Catalytic water production

Prior to methanation, the gas product from the gasifier must be thoroughly purified, especially from sulfur compounds the precursors of which are widespread throughout coal (23) (see Sulfurremoval and recovery). Moreover, the composition of the gas must be adjusted, if required, to contain three parts hydrogen to one part carbon monoxide to fit the stoichiometry of methane production. This is accompHshed by appHcation of a catalytic water gas shift reaction. 

Conditioning of the raw syngas, meeting the quality stipulated for manufacture of DME or other potential products. This is attained by catalytic water-gas shift to adjust the CO/H2 ratio and catalytic hydrogenation of minor contaminants followed by the removal of C02 and acidic gases in a conventional wash system or in a novel, selective processes for deeper S-removal. 

Hydrogen Production by Mechano-catalytic Water Splitting... 

Phenylthietane was ring-opened with lithium and a catalytic amount of 4,4 -di-/ -butylbiphenyl (DTBB) in THF at — 78 °C to give the intermediate 39, which by treatment with an electrophile gave, after hydrolysis with water, product 40. When carbon dioxide was used as electrophile, the corresponding thiolactone 41 was isolated after workup (Equation 10) <1997T5563, 2003PAC1453>. 

Wist J, Sanabria J, Dierolf C, Torres W, Pulgarin C (2002) Evaluation of Photo-catalytic Disinfection of Crude Water for Drinking-water Production, J. Photochem. Photobiol. A Chem. 147 241-246. 

Currently used for syngas production in conjunction with catalytic water-gas shift reaction for H2 production. 

The counterpart of catalytic water oxidation to O, catalytic evolution via water reduction, is of equal importance in the context of water splitting (artificial photosynthesis) [15]. Innature, hydrogenase enzymes show excellent catalytic rates and efficiencies and can catalyze both proton reduction and oxidation. Consequently, several biomi-metic complexes have been developed which show excellent catalytic activity towards electrochemical production from water. 

Similarly, octaethylporphyrin iron (lll)-(r-bonded pyrrole [(OEP)FePy], either adsorbed on a glassy carbon electrode, or buried in a polypyrrole film of different thickness (from 0.9 to 60 pm), deposited on a GC electrode, displays an excellent activity towards oxygen reduction leading to water production efficiencies of nearly 90% [150]. These [(OEP)FePy] electrodes buried into a PPy film are remarkably stable leading to a catalytic activity similar to that obtained with platinum electrodes and limited by the diffusion of dioxygen in the solution phase. 

Non-Equilibrium Plasma-Catalytic Syngas Production from Mixtures of Methane with Water Vapor... 

Operation mode of fuel cell is strongly determined by water balance. Water production by electrochemical process and also water transport due to proton migration and diffusion were measured with use of special complex. For MEA based on MF-4SK proton exchange membrane with hydrophobic catalytic layer an effective water drag coefficient =0.28 for air and =0.53 for pure oxygen, water diffusion coefficient trough membrane T) , =l.55x10 mVs. 

Although the last step in the reaction sequence, abstraction of a proton from C4, followed by aromatization of the a, 6-unsaturated ketone, will occur spontaneously without assistance by a protein, it seems reasonable to assume that product formation is accelerated considerably by an enzymatic mechanism. Again, DFT calculations suggest that deprotonated HisllO could accept a proton from the previously generated water molecule, which in turn accepts the C4 proton. Protonation of the ketone could occur by the catalytic water bound by the two tyrosines. 

---