Solar Hydrogen Update 24 th November 2009
Updates -Carver’s reactor - Reactor fitting - Mirrors - Improvements on model - Reactor models discussion - Mechanistic studies - Kinetic data - Feasibility of annular configuration
H2H2 O2O2 Reactor Carver’s Reactor Reactor setup Pump Feed Tank Issues Extra pumps Extra inventory
H2H2 O2O2 Reactor Carver’s Reactor Reactor setup Pump Feed Tank Issues Limited feed tank opening
H2H2 O2O2 Reactor Carver’s Reactor Reactor setup Pump Feed Tank Issues Rate of gases separate from liquid Might need a hydrocyclone for gas-liquid separation
Mirror From Optical Mechanics Inc. Quotation is yet to receive
Mirror
Reaction Kinetics H2OH2O H2H2 ½ O 2 + Semiconductorhνhν+Semiconductor (e -, h + ) 2H + H2H2 +2e - +2h + H2OH2O½ O 2 +2H + k1k1 k2k2 k3k3 How fast is the hydrogen generation ? This rate might overcome the low efficiency performance Mechanistic study get help from chemistry ? Study on the reaction rate can be obtained from the current reactor This would improve the reactor model
Annular Configuration Spoken to Prof. James R Taylor (Imperial College Physics Dept.) Energy loss ~10 db/km Could Si or quartz as fibre material It is feasible and worth investigating in future
Annular Configuration Fibre optic coated with photo-anode at the outer surface Hollow fibre membrane Cathode Lens in focusing the light
Focusing task Setting up carver’s reactor for preliminary testing Should we get new burette? Improve on the current reactor model Run the plasma deposition unit for photo-anode characterisation
Light Intensity - Spectra: PBR1 – Low intensity LED arrayPBR2 – High intensity LED array Sartorius reactor – Cool white fluorescent lightsCulture reactor – Cool white fluorescent lights
Light Intensity – Spectral matches: CC-124 absorption to LED emission CC-124 absorption to fluorescent emission
Pumps – Watson Marlow: Peristaltic 300 series - £ Peristaltic 500 series - £ Flow up to 2l/min Microprocessor or manual control Brushless DC motor 2 year warranty 5.6kg, 233x230x132mm Flow up to 4.5l/min Fixed speed pump AC motor gearbox 2 year warranty 11kg, 360x170x140mm
Pumps – KNF Neuberger: Liquid Diaphragm Pump, NF30 series - £114.06* Gas Diaphragm Pump, modified NMP830 - £182.73* General: Oscillating displacement pump DC motor Mounted in any position Oil/maintenance free Weight ≈ 500g Flow: Around 0.3l/min for liquid pump Around 2l/min for gas pump Flow rate adjusted by changing input voltage – 4 lead DCB (brushless) motor for optimum control Modification: NMP830 gas-tight Aluminium head EPDM diaphragm and valves G1/8 threaded port (Swagelok connection) Designed for He pumping
Pumps – KNF Neuberger: Modified Liquid Diaphragm Pump, NMP015 series Solar simulator (Fessehaye) reactor: NMP015 may be modified to be gas-tight (expensive) Stainless steel/aluminium head EPDM diaphragm and valves “Low algal death rates” MSc/PhD Students: Stephanie Hoarau (SEF): Develop MIMS system Develop filtration system Annalisa (University of Milan)
FZ Design – flat panel bioreactor Update on instrumentation and data analysis
Flat Panel design : gravitational flow Cleaning Probes Support
Assembling the system:
16-Bit, 250 kS/s M Series, Integrated BNC, External Power 16 differential BNC analog inputs (16-bit, 250 kS/s) 4 BNC analog ouputs (16-bit, 833 kS/s), 48 digital I/O (32 clocked, 8 BNC), and 32-bit counters NI Signal Streaming for sustained high-speed data streams over USB; OEM version available Compatible with LabVIEW, ANSI C/C++, C#, Visual Basic.NET and Visual Basic 6.0 NI-DAQmx driver software and NI LabVIEW SignalExpress LE interactive data-logging software NI USB-6229 BNC
Fe 2 O 3 : spray pyrolysis Effect of Sn doping on: –Electrochemical properties –Morphological properties
Undoped Fe 2 O 3 : 10 layers
Undoped Fe 2 O 3 : 20 layers
Doped Fe 2 O 3 : 10 layers
Doped Fe 2 O 3 : 20 layers
Doped Fe 2 O 3 : 15 layers
Undoped Fe 2 O 3 : 15 layers
Doped Fe 2 O 3 : 20 layers
On-going work Effect of Sn-doping –Lower/higher doping concentrations Film thickness measurements Quantum efficiency measurements –Effective H 2 yields
CO 2 Reduction Mechanism CO 2 + e - CO 2 - –CO H + + e - HCOO - –CO H 2 O + e - HCOO - + OH - –CO H + + e - CO + OH - –CO H 2 O + e - CO + 2OH -
Low CO 2 concentration in aqueous systems Feed CO 2 in gas phase through gas diffusion electrodes along with steam
PEC Reactor Development