PRODUCTION OF SODIUM BORON HYDRIDE AND FUEL CELL WITH DIRECT SODIUM BORON

Decreasing of fossil fuels and unfavourable environmental effects caused by the use of fossil fuels in energy out put are forcing trend to new and clean energy production sources. Fuel cell, which uses hydrogen as fuel is one of the alternative technologies that are examined intensely in the last years.

Fuel cells are energy transformation systems with high productivity and through this system electrical energy can be directly produced using hydrogen's chemical energy. They have advantages such as being quiet, avoiding environmental and noise pollution, excluding mobile components and gaining much more transformation than the fossil fuels do. Fuel cells can be designed in different capacities such as small enough to compensate the requirements of the mobile phones or big enough to produce power to satisfy a city. For that reason, they have a wide industrial usage potency ranging from transportation vehicles to industrial applications. Fuel cell market is estimated to reach up to 1-2 billions of dollars in a few years time and (as the vehicle practices become widespread) 20 billions dollars in a ten year time. Also production, storage and transport of hydrogen is one of the bottlenecks in usage and development of the fuel cell technology. Hydrogen can be produced from fossil fuels, biomass or water. But its cost is still expensive than the fossil fuels. Also storage and transport problems still remain unsolved. Since the first World Hydrogen Energy Conference organized in 1976 in Miami, many countries have been doing extensive research studies on hydrogen production, storage, transport and final usage. In the world, various methodologies such as pressured cylinders, liquid hydrogen storing, cryogenic cylinders, metal hydrides, carbon nanotubes, glass microspheres and zeolites have been tried for hydrogen transport and storage. None of these methodologies meet the expected criteria on hydrogen storage.

Most important points of the criteria can be described as:

• Density of the usefull hydrogen (both as weight and volume)
• Usage security
• Cost
  
  

At this point sodium boron hydride which is a boron chemical being studied extensively by the rest of the world is an important solution. Moreover, considering that Turkey has the richest and best quality reserves, up to 65% of the World, reserves, importance of using sodium boron hydride in fuel cells is doubled.

Advantages of sodium boron hydride compared to the other hydrogen transport mediums are summarized below.

• It can store 20 % hydrogen by weight.
• It is not flammable/explosive
• Reaction can be easily controlled.
• Half of the hydrogen sources from hydride, the other half sources from water.
• Catalyser and sodium metaborate are re-used.
  
  

In fuel cells, sodium boron hydride can be used mainly by two ways; directly or apart from the fuel cell to be used for hydrogen production when needed.
Extensive research studies for demand based hydrogen production system apart from the fuel cell are going on with the transfer of important sources. Sodium boron hydrid solution is converted to hydrogen by passing it through hydrogen production unit and this hydrogen can be used in low-temperature fuel cells without a fuel cell modification. In this system, sodium boron hydride yields hydrogen in hydrated medium, catalytically. This technology is necessary in applications especially like storage and transport which have problems such as mass, volume and security. In the direct sodium boron hydride fuel cell, electricity is produced without a hydrogen producing intermediate step. Direct sodium boron hydride is used as fuel without hydrogen production and storage units. Direct sodium boron hydride fuel cell is necessary for applications with low power demand such as mobile civil (phone, radio, small television, vacuum cleaner) and military (local illumination (tight spot ,etc), mobile transceiver, electronical war apparatus (radio receiver, etc), personnel calefactory, dismounted soldier, unmanned vehicles, sensor applications.

For Turkey, to convert the boron ore abundance to added value and to gain a place in world boron market parallel to the abundance it has, starting to produce bor compounds with high added value that can be used widely in great amounts, is essential. Boron Research Institute (BRI) is executing and coordinating research and development studies in order to produce boron compound with high added value and to use them in critical technological areas. Sodium boron hydride production and usage in fuel cells is a good example of these compounds.

Boron hydride has different usage areas other than hydrogen storage and fuel cells. These can be listed as; bleaching cellulose in paper industry, cleaning of metal surfaces, gaining valuable metal in photography and metal surface procedures, and removal of heavy metals in waste water. The most important difficulty against spreading its usage is its high cost due to present production methodologies. One of the aims of this project is to reduce the cost of sodium boron hydrid production. When this becomes true there will be a wide usage in present utilization areas (paper industry and purification) and as hydrogen storing medium all over the world and Turkey's market share will increase.

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Two projects; "Sodium Boron Hydride Shynthesis and Production" and "Direct Sodium Boron Hydride Fuel Cell Production and Its Integration" which are supported by BRI, are going to be conducted synchronously.

"Sodium Boron Hydride Shynthesis and Production" Project includes the development of sodium boron hydride production firstly at laboratory scale, in order to achieve necessary data for the industry scale production. Moreover, within this project, a pilot boron hydride production facility will be established with the help of the data achieved by the laboratory research. In the "Direct Sodium Boron Hydride Fuel Cell Production and Its Integration" Project development of direct sodium boron hydride fuel cell and final user integration are going to be performed. For this reason; data, basic facilities and unique technology required for sodium boron hydride fuel cell module and system components are going to be built, direct sodium boron hydride single fuel cell and triple fuel cell and direct sodium boron hydride fuel cell components are going to be developed and for various military/civil application fields, direct sodium boron hydride fuel cell prototype of 70-100W is going to be developed.

Sodium boron hydride production which creates a chance for wide usage of boron and its usage in fuel cells is going to open up new frontiers for evaluating this abundant and strategic resource of our country in the energy area.