Return to Table of Contents
1. All commercial plants in Germany making synthetic oil by the Fischer-Tropsch process were operating under the following condition:
(a) Synthesis gas made in the majority of plants from coke by means of the water-gas reaction, with a few plants using special processes with brown coal as raw material.
(b) Catalyst of a more or less standard type containing cobalt, thoria, magnesia, and kieselguhr. Details of preparation, breaking-in, and regeneration were obtained.
(c) Two types of catalytic conversion--(1) at atmospheric pressure, and (2) at medium pressure of about 10 atmospheres. Different types of catalyst chambers were used for each of these methods of operation. In general, medium-pressure operation was considered preferable.
(d) Temperature of 180-200°C. in the catalyst chambers.
(e) Yield and quality of products did not differ materially from published information. Olefines of the C3-C4 fraction were converted to alcohols, etc., and residual paraffins used as motor fuel. Light gasoline of low octane number was blended for motor fuel. Middle fractions of a high cetane number were used as Diesel oil. Paraffin Wax was converted largely to fatty acids for soap manufacture, etc. A considerable volume of lubricating oil was also synthesized from heavy fractions.
2. Results of research and pilot plant development work on iron catalyst for synthesis of hydrocarbons and oxygenated compounds, chiefly alcohols, include the following:
(a) Control of the boiling range of the product is most effectively exercised by varying temperature and gas recycle rate. At higher temperatures and higher gas recycle rates the chief product is gasoline. At lower temperatures and higher recycle rates, the product is a mixture of hydrocarbons and alcohols plus some aldehydes, and ketones.
(b) Types of operation included the hot-gas recycle, gas recycle with product condensation and carbon dioxide removal on each cycle, liquid phase suspension of powdered catalyst, and cooling by oil circulation through an external heat exchanger.
(c) No data were found on fluid flow operation.
3. Some gas recycle development work using cobalt catalysts is described.
4. Results of laboratory research using difficulty reducible oxides such as thoria-alumina, and zinc oxide-alumina as catalysts are as follows:
(a) Synthesis of isoparaffins, chiefly C4, C5, and C6 hydrocarbons at 400°-450°C. and 300 atmospheres pressure.
(b) Synthesis of aromatics and naphthenes at 450°-500°C. and 30 atmospheres pressure.
5. Laboratory research on iron catalysts shows the importance of precarbiding the catalyst, and indicates that the steady-state catalyst is a mixture of iron, iron oxide, and iron carbide.
6. Laboratory research indicates that alpha rather than beta olefines are first produced on both cobalt and iron catalyst.
Return to Table of Contents