DEHYDROGENATION OF PROPANE (Propene Production)

The catalytic dehydrogenation of propane is a selective reaction that produces mainly propene:

The process could also be used to dehydrogenate butane, isobutane, or mixed LPG feeds. It is a single-stage system operating at a temperature range of 540–680°C and 5–20 absolute pressures. Conversions in the range of 55–65% are attainable, and selectivities may reach up to 95%. Figure 1.1 shows the Lummus-Crest Catofin dehydrogenation process.

For a given dehydrogenation system, i.e., operating temperature and pressure, thermodynamic theory provides a limit to the per pass conversion that can be achieved. A general formula is

Kp = X₂P/ (I-X₂)

Kp = equilibrium constant at a given temperature

X = fraction paraffin converted to mono-olefins

P = reaction pressure in atmospheres

Figure 1.1. The Lummus Crest Catofin dehydrogenation process:3 (1) reactor, (2) compressor, (3) liquid product recovery, (4) product purification.