1. INSTRUMENTATION & CONTROL

2. INSTRUMENTATION & CONTROL
INTRODUCTION
Product specifications
Process stability.
Environmental regulations
Safety
Economics
(Stephanopoulos, 1984)

3. INSTRUMENTATION & CONTROL
INTRODUCTION (cont.)
“Chemical processes usually have two or more controlled output, requiring two or more manipulated variables” (Stephanopoulos, 1984)

4. INSTRUMENTATION & CONTROL
INTRODUCTION (cont.)
Did not consider overall plant performance.
Did not consider process interactions.
Single Input – Single Output System
Designing a control system (of complete chemical plant) is not simple but requires
experience and good chemical engineering background (Stephanopoulos, 1984)

5. INSTRUMENTATION & CONTROL
Available Control Configurations:
5. Adaptive and Inferential Control
4. Multivariable Control
3. Multiple Loop Control (Cascade)
2. Feed Forward (Ratio Control)
1. Feedback Control
(Stephanopoulos, 1984)

6. INSTRUMENTATION & CONTROL
PRIMARY REFORMER, R-101.
Highly endothermic reaction.
Temperature, 770˚C .
Pressure, 3770 kPa.
Ratio of methane to steam, 3:1.
Control Objective
To control the ratio of the two inlet stream, temperature and pressure by manipulating the steam flow rate and feed inlet flow rate.

7. INSTRUMENTATION & CONTROL
PRIMARY REFORMER, R-101 (cont.)

8. INSTRUMENTATION & CONTROL
FLASH DRUM, S-103.
Separation between phases
Gas and liquid
Level of the liquid
Control Objective
To control the level of the liquid in the flash drum by manipulating the outlet flow rate.

9. INSTRUMENTATION & CONTROL
FLASH DRUM, S-103 (cont.)

10. INSTRUMENTATION & CONTROL
PRILLING TOWER, V-201.
Product specification
Temperature
Control Objective
To control the composition (purity) of the product manipulating the steam flow rate.

11. INSTRUMENTATION & CONTROL
PRILLING TOWER, V-201 (cont.)