nitrosamine formation in amine scrubbing
TRANSCRIPT
Nathan A. Fine
Texas Carbon Management Program University of Texas at Austin
Department of Chemical Engineering September 18, 2013
1
Nitrosamine Formation in Amine Scrubbing
Outline
2
Motivation Carcinogenicity Nitrosamine Cycle
Current Work NO2 absorption Nitrosation from nitrite
Nitrosamine accumulation
Maximize environmental benefit of amine scrubbing
3
Motivation
Nitrosamine Carcinogenicity
4
React in target organs to form diazonium-carbocation intermediates
Leads to DNA alkylation and tumor growth Over 80% are carcinogenic
Inami et. al 2009
5
Stripper Absorber
Nitrosamine Cycle
NO2 absorption Nitrosation from nitrite
6
Nitrosamine Formation
NO2 Absorption Chemistry
7
The Wetted Wall Column
8
Solvent reservoir
N2
CO2
Vent
NO2 flux
Kg and kg’
FTIR
[NO2]WWC [NO2]bypass
5000ppm NO2/N2
NO2 Absorption into Water
9
WWC
Shen 1997
0.001
0.01
0.1
1
10
0.1 1 10 100
NO
2 Flu
x*10
5 (m
ol/s
m2 )
PNO2 LM (Pa)
6% NO2 absorption For 5ppm NO2 0.01 M NaOH, T=20 °C
NO2 Absorption into MEA
10
MEA Water
0.001
0.01
0.1
1
0 1 10
NO
2 Flu
x*10
5 (m
ol/s
m2 )
PNO2 LM (Pa)
9m MEA, α=0.38 T=40 °C
Absorption dominated by k’g MEA at 5 ppm NO2
NO2 Absorption Into Amines
11
Loaded 9m MEA
Loaded 8m PZ
Unloaded MDEA
1
10
100
0.01 0.1 1 10
k'g
Am
*10
5 (m
ol/s
m2 P
a)
Free Alkalinity (m)
β=65% NO2 absorption
β=98% NO2 absorption
β=100% NO2 absorption
12
Stripper Absorber
Nitrosation from Nitrite
Nitrosation of 1°/2° Amines with Nitrite
13
MEA
MAE
DEA
PZ
1
10
100
1000
1 10 100 1000
k Mod
el *
106
(s-1
)
kObs *106 (s-1)
k3 100C (M-2s-1) Ea (kJ/mol)
84
62
42
680 73
Nitrosamine yield: 1° Amines
14
0%
1%
2%
3%
4%
5%
0.000 0.005 0.010 0.015 0.020
ND
ELA
Yie
ld
[DEA]/[MEA]
Dilute DEA in MEA
15
DEA diluted in 9m MEA, α=0.38 T=150 °C for 3 hours
Reactivity in 9m MEA
16
HEEDA
HEGly
1
10
0 0.1 0.2 0.3 0.4
Rel
ativ
e R
eact
ivit
y (R
)
MEA Loading (Mol CO2/mol MEA)
DEA Experimental
*Carbamate and protonate stability for DEA/MEA extrapolated from 40 °C
2° Amine diluted in 9m MEA, α=0.38 Heated at 120 °C for 24 hours
Nitrosamine yield: 2°/3° Amine Blends
17
Tertiary amines do not form carbamates Nitrosate very slowly Yield from 2° amine nitrosation is close to unity at promoter
concentrations
Blend MNPZ Yield (%)
0.1-8m PZ 95±11
PZ/Methyldiethanolamine (MDEA) 85
PZ/Triethanolamine (TEA) 102
PZ/Dimethylaminopropanol (DMAP) 93
PZ/Diethylaminoethanol (DEAE) 96 2m PZ / 7m 3° amine; α=0.25; Heated for 3 hours at T = 150 °C
Balancing NO2 absorption and nitrosation with nitrosamine decomposition
18
Nitrosamine Accumulation
Nitrosamine Accumulation
19
0.1
1
10
100
9m MEA, 10 mM HeGly, T=120 °C
9m MEA, 50 mM HeGly, T=120 °C
8m PZ, T=150 °C 7m MDEA/2m PZ T=135 °C
Nit
rosa
min
e (m
M)
Nitrosamine Accumulation
20
0.1
1
10
100
9m MEA, 10 mM HeGly, T=120 °C
9m MEA, 50 mM HeGly, T=120 °C
8m PZ, T=150 °C 7m MDEA/2m PZ T=135 °C
Nit
rosa
min
e (m
M)
Nitrosamine Accumulation
21
0.1
1
10
100
9m MEA, 10 mM HeGly, T=120 °C
9m MEA, 50 mM HeGly, T=120 °C
8m PZ, T=150 °C 7m MDEA/2m PZ T=135 °C
Nit
rosa
min
e (m
M)
Nitrosamine Accumulation
22
0.1
1
10
100
9m MEA, 10 mM HeGly, T=120 °C
9m MEA, 50 mM HeGly, T=120 °C
8m PZ, T=150 °C 7m MDEA/2m PZ T=135 °C
Nit
rosa
min
e (m
M)
Nitrosamine Accumulation
23
0.1
1
10
100
9m MEA, 10 mM HeGly, T=120 °C
9m MEA, 50 mM HeGly, T=120 °C
8m PZ, T=150 °C 7m MDEA/2m PZ T=135 °C
Nit
rosa
min
e (m
M)
October 5 - 9, 2014 | AUSTIN, TX - USA
www.GHGT.info
UTCCS-1 January 28-30, 2014 Austin, TX
Open to sponsors of the Texas Carbon Management Program And to non-profit institutions with presentations
Titles and abstracts due October 15, 2013 to [email protected]
Thermal Cylinder Experiments
25
Solution Preparation 0.1-8m amine, α=0.1-0.4 50 mmol/kg NaNO2
Batch Experiment Loaded in \ inch Swagelok thermal cylinders Convection oven at 80-150°C Quenched in water bath at 21 °C Stored in amber vials and analyzed within a week
Pseudo-first order observed rate determined from nitrite disappearance
‹#›