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transcript
Shravan Dommaraju
Email: srdn96@mail.missouri.edu
Chance Drewery Email: cmdr7f@mail.missouri.edu
Department of Chemistry
University of Missouri-Columbia
101 Schlundt Hall
521 S. College Ave
Columbia, MO 65211
USA
April 25, 2017
Dr. Rainer Glaser, Professor in Chemistry
Editor, Journal of Organic Chemistry
Department of Chemistry, University of Missouri-Columbia
Columbia, MO 65211
Re: REVISED
Carbon Capture, Utilization, and Storage: A New Method for Lower Temperature
Recovery of Carbon Dioxide from Sorbents Using Polyethoxyamines
By Shravan Dommaraju and Chance Drewery
Dear Dr. Glaser,
Thank you for your communication on April 20 with the peer reviews of our original
manuscript. We were pleased with their suggestions and have taken both of them into
consideration during our revision. We have prepared a revision and the changes made are
described below.
Major Changes
[M.1] Assessment of responses in regards to our abstract, materials & methods, and results &
discussion have left us in belief that we have constructed these sections in a manner that has a
common ground between our reviewers. Some changes were made as addressed later.
[M.2] The Reference heading has been moved so that it appears on the same page as the
references.
[M.3] A general review of reference formatting was conducted to ensure format follows that of
the JOC.
[M.4] Some small formatting, spelling, and grammar errors were corrected.
Response to Reviewer 1 (9)
2
[1.1] Reviewer requested further explanation of figures in this section. Prior explanation was
given in both paper and in figure titles. Further explanation was added to the figure titles.
[1.2] Concern was raised about the number of figures in the results and discussion section. Upon
review, we feel that both figures 3 and 4 are necessary. Figure 3 provides concise and easily
understood verification of mechanism. Figure 4 provides a comparison point between T-403 and
the comparison sorbents. This is necessary to demonstrate the superior performance of T-403.
Response to Reviewer 2 (G3)
[2.1] See [M.1]. The request asked us to include more detail in the abstract. We have added some
data to the abstract to be more specific to polyethoxyamine performance.
[2.2] Reviewer recommended the deletion of the “Discussion” sub-heading. Following your
suggestion, we further reviewed the Discussion sub-heading from page 16 and have removed it
to avoid confusion.
[2.3] Reference 4 may appear in an unusual format because we are citing the Intergovernmental
Panel on Climate Change. The last name of one of the authors is de Coninck which may seem
like a misspelling but we have ensured that she is being properly cited.
[2.4] Reference 16 was cited incorrectly, as issue information is only required for journals that
reset to page 1 for each issue. This is not the case for J. Phys. Chem. so the issue field has been
removed.
[2.5] We believe you meant to say reference 15 with regard to having a day, month, and year.
This source is a patent so this citation follows ACS standards for patents.
[2.6] The reviewer recommended that bolding of years be checked. Upon review, all references
published in journals, online articles with available publication date, and technical reports (Ref.
4) have bolded year fields, while the rest do not. This follows the ACS style guide.
We believe we have addressed all the comments and suggestions of the reviewers and are
thankful for their evaluations of our original submission. The revision has incorporated those
comments which prove to enhance the focus of our manuscript.
Best regards,
Shravan and Chance
1
Carbon Capture, Utilization, and Storage: A New Method for Lower Temperature ecovery
of Carbon Dioxide from Sorbents Using Polyethoxyamines
Shravan Dommaraju† and Chance Drewery†
†Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211, USA
Email: srdn96@mail.missouri.edu; cmdr7f@mail.missouri.edu
2
Abstract
An inexpensive, novel polymer/silica sorbent system using Jeffamine® T-403 and fumed
silica for carbon capture has been characterized. After synthesis of the sorbent system, use of
Fourier Transform-Infrared (FTIR) Spectroscopy demonstrated the mechanism of sorption onto
the sorbent, with the peak corresponding to the primary amine diminishing under CO2
atmosphere. The T-403/silica sorbent system was also compared to sorbent systems consisting of
polyethylenimine (PEI) and polyethyleneglycol (PEG). The T-403/silica sorbent system
adsorbed 53.7 mg/g sorbent at industrial flue gas temperatures, approximately the same
proportion of CO2 as the PEI/silica (56.1 mg/g sorbent) and the PEI/PEG/silica system (67.3
mg/g sorbent). However, it adsorbed and desorbed at a faster rate, reaching half desorption in 4.3
minutes, and showed better percent regeneration, at 96.3 percent. The higher rate of sorption and
desorption, coupled with the lower temperatures used and better regeneration, indicates potential
widespread use as a carbon capture sorbent with minimal energy input, especially as compared to
current sorbent systems requiring additional heat for desorption and consistent maintenance and
replacement of the sorbent.
