Steam optimization characteristics

Important inherent characteristics of an enzyme that should be considered are the substrate affinity, characterized by the Michaelis constant the rate of turnover fecat> providing the catalytic efficiency fecat/ M. and the catalytic potential. Several attempts to compare enzyme catalysis with that of platinum have been published. Direct comparisons are difficult, because enzyme electrodes must be operated in aqueous electrolyte containing dissolved substrate, whereas precious metal electrodes aie often supplied with a humidified gaseous stream of fuel or oxidant, and produce water as steam. It is not straightforward to compare tme optimal turnover rates per active site, as it is often unclear how many active sites are being engaged in a film of enzyme on an electrode. 

What are the characteristics of an optimized steam system The main characteristics can be summarized as follows ... 

The process is carried out in the gas phase at a temperatures above 160°C. The reaction is exothermic, so heat control in the production process is important. Vinylacetate is used as intermediate in a large number of production processes. The catalysts can be produced by impregnation of an activated carbon with zinc acetate, followed by drying. The zinc concentration is in the order of 11 up to 13%. The optimal activated carbon support is a high steam activated and acid washed 3 or 4 mm extrudate like the NORIT RX 3 EXTRA or NORIT RX 4 EXTRA. Important characteristics of the impregnated carbon are ... 

Number of start-up feedwater pumps - the number of smaller feedwater pumps that may be used to feed the steam generators or the reactor at low reactor power (usually up to 5% of power), when the main feedwater pumps would be too powerful (would not operate under optimal flowrate conditions). This characteristic applies only to units that have these start-up feedwater pumps in addition to auxiliary feedwater pumps. For units that use auxiliary feedwater pumps to feed the steam generators/reactor at low reactor power, data providers should enter "N/A". 

The shown start-up example did not include an optimization or exploration of optimizing the start-up time. But several parameters can be adjusted to affect the dynamic characteristics of the initial preheating process of the reformer in question fuel flow, air-to-fuel ratio, oxidant supply control, and steam-to-carbon ratio. 

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