heterocycle from bipyridine PBI . In addition, hydrophilic â hydrophobic blocks of polymer backbones also create supramolecular interactions, resulting in bi-directional proton conductivity. Membrane characterization techniques including: differ
Dec 1, 2009 - Direct methanol fuel cell (DMFC) is a kind of PEMFC except .... The split type channels were made in the micro vaporizer region to reduce the ...
two-cell stack has been fabricated and the results are reported proving the viability of the design. Keywords : Micro fuel cell, Black silicon, Stack- ing, Proton ...
May 9, 2009 - Various routes to synthesise functional fluoropolymers used in membranes for fuel cells applications are .... Exchange Membrane for Fuel Cell (PEMFC) [C. W. Martin, P. J. Nandapurkar, S. S. Katti, in. Polymeric Materials ... 2003, 33, 5
During 1962â1965,. GE attempted to improve the power density by develop- ing partially sulfonated polystyrene sulfonic acid membranes. (prepared by dissolving polystyrene sulfonic acid in ethanol- stabilized chloroform followed by sulfonation at ro
increase permeation rate of water vapour and the separation factor of water vapor over gases16. Perfluorinated ion-exchange polymers (Nafion,. Flemion ...
consisting of SiO2/polymer [polyethylene oxide (PEO); polypropylene oxide (PPO); polytetramethylene oxide. (PTMO)] with urethane linking structure through ...
Nov 23, 2009 - For 1M glucose/2M KOH solution, an initial OCV of 120-160mV ... 2.2 Hydrogen fuel cells â basic principle. 5 ...... Pe estimates the relative importance of mass transfer by convection ...... Another design concept for reactant separa
nameplate capacity, minimum operating set point, and stack degradation via performance loss rate proportional .... balance-of-plant, and a supplementary heat-only unit (e.g. a condensing boiler) to help meet heat demands. ..... would be expected that
Pervaporation experiments consist on measuring the amount of permeated ... and pervaporation experiments can be effectively used as critical parameters.
The complex environments experienced by water molecules in the hydrophilic channels of Nafion membranes ... Initial wavelength-dependent results for the anisotropy show no clear variation ... the hydrogen bond network in Nafion is weaker than in bulk
Dec 9, 2008 - the electrolyte phase and vice versa.1-5 The overpotential is typically .... A. 3 where L is the thickness, A is the area, and is the ionic conduc- tivity of the membrane. Assuming that protons are the only charge- carrying ions, is giv
Polymer electrolyte membrane or solid electrolyte membrane fuel cell is the most .... are polyimides, poly (arylene ether sulfones), polybenzimidazoles, poly ...
Nov 24, 2015 - Electrochemical characteristics of the membranes in DMFC (2M CH3OH). Membrane ..... Desalination 2002, 147, 173â178. 18. Choi, B.; Nam ...
âInnovative Economies Initiativeâ, to drive small business growth in this sector across the 7-state region spanned from New York to. Maine. NEESC Background ...
small photovoltaic (PV)âfuel cell hybrid energy system. Simulation consists ... power converter. ..... The controller in the boost converter maintains a 200 V DC at.
Jun 9, 2015 - Keywords: hybrid renewable energy system; fuel cell bus; PI control; photovoltaic;. PEM fuel cell; NiCd battery; hydrogen; economic analysis. 1.
Keywords: Refuse collection vehicle; Fuel consumption; Hybrid hydraulic vehicle ..... Keywords: Hybrid electric vehicle; Battery; Supercapacitor; Model predictive ...
glucose and methanol by an order of magnitude over the currently available membrane ...... The maximum flow rate was recorded on 4/25/2003 at 70 mL/hour. ...... F. R. , (O hm s/cm. 2). Figure 3.9: Polarization curve and cell impedance for a typical c
Results concerning the coupling of the steam reforming (SR) and total ... It is shown that the transient behavior is mainly determined by the thermal inertia of the ...
Aug 29, 2014 - Solid oxide fuel cells (SOFCs) are promising electrochemical .... degradation of anode-supported micro-tubular SOFCs under redox ... As shown, the support layer porosity was 37% for the sample co- ... and free of pinholes.
Dec 16, 2017 - To cite this article: A Balakrishnan et al 2013 J. Phys.: Conf. Ser. 476 012030. View the article online for updates and enhancements. Related ...
P.F. van den Oosterkamp1, P.C. van der Laag .... the PROX unit are being cooled with water; these heat sources can be utilised for co-generation of heat. ... In particular, the air dosing to the PROX reactor was tuned to establish a suitable reformat
density (A/m2), Î»TPBL is the triple phase boundary line length per geomet- ric volume (m/m3), ... where Î· = (Ïioâ Ïel). (6) and the local exchange current density can be written as i0 = i ref. 0. ( O2. O ... Ïel = 0, n Â· Jio = 0, wO2 = 0.21.