3
Introduction
Carbon capture is the use of technologies to effectively bind CO2 in industrial settings
and from the atmosphere.1 Capturing CO2 emissions from fossil fuels, which are still the greatest
energy source for humans, would reduce the level of greenhouse gases in the atmosphere.2 Even
with advances in energy efficiency and clean technology, there is still need to reduce CO2
concentrations in the atmosphere.1 CO2 emissions are increasing and are at a current
concentration of over 400 ppm.3 Once captured, the CO2 must be handled in either of two ways,
utilization or storage.4 Carbon dioxide can be utilized in some way to reduce overall emissions or
stored to remove it from the environment over large periods of time.4 Captured CO2 currently has
some small scale uses in flame extinguishing, refrigeration, decaffeination of coffee, extraction
of edible oils, beverage carbonation, and formation of baking soda.2,5 In addition, CO2 has
applications in synthesis of biologically important molecules via algae.2,6 As it stands currently,
carbon capture, storage, and utilization require large energy inputs, such that they may be
emitting more CO2 than they are removing.7 This means that further research must still be
conducted into carbon capture, utilization, and storage techniques with an emphasis on reducing
energy inputs for the technology.7 Low energy capture, utilization, and storage techniques may
be more widely used in industry for lower cost and would remove more net CO2 from the
atmosphere, provided the efficiency of the technique remained the same.7
Current techniques for carbon capture include post-combustions capture, where CO2 is
separated from flue gas by the use of sorbents, pre-combustions capture, where CO2 is made
from carbon fuels in producing hydrogen gas as an energy source, and oxy-fuel combustion,
where increasing the concentration of O2 in the combustion chamber leads to a pure stream of
CO2 gas for capture.2 Amines are a type of sorbent being used and researched for capturing
4
CO2.8 Amines can bind to CO2 at room temperature and most can be regenerated (removal of the
CO2) at 85 ℃.8 Another sorbent being used for capture of CO2 is caustic soda (NaOH).3 Other
methods model capture after natural photosynthesis, a biological process which converts 100
billion tons of CO2 to biomass annually.9 One group has created a synthetic CO2 fixation
pathway called the CETCH cycle, which carboxylates with 37 times more efficiently that
RuBisCO, the enzyme responsible for fixation in photosynthesis.9 Carbon capture can be
conducted directly from power plant flue gases or in open air.8 Open air capture is more difficult
because the CO2 concentration is 300 times less in open air,8 but it has the advantage of being
location independent.3 Carbon capture techniques vary greatly, but the most common current
techniques involve amine sorbents for capture from flue gases, using temperature swings to
regenerate the sorbent and release the CO2.4 The current sorbent most commonly being used for
carbon capture is monoethanolamine (MEA). MEA has high reactivity and selectivity, is low-
cost, and has high sorption capacity, but it also has many drawbacks, including corrosion, high
cost of regeneration, and solvent loss. For example, a 31% MEA solution by weight requires
over 4.8 MJ energy input per kg CO2 captured, with over 80% of the energy cost coming from
cost to heat the solution and solvent loss.10 To handle these drawbacks, sorbent systems are being
investigated.11 Prior research tested polyethyleneimine (PEI) as a carbon capturing polymer
adsorbed onto silica, but the sorbent systems suffered from leaching of the polymer from the
silica. Longer chain polymers were able to adsorb less CO2 per gram sorbent, but leached less
frequently. Addition of polyethyleneglycol (PEG) improved the regeneration of the PEI sorbent
system.12 This is suspected to be due to the Lewis acid/base interactions between CO2 and the
ether functional groups of the PEG molecule, but the full mechanism is yet to be determined
fully.13 The T-403 molecule contains both ether sites and amine sites, so the PEG/PEI sorbent
5
system and the T-403 sorbent system may be acting with similar mechanism. Structures of T-
403, PEI, and PEG can be found in Scheme 1.
