Page 193 - Introduction to chemical reaction engineering and kinetics

7.4 Problems for Chapter 7 175

selectivity.

(14) C&, + C2H; --f C4Hs + Ho ; k14 = 2 x 10 11

Plot the selectivity to C4Hs as a function of ethane conversion. Does it behave like
a secondary or primary product? Consult the paper by Dean (1990), and describe
additional reactions which lead to molecular weight growth in hydrocarbon pyroly-
sis systems. While some higher molecular weight products are valuable, the heavier
tars are detrimental to the process economics.

Much of the investigation you have been doing was described originally by Wojciechowski
and Laidler (1960), and by Laidler and Wojciechowski (1961). Compare your findings with
theirs.