NIFE process

The NIFE process has been in operation for several years, and it has been fine-tuned over the years to produce very low emissions and products that can be reused by the battery industry or sold to chemical and/or metallurgical manufacturers. 

We will use here the main results obtained for two complex and distinct situations the structural and spectroscopic information gathered for D. gigas [NiFe] hydrogenase and AOR, in order to discuss relevant aspects related to magnetic interaction between the redox centers, intramolecular electron transfer, and, finally, interaction with other redox partners in direct relation with intermolecular electron transfer and processing of substrates to products. 

B. Fodor, G. Rakhely, A. T. Kovdcs, K. L. Kovacs (2001) Transposon mutagenesis in purple sulfur photosynthetic bacteria Identification of hypF, encoding a protein capable to process [NiFe] hydrogenases in a, p and y subdivision of proteobacteria. Appl. Environ. Microbiol., 67 2476-2483... 

C-terminal sequences of Ni-binding subunits in NiFe(Se) hydrogenases and C-terminal processing... 

Gollin, D. J., Mortenson, L. E. and Robson, R. L. (1992) Carboxyl-terminal processing may be essential for production of active NiFe hydrogenase in Azotobacter vinelandii. FEBS Lett., 309, 371-5. 

Higuchi, Y, Toujou, R, Tsukamoto, K. and Yagi, T. (2000) The presence of a SO molecule in [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki as detected by mass spectrometry (In Process Citation)./. Inorg. Biochem., 80, 205-11. 

Menon, A. L. and Robson, R. L. (1994a) In vivo and in vitro nickel-dependent processing of the [NiFe] hydrogenase in Azotohacter vinelandii. ]. Bacterial., 176, 291-5. 

Despite the fact that cadmium is very toxic and that the number of batteries based on this metal (i.e. nickel-cadmium cells) is very significant, there are very few recycling plants in operation. One very effective recycling process has been designed and developed by SAFT NIFE AB in Sweden to treat both industrial and consumer nickel-cadmium batteries. The flow... 

Fig. A3.2 Flow sheet for the SAFT NIFE AB nickel-cadmium cell recycling process.

Dynamic micromagnetics simulations show that shape, size, and damping constant significantly influence the switching behavior of thin film elements. The magnetization reversal of submicron NiFe elements was found to be a two stage process. At first, the magnetization rotates almost in plane towards... 

The actual catalytic cycle of [NiFe] hydrogenase encompasses only three states Ni-SIa, Ni-C and Ni-R, which are interconverted by one-electron/one-proton equilibria (Figure 3.4.7A) [123, 124], In the catalytic process, the approaching H2 is attached to the Ni, and the bond is polarized followed by base-assisted heterolytic cleavage of the H2 molecule leading to a bridging hydride species. One of the candidates for acting as a base is a terminal cysteine at the Ni. Alternatively, a water molecule bound to the iron has been proposed [120]. Concomitant electron transfer to the proximal FeS cluster then leads to the Ni-C state, which has been shown to... 

Ogata H, Hirota S, Nakahara A, et al. Activation process of [NiFe] hydrogenase elucidated by high-resolution X-ray analyses conversion of the ready to the unready state. Structure. 2005 13(11) 1635-42. 

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