Oxygen concentration/content

The conditions for the carbon bum step are typically less than about 1.0 mol % oxygen, 400°C inlet temperature, 455°C maximum oudet temperature, which is controlled by adjusting the oxygen content of the circulating gas, and 0.45 to 2.2 MPa. The carbon bum is considered to be complete when no exotherm is observed for several hours. The oxygen concentration at all reactor inlets and outlets should be equal at this point. 

The solubility of oxygen in water with a salt content up to 1 mol L is only dependent on the temperature. The oxygen concentrations in equilibrium with air amount to (in mg L- ) 0°C, 14 10°C, 11 20°C, 9 and 30°C, 7. The depth of water has no effect in the case of ships. In Hamburg harbor in summer, 7.3 mg L are measured in depths up to 7 m. The value can be much lower in polluted harbors and even fall to zero [8]. In the open sea, constant values are found at depths of up to 20 m. With increasing depth, the Oj content in oceans with low flow rates decreases [12] but hardly changes at all with depth in the North Sea [13]. 

A more comprehensive purification procedure uses a sequence of steps as follows filtration at 200°C through a stainless steel powder compact filter of 10-jum pore size reduces the oxygen content and removes any solid impurities. Gettering with Zr foil for 46 h at 760°C reduces the oxygen concentration to 200 ppm. The weight ratio of K to Zr is 13 1 with a surface area to volume ratio of Zr to K 4 1. A second gettering with zirconium foil for 72 h at 800°C reduces the oxygen content 50 ppm. 

Mauersberger S, RN Matyashova, H-G Muller, AB Losinov (1980) Influence of the growth substrate and the oxygen concentration in the medium on the cytochrome P-450 content in Candida guilliermondii. Eur J Appl Microbiol Biotechnol 9 285-294. 

R. eutropha is actually an autotrophic hydrogen-oxidizing bacterium which can also produce poly(3HB) from C02, H2, and 02 [34]. The critical factor in such autotrophic cultivation processes is to avoid possible gas explosions. Therefore, a recycled gas, closed circuit culture system equipped with several safety features was developed and the oxygen concentration in the substrate gas phase was kept below the lower limit for gas explosions. A bacterial biomass of 91.3 g 1 1 has been achieved and the poly(3HB) content reached up to 67% per cell dry weight under these oxygen-limited conditions [35]. 

The objectives of Aho s study [8] were to investigate the effects of peat type, particle density, diameter and moisture content, and oxygen concentration on the flue gas emissions of nitrogen oxides and sulphur dioxide from a homogenous countercurrent batch bed combustion using a pot furnace. His aim was to simulate the interaction of chemistry between the fuel bed system and the combustion chamber of a overfired batch bed. However, he also presented some results on the combustion heat rate. 

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