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Table 3

Comparison between High-Temperature Iron-Catalyst Process and Conventional Cobalt-Catalyst Process

Source of data Present experiments German commercial practice
Catalyst Iron (synthetic-ammonia) Cobalt
Type of Process Fixed bed Fluid bed Fixed bed
Space velocity, vol./vol. catalyst/hr. 1000 1000 50 70
Pressure, atmos. gauge 20 20 0 10
Temperature, ºC. 318 300 190 190
CO converted, percent 95 99+ 93 94
CO converted to CO2 percent of total 10 Nil 0.5 0.1
CO converted to CH4 percent of total 13 20 10.5 8.9
CO converted to higher hydrocarbons, percent of total 77 80 89 91
Yield of C2 to C4 g./N.cu.m. inert free gas 90 110 21 16
Yield of liquid hydrocarbons g./N.cu.m. inert free gas 70 35 142 147
Total yield of higher  hydrocarbons, g./N.cu.m. inert free gas 160 145 163 163
Space-time-yield- of higher hydrocarbons, tons/cu.m. catalyst/day 3.8 3.5 0.22 0.25
Composition of higher hydrocarbons, percent by weight
C2 to C4 hydrocarbons
56 75 14 10
Spirit, 30º to 200ºC 34 18 51 37
Middle oil, 200° to 300°C 6 4.5 25 26
Wax, residue above 300°C 4 2.5 10 27

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