A GENERAL RUNAWAY CRITERION FOR FIXED-BED REACTORS

Abstract

The safe design and operation of fixed bed reactors require the consideration of potential runaways. The steep temperature rise may affect the selectivity, activity and stability of catalysts and in certain cases the reactor safety.

Mathematical models simulate the runaway conditions. Such simulations require extensive calculations to define the range of safe operation. A new runaway criterion was developed to replace the need to solve the differential reactor balances. The criterion is simple, defined by one algebraic equation. It can be applied to any kinetic expression. Extensive testing shows an excellent agreement between the runaway criterion and the two-dimensional model predictions. It also predicts the runaway conditions in agreement with experimental data.

KEYWORDS:

• Runaway
• Criterion
• Fixed-bed reactors