EG Flashcards
What is the purpose of the EG Reactor system?
To create EC (ethylene carbonate in the EC RX
To create EG (ethylene glycol) in the EG RX
What kind of reaction is the EC reaction
Exothermic
What kind of reaction is the EG reaction
Endothermic
Explain EC1 reactor
Converts ethylene oxide to ethylene carbonate
About 86% conversion
Feed streams:
- EO, Recycle CO2, water, EC1 recycle, Omega Catalyst
Explain EC2 / GDR02 reactor
Continues ethylene carbonate reaction to:
~98.5%
- Higher temp than EC1
Explain EC3 / GDR03
- Resonance time
- allows remaining EO to react with dissolved C02
Explain GDD05
Separates the liquid recycle prior to EC2 RX
Explain GDE08
- Keeps temps high enough to continue EO conversion in EC2
- 120 psi steam
Explain GDD07 / C02 Separation Vessel
Separates free C02 from the product streams of EC2 RX
- some goes to TOX
- The rest goes back to GDC02
Explain EG1 / GDR04 reactor
- converts ethylene carbonate and water to ethylene glycol and CO2
- EC conversion is about 90%
- kettle reactor
- runs about 290 psi
- 120# steam
- large amount of co2 released
- liquid level influences the residence time in the RX and the % of EC to EG conversion
Explain EG2 / GDR05 reactor
- continues the EC conversion to virtually 100%
- runs around 29 psi
- open steam injected @ 120#
Issues and Concerns from EC / EG side
- incomplete conversion = Meg quality issues
- Runaway reaction
- crystallization from reduced flow
- High pressure from EG1 to EG2
- Largest concentration of EO (except GBD06)
Explain GDT01 / Glycol Dehydrator
- remove water and impurities from the MEG product stream
- water goes overhead to WW - column under Vacuum
- Bottoms contains mainly MEG / 93%
- temps over 140f glycol can boil up overhead / bad
- water can cause off spec MEG
- too high of temps can break down OMEGA cat
Explain GDT02 / Glycol bleed flasher
Removes heavy glycols and sodium salts from glycol bleed stream
- under vacuum
- sodium coms from caustic injection
- if sodium is over 1% then its re-ran through tower
- heat tracing is critical to prevent fouling
- 40% surplus capacity
Explain GDX02 / vacuum system
Maintains vacuum on the overheads of GDT01 / GDT02
- 200# steam
- non condensable are sent to TOX
- discharge is sent to GED03 then to WW
Explain GDTK02 / container first flush sump tank
Collects storm water and potentially contaminated drains
- will trap the first 2” of contaminated water
- if no leaks or oil sheen can send to WW
Explain the MEG purification system
- purify MEG to meet product specs
- Remove OMEGA and heavy glycols (deg, teg)
- entire process under vacuum
- damage to catalyst / keep around 324f
*loss of vacuum
*financial implications due to off spec MEG
Explain the GET01 / Meg purification column
Receives bottoms stream from Dehydrator
Flashes off MEG and heavy glycols
- Bottom section: CSS
- recovers OMEGA by flashing off glycols
- 314* F to avoid thermal decomposition of OMEGA
- 43% cat solution is recovered and recycled back to EC1
- Top section (pasteurizing section)
- separates residual water and light components from MEG
- contains Mellapack packing
Explain GED01 / Meg polishing Vessel
- removes any traces of iron to improve the UV
- GEFIL04 / filter removes any further traces of iron before sent to rundown tank
Explain GETK01 / glycol slops tank
Storage for glycol slops during:
-S/U and S/D
-off spec
- ATM tank with n2 blanket
- pumps to Glycol bleed flasher GDT02 if sodium is > 1ppm
Explain GETK02 a/b
- Nitrogen blanket
- Fill one rundown tank for 72 hours, swap tanks, sample, certify, pump OSBL
- Product is sent OSBL, railyard, trucks or docks
Explain GET03 / MEG side stripper
Further Removes MEG, sent back to GET01
-DEG and heavier go from 2% feed to 35-45% bottoms
- pulls from middle section of GET01
- overheads mostly vapor go back to GET01
-GEE05 reboiler controls temp via 200# steam
Explain GET02 / Meg Recycle Column
Recovers residual MEG from the GET03 bottoms stream
- Top product is sent to GDT01 glycol dehydrator via GEP08
- Bottoms go to OSBL via GEP07 & GEFIL02, then cooled @ GEE08
- TEMP control via GEE07 reboiler 200# steam
Explain GEX01 / vacuum system
- Maintains vacuum for columns in MEG purification / recycle system
- Vacuum allows low operations temp, this minimizes MEG degradation and omega catalyst thermal decomposition.
- # 200 steam powers multi stage ejectors system
What 2 types of stream are in the OMEGA system
- concentrated catalyst solution
- Dilute catalyst solution
What two Components are in the OMEGA streams
- Component A: susceptible to thermal decomposition
- Component B: susceptible to deactivation by chlorides
Explain GDD08 / Catalyst Charge vessel
Used to store fresh and regenerated catalyst
- makeup catalyst is sent from this vessel to process EG2
- LP n2 helps prevent degradation
- during shutdowns the concentrated cat solution of the CSS is stored here
Explain GDTK01 / Catalyst storage Tank
Used to store dilute OMEGA during unit shutdowns
- large enough to store the entire system volume of the EG section plus one washing and flushing
Explain GDD09 / catalyst drips vessel
Is used to collect the catalyst drain from process systems during shutdowns and equipment maintenance
- pumps to GDTK01
- relief from other vessels
Explain GUTK01 / chilled water storage tank
- Receives and stores chilled water for users
- Absorb fluctuations in chilled water temp
- Buffer capacity for stage storage during plant shutdown
Explain GUD02 / Hot water Buffer Vessel
- Absorbs fluctuations in the water temp
- Collects the circulated hot water from users
GDE05, GBE11 - Make up condensate from GUD01 during start up or make up
Explain the purpose of the Chillers / GUX01 A-J
to provide chilled water to users whose cooling requirements are not met by cooling water.
- required to supply water at 50f
- CHW is used to recover and condense EO
- Cool lean absorbent so that it can absorb EO
- Analyzer shelter
* 10 chillers in parallel arrangement * Number of chillers in operation depend on demand and atmospheric conditions
How do the Chillers work?
Absorption Refrigeration
- operates on the principle of evaporating water at low pressure
- Absorption in a lithium bromide solution
-(strong absorbent for water)
-(skin and eye irritant)
What style of Trays are in GET01
Total Liquid Draw off
What % (Meg, omega, other) are sent to GET01 / Meg Purification Column
Meg: 93%
OMEGA: 6%
DEG/other: 1%
Explain GUD02.
Hot water Users?
Closed circuit hot water Buffer vessel
GDE05
GBE11 (removed)
What does OMEGA stand for?
Only MEG advantage
