EDT’s
What separation is taking place in the EDT’s
Butenes overhead and 1,3 BD/solvent out the bottoms
What kind of compressor is C-701
Multi-stage centrifugal compressor
What provides the heat for the solvent t loop
E-708 50# de-superheated steam
What is the equipment and purpose of the BD finishing section
BD is pumped to the LET (T-708) where the lights are removed (MAC) and then pumped to the PF (T-709) where the 1,2 BD and ACN are removed before being routed to utilities
What is the purpose of the SRT (T-711) and where are the streams routed
The SRT is used to recover and purify solvent the bottoms is water routed to the pad and the overhead is ACN/water mixture routed to the suction of 701 pumps
What is the purpose of the solvent (ACN) in the EDT’s
To increase the boiling point of the 1,3 BD to make the separation of butenes and BD
What are the stages of the compressor and where is it routed to (bonus points for discharge Temperature & control valve #’s)
1st stage suction from D-702, 1st stage discharge to D-703, 2nd stage suction for D-703, 2nd stage discharge (218 degrees) 1,3 BD routed to T-702 (FCV-706 EDT’s) and T-705 (PCG-738 SET)
What pumps are used to circulate the solvent loop
G-704A/B
What is the equipment and purpose of the butenes finishing section
The butenes washer (T-710) is liquid full and catches ACN from the butenes and M-703 coalescers collect water from the butenes before sending it to the pipeline
What is the purpose of D-710 and the BEU having its own flare drum
To recover ACN
What are the 3 uses of the EDT overheads (butenes)
1.) Butenes product
2.) EDT reflux
3.) diluent (when needed)
What is the purpose of D-703 and where is it routed
It is a knock out pot to prevent liquid from entering the compressor and is routed to D-702 or D-710
Explain the flow of the solvent loop start to finish (bonus points for solvent temp at end of solvent loop)
Solvent loop starts in T-704 and is pumped out with G-704 to E-709 then to E-704 then to E-703 and cooled in E-702 to 130 degrees
What pressure steam is used on E-712 and E-714 and why
6# steam is used on both reboilers for low temperatures to prevent polymer formation
Explain the process for swapping and cleaning a strainer
Pull procedure, coordinate with board ops when swapping in to clean strainer, N2 purge strainer to blowdown drum, clean strainer and spray with DEHA, pressure/depressure to atmosphere to O2 free new clean strainer, inventory with downstream side of strainer to blowdown drum, leave strainer inlet isolated. Inform board ops when completed
What is the heat source for the EDT’s
Reboil from C-701 discharge through FCG-706
What are the 5 compressor trips
1.) high level in D-702
2.) high level in D-703
3.) low lube oil pressure
4.) low seal oil pressure
5.) ESD button
Where is the solvent loop routed downstream of E-702 (bonus points for pumps that use it)
The solvent loop it used as solvent bleed to the SRT, solvent to the EDT’s and SET, and seal flush on 701, 706, & 716 pumps. In rare cases it can be used to transfer solvent loop to loop between the two BEU’s
What are the two product coolers and what what is the cooling medium
Butenes uses E-721 and BD uses E-726 both are cooled with propylene
What is the purpose of DEHA and why do we use it (bonus points for 1,3 BD spec)
DEHA is an oxygen scavenger and is used to help prevent the formation of polymer throughout the BEU the BD product spec is 2-10 but is desired above 4ppm and below 10ppm
Explain how and when to spare out G-701 and why it’s necessary
We spare out G-701 when there is not enough pressure to push the bottoms of T-702 to D-702 (in preparation for C-701 shutdown and during start-up). First step is to pull a procedure, then communicate with the board operator and then open the bottoms of T-702 to the suction of G-701 and the discharge of G-701 to E-704 and isolate suction from T-703 and discharge to inter tower transfer to T-702. Start the pump and ensure distance piece remains de-pressured.
Where does the cooling water come from on E-706
Second pass cooling water from E-710
Why and where can you get import/export solvent to/from
Solvent can be imported/exported at the Christmas tree from AF-1103 (clean solv.) and to/from AF-1104 (slop solv.) and to/from AF-3101 (slop solv.) and in certain occasions to/from the other BEU
Where can the off spec products be routed
AD-1901/1902 AD-3901/3902 and flare
What is the hazard of ACN if it burns
It creates cyanide