Validation hydrocracking

For this purpose selectivities of hydrocracking of the n-alkanes are expressed in terms of probabilities of overall cracking reactions. The latter are calculated from the carbon number distributions of the cracked products (n. = number of moles of cracked products with carbon number i, from Figures 7, 8 or 9). Examples for the mode of calculation are represented in the following scheme which is valid for pure primary cracking. 

We decided to validate it under conditions representative of various industrial processes isomerisation, catalytic reforming, hydrocracking and fluid catalytic cracking (FCC). 

The model was optimized with the lumped data from experiments (the unconverted Cie, the mono-branched and multi-branched Cie, and all the cracked products). Then the model was used to predict the carbon number distribution and iso-to-normal ratio for the various carbon numbers. Figures 5a and 5b show the parity plots for the Cie paraffin hydrocracking for both (a) the lumped observations and (b) the carbon number distribution at various conditions (T, P, LHSV and NH3). The agreement between the predicted and experimental data sets for all the high and low yield compounds is good, as all predictions are within the experimental error. The good prediction validates the fundamental nature of the model. 

The considerations for methanol production are valid also for manufacture of synfuels. The manufacture of synthetic gasoline by the Mobil MTG (Yurchak, 1988) or Topsoe TIGAS process (Topp-Joergensen, 1988) proceeds via methanol or dimethylether as intermediate. Diesel can be manufactured by the Fischer-Tropsch synthesis followed by hydrocracking of the wax product (v.d. Burgt et al., 1988). Slurry b Fischer-Tropsch processes for diesel may operate at a Hj/CO ratio slightly lower than for methanol synthesis (Dry, 1988). 

The actual lifting of the hydrocracker in this example is shown in Figures 7.22 and 7.23. This is validation that the analysis works, as there were 10 similar vessels lifted and installed on site. 

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