Iron/air

The seeds are transferred to tanks containing scrap iron and a ferrous sulfate solution, and the mixture is heated to a temperature between 70 and 90°C. While the seeds circulate over the scrap iron, air is bubbled through the medium causing the seeds to grow. The process can be described by the following reactions ... 

Iron—Air Cells. The iron—air system is a potentially low cost, high energy system being considered mainly for mobile appHcations. The iron electrode, similar to that employed in the nickel—iron cell, exhibits long life and therefore this system could be more cost effective than the ziac-air cell. Reactions iaclude ... 

Fig. 27. Cross-section of SNDC iron—air battery pile (93).

Cold water Warm water Wrought iron Air bubbled into water surrounding coil 150-300... 

Iron-air cells, 3 515-516 Iron(III) alkoxides, 74 533 Iron alloys, 74 490... 

Iron-air cells have been developed by Matsushita Battery Industrial Co. and by the Swedish National Development Co., which have given an energy density of 80 Wh/kg at C/5 and a cycle life of 200 cycles to 60% depth of discharge. The latter company have produced 15-30 kWh batteries for EV testing. One limitation of the iron-air system for this application is the low power density achieved - a maximum value of 30-40 W/kg is reported. Similar cells are also being developed by Westinghouse (USA) and Siemens (Germany). 

Amongst other new systems under study are the sodium/sulphur battery with sodium / -alumina solid electrolyte operating at 300-375°C and Li-FeS batteries operating at about 450°C. Long-term battery research is directed towards batteries that can operate at room temperature with aqueous electrolyte, such as zinc-halogen, aluminium-air, and iron-air. 

The iron-air battery has been under development in Sweden (SNDC, SAB NIFE, KTH ), the USA (Westinghouse Electric 160,165 (SAFT), West Germany (Siemens A.G. ), and... 

Tip The efficiency level is estimated as follows tables show the heat value of 46000 kJ per 1 kg of liquid gas this would mean that 1 g of that fuel supplies the thermal energy of 46 kJ. 100 g of water use this amount of energy 100 g x 15 K x 4.2 J/gK = 6270 J = 6.27 kJ for a temperature increase of 15°C. This amount of energy correlates to 13.6% of 46 kJ - therefore the efficiency level is only 13.6% more than 86% of the produced thermal energy is released into the environment (glass, iron, air, etc.). 

The iron/air cell is especially attractive as it can utilize resources that are virtually inexhaustible. Only electrically rechargeable batteries have been developed owing to the good reversibility of the iron electrode and cycling behaviour. 

The development of iron/air batteries was initiated at the Swedish National Development Company in 1969. Since then other groups and companies have been developing iron/air systems. Among these are the Indian Institute of Sience, Matsushita in Japan, Westinghouse Electric Corporation in United States and Siemens A. G. in Germany. 

When the cotton is found to be dry the bottom of the drying cylinder is removed, and the cotton pushed out from the top by means of a piece of flat wood fixed on a broom-handle. It is then packed away in galvanised-iron air-tight cases, and is ready for the next operation. At some works the eotton is dried upon shelves in a drying house through whieh hot air circulates, the shelves being of canvas or of brass wire netting. The hot air... 

Manohar A, MaUshandi S, Yang B, Prakash GKS, Narayanan SR. Electrochemical properties of carbonyl iron electrodes for iron-air batteries. Abstracts of Electrochemical Society Meeting 2011. p 303. 

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