gmallows
Chemical
- Feb 25, 2005
- 1
TOPIC- Help from anyone with experience with-
MDEA based CO2 removal process
dehydration of CO2 using TEG
Compression of CO2 to 200 barg for reinjection into the disposal reservoir.
INTRODUCTION-
I work for a large oil company and one of our gas plants removes CO2 from natural gas, and then re-inject the extracted CO2 into disposal wells.
Approx flowrate of gas for reinjection is 80mmscf/day.
CO2 removal is by a MDEA based process.
CO2 is then compressed using 2x50% Mitsubishi centrifugal compressors.
Compression train has 4 stages- inlet pressure to the 1st stage is 0.15 to 0.3 barg. Outlet pressure from 4th stage is approximately 160 barg (this will rise to 200 barg within 6 years due to the behaviour of the reservoir).
Each of the 4 stages has it's own anti-surge recycle loop and interstage suction fin fan cooling.
Discharge temperatures for compression stages are approx 170 to 220 deg C.
Fluid for stages 1 to 3 is wet CO2.
At the 3rd stage discharge (approx 70 barg), the CO2 is dehydrated using TEG.
PROBLEMS-
3rd and 4th stages of the compression train have been under performing (by 5 to 10%)
Upon further investigation the 3rd and 4th stages of the compressor/ associated pipework/ suction scrubbers/ glycol contactor have become heavily coated with a black sticky tar like substance.
Black sticky substance has been seen upstream of glycol contactor- but if it was generated in the glycol contactor, then it could be transported upstream, due to the anti-surge recycle loops.
Black substance is being analysed for amine/ glycol degradation products.
REQUEST-
Does anyone have any experience with any similar plant or problems that they can share with me?
Does anyone have any advice on what areas we should be looking during our investigations?
MDEA based CO2 removal process
dehydration of CO2 using TEG
Compression of CO2 to 200 barg for reinjection into the disposal reservoir.
INTRODUCTION-
I work for a large oil company and one of our gas plants removes CO2 from natural gas, and then re-inject the extracted CO2 into disposal wells.
Approx flowrate of gas for reinjection is 80mmscf/day.
CO2 removal is by a MDEA based process.
CO2 is then compressed using 2x50% Mitsubishi centrifugal compressors.
Compression train has 4 stages- inlet pressure to the 1st stage is 0.15 to 0.3 barg. Outlet pressure from 4th stage is approximately 160 barg (this will rise to 200 barg within 6 years due to the behaviour of the reservoir).
Each of the 4 stages has it's own anti-surge recycle loop and interstage suction fin fan cooling.
Discharge temperatures for compression stages are approx 170 to 220 deg C.
Fluid for stages 1 to 3 is wet CO2.
At the 3rd stage discharge (approx 70 barg), the CO2 is dehydrated using TEG.
PROBLEMS-
3rd and 4th stages of the compression train have been under performing (by 5 to 10%)
Upon further investigation the 3rd and 4th stages of the compressor/ associated pipework/ suction scrubbers/ glycol contactor have become heavily coated with a black sticky tar like substance.
Black sticky substance has been seen upstream of glycol contactor- but if it was generated in the glycol contactor, then it could be transported upstream, due to the anti-surge recycle loops.
Black substance is being analysed for amine/ glycol degradation products.
REQUEST-
Does anyone have any experience with any similar plant or problems that they can share with me?
Does anyone have any advice on what areas we should be looking during our investigations?
