An Efficient Method for Conducting Step Testing ofCrude Distillation Unit

The objective in implementing the process control strategy is to maintain the process
at desired condition, safely and efficiently, while satisfying environmental and
product quality requirement. There are seven layers of a process control hierarchy
which are instrument, safety, regulator, multivariable, real time optimization and
planning and scheduling. Some of the strategies, as for example model predictive
controller which located at multivariable stage requires a model to enable it to be
implement. There are four phase in developing a model-required process control
strategy such as MPC. The phases are; 1) pretest and preliminary MPC design 2)
plant testing 3) model and controller development and 4) commissioning and
training. The accuracy and reliability of the deliverables from each phases is
extremely crucial in determining the success of the developed process control
strategy.
According to literature, plant testing took the longest period of among all the stages.
The plant testing could consume up to 50% of the time used in order to develop the
model. In orderto run the plant testing, taking steptesting as for an example, there is
a literature suggested that the step testing shall be made between eight and twelve
step, where for each step, the developer have to let the process to reach steady state
before implementinganother step.
This study has the objective to reduced the effort, generally, and time particularly,
while conducting a plant testing. In this report, the Case Study of Crude Distillation
Unit by Aspen HYSYS was used to generating the experimental data. From the data
generated, the MATLAB System Identification Toolbox was later used to generate
the model. The model generated later was analyzed to investigate the project
objective. All the necessary steps that are required will be explained through this
report.