Micro Fuel Cell Vent Membranes A Study in CO2/Methanol Selectivity GA Tech. Step-Up Summer 2006 Jeff Burmester Peachtree Ridge High School Gwinnett County Georgia
Purpose • Why fuel cells? – More devices are going mobile – The energy needs of mobile devices are increasing – No one wants to spend time recharging
• What are fuel cells? – Electrochemical devices that convert chemical energy to electrical energy
• Batteries vs. Fuel Cells? – No time lag in recharging (they refuel) – Higher energy density – Battery technology may be reaching maturity
1,9 Decadiene seems to improve the selectivity of PDMS Av e rage Se le ctiv ity (CO2/M e OH) v s Conce ntration of PDM S with De cadie ne 3.5 3.0
2.5 2.0 1.5 1.0 0.5 0.0 0
Decadiene compound concentration by w eight (%)
Next Step: A more rigorous study of membrane selectivity • •
• • • • • •
Multiple upstream phases – in fuel cells the vent will be exposed to methanol in both liquid and gas phases Multiple upstream materials – it is widely documented that permeability of a particular gas through a membrane depends on the other gases present – the selectivity of the membrane should be measured with carbon dioxide and methanol together Ability to precisely control the concentration/pressure of upstream materials at the membrane face – as different material permeate through the membrane at different rates the upstream concentrations can change Analytics to measure quantity and makeup of materials that have crossed over the membrane – typically done with a GC or mass spec. Ability to support the membrane so that it does not deform under pressure – often achieve by supporting the membrane with sintered glass or metal Ability to evacuate both sides of the cell to eliminate atmospheric gases Ability to precondition the membrane prior to the experiment – the permeability of the membrane depends on what materials it already contains Improved consistency of membrane thickness and precision of thickness measurement
Acknowledgements • I would like to thank Dr. Paul Kohl for offering me the opportunity to work in his lab, identifying a value-adding project and treating me like a member of his team. • I would like to thank Shruti Prakash for all the time she spent teaching, helping and answering my questions at a time when she had lots of other pressing things to do. • I would like to thank Dr. A.F. Burmester for helping me with both the theory and the mechanics of membrane permeability experimentation. • I would like to thank Dr. Leyla Conrad and Dr. Edward Conrad and everyone else that made the STEP-UP program possible, it has been hugely valuable to both me and my future students.
Spin Coater – Used to spread polymer into a uniform film Cee 100CB Coat-Bake System • Features the Cee 100 spin coater and Cee 1110 hotplate in one compact and microprocessor controlled bench-top unit • Up to 200mm round or 6" square substrates; • 0-6000 rpm spin range; • 1-30,000 rpm/sec acceleration, unloaded • Repeatability is ±5 rpm with a resolution of 1 rpm for the spincoater
CO2 Permeability Cell – Used to measure the rate at which CO2 diffuses through the membrane Custom designed and built at Ga. Tech. • Made from stainless steel • Membrane is inserted between two halves of the cell • An o-ring on each side of the membrane creates the seal • Six bolts around the perimeter hold the two halves together • Cavity on down-stream side of the membrane is of known volume • Pressure transducer is connected to cavity
Permeability Test Cell •
• • • •
Custom cell designed by Shruti Prakash and custom fabricated of stainless steel in the Georgia Tech Chemical Engineering machine shop A) CO2 inlet B) test membrane C) rubber O-ring D) pressure transducer
Measures in millimeters of mercury, pounds per square inch, bar, meters of water, and atmospheres Transducer has a 1/4 NPT malethreaded stainless-steel end Accuracy is 1% full-scale +1 digit
Range from -736 to +1500mmHg
Balance – used to measure polymer and additives Mettler AE200 Analytical Balance • •
• • • • • •
Range: 0 to 205 Gram by 0.0001 Grams The Mettler AE Series of analytical balances is considered by many to be the best analytical balances ever produced Extremely easy to use, all balance functions are controlled by the front panel control bar- automatic taring, integration time selection, calibration, and to turn the balance display on or off Capacity/Weighing Range: 0 to 205g Taring Range: 0 to 205g Readability: 0.1mg Reproducibility: 0.1mg Linearity: +/- 0.3mg Stabilization Time: ~5 sec,
Tummala, R.R, Fundamentals of Microsystem Packaging. McGraw - Hill 2001 Shruti Prakash Dissertation Proposal 2006 unpublished
Key approach • Fuel cells are power limited, while batteries are energy limited • Current results, high performance reliability of batteries • Target areas: where batteries cannot “do the job” – REMOTE APPLICATIONS IS THE KEY – Extended operation period – Go HYBRID! Shruti Prakash Dissertation Proposal 2006 unpublished