Step 3 comes before determining the throughput manipulator, since the reactor is typically
the heart of the process and the methods for heat removal are intrinsically part of the reactor
design. In order to avoid recycling of disturbances they suggest to set a flow-rate in all
recycles loops; this is discussed more in section 2.6. They suggest in step 6 to control all
inventories, but this may not be necessary in all cases; e.g. it may be optimal to let the
pressure float (Shinskey, 1988). They apply their procedure on several test problems; the
vinyl acetate monomer process, the Tennessee Eastman process, and the HDA process.
Larsson and Skogestad, in Chapter 4, question the rule proposed by Luyben. By using
the simple recycle plant they are able to show that application of his rule may lead to large
problem.