Formation and destruction of NDELA in MEA and DEA

Transcription

1 Formation and destruction of NDELA in MEA and DEA Hanna Knuutila, Hallvard Svendsen and Naveed Asif NTNU- Department of Chemical Engineering Trondheim, Norway 1

2 Content Background Experimental work Results Conclusions 2

3 Background Objectives To study the formation of NDELA with NO and NO+NO 2 present in the gas phase To study the destruction of NDELA in these solutions with UV-light 3

4 Background UV-reactor Sampling after UVlight Power consumption Lamp power Max. flow rate Chamber material Chamber length Chamber diameter Lamp Sleeve Value 46 W 37 W 37.9 L/min 304 stainless steel 90.0 cm 6.4 cm Sterilume-EX model S810RL Quartz Model QS-810 Centrifugal pump Valve Flow meter Sampling before UV-light 4

5 Background Batch experiments Decomposition of NDELA and NDMA in artificial water wash solution Start concentration NDMA 307 ng/ml NDELA 290 ng/ml LOQ NDMA 25 ng/ml NDELA 5 ng/ml Concentration of NDMA and NDELA are below the LOQ after 1 hour 5

6 Background Batch experiments Decomposition of NDELA and NDMA in fresh 30wt% MEA Start concentration NDMA 7620 ng/ml NDELA 624 ng/ml LOQ NDMA 250 ng/ml NDELA 50 ng/ml Concentration of NDMA and NDELA are below the LOQ after 2.5 hours 6

7 7 Experimental setup

8 Background Campaigns 30wt% MEA 50wt% DEA Campaign duration 990 hours 410 hours NO feeding hours 715 hours 250 hours N 2 O feeding hours 187 hours 100 hours UV-light radiation in the main solvent circulation 37 hours 48 hours UV-light radiation in the water wash circulation - 5 hours 8

9 Results 30 wt% MEA 50wt% DEA 9

10 Results 30 wt% MEA 50wt% DEA 10

11 Results 30 wt% MEA 50wt% DEA 11

12 12 Results

13 Results 30 wt% MEA 50wt% DEA 13

14 Results Penetration of UV-light 14

15 Penetration Depth (cm) Penetration depth measurements Effect of colour (degradation products) Fresh amine solutions 10 30wt% MEA 50wt% DEA 50wt% DEA used in a pilot for 410 hours wt% MEA used in a pilot for 1690 hours. a) Amount of used 30 wt% MEA/50wt% DEA in fresh 30wt% MEA/50wt% DEA (weight fraction) 15

16 Experiment in water wash loop Air CO2 N2+ NO + NO2 N2+ NO N2 BACK PRESSURE VALVE CO2 GAS OUT ABSORBER WATER WASH COLUMN IR ANALYSER ABSORBER LIQUID IN ABSORBER GAS-LIQUID SEPARATOR GAS-LIQUID SEPARATOR CONDENSER CO2 UV-light LIQUID IN THE STRIPPER STRIPPER GAS CIRCULATION FAN Bleed STORAGE/MIXING TANK LIQUID SAMPLING HEX 4 CONDENSATE HEATER GAS SAMPLING CO2 FTIR HEX 2 P-210 HEX 1 GAS IN ABSORBER LIQUID SAMPLING REBOILER COOLER LIQUID SAMPLING UV-light CIRCULATION PUMP LIQUID OUT FROM REBOILER WASH WATER OUT WATER WASH TANK LIQUID SAMPLING OPTIONAL COLUMN LIQUID SAMPLING LIQUID OUT FROM ABSORBER WASH WATER IN HEATER CIRCULATION PUMP PUMP 16

17 NDELA (ng/ml water wash solution) UV-light in the water wash UV-reactor inlet/wash water in to the wash section UV-reactor outlet Out from the water wash section into the tank Campaing hours 17

18 Results Concnetration (mmol/l) Degradation (30wt% MEA) Start of UV-light irradiation experiments Nitrate, lean amine Formate, leann amine DEA, lean amine Campaign hour 18

19 Results Concentration [µg/ml] Degradation (30wt% MEA) HEPO HEGly BHEOX HEI HEF OZD HEA Campaign duration (hours) 19

20 Conclusions the decomposition of NDELA decreases with increasing colour of the solution amine concentration To use UV-light in the main solvent loop would require an optimization of the UV-light reactor. Open questions: UV-light and amine degradation Influence of temperature 20

21 Thank you! The work is done under the RenicUV project. The project was performed under the strategic Norwegian research program CLIMIT. The authors acknowledge the partners: Det Norske Veritas AS, Fluor Enterprises, Inc., Maasvlakte CCS Project C.V. and Mitsubishi Heavy Industries, Ltd. 21