Scheme 1. Structures of Jeffamine T-403, polyethyleneglycol (PEG), and polyethylenimine
(PEI). All three compounds are used to bind CO2 as part of a polymer and silica sorbent system.
Proposed methods of interaction are highlighted by color.
Here we report that use of Jeffamine® T-403, a polyethoxyamine, in a silica sorbent
system, provides a low-cost, readily available, and stable sorbent for CO2 capture that
regenerates CO2 with minimal temperature input. The T-403/silica system is chemically selective
6
for CO2 and regenerates sorbent using only a vacuum and at a temperature of 45 ℃, as compared
to the higher temperatures required of the PEI and PEI/PEG systems. In addition, T-403/silica
sorbent systems have higher regeneration speeds and desorb a higher percentage of CO2 relative
to the PEI and PEI/PEG systems. Problems associated with MEA, such as long-term stability and
high cost of regeneration,10 were reduced with T-403 as well. Polyethoxyamines are available for
implementation in industry, as large-scale preparation of a Jeffamine T-403/silica sorbent system
is extremely cost effective, since Jeffamines are available in bulk quantities at low prices. The
price for 18 metric tons of T-403 can be as low as $2/kg T-403.14
Materials and Methods
Preparation of Materials
Polyethoxyamines can be synthesized using static beds, which catalyze amination of
branched polyethers.15 Formation of polyethoxyamines has been conducted on an industrial
scale. Jeffamines®, such as T-403, a type of polyethoxyamine, were purchased from Huntsman
International, LLC based in The Woodlands, Texas. In addition, methanol (>99.9%),
polyethylenimine (PEI, Mw ~25,000), polyethyleneglycol (PEG, Mw ~400), polyvinylacetate
(PVAc, Mw ~150,000), polymethylmethacrylate (PMMA, Mw ~35,000), and fumed silica powder
were obtained from Sigma Aldrich (St. Louis, MO). Structures of these polymers can be found in
the supplementary information. Gases used in the experiment, CO2 and N2, were bought from
Air Gas.
Sorbent Preparation
The standard method for preparation of the polymer/silica sorbent using an illustrated
example of T-403 on 14 nm fumed silica. A predetermined weight of 14 nm fumed silica was
7
measured out and placed inside a pre-cleaned vial and dispersed in methanol. A stock solution of
T-403 in methanol was freshly prepared. Depending on the desired polymer-to-weight ratio, the
appropriate volume of T-403/methanol solution was added to the silica dispersion to achieve the
desired T-403/silica ratio based on weight. The dispersion was stirred for a least 1 hour, followed
by heating at 45°C to evaporate the methanol. This leaves the T-403 coated silica as a white,
powdery material.
CO2 Capture and Regeneration Tests
In order to measure the CO2 sorption capability of the polymer/silica systems, 0.5 g of
each polymer/silica powder was placed in a vial. The sorbent was then blanketed with glass wool
so that the nanoparticles would not be lost in the upcoming steps. The vial was sealed with a
septum lined cap. A needle connected to vacuum was inserted through the septum, and the
sorbent was dried under vacuum for three hours at 90 ℃. Using a manifold, a branched piece of
glassware with multiple openings, the sorbent was placed under nitrogenous atmosphere with N2
gas. Immediately afterward, the sample was held at 45 ℃ and 1 atmosphere, unless otherwise
indicated. The vial was weighed, to measure the mass of the sorbent and N2 atmosphere in the
vial. Two needles were introduced into the septum, with one connected to CO2 gas and the other
providing an exit route for the added CO2. Each sorbent was exposed to CO2 gas atmosphere at
45 ℃ and 1 atm for 1 hour, unless otherwise specified. At this point, the vial was weighed again,
to measure the mass of sorbent, adsorbed CO2, and the CO2 atmosphere. A correction factor was
applied to the mass to account for the difference in molecular weight of CO2 and N2. All total
sorption data can be found in the supplementary information.
In addition to testing the capabilities of various sorbents, the carbon sorption capabilities
of neat Jeffamines, meaning Jeffamines not adhered to silica, was also tested. A vial was filled
8
with a measured mass of each polymer, followed by weighing of the vial. CO2 gas was bubbled
through the Jeffamine polymers, and the mass of the vial was taken again after 1 hour of CO2
bubbling. The amount of CO2 adsorbed by the neat Jeffamines was determined by the increase in
mass of the vial.
