DISCUSSION WITH DRS. HERBERT AND DANULT OF LURGI
The Lurgi company informed us of the development of the hot gas recycle process for the "oxyl” synthesis. This is a variant of the synol process using a precipitation iron catalyst instead of a fused catalyst. The pilot unit is arranged as shown in figure 3. Part of the recyle stream is cooled to 20°C. and fed into the reactor in five streams. The fresh gas SVH is 100 and the recycle ratio is approximately 20:1. The process operates at 10 atmospsheres, at 185°C., and used dried filter cake granules 2-4mm. in size. The product is 80% of C2 to C20 alcohols, with methane production amounting to about 4% of the CO reacting. The CO:H2 ratio is about 1 to 1.
In the “oxyl” synthesis, alcohols will be recovered from the hydrocarbon layer by extraction and azeotropic distillation. The first oxyl plant to go into operation will be at Krupp Treibstoffwerke, Wanne-Eickel, early in 1952.
Under substantially the same conditions, the fused catalyst gives higher methane, less alcohols in the C2 to C20 range, and more alcohols above C20. The methane production by a fused catalyst is not affected significantly by temperature whereas methane formation increases with temperature with the precipitated catalyst. The methane production by sintered catalysts is intermediate between precipitated and fused catalysts.