(3c) Thermochemistry of Catalyst Deactivation II: Competition between Hydrogenation, Condensation and Hydrocracking

The
first paper in this series presented the results of equilibrium calculations
for the competition between the hydrogenation of naphthalene to form tetralin
and decalin (Reactions 1-2) and the condensation of naphthalene with o-xylene
to form chrysene (Reaction 3). This set of reactions was proposed as a simple model
for the coke-induced deactivation of hydrotreating catalysts.

Saturation
(Reversible)

1. Naphthalene (C₁₀H₈)
+ 2H₂  ↔  Tetralin (C₁₀H₁₂)

2. Tetralin + 3H₂ 
↔  Decalin (C₁₀H₁₈)

Condensation
(Irreversible)

3. Naphthalene + o-Xylene  →
 Chrysene (C₁₈H₁₂) + 3H₂

4. Chrysene  →
→ →  Coke + xH₂

This
paper shows the effect of adding a hydrocracking reaction (Reaction 5).

Hydrocracking
(Irreversible)

5. Tetralin + H₂
 →  1-propyl-2-methyl benzene (C₁₀H₁₄)

In
addition, for all reactions the thermochemical effects of hydrogen purity at
constant total pressure are computed, along with the effects of excess
hydrogen, i.e., ?gas-to-oil ratio.?