Fixed Bed Work at Fuel Research Board
The results of fixed bed work with a sintered catalyst were as follows:
Ford’s mill scale (through 72 and on 170 British Standard sieve) was impregnated with alkali by evaporation to dryness with constant stirring in the presence of a K2CO3 solution. The K2CO3 present was adjusted to give 1 to 1.5 parts of K2O per 100 parts of Fe. The mixture was heated in a fire clay sager in a gas fired muffle furnace at 1050°C. for 2 hours. Under these conditions, the mixture does not fuse but cakes. The fixed bed operation uses catalyst having a particle size through 7, and 14 mesh.
The catalyst is reduced in H2 at 450°C. for 3 hours. Small concentrations of CO in hydrogen give a slightly less active catalyst. Completely dried H2 is essential for maximum activity. With a mill scale catalyst, 72 hours of treatment with synthesis gas at 250°C. develops 70% of the activity of the same catalyst reduced in H2.
The results of a three week operating period at 20 atmospheres, 265°C., SVH = 450°, and a 2:5 to 3:1 recycle in a fixed bed containing 7 to 14 mesh sintered catalyst were as follows:
|
CO converted |
99% |
|
CO converted to CO2 |
5-7% |
|
CH4 |
25 g./m.3 fresh feed |
|
C2 to C4 |
50-60 g./m.3 fresh feed |
|
C5+ |
85-89 g./m.3 fresh feed |
The testing iron catalysts, the Fuel Research Board operates at 265°C. and approximately 400SVH.
Hall has found that the synthetic ammonia catalyst makes more methane than unfused magnetic ore. Maximum activity of catalysts promoted with alkali is developed at a K2O concentration of 0.5% by weight.