You are a process engineer in an aging cumene production facility (Unit 800). Your facility provides high-purity cumene to a phenol production plant adjacent to it. The target production rate for cumene is 90,000 mt/year. The plant operates 24 hr./day, 350 days/year (8400 h/year). The expected purity is 99 wt.% cumene. Recently, the process has not been operating at design conditions. We have recently switched suppliers of propylene; however, our contract guarantees that the new propylene feed is within the specifications in Table 1 (found in the Unit 800 process information packet). Upon examining present operating conditions, we have made the following observations:

1. Production of cumene has dropped by about 8%, and the reflux in T-801 was increased by approximately 8% in order to maintain 99 wt.% purity. The benzene (Stream 5) and propylene (Stream 2) flows remained the same. Pressure in the storage tanks has not changed appreciably when measured at the same ambient temperature.
2. The amount of fuel gas being produced has increased significantly and is estimated to be 78% greater than before. Additionally, it has been observed that the pressure control valve on the fuel gas line (Stream 9) coming from V-802 is now fully open while it previously controlled the flow.
3. The benzene recycle Stream 11 has increased by about 5%, and the temperature of Stream 3 into P-801 has increased by about 3°C.
4. Production of steam in the reactor has fallen by about 6%.
5.  The catalyst in the reactor was changed 6 months ago, and the previous operating history (over the last 10 years) indicates that no significant drop in catalyst activity should have occurred over this time period.
6. DIPB production, Stream 14, has dropped by about 20%.

We are very concerned about this loss in production since we can currently sell all the material we produce. Therefore, the Director of Engineering assigns you and your team the high-priority task of creating a simulation of the current cumene process based on the design documents (included with this assignment) and identifying possible causes for the problems identified above. Then, using modifications to your process model, develop alternatives that address these issues. Replacement/upgrades of existing equipment may include relatively new processes such as reactive distillation and divided wall distillation columns.

Chemical Engineering Student Design Teams: 

1. Maureen Kelley, Lillie Lindgren, Dominique Mauhar, Jordan Scharf, Olivia Stellflug
2. ​​Cameron Koseor, Jonah Peplinski, Michael Sommers, Brandon Springer, Conner Steeno
3. ​Alyssa Kirsling, Cole McCabe, Peter McMahon, Jackson Mikel, Karl Unruh​​