Big distillation column
Contents
Description
The glass distillation column was a donation made by Exxon Mobil in 1978. It is a standard glass distillation column with the main function of distilling ethanol/water mixtures. The column has 10 stages, custom made to include sample points on each stage. The column makes use of donut trays for each stage. Each stage is fitted with an RDT (resistance temperature detector) temperature measurement device. Column instrumentation include various Coriolis mass flow meters and refractive index analyzers. Feed plate 3 and feed plate 6 can be used to feed to the column. This is a closed system with the top product and bottom product being recycled and added to the feed mixing tank.
Diagram
Control system
The column is currently controlled making use of the Emerson DeltaV v.14 software. The designed operator interface is shown below. Most of the control loops can be run either in manual or auto using the postulated base-layer control scheme. No APC is currently being employed for process control.
Operator interface
Projects
Deon Pretorius, Greg Laycock, 2018
Set-up The DeltaV software was updated from version to 9 and 14. This required the old hardware to be removed and new hardware to be installed.
Operator interface The original SASOL graphical user interface was removed and a new user interface was designed and implemented.
Control valve response tuning The control valve responses to set-points were insufficient. The control valve responses were tuned to ensure smooth transition to set-point with no offset or hunting.
Maintenance The following maintenance was completed on the system:
- Substantial leak below reflux drum repaired
- Fouling in reflux line removed
- Some RDT wiring redone
- Some flow indicator wiring redone
- New regulator installed
- New steam trap installed
Base-layer control Initial base-layer control implementation. A reasonable base-layer control scheme postulated and added to the operator interface.
Contact persons
For help with the Emerson control system (Delta V) the contact person as of 2018-12 is:
Name: Daniela Straulino
Company: Avenge ACS
Tel: +27-11-249-6700
Cell: +27-82-407-8590
E-mail: Daniela.Straulino@avenggroup.com
For other general maintenance concerns and instrumentation problems the contact person is:
Name: Andre Joubert
Company: SASOL
Cell : +27-82-905-0090
E-mail : Andre.Joubert@sasol.com
Documentation
Documentation on past projects that were done on the distillation column can be found here.
Help
For help on the Delta V system click here.