For regeneration studies, the sorbents were adsorbed as described above. Following
sorption, the samples were put into a ~1 torr atmosphere at 45 ℃ for 1 hour, unless otherwise
indicated. The vial was weighed again to determine the amount of CO2 that became desorbed.
This process was repeated multiple times at 45 ℃ to determine how the sorbents performed under
cycling. Measurement of repeated sorption and desorption of CO2 serves as a better indicator of
potential success as a sustainable and reusable sorbent for large-scale carbon capture. If a sorbent
absorbs and desorbs exceptionally in the first cycle, but quickly loses sorption function, then it
will not be best suited for use in industrial carbon capture.
Sorption capacity of the T-403/silica sorbent is provided in Figure 1 at different
temperatures. This shows ability of the T-403/silica sorbent to adsorb relatively large amounts of
CO2 at low temperatures. In an industrial power plant, 45 ℃ is attainable for a sorbent without
additional heating, and thus does not require energy input for carbon capture. In addition, the
sorbent easily desorbs CO2 in a vacuum without requiring cooling, as shown in the
supplementary information.
Spectral characterization
FTIR characterization was performed on a Nicolet 4700 using a Thermo Smart Performer
germanium crystal Attenuated Total Reflectance (ATR) attachment. For each sample, 36 scans
were performed with a resolution of 6 cm-1. FTIR was performed to determine that T-403
obtained had the proper functional groups to properly adsorb CO2, specifically the primary amine
9
functional group. In addition, FTIR was performed on adsorbed T-403 to check that the primary
amine functional group was lost, since CO2 sorption will eliminate primary amines. This allows
verification of the carbon capture mechanism, and the data can be found in the supplementary
information.
Kinetic Analysis
Finally, kinetic analysis was performed on the T-403/silica sorbent. A sample was dried
under vacuum at 90 ℃ for 3 hours using a needle inserted through a septum-liner cap. The mass
of the uncapped vial was measured. The vial was recapped and 2 needles were inserted into the
septum. One needle allowed CO2 gas flow in at a rate of 65 mL min-1. The other needle allowed
pressure relief where gas could exit the vial. Gas flow rate was monitored with an Aalborg model
GFC17 model mass flow controller. Every 30 seconds, the vial was uncapped and the mass of
the vial was taken until the mass no longer changed. This mass corresponds to the maximal
sorption of CO2, as the T-403/silica system will eventually saturate with CO2 until the point
where no more CO2 can adsorb under these conditions.
Figure 2 demonstrates the faster speed of sorption for the T-403/silica sorbent system.
Faster saturation with CO2 presents better applications in carbon capture, especially in capture
from flue gas, as more carbon can be captured in a shorter amount of time, with less investment
into the sorbents. Further sorption capacities and speeds can be found in the supplementary
information.
10
Figure 1. CO2 adsorption capacity for the T-403/silica system under varying temperature
conditions. The ratio of the mass of adsorbed CO2 in mg to the mass of sorbent in g was
measured and plotted against the temperature of each trial. T-403 is prepared in a 1:1 ratio to
silica. 14 nm fumed silica nanoparticles were used.
11
Figure 2. Kinetic analysis of CO2 sorption. Each curve measures the amount of CO2 captured
per gram of Jeffamine polymer in the vial. Each sorbent was measured at 30 second intervals to
measure the amount of adsorbed CO2. Study was performed at 45 ℃ with CO2 flow rate into the
vial at a rate of 65 mL/min.
12
Results and Discussion
Jeffamines considered for CO2 capture
The Jeffamines D-230, EDR-148 (Scheme 2), and T-403 were tested for a polymer/silica
CO2 sorption material. Based on data and observations collected for the neat Jeffamines, they
had the capability of adsorbing CO2. Sorption occurred at rates of 135, 131 and 76 mg of CO2
per gram of polymer, respectfully, but needed a solid nanosilica support system to avoid
increased viscosity and eventual solidification (observed in D-230 and T-403). T-403 is
noticeably different in that it contains three primary amine groups instead of two, like the other
Jeffamines that we investigated. This structural feature allows for the T-403 polyethoxyanime to
bind the CO2 molecule using only its components. Scheme 3 illustrates this.
