Oxygen large-scale production

Natural Gas Upgrading via Fischer-Tropsch. In the United States, as in other countries, scarcities from World War II revived interest in the synthesis of fuel substances. A study of the economics of Fischer synthesis led to the conclusion that the large-scale production of gasoline from natural gas offered hope for commercial utiHty. In the Hydrocol process (Hydrocarbon Research, Inc.) natural gas was treated with high purity oxygen to produce the synthesis gas which was converted in fluidized beds of kon catalysts (42). 

Carbon monoxide may be prepared by several methods. Large scale production is carried out by controlled oxidation of natural gas or by the catalytic steam reforming of methane or light petroleum fractions. The products obtained are mixtures of CO, H2, and CO2. It also is made by gasification of coal and coke with oxygen at about 1,500°C. 

Metal Oxides. A process based on the reaction of metal oxides rather than more expensive metal powders and nitrogen or ammonia in the presence of carbon is economical and has possibilities for large-scale production. However, the products, which contain oxygen and carbon, are not very pnre. 

Activation in C02 is often used on a laboratory scale, but steam activation is generally favoured for the large-scale production of most activated carbons of industrial importance (Baker, 1992). The steam reaction is considerably faster than the carbon dioxide reaction (Wigmans, 1989). Steam activation is normally carried out at temperatures of 750-950°C. Direct contact between oxygen and carbon must be avoided since at these temperatures oxygen would aggressively attack the carbonized material. 

Bioreactors must fulfill a number of requirements to be suited for large-scale production. They must allow efficient mixing without exerting too much mechanical stress on the microorganisms. They must allow temperature and pH control and effective introduction of oxygen (for aerobic processes). They must allow on-line measurement of the process parameters and must be easy to clean and sterilize between operations (Fig. 9.5). 

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