Iron processes

Process iron Process management Process monitoring... 

Metal—Water Processes. The steam-iron process, one of the oldest methods to produce hydrogen, iavolves the reaction of steam and spongy iron at 870°C. Hydrogen and iron oxide are formed. These then react further with water gas to recover iron. Water gas is produced by reaction of coal with steam and air. 

Vanadium was first discovered in 1801 by del Rio while he was examining a lead ore obtained from Zimapan, Mexico. The ore contained a new element and, because of the red color imparted to its salts on heating, it was named erythronium (redness). The identification of the element vanadium did not occur until 1830 when it was isolated from cast iron processed from an ore from mines near Taberg, Sweden. It was given the name vanadium after Vanadis, the Norse goddess of beauty. Shordy after this discovery, vanadium was shown to be identical to the erythronium that del Rio had found several years eadier. 

Where present in boiler MU water, both iron and manganese may present fouling and deposition problems in the pre-boiler section. These problems may extend to the boiler section, and therefore these metals must be removed at source. Typically, this is achieved by oxidation followed by filtering off the flocculated iron. (Process examples are aeration towers, contact with chlorine, pressure filters with BIRM media, manganese greensand filters, etc.)... 

Steam-Iron Process Using Methane as Feedstock... 

Schematics of cyclic (a) and continuous (b) reactor for hydrogen production by steam-iron process. I—IV denote the reactor zones.

Hacker, V. Fankhauser, R. Faleschini, G. Fuchs, H. Friedrich, K. Muhr, M. Kordesch, K., Hydrogen production by steam-iron process. Journal of Power Sources 2000, 86, 531-535. 

Gasior, S.J. et al., Production of synthesis gas and hydrogen by the steam iron process—Pilot-plant study of fluidized and free-falling beds, Bureau of Mines Report of Investigations, Pittsburgh, PA, 5911,49,1961. 

Katell, S., Faber, J.H., and Wellman, P.,An Economic Evaluation of Hydrogen Production by the Continuous Steam-Iron Process at Seven Atmospheres, Bureau of Mines Report of Investigations (No. 6089), Pittsburgh, PA, 13,1962. 

The cuprammonia process, the viscose process, and the acetate process have been employed for the production of rayon. Cuprammonia and viscose rayons have similar chemical and physical properties. Both are easily dyed and lose their strength when wet because of a disruption of hydrogen bonding this wet strength is improved through chemical treatment of the rayon fabrics. Acetate rayon is readily softened in the ironing process and loses its luster in boiling water. 

The durability of the steady state in the Ruhr-chemie process (granular catalyst bed, externally cooled) was 150 to 200 days. In the fluidized iron process, it is about 20 days, and in the oil circulation process it is 100 to 200 days. The high space-time yield of the fluidized iron catalyst process compensates for the relatively short life of the steady state. Thus, the total weight of oil synthesized per pound of catalyst during the life of the steady state is approximately the same for the fluidized iron catalyst and the oil circulation processes. 

Foreseeable improvements that will increase operability and decrease operating costs of Fischer-Tropsch processes are the development for the fluidized-iron process of a catalyst that will not accelerate the reaction 2CO = C02 + C and will not be appreciably oxidized during the steady-state life of the catalyst and the development of a more active and mechanically stable catalyst for the oil-circulation process so as further to reduce Ci + C2 production. The hot-gas recycle process could be made operable by use of a catalyst that will be less active but more resistant to thermal shock which occurs during regeneration to remove carbon deposits, and during operation at lower end-gas recycle rates. The powdered catalyst-oil slurry process recently has been satisfactorily operated in a pilot plant by K6lbel and Ackerman (21). Although the space-time yield in this operation was low (10 to 20 kg. of C3+ per cubic meter of slurry per hour), the Ci + C2 production was less than one third of that... 

Ferrous sulfate is a commonly used reducing agent for chelated waste streams that provides an illustration of the above problem. Although it is effective in removing process metals from complexes, the iron in the ferrous sulfate precipitates out along with the process metal. Since ferrous sulfate is typically added in sufficient quantity to raise the iron/process metal ratio to 8 1, considerable extra sludge is generated (Couture 1984). 

Another process option is the LO-CAT process, which employs chelated iron liquid redox chemistry and has been popular for smaller operations. Solution compositions include iron, proprietary chelates, a biocide, and a surfactant that facilitates sulfur sinking to the bottom of the oxidizer, where it is removed as a slurry. Other chelated iron processes include Sulferox and Hiperion (Dalrymple 1989). 

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