Implementation, hydrogen cycle

Enzymatic activity of the substrate in the respiratory process (3.49) is implemented by Krebs cycle hydrogenases (3.52) (the endergonic component of the respiratory process), where chemical energy is accumulated in the form of an active intermediate compound (linked hydrogen atom). There is no doubt that linked 8H and 2C02 forms, in which these intermediates exist in the cell environment, will significantly decrease AG° [21]. The final product of the respiratory process is synthesized by enzymes of the respiratory chain (exer-gonic component). 

Safely implementing a thermochemical nuclear hydrogen generation scheme requires a robust understanding of the interaction between the nuclear plant and the chemical plant. In turn, this requires robust models of the chemical plant, reactor thermal-hydraulics and reactor physics. Efforts have been conducted in both the transient modelling of the sulphur-iodine (S-I) and hybrid sulphur (HyS) thermochemical cycles, as well as coupling to models of the pebble bed modular reactor (PBMR-268) (Brown, 2009). 

In this respect, much interest may be focused on the photoreduction cycle of water decomposition to produce hydrogen [384] this is represented by Scheme 123, in which S is a sensitizer and R is an electron-transfer agent (ETA), Q is an electron donor. The macrobicyclic complexes in this cycle act as ETAs. Such a cycle, in which [Ru(bpy)3]2 cation is used as a sensitizer and cation as an ETA, has already been implemented. 

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