PART A: Gas releases and flammability diagram
1. Draw the flammability diagram of carbon monoxide (CO):
Your graph must clearly show the:
The air line and the
stoichiometric line;
• The LFL, UFL, LOC, LFL in O₂
and UFL in O₂;
The flammable region;
Flammability Data for CO
12.5%
LFL
UFL
LFL in O₂
UFL in O₂
LOC
74.0%
15.5%
94.0%
5.5%
100%
Oxygen
90%
80%
0%
70%
60%
%OT
50%
40%
20%
30%
20%
30%
10%
0%
40%
100%
50%
90%
Nitrogen
80%
70%
%09
€60%
50%
70%
40%
Carbon
Monoxide
30%
%08
20%
%06
10%
/5
.0%
100% PART B: HAZOP Study on a Acrolein Tank 974, ACROTANK, Marseille, Fos sur mer, France
A risk assessment is being performed by your Process Safety team on a tank containing liquid acrolein in a tank farm.
Your team has done a pretty good job under the Process Knowledge Management Element of your PSM system and has
prepared the technical document TANK974-TECHDOC (Version 1).
ATEXAS A&M
UNIVERSITY GATAR
CHEMICAL ENGINEERING
Your team chose to use the HAZOP technique to identify the hazards and evaluate the risks of the identified scenarios.
You can find the HAZOP document in Table 1 that was started by your team. This table is incomplete and needs your input.
The scenarios identified by your team mainly involve the catastrophic rupture acrolein tank 974 which would lead to the
entire inventory of acrolein to spill into the bund. This would form a pool of acrolein that would vaporize and form a vapor
cloud. The plant is nearby a residential area. The emergency response team indicated that they need at least 1 hour to
evacuate people in the residential area in case of release of acrolein.
The following questions are designed for you to evaluate the consequences of such scenario, complete the HAZOP table
and propose risk reduction measures if needed.
The results of the HAZOP study will be conveyed to higher leadership who will make the necessary to ensure the safety of
the operations following your recommendations.
ACROTANK counts on you and your expertise.
1. Is the bund big enough to hold the spilled liquid in case of catastrophic rupture acrolein tank 974?
Demonstrate your answer.
/2 2. Leaking pipe in a pressurized process unit (Figure 1)
Case A
Process unit at 3 bara
Gas at 10 bara
se A: Will the gas release flow be choked?
tify your answer
Gas leak
ill the gas flow be higher than case A?
answer
Case B
Process unit at 1.5 bara
Figure 1: Leaking pipe located into a pressurized process unit (choking pressure ratio is 0.5)
Gas at 10 bara
W Gas leak
12 AM
od 10 bara
Figure 1: Leaking pipe located into a pressurized process unit (choking pressure ratio is 0.5)
Case A: Will the gas release flow be choked?
Justify your answer
an
Case B: Will the gas flow be higher than case A?
Custify your answer
Gas at 10 bara
Gas SPRING 2022-CHEN 455 Final Exam
AM
2. How long will it take for the pool of acrolein to fully vaporize? Demonstrate your answer.
Note: you can use a simple approach by ignoring the wind effect on the vaporization rate.
TEXAS A&M
UNIVERSITY at QATAR
CHEMICAL ENGINEERING
/6
