 electrode. Sparge with H 2 ≈ 30ml/min. Natural rise up to pH 2 = 23.0%. Max pO 2 = 48.3%. Flush with He. Suspected temperature variations. Flush with He. Switch probe polarity to pO 2. Stop H 2 sparging, pH 2 = 10.1%. - PowerPoint PPT PresentationTRANSCRIPT
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General Update
Bojan Tamburic
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Investigating the pO2/pH2 electrode
Max pO2 = 48.3%
Flush with He
Stop He flushing, min pO2 = 8.2%
Switch probe polarity to pH2
Sparge with H2 ≈ 30ml/min
Stop H2 sparging, pH2 = 10.1%
Stop He flushing, min pH2 = 7.3%
Natural rise up to pH2 = 23.0%
Switch probe polarity to pO2
Flush with He
Suspected temperature variations
pO2
pH2
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Investigating the pO2/pH2 electrode
pO2
pH2
T stabilisation
Flush with He
pO2 recovery
Flush with He
pO2 recovery
Switch to pH2
Probe instability
Sparge H2
Sparge H2
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Transfer report outline
Literature review• H2 production
• Photosynthetic H2 production• Parameters affecting algal growth• Parameters affecting H2 production• Photobioreactor systems
Experimental Method• Growing C.reinhardtii• Measuring growth and H2 production kinetics• Sartorius reactor: calibration and improvement• Sulphur deprivation procedure• Flat plate bioreactor design
Results• C.reinhardtii growth in the column reactors• Growth kinetics in the Sartorius reactor• Stirred-tank batch reactor H2 production results• Sartorius H2 production results
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Research paper summary
Review of resultsHYSYDAYS Turin paperRewrite?
Photobioreactor design & Algal comparative studyLocked up with WHEC Essen abstractsRelease?
Good at:Controlling light intensity, agitation, spargingMeasuring OD, pH, pO2
Not good at:Measuring H2
Growth kinetics experiment
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Growth kinetics experiment
Algal strain = CC-124 Temperature = 25°C
Agitation = 40%Light intensity = 20%
Algal strain = CC-124 under dilution Temperature = 20°C
Agitation = 50%Light intensity = 44%
K = 0.345r = 0.0720t0 = 29.3
K = 0.432 r = 0.0523t0 = 35.6
)tr(t 0e1KOD(t)
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Growth kinetics experiment
CC-124 growthOD as a function of time at various light
intensities
Determine optimal ODOD as a function of light intensity
)tr(t 0e1KOD(t)
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Growth kinetics experiment
CC-124 growthOD as a function of time at various
agitation rates
CC-124 growthOD as a function of time with and
without CO2 sparging
)tr(t 0e1KOD(t)
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WHEC 2010 abstracts
Some unicellular green algae have the ability to photosynthetically produce molecular hydrogen using sunlight and water. This renewable, carbon-neutral process has the additional benefit of sequestering carbon dioxide during the algal growth phase. The main costs associated with this process result from building and operating a photobioreactor system. The challenge is to design an innovative and cost effective photobioreactor that meets the requirements of algal growth and sustainable hydrogen production. We document the details of a novel 1 litre vertical flat-plate photobioreactor that has been designed to accommodate green algal hydrogen production at the laboratory scale. Coherent, non-heating illumination is provided by a panel of cool white LEDs. The reactor body consists of two compartments constructed from transparent polycarbonate sheets. The primary compartment holds the algal culture, which is agitated by means of a recirculating gas flow. A secondary compartment is filled with water and used to control the temperature and wavelength of the system. The reactor is fitted with instruments that monitor the pH, pO2, temperature and optical density of the culture. A membrane inlet mass spectrometry system has been developed for hydrogen collection and in-situ monitoring. The reactor is fully autoclaveable and the possibility of hydrogen leaks has been minimised. The modular nature of the reactor allows efficient cleaning and maintenance.
Some unicellular green algae, such as Chlamydomonas, have the ability to photosynthetically produce molecular hydrogen under anaerobic conditions. They offer a biological route to renewable, carbon-neutral hydrogen production from two of nature’s most plentiful resources – sunlight and water. This process provides the additional benefit of carbon dioxide sequestration and the option of deriving valuable products from algal biomass. The aim of this study is to analyse the hydrogen production rates of green algae, focusing on multiple strains of Chlamydomonas, including several laboratory wild types, marine species and diverse mutant strains. Hydrogen production is initially screened by water displacement measurement in a 300ml batch photobioreactor with the aim of conducting a preliminary comparison and identifying promising strains for further study. Selected strains are analysed in a 3l tubular flow photobioreactor featuring a large surface-to-volume ratio and excellent light penetration through the culture. Key parameters of the hydrogen production process are continuously monitored and controlled; these include pH, pO2, optical density, temperature, agitation and light intensity. A membrane inlet mass spectrometry system has been developed for hydrogen collection and in-situ monitoring.
Design of a novel flat-plate photobioreactor system for green algal hydrogen production
B. Tamburic, F.W. Zemichael, G.C. Maitland, K. Hellgardt
A comparative study of hydrogen production by selected Chlamydomonas strains
B. Tamburic, F.W. Zemichael, S. Burgess, M. Boehm,K. Hellgardt, P.J. Nixon
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Other issues
Flat plate reactorBase designPumpsMIMS system
HPLCDevelop organic acid methodologyMake standardsPurchase RI detector to measure ethanol
Filtration systemSet it up and test it
Purchase Hydrogen peroxide
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Experimental Update
Palang
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0 20 40 60 80 100 120 140 160
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
On Vitreous Carbon
-0.3V -0.4V -0.5V -0.6V -0.7V
t (s)
j (A/
m2)
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0 2 4 6 8 10 12 14 16
-10
-8
-6
-4
-2
0
2
4
6
8
10
Grew on WO3 at -0.2V for 15s
t (s)
j (A/
m2)
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0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
WO3-IrOx in 1M H2SO4
Bare WO3 Grew at -0.2V for 5s Grew at -0.2V for 15s
E (V) vs. SCE
j (A/
m2)
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Experimental Update
Chris Carver
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0 1 2 3 4 5 6 70
200
400
600
800
1000
1200TnO Voltage-Current Response
no membrane, single channel 100rpm
membrane, dual channel 200rpm
Voltage (V)
Curr
ent (
mA)
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Model Update
Zachary Ulissi
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Justification of Tafel Kinetics
Low Overpotential High Overpotential
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Justification of Tafel Kinetics
Si-Doped Fe2O3, with and without Co-Phosphate catalyst
Gratzel Lab Si-Doped Fe2O3 films
Gratzel Lab Si-Doped Fe2O3 film supported on WO3 Substrate
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Justification of Tafel Kinetics
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Justification of Tafel Kinetics
Bubble Formation
Semiconductor transport important
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