development of mixed amine solvents - sintef of mixed amine solvents ... mdea+teta, aeea,deta,pz....
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Slide 1
Development of mixed amine solvents
Prof. Mengxiang FangZhejiang University
Email:mxfang@zju.edu.cn
Slide 2
What is Chemical Absorption ?
Absorption with chemical reaction has long been considered one of the most feasible routes to post combustion CO2 capture.
--- Technology roadmap carbon capture and storage, IEA,2010
Slide 3
Chemical absorption technology
Advantages
Disadvantages
Extensive use in the chemical lines
Mature technology and process
Lower demand for flue gas purity
High regeneration energy consumption
High water consumption
Some operating problems including degradation, corrosion, foaming, flooding, channeling and entrainment
Main puzzle?
Advanced solvents
New process
Larger unit size and space occupation
Challenge of Chemical Absorption
Slide 4
Demonstration Plant in China
Huaneng Beijing3,000t/y CO2 Capture demonstration project
Huaneng Shanghai120,000t/y CO2 Capture demonstration projectChina power Investment
Hechui 10,000t/y CO2 Capture demonstration project
Amine based solvents,Packing Column,Heat regeneration process
Energy consumption 3.6-4Mj/kg,Energy penalty 8-11% Investment increase 50-90% Electricity price increase 70-90%
Slide 55
How to decrease cost and energy consumption?
CO2>99%
Absorptionprocess
Regenerationprocess
Flue gas
Gas absorbent
Advanced solventsKs series mixed amineAmmonia basedIon-liquidPhase change
New RegenerationProcessMulti-stage Vacuum regeneration
New ReactorPacking materialRotating bedMembrane Co
Heat IntegrationInnersystem
---Technology roadmap carbon capture and storage, IEA,2010 More cost and energy effective solutions by chemical absorption, which
is environmental friendly and less water consumption, is still needed!
Slide 6
Principe of Mixed amine
• Principle In combination with high reactivity with CO2 and low regeneration energy consumption.
Research of mixed amine
Primary amine/ tertiary amine
Tertiary amine/ active ingredient
Secondary amine/ hindered amine
Based on high CO2reactivity, reduce the energy consumption
Based on the low energy consumption , increase the CO2reactivity
Use the sterically hindered amines
Mixed amine Ⅰ
Mixed amine Ⅱ
Mixed amine Ⅲ
Slide 7
Absorbent Concentration Research objective
MEA 30%,20%,10% Set a study basis and tested the concentration effect on absorption performance
MDEA 30% Set a study basis
MEA+MDEA Total concentration 30%(activator concentration 5%
,10%,15%)
Adding tertiary amine into primary amine, to decrease regeneration energy consumption while keeping
high absorption rateMEA+AMP Total concentration 30%
(activator concentration 5%,10%)
Adding sterically hindered amine into primary amine, to decrease regeneration energy consumption
while keeping high absorption rateMEA+TETA,A
EEA,DETA,PZTotal concentration 30%
(activator concentration 5%,10%)
Adding polyamine and cyclic amine into primary amine, to keep the regeneration energy consumption constant or less increase while further improving the absorption
performanceMDEA+TETA,
AEEA,DETA,PZTotal concentration 30%
(activator concentration 5%,10%,15%)
Adding polyamine and cyclic amine into primary amine, to keep the regeneration energy consumption constant or less increase while further improving the
absorption performanceMEA (Sigma-Aldrich, purity≥99.9mass%);MDEA (Sigma-Aldrich, purity≥99.9mass%);AMP (Fluka, purity> 97mass %);PZ (anhydrous 99%); AEEA (Adama-beta, purity 99mass%);TETA (Adamas-beta, purity 99mass%) ;DETA(Shanghai Lingfeng Chemical, purity 99mass%)
Test amine
Slide 8
Experimental study
1.Experiments schematic
Figure 1 Experimental apparatus for absorption study1、MFC 2、Mixing tank 3、Valve 4、Thermostatic
water bath 5、Acid wash 6、Desiccators 7、Gas analyzer 8、Computer 9、Vent
