Design of prototype reactor for hydrogen production from sodium borohydride

Boran, Aslı
Sodium borohydride (NaBH4) offers a simple and safe technology for storage and on demand production of hydrogen being a promising and a feasible method for fuel cell applications. The objectives of the present study are to emphasize the role of sodium borohydride as a part of future hydrogen energy system, to investigate the kinetics of the catalytic hydrolysis reaction of NaBH4 in a batch and flow system with respect to temperature, concentration, catalyst and flow rate for flow reactor by proposing a kinetic model and finally based on kinetic analysis, to design a prototype reactor to meet the hydrogen requirement for a 100W PEM fuel cell and operate it in steady state conditions. To express hydrolysis reaction by a kinetic model, series of batch experiments was performed in a glass flask (30mL) where the following parameters were systematically changed: the solution temperature varied as 20, 30 and 50°C, the NaBH4 concentration changed as 0.17, 0.23 and 0.3M, NaOH concentration varied as 0.27, 1.32 and 2.85M and catalyst amount was changed as 0.048, 0.07 and 0.1g Pt/C (ETEK®). In the kinetic model catalyst effect proposed within the rate constant. The kinetic model was purposed as: For flow reactor system, in a differential glass reactor (5mL) concentration, catalyst amount, catalyst type and flow rate was systematically analyzed at a constant temperature. For Pt/C catalyst the purposed model was: Also, for intrazeolite Co(0) nanoclusters, as a result of controlled experiments, the rate expression was found as: Based on these data prototype reactor (recycle) with internal volume of 122cm3 and storage volume of 1336 cm3 was designed, manufactured from Delrin® and operated.


Preparation and performance of membrane electrode assemblies with nafion and alternative polymer electrolyte membranes
Şengül, Erce; Eroğlu, İnci; Department of Chemical Engineering (2007)
Hydrogen and oxygen or air polymer electrolyte membrane fuel cell is one of the most promising electrical energy conversion devices for a sustainable future due to its high efficiency and zero emission. Membrane electrode assembly (MEA), in which electrochemical reactions occur, is stated to be the heart of the fuel cell. The aim of this study was to develop methods for preparation of MEA with alternative polymer electrolyte membranes and compare their performances with the conventional Nafion® membrane. Th...
Development of different carbon supports for proton exchange membrane fuel cell electrocatalysts
Güvenatam, Burcu; Eroğlu, İnci; Bayrakçeken, Ayşe; Department of Chemical Engineering (2010)
Proton exchange membrane (PEM) fuel cell technology is promissing alternative solution to today’s energy concerns providing clean environment and efficient system. Decreasing platinum (Pt) content of fuel cell is one of the main goals to reduce high costs of fuel cell technology in the way of commercialization. In this target, porous carbons provide an alternative solution as a support material for fuel cell electrocatalysts. It is also essential to increase surface area of carbon support material to have w...
Development of organic-inorganic composite membranes for fuel cell applications
Erdener, Hülya; Baç, Nurcan; Department of Chemical Engineering (2007)
Hydrogen is considered to be the most promising energy carrier of the 21st century due to its high energy density and sustainability. The chemical energy of hydrogen can be directly converted into electricity by means of electrochemical devices called fuel cells. Proton exchange membrane fuel cells (PEMFC) are the most preferred type of fuel cells due to their low operating temperatures enabling fast and easy start-ups and quick responses to load changes. One of the most important components of a PEMFC is t...
Production of lactic acid esters by reactive distillation
Yalçın, Özgen; Karakaş, Gürkan; Hamamcı, Haluk; Department of Chemical Engineering (2011)
The esterification of lactic acid with ethanol over Lewatit S 100, strong cation ion exchange resin catalyst, was studied in counter current vapor-liquid contactor type differential reactor by feeding ethanol and lactic acid solution as vapor and liquid phases, respectively. The ethanol vapor phase was diluted by dry air and the water removal was achieved by the mass transfer of water from liquid to vapor phase. Effect of ethanol to lactic acid feed molar ratio and vapor flow rate on fractional conversion a...
Realization of Concentrated Photovoltaic Module Based on Horizontally Staggered Light Guide
Turan, Raşit (2018-06-01)
Concentrated photovoltaic (CPV) systems have proven to be an important alternative to conventional crystalline silicon and thin film photovoltaic (PV) energy conversion systems. In CPV systems, lenses or mirrors are used to collect sunlight from a large area and to focus it onto a small area of a high efficiency photovoltaic cell. In this paper, we report the realization of a new CPV concentrator that is based on a horizontally staggered light guide system with a medium concentration level. The optical comp...
Citation Formats
A. Boran, “Design of prototype reactor for hydrogen production from sodium borohydride,” M.S. - Master of Science, Middle East Technical University, 2011.