CORRELATION OF SLURRY REACTOR FISCHER-TROPSCH YIELD DATA

First stage slurry reactor Fischer-Tropsch (FT) yield data from Mobil' s two-step pilot plant operations for the DOE have been correlated usi ng a modified Schulz-Flory approach but allowing for changes in the pr obability of chain growth, alpha, at key product molecular weights. Tr iple values of a are invoked to explain (1) the high methane yield and (2) the very broad molecular weight distribution of the wax fraction, as compared to (3) moderate values of alpha(2) of between 0.79 and 0. 85 for the C-2-C-20 hydrocarbons. Over this range, wax yields from 10 to 76 wt% are accommodated, at values of alpha(3) from 0.90 to 0.98. T he second break in the yield-molecular weight curve occurs at the carb on number where most of the component remains in the reactor as liquid rather than leaving as vapor product. It is assumed that this is a fu nction of vapor-liquid equilibrium. The correlation has proven useful in developing a computer model of the FT synthesis loop which is part of a baseline design and economic study for DOE/PETC.