Question

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

Fig: 1