The efficiency of a broad class of continuous processes operated under unsteady conditions must often be expressed as a ratio of two integrals: in chemical reactor problems this may represent the selectivity of a desired product in a complex reaction scheme. Objective functions taking this form are included in the optimal control formulation of unsteady state-operation of lumped parameter continuous processes; the resultant additional necessary condition of optimality appears in a convenient form so that the complexity of the problem is only marginally increased. The difference between the dynamic and the steady performance of continuous chemical processes is only meaningful under strictly comparable conditions. A computationally efficient procedure is developed which, without any assumptions about the form of the inputs, enables the determination of optimal continuous periodic modes of operation under comparable conditions. The proposed procedure can also be effectively used to test the optimality of a given periodic operation. The application of the proposed procedure to chemical reactor problems under inlet control conditions indicated that in many cases the optimal steady performance can be improved by on-off periodic inputs. In particular, simultaneous increases in both the yield and selectivity of a desired product in a complex reaction scheme are attainable while using the same sources and equal*average amounts of the raw materials.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:455143 |
| Date | January 1977 |
| Creators | Farhad Pour, F. A. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1349282/ |
Page generated in 0.0104 seconds