4th EucheMs chemistry congress

Poster Session 2
s1173
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - Energy and Carbon Dioxide
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ABSorPtion of Co into AqueouS PotASSiuM
2
SALt SoLutionS of AMino ACidS
S. K. JeonG 1 , J. A. LiM 1 , y. yoon 1 , S. C. nAM 1 ,
i. h. BAeK 1
1 Korea Institute Of Energy Research, Greenhouse Gas
Research Center, Daejeon, Republic of Korea
Since the industrial revolution, fossil fuel consumption has
drastically increased. Carbon dioxide discharged from combustion
processes is now believed responsible for global warming and an
increase in the earth’s average temperature. The development of
CO capture technologies is critical for reducing greenhouse gases
2
and coping with the climate change problem at its root.
Monoethanolamine (MEA) is the leading alkanolamine absorbent.
Although it features a fast absorption rate and a high alkalinity, it
has the drawbacks of loss of absorbent due to degradation and
corrosion of the equipment as well as the high amounts of energy
required for absorbent regeneration. To solve these problems, the
absorption of CO using an amino acid salt solution as an
2
alternative absorbent was studied. In this study, the CO2 absorption capacity and absorption heat of the aqueous potassium
salts of L-alanine and L-proline were investigated using a semibatch
absorption system and a differential reaction calorimeter
(DRC). The speciation in the CO -loaded absorbents was
2
investigated using NMR spectroscopy. The results were compared
with primary amine, MEA and secondary amine, diethanolamine
(DEA). The CO loading capacities were found to be 0.50 and
2
0.68 mol CO /mol solute for aqueous MEA and potassium salt of
2
L-alanine at 298 K, respectively. The CO absorption heats of the
2
potassium salt of L-alanine and potassium salt of L-proline were
lower than those of MEA. The absorption heats were found to be
81.77, 67.06, 53.26 and 90.20 kJ/mol-CO for aqueous MEA
2
DEA, potassium salt of L-alanine, and potassium salt of L-proline,
respectively. It was found that the potassium salt of L-alanine had
an excellent for CO capture. Therefore, the potassium salts of
2
L-alanine and L-proline are deemed to be the potential CO2 absorbent to replace the existing amines.
Keywords: CO Capture; Amino Acids; Amine