(147b) General Objectives and Benefits of an Advanced Process Control System for a Refinery

General Objectives
and Benefits of an Advanced Process Control System for a Refinery

By

Neda
Felorzabihi, David H. Jones and Javier Vazquez-Esparragoza

KBR Technology

Abstract

The objective of the paper is to present some of the basis
of design for the Advanced Process Control (APC) applications to be implemented
in a typical Oil Refinery, and a brief survey summary of APC Potential benefits
for applicable units in the refinery and also it is intended to provide a
common understanding between all the project team members participating in an
APC project.

Advanced Process Control is a critical component of
“best-in-class” operation, enabling significant improvements in asset
utilization and energy consumption for most processes. Specifically, APC is any
process control system application that has functions beyond those commonly
associated with basic or regulatory controls.

Advanced Process Control could be defined as multivariable,
model-predictive control (MVC) consisting of a suite of applications that uses
either linear or non-linear dynamic models to design, implement and maintain
MVC strategies in order to effectively improve the plant stability, increase
plant safety and maximize plant profitability. 

In this article, the general functionality is presented for
an APC system design developed for a pre-FEED (Front End Engineering Design)
phase of a 400,000 barrels per day (BPD) grassroots Refinery Complex.  

The refinery complex was separated into several units or
operational areas for APC application as listed below:

µ   CDU,
crude distillation unit

µ   VDU,
vacuum distillation unit

µ   Naphtha
stabilizer

µ   NHT,
naphtha hydrotreater

µ   Continuous
catalytic reformer unit

µ   Isomerization
unit

µ   Hydrocracker 
unit

µ   Distillate
Hydrotreater

µ   Other
units

Not every operational area would have APC applications and
some of them would have more than one controller.   

As an example of general control Philosophy, the following
items are included in the paper:

µ   APC General
Control Objectives

µ   APC General
Control Strategy

µ  
Typical
Benefits
per plant and global

The estimated potential benefits in  dollar amount from the
APC applications is included in the scope of work and the expected cost for a
refinery wide APC is presented. Proper implementation and maintenance would be
necessary to achieve and maintain these benefits.