Figure 2 Experimental apparatus for regeneration study1.Oil bath 2.Glass reactor 3.Stirring Cell 4.Condenser
5.Flow meter 6.Gas flow meter by drainage 7.Sampling port 8.Condensation water inlet 9.Condensation water outlet
10.Plug-in heat resistance 11.Thermocouple
Slide 9
2. Experimental conditions
ParametersSerial number of the reactor
1 2 3 4Shape column column column column
Average inner diameter/mm 48.5 41 36.5 27
Volume of absorbent/mL 120 120 120 120
Liquid surface height / Average inner diameter
1.5 2.5 3.5 8.0
Table 2 Design parameters of the semi-batch reactor
Figure 2 Design forms of the gas inlet for the reactor
Absorption•Absorption temperature:40℃;•Absorption pressure: 1 atm;•Initial solution volume: 120mL•Gas flow:N2, 0.8 L/min;CO2, 109 ml/min,CO2 concentration of the simulated gas,12%。
Regeneration•Volume of glass reactor :800ml • Volume of rich-CO2 solution:500ml;•Temperature rising period:5 min;•Regeneration temperature: 100℃;•Regeneration pressure: 1 atm;
Slide 10
=2 2
2
, ,
,
CO in CO out
CO in
v vv−
2 ,CO Aη 2 2
2 2
, ,
, ,(1 )CO in CO out
CO in CO out
C CC C
−
−
v
3. Analysis method
CO2 removal efficiency
V is the gas flow rate,mL/min;C is the gas concentration in the simulated gas
=
Solution CO2 loading
——The volume of tested sample ,L;
——The initial volume of the gauges tube before titration
—— The ending volume of the gauges tube after titration,——The mole concentration of ammonia,mol/L;
——The gas volume correction factor when the experimental operating conditions are converted into standard operating conditions. It is a dimensionless coefficient and its calculation formula is as follows:
Slide 11
CO2 regeneration extent
2 ,CO Rη = int 100%eve
eve
A AA−
∗
Aint is the instantaneous CO2 loading in the solvents during regeneration ,molCO2/mol absorbent;Aenv is eventual CO2 loading in the solvents during regeneration ,molCO2/mol absorbent
CO2 regeneration rate
Veve——Released CO2 volume of the initial solution,L;
t——The regeneration time,min;
intv veveBt−
=
Vint——Released CO2 volume of the inatantaneous solution,L;
Slide 12
Experimental results
• MEA-based |Absorption performance
Addition EffectPZ +DETA +AEEA +TETA +AMP -MDEA -Initial Max RECaused by PZAver RECaused by DETA
Slide 13
• MEA-based |Absorption performance
Addition EffectDETA +TETA +AEEA +PZ +AMP -MDEA -Weight concenHas a stronger effectEven Max CO2 LoadingCaused by DETAAver CLCaused by TETA
Slide 14
• MDEA-based |Absorption performance
Addition Effect
DETA +TETA +AEEA +PZ +
Initial Max RECaused by DETAAver RECaused by DETA
Slide 15
• MDEA-based |Absorption performance
Addition Effect
TETA +DETA +AEEA +PZ +
Initial Max RECaused by TETAAver RECaused by TETA
Slide 16
• MEA-based |Regeneration performance
Addition EffectMDEA +AMP +PZ -DETA -AEEA -TETA -
Initial Max RECaused by 15%MDEAAver RECaused by 15% MDEA
Slight difference
Slide 17
• MEA-based |Regeneration performance
Addition EffectComparable to 30%MEA
Initial Max RRCaused by 5%AMPAver RRCaused by 15% MDEA
Slight difference
Slide 18
• MDEA-based |Regeneration performance
Addition Effect
PZ -AEEA -TETA -DETA -
5% seems to be acceptable
Slide 19
• MDEA-based |Regeneration performance
Addition Effect
All positive
Initial Max RRCaused by 15%AEEAAver RRCaused by 15% DETA
Slide 20
Analysis and evaluation
• AbsorptionAbsorption capacity--- How much CO2 can be absorbed?
During industry operation, absorbent mass has the direct relation with the operation cost of the pumps. Due to the molecular weight difference, the absorption capacity is more suitable to be given in form of mass rather than mole. The absorption capacity almost equals to the ultimate CO2 loading.
Absorption rate--- How fast CO2 can be absorbed? Mean absorption rate during CO2 loading linearly increasing
phase(R2>0.95) Average absorption rate during whole absorption process
Other factors also should be considered, such as degradation rate, precipitation, foaming and so on.