Scheme 2. Jeffamine® structures used.
Scheme 3. Binding of T-403 with CO2.
Characterization of Jeffamine sorbents
All polymer/silica sorbents used were analyzed using FTIR to confirm the polymers
presence on the silica support. The silica support has a characteristic strong, broad, IR absortion
band at 1110 cm-1 with a broad shoulder at 1180 cm—1. The T-403 has characteristic C-O-C
stretches in the 1000 – 1400 cm-1 region, C – H anti-symmetric and symmetric stretches from
13
2850 – 2990 cm-1, and N – H bands at 3100 – 3400 cm-1 (stretching), 1590 cm-1 (deformation),
and 750 – 850 cm-1 (wagging). The FTIR spectrum clearly allows us to see the T-403/silica
forming a composite by evidence of the sample containing band characteristics of both.
Sorption and desorption of Jeffamines
We compared the sorption and desorption rates of all three Jeffamines that we had
selected by running them in a 1:1 (w/w) ratio of polymer/silica. Our results indicated that T-403
was best for sorption of CO2. To further test T-403, we tested the ratios of T-403/silica at 1:2
(w/w) and T-403/silica at 2:1 (w/w) ratios. These results showed poor performance which is
noted in the supplemental information. The weight of CO2 sorption in mg per gram of Jeffamine
shows that T-403 is the clear decision for polymer/silica Jeffamine (Figure 2).
To confirm the sorption of the CO2 on T-403, ATR-FTIR was used to analyze the
polymer/silica with and without the sorption of CO2 as shown in Figure 3 on the following page.
The absorbance of T-403/silica (red curve) and T-403/silica after CO2 sorption (green profile)
confirms the absorption of CO2, leading to the formation of carbamate.16 The absorbance
increases in the range of 1335 - 1430 cm-1 and ~1564 cm-1 are indicate the symmetric and
asymmetric CO2 stretches arising from carbamate. Additionally, the T-403/silica with CO2
sorption contains peaks consistent with NH3 deformations seen for amine/carbamate species and
the disappearance of the N-H stretch at 3370 cm-1.
14
Figure 3. FTIR spectra of T-403/silica with (green) and without (red) the sorption of CO2. The
loss of the N-H stretch is noted by the * in the inset.
Comparison of T-403 to PEI and PEI/PEG
The sorbent T-403/silica and PEI/silica were tested along with different combinations of
the Lewis base modifiers to see how these modifiers affected the sorption capacity of the sorbent.
Table 1 shows the theoretical maximal CO2 sorption capacity of the T-403 is less than half that
of the PEI sorbent. Despite this difference, the PEI only performed a few mg higher than the T-
403, and was well short of its theoretical maximal sorption capacity while the T-403 was able to
capture over 70% of its theoretical maximal sorption capacity. The regeneration studies further
displayed the T-403 with a percent regeneration of 96.3% with only 4.3 minutes to reach its t50%
15
Table 1. CO2 sorption capacities of sorbents from this study. Sorption capacity and percent
regeneration were at 45°C.
regeneration. The PEI/silica sorbent was only able to regenerate 20.8 % and had a t50%
regeneration of 30.1 minutes. The PEI’s best sorption was when combined with PEG400, at 67.3
mg CO2 g-1, but still only had a 35.0% regeneration with a t50% of 14.9 minutes. Additional data
of different combinations of sorbents can be found in the supporting information.
The CO2 sorption of T-403 and PEI is expected to involve carbamate formation, CO2
mass transfer through the polymers, and possible Lewis acid – base formation. The
supplementary information shows CO2 sorption over time for T-403 and PEI-based sorbents.
sorbent
theoretical
maximal CO2
sorption
capacity (mg
CO2 g−1)
experimental
CO2 sorption
capacity (mg
CO2 g-1)
% of theor.
max.
sorbed
%
regeneration
(10 min of N2)
t50%
regen.
(min)
T-403:silica
1:1 75.2 53.7 ± 3.6 71.4 96.3 ± 2.5 4.3
PEI:silica
0.5:1 169 56.1 ± 5.1 33.2 20.8 ± 1.8 30.1
PEI:PEG400:silica
0.5:0.5:1 128 67.3 ± 6.8 52.6 35.0 ± 5.9 14.9
16
Figure 4. CO2 sorption over time for T-403 and PEI-based sorbents with and without Lewis base
modifiers.
