by gary t. rochelle [email protected] - ieaghg
TRANSCRIPT
Concentrated PiperazineConcentrated PiperazineA new standard solvent
by GGary T. Rochelle
[email protected] Luminant Carbon Management ProgramLuminant Carbon Management Program
Department of Chemical Engineering The University of Texas at Austiny
September 30, 2010
Why 8 m (40 wt% Piperazine?
• 10-20% less energy than 30 wt% MEA– 2 x CO mass transfer rate– 2 x CO2 mass transfer rate – 1.8 x capacity– High P (6 – 15 atm) Stripper, stable to 150°C
• Oxidatively stable, esp. with Inhibitor Ay , p• Less volatile than 7 m MEA
S l bl 0 C i l di• Soluble at 0oC at operating loading• Good Opportunities for Reclaimingpp g
Energy Properties• Chemistry 2 active amines per molecule• Chemistry – 2 active amines per molecule• Viscosity & Solubility allow 8 m PZ when loaded• CO2 solubility
– Capacity – 0.84 moles/kg solvent– Heat of Desorption – 76 kJ/mole
• Thermal Stability to 150oCe S b y o 50 C• 2-stage heated flash reduces energy 15%
Solubility Envelope for PZ
H PZCOO H O ( )Aqueous PZ
H+PZCOO-·H2O (s)qSolution
10 m PZ
8 m PZ Expected loading range
PZ·6H2O (s)
5CO2 Capture with of Concentrated Aqueous PZ
Viscosity Comparison
40°C, αrich 10 m PZ40 C, αrich 10 m PZ
13.7 m DGA
7 m MDEA/2 m PZ7 m MDEA/2 m PZ
7 m MDEA 7 m PZ
8 m PZ
8 m PZ has lower viscosity with higher alkalinity than DGA7 m MEA
7 m MDEA
6CO2 Capture with of Concentrated Aqueous PZ
CO2 solubility in Aqueous PZ
1.E+06
1.E+07
80
85
160oC
ΔHCO222
Q1.E+05
ar)
70
75
mol
)
160 C
120
6
1
reb (
1.E+04
P CO
2 (ba
65
70
Hab
s (kJ
/m
800.05(kJ/mol1.E+02
1.E+03
P
55
60 ΔH
400.005
0 84 mol CO /kg solvent ol)
1.E+01
1.E 02
50
550.84 mol CO2/kg solvent(0.48 for MEA)
0.20 0.25 0.30 0.35 0.40 0.45CO2 loading (moles/equiv PZ)
CO2 Absorption Rate, 40oC1E-05
8 PZ
a. m2 ) 8 m PZ Operating
Range
1E-06
ol/s
. Pa
7 m MEA
k g' (
mo
8 m 2-PE1E-07
10 100 1000 10000
k 8 m 2-PE
5%0.5%P*CO2 @ 40C (Pa)
5%0.5%
Thermal Degradation at Rich Loading100
k)g g
Ea=133 kJ/mol
10
%/w
eek
Loss (% 7 m MEA 8 m PZ
1
Amine L
10 m PZ
0.1
A
135100 175150120 oT (oC)
Stripping 8 m PZ
160 kPa
160 kPa
ΔT=5oCRich P*CO2=5 kPa
150oC
comppumpreb
sinkrebrebeq W
KTTKTQW /10
1075.0 +⎥⎦
⎤⎢⎣
⎡⎟⎟⎠
⎞⎜⎜⎝
⎛+
−+⋅= ∑
Solvent Management
• Volatility <20 ppm at lean conditions– Air Impacts minimized by Water Wash
• Oxidation 3 x less than MEA- Eliminated by inhibitor A
• 316 SS resistant to corrosion316 SS resistant to corrosion• Piperazine easily reclaimed by existing options
SS316 corrosion in thermal degradation experimentsdegradation experiments
167 m MEA, 135°C
12
14
mM
)
,(6.7% loss/wk)
Fe & Ni
8
10
atio
n (m
8 m PZ 150°C
4
6
once
nt 8 m PZ, 150°C(0.4% loss/wk)
Fe & Ni
0
2
4C Fe & Ni
22CO2 Capture with of Concentrated Aqueous PZ
0
0 5 10 15 20Time (weeks) (Voice 2009)
Reclaiming concepts• Traditional Thermal or distillation Reclaiming
Atm or vacuum– Atm or vacuum– PZ more volatile than MEA
PZ th ll t bl– PZ thermally stable• Inhibitor A recovered from conc soln by supplier• Ion Exchange or electrodialysis as with MEA• K2SO4 crystallization with addition of KOH2 4 y
– 0.17 m sulfate solubility
Pilot Plant
• Results in 0.1 MW with air/CO2– Mass Transfer RateMass Transfer Rate– Energy
• Plans for 0 1 MW with high P 2 stage flash• Plans for 0.1 MW with high P 2-stage flash
Selected Pilot Plant Runs, 8 m PZ20 ft Mellapak 2X 200m2/m320 ft Mellapak 2X, 200m /m
Gas Liq PSTRP Rem Lean Rich(acfm) (gpm) (psia) (%) Ldg Ldg
350 18 51 93.2 0.27 0.34350 18 51 93.2 0.27 0.34
350 15 20 93.4 0.25 0.33350 15 20 93.4 0.25 0.33
350 18 20 79.3 0.30 0.36350 18 20 79.3 0.30 0.36
350 15 60 76.1 0.31 0.36
Loading = mol CO2/Total Alkalinity
Wetted wall kg’ & Pilot plant KG
9m PZ
8 PZ 60 C
9m PZ8m PZ
8m PZ 40oC
8m PZ 60oC 5m PZ
7 5m PZ7.5m PZ
5m K+/2.5m PZ 7m MEA
6.4m K+/1.6 m PZ9 m MEA
7m MEA
6/15/2009 The University of Texas at Austin 26
Stripper PerformanceStripper Performance
*Yokoyama T. 2004. Japanese R&D on Large-Scale CO2 Capture. 2004 ECI Conference on Separations Technology VI: New Perspectives on Very Large-Scale Operations. Fraser Island, Queensland, Australia
6/15/2009 27The University of Texas at Austin
Conclusions
• 10-20% less energy than 30 wt% MEA– Double the CO2 mass transfer rate – 1.8 x capacity– High P (6 – 15 atm) Stripper, stable to 150°C
• Oxidatively stable esp with Inhibitor A• Oxidatively stable, esp. with Inhibitor A• Less volatile than 7 m MEA • Soluble at 0oC at operating loading• Soluble at 0oC at operating loading• Good Opportunities for Reclaiming