Slide 21
Absorbents of good absorption performance
Absorbent Initial absorption rate A1(by RE) Score 1
Effective absorption
capacity A2(kg/kg)
Score 2 Total score A(High to low)
30%MEA 88.596 1.00 0.3638 1.00 1.00
20%MEA+10%DETA 91.18 1.04 0.55617 1.53 1.58
25%MEA+5%PZ 94.157 1.06 0.48722 1.34 1.42
20%MEA+10%AEEA 89.21 1.01 0.49674 1.37 1.38
20%MEA+10%PZ 97.85 1.10 0.42794 1.18 1.298
25%MEA+5%DETA 89.016 1.00 0.46185 1.27 1.27
20%MEA+10%TETA 88.307 1.00 0.45143 1.24 1.24
25%MEA+5%AEEA 88.435 1.00 0.40828 1.12 1.12
15%MDEA+15%DETA 84.191 0.95 0.36256 1 0.95
15%MDEA+15%TETA 79.032 0.89 0.33756 0.93 0.84
20%MDEA+10%DETA 74.251 0.84 0.29083 0.8 0.672
20%MDEA+10%PZ 81.767 0.92 0.23411 0.64 0.59
Slide 22
Regeneration Evaluation
• Mean regeneration rate (D1) D1 refers to the average regeneration rate before the regeneration extent of CO2-rich solution reaches 50%.
• Regeneration extent (D2 ) D2 is defined as the CO2 regeneration extent at the 50min in the solvents
Slide 23
Absorbent
Mean regeneration
rate scoreD1 by CL
Regeneration extent score
D2
Total scoreD=D1*D2
High to low
25%MDEA+5%TETA 1.99 1.44 2.87
15%MDEA+15%AEEA 2.11 1.24 2.61
20%MDEA+10%PZ 1.73 1.51 2.61
20%MDEA+10%TETA 1.75 1.42 2.49
25%MDEA+5%DETA 1.67 1.43 2.39
15%MDEA+15%PZ 1.69 1.31 2.21
15%MDEA+15%DETA 1.95 1.04 2.03
15%MDEA+15%TETA 1.73 1.17 2.02
20%MEA+10%MDEA 1.40 1.19 1.67
15%MEA+15%MDEA 1.29 1.29 1.66
25%MEA+5%AMP 1.31 0.97 1.27
30%MEA 1.00 1.00 1.00
Absorbents of good regeneration performance
Slide 24
Overall performance evaluation of absorbents
Absorbent Absorption Score A
Regeneration ScoreD Total Score(A×D)
30%MEA 1 1 120%MEA 0.9384 0.9516 0.8929814
30%MDEA 0.0345 1.63 0.056235MEA-Based
15%MEA+15%MDEA 0.5751 1.6641 0.957023920%MEA+10%MDEA 0.747 1.666 1.24450225%MEA+5%MDEA 0.8736 0.9996 0.873250620%MEA+10%AMP 0.7719 0.927 0.715551325%MEA+5%AMP 0.893 1.2707 1.1347351
20%MEA+10%AEEA 1.3837 0.609 0.842673325%MEA+5%AEEA 1.12 0.684 0.7660820%MEA+10%TETA 1.24 0.6675 0.827725%MEA+5%TETA 1.224 0.7905 0.967572
20%MEA+10%DETA 1.5759 0.5751 0.906300125%MEA+5%DETA 1.27 0.7654 0.972058
20%MEA+10%PZ 1.298 0.666 0.86446825%MEA+5%PZ 1.4204 0.7912 1.1238205
MDEA-Based15%MDEA+15%AEEA 0.6142 2.6164 1.606992920%MDEA+10%AEEA 0.4725 1.792 0.84672
25%MDEA+5%AEEA 0.2744 1.8876 0.517957425%MDEA+5%PZ 0.3848 2.3868 0.9184406
20%MDEA+10%PZ 0.5888 2.6123 1.538122215%MDEA+15%DETA 0.95 2.028 1.926620%MDEA+10%DETA 0.672 2.0124 1.352332825%MDEA+5%DETA 0.33 2.3881 0.788073
15%MDEA+15%TETA 0.8277 2.0241 1.675347620%MDEA+10%TETA 0.6075 2.485 1.509637525%MDEA+5%TETA 0.3286 2.8656 0.9416362
Slide 25
Energy consumption analysis
Total regeneration heat demand QCO2 EstimationQCO2=Qsens+ Qrea+Qvap
Qsens=Cp*m*△tCp refers to the specific heat of the solutions;m is the mass flow rate of the absorbents;△t stands for the temperature difference between CO2-lean solution and
CO2-rich solution.
Qrea= --△H*MM refers to the CO2 recovery during the regeneration process, mol/h△H is 72 kJ/molCO2 for MEA
Qvap=rH2O*R*A kj/hrH2O is the evaporation heat of H2O,kJ/molH2O. The value is 40 kJ/ molH2O when the operating pressure is 2bar. R is the reflux ratio at the top of regenerator
2
2
H O*
CO
PR P=
2H OP
2
*COP
.
is the saturated steam pressure of the CO2-rich solution,kPa;
is the CO2 partial pressure at the top of regenerator,kPa
Note:For different absorbents, the actual optimal CO2-rich solution CO2 loading and CO2-lean solution CO2loading are inconsistent. In order to facilitate the Rec comparison for absorbents, Rec-50%, which refers to the regeneration energy consumption when the regeneration extent reaches 50%, is chosen as the base.
Slide 26
Relative energy consumption Rec-50%
AbsorbentCO2 loading in the CO2-rich
solution
CO2 loading in the CO2-lean
solution
Relative regeneration
Energy consumption
Energy saving compared to MEA
kg/kg kg/kg KJ/kg CO2 %30%MEA 0.422 0.211 54.74 0.0020%MEA 0.491 0.245 60.3 -10.16
MDEA-BasedMDEA25%+AEEA5% 0.250 0.125 54.54 0.37
MDEA20%+AEEA10% 0.345 0.172 46.57 14.93
MDEA15%+AEEA15% 0.387 0.193 41.59 24.03MDEA25%+PZ5% 0.351 0.175 38.37 29.90
MDEA20%+PZ10% 0.366 0.183 38.52 29.63MDEA15%+PZ15% 0.411 0.205 40.29 26.40
MDEA25%+TETA5% 0.310 0.155 44.53 18.65MDEA20%+TETA10% 0.372 0.186 40.65 25.74
MDEA15%+TETA15% 0.440 0.220 39.12 28.54MDEA25%+DETA5% 0.379 0.189 36.01 34.22
MDEA20%+DETA10% 0.403 0.202 38.50 29.67
MDEA15%+DETA15% 0.463 0.232 41.18 24.78MEA-Based
MEA25%+AEEA5% 0.462 0.231 60.85 -11.16MEA20%+AEEA10% 0.479 0.240 61.34 -12.06MEA25%+AMP5% 0.449 0.225 51.04 6.76
MEA20%+AMP10% 0.404 0.202 51.15 6.55MEA25%+DETA5% 0.500 0.250 59.88 -9.38
MEA20%+DETA10% 0.517 0.258 67.12 -22.62MEA25%+MDEA5% 0.373 0.186 53.54 2.20
MEA20%+MDEA10% 0.352 0.176 45.21 17.42MEA15%+MDEA15% 0.307 0.154 47.21 13.76
MEA25%+PZ5% 0.468 0.234 64.29 -17.44MEA20%+PZ10% 0.488 0.244 56.50 -3.22
MEA25%+TETA5% 0.479 0.240 66.17 -20.89MEA20%+TETA10% 0.508 0.254 58.98 -7.75
Slide 27
Conclusion
29 kinds of absorbents have been tested,7 of them have been expected to have better overall performance relative to 30 wt% MEA by two methods. The energy consumption reduction for novel solvents is nearly 30%.
The evaluation method still needs to be improved. Although a tendency can be predicted, the method is too rough to give a precise answer due to too much assumption and approximation.
Mixing amines is a promising way of solvent selection for CO2 capture.
Slide 28
Outlook
• To improve the evaluation method for solvent selection.
• To testify the true energy consumption in pilot study.
• To complete the systematic study of mixed amines, such as degradation, corrosion and environmental impact.
Slide 29
Thanks for your attention!
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