3. Towards the industrial reactor configuration

We have seen that, to avoid excessive pressure drop, the reactor should have a large cross-section; conversely, to avoid a sharp temperature profile in the reactor, it should have a small diameter. In order to satisfy both conditions simultaneously, the solution is to use a tubular beam reactor. This reactor is made up of a very large number of small fixed-bed tubular reactors placed in parallel (tube bundle) inside a calandria in which the heat transfer fluid circulates.

Standard" tube dimensions are generally used; in our case, we'll be choosing 26 × 32 tubes 6 m long, i.e. 26 mm inside diameter and 32 mm outside diameter.

To avoid preferential flow at the walls, the ratio between reactor diameter and catalyst grain size must be at least 10 [8] , a condition satisfied by...