The PEI:silica sorbent had the highest theoretical maximal CO2 sorption capacity of all
the combinations of polymers and Lewis base modifiers we tried. Despite this maximal capacity,
the PEI was unable to match the percent of theoretical maximal capacity that the T-403 achieved.
We were able to find that the PEI:PEG400:silica sorbent was able to capture more CO2 than the
PEI:silica sorbent did by itself. The combination of T-403 with Lewis base modifiers gave
different trends than the PEI. This is due to the T-403 already having a PEG-like backbone.
Although the mechanism is not fully understood, the PEI:Lewis base modifier:silica sorbents
show that the addition of a Lewis base site to the amine polymer allows it to better bind the CO2.
Modifiers like PEG have actually been used for the removal of CO2 and have even been
combined with amine compounds and shown to have the same effect.17
We tested the regeneration abilities of the sorbents at 45°C with slight vacuum. The PEI
was only able to regenerate 20.8% and the PEI:PEG400 only performed mildly better at 35.0%
regeneration. The T-403 was able to regenerate 96.3% and at only a half max of only 4.3 minutes
compared to the 30.1 and 14.9 for PEI and PEI:PEG400, respectfully. These findings further
17
support the need to a new step towards development of a T-403 sorbent system to be tested in
flue like conditions to show that the sorbent system will hold up.
Conclusion
The T-403 based sorbent is able to perform well under test conditions. The T-403
polymer/silica has a modest theoretical maximal CO2 sorption capacity at 75.2 but is able to
experimentally absorb 71.4% of that under favorable thermodynamic conditions of only 45°C.
The T-403 further supports its credibility by having one of the highest regeneration abilities at
around 96% with a T50% of just 4.3 minutes. The importance of an economically favorable
sorption system is that companies would not have additional strain of high heat systems whose
heating cost accounts for a sizable portion of their entire capture cost.
The T-403/silica sorbent would be able to operate at the temperature of the gas flue due
to its low heat requirements and with its low regeneration time, companies will be able to capture
more frequently meaning less downtime for a system or capture unit of a system. The Jeffamine
T-403 is already a commercially available polyethoxyamine that can also be produced with the
right system in place which could further reduce the cost of creating the system long term. The
T-403 polymer is evidence enough that the need for more research into economically favorable
systems may help sway companies to invest in these technologies.
Supplementary Material Available
The appendix contains more information on the characterization of T-403 and other
sorbents. FTIR data is presented for T-403, silica, T-403/silica system, and the T-403-CO2/silica
system. In addition, sorption and desorption data for a wide range of sorbents is given in the
appendix.
18
References
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Industrial Carbon Dioxide. ChemSusChem 2010, 3, 306-322.
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(http://www.nytimes.com/2013/01/06/business/pilot-plant-in-the-works-for- carbon-
dioxide-cleansing.html. Accessed 29 Jan. 2017) 2013.
4 Rubin, E.; Meyer, L.; de Coninck, H. IPCC Special Report: Carbon Dioxide Capture and
Storage. Cambridge University Press 2005, 18-50.
5 Harrabin, R. The Guardian. Indian firm makes carbon capture breakthrough.
(http://www.theguardian.com/environment/2017/jan/03/indian-firm-carbon-capture-
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6 Cole, A.J.; Mata, L.; Paul, N.A.; de Nys, R. Using CO2 to enhance carbon capture and biomass
applications of freshwater macroalgae. Bioenergy 2014, 6, 637-645.
7 Petrakopoulou, F.; Tsatsaronis, G. Can Carbon Dioxide Capture and Storage from Power Plants
Reduce the Environmental Impact of Electricity Generation? Energy Fuels 2014, 28,
5327-5338.
8 Kintisch, E. MIT Technology Review. Can Sucking CO2 Out of the Atmosphere Really Work?.
(https://www.technologyreview.com/s/531346/can-sucking- co2-out-of-the-atmosphere-
really-work/. Accessed 27 Jan. 2017)
9 Gong, F.; Li, Y. Fixing carbon, unnaturally. Science 2016, 354, 830-831.
19
10 Singh, P.; Swaaij, W. P. M. V.; Brilman, D. W. F. Energy efficient solvents for CO2
absorption from flue gas: Vapor liquid equilibrium and pilot plant study. Energy Proc.
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11 Hao, G.P.; Li, W.C.; Lu, A.H. Novel porous solids for carbon dioxide capture. J. Mater.
Chem. 2011, 21, 6447-6451.
12 Goeppert, A.; Meth, S.; Prakash, G.K.S.; Olah, G.A. Nanostructured silica as a support for
regenerable high-capacity organoamine-based CO2 sorbents. Energy Environ. Sci. 2010,
2, 1949-1960.
13 Kazarian, S.G.; Vincent, M.F.; Bright, F.V.; Liotta, C.L.; Eckert, C.A. Specific Intermolecular
Interaction of Carbon Dioxide with Polymers. J. Am. Chem. Soc. 1996, 118, 1729-1736.
14 Huntsman International, LLC. Personal Communication. 2011.
15 Fang, L.; Dong, X; An, S.; Guan, D.; Wang, S.; Bi, J.; Cui, Q.; Zheng, J. Production Method
for Continuously Synthesizing Polyether Amines through Static Bed. Chinese Patent
104693434A, June 10, 2015.
16 Danon, A.; Stair, P. C.; Weitz, E. FTIR Study of CO2 Adsorption on Amine-Grafted SBA-15:
Elucidation of Adsorbed Species. J. Phys. Chem. C 2011, 115, 11540-11549.
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Supported Amines for CO2 Capture. ChemSusChem. 2010, 3, 957-964.
S1
Supporting Information
Carbon Capture, Utilization, and Storage: A New Method for Lower Temperature
Recovery of Carbon Dioxide from Sorbents Using Polyethoxyamines
Shravan Dommaraju† and Chance Drewery†
†Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211, USA
Email: srdn96@mail.missouri.edu; cmdr7f@mail.missouri.edu
S2
Table of Contents
Structure of Polyvinylacetate and Polymethylmethacrylate..…………………………………….S3
ATR-FTIR Spectra Characterizing CO2 bound T-403………………………………………..….S4
ATR-FTIR Spectra Characterizing T-403/Silica system…………………………………………S5
Comparison of Jeffamine Sorption Capacities……….……...……………………….…………..S6
Comparison of Various Polymer Sorption Capacities……………………………………………S7
Comparison of Jeffamine Regeneration Capacities..……………………………………………..S8
Comparison of Various Polymer Regeneration Capacities………………………………………S9
Comparison of Average Percent Regeneration after 10 minutes………………………………..S10
Bibliography……………………………………………………………………………………S11
S3
Scheme S1. Polyvinylacetate (PVAc) and Polymethylmethacrylate (PMMA) are polymers
containing Lewis base sites. These sites are denoted in the scheme with the color red.
S4
Figure S1. ATR-FTIR spectra of T-403 showing before and after exposure to CO2. The inset
shows the true graph with the * denoting the loss of the NH stretching, which is lost upon CO2
binding.
S5
Figure S2. ATR-FTIR spectra for 14 nm silica (blue), neat T-403 (green), and T-403/14 nm
silica (1:1, w/w) sorbent (red). The inset shows the presence of a primary amine stretch present
in the T-403 polymer, denoted by *, showing an availability of a CO2-reactive amine for both.
S6
Figure S3. Comparison of the CO2 sorption capacities of various Jeffamine/nanosilica sorbents.
This data shows the sorption of CO2 by T-403/14 nm silica sorbent in a 1:1, w/w ratio to be the
highest rate.
S7
Figure S4. CO2 sorption capacities for each polymer sorbent tested in this study
S8
Table S1. CO2 sorption capacities and percent regeneration for various sorbents which were used
to test the sorption and regeneration
S9
Table S2. CO2 Sorption Capacities for Sorbents in This Study and Previously Reported
Literature
S10
Figure S5. The Average percent regeneration of sorbent after 10 minutes of N2 flow of 66
mL/min at 45°C and time to reach 50% regeneration of sorbent.
S11
Bibliography
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2012, 385, 154-159.
Zhu, J.; Baker, S. N. Lewis Base Polymers for Modifying Sorption and Regeneration Abilities of
Amine-Based Carbon Dioxide Capture Materials. ACS Sustainable Chem. Eng 2014, 2, 2666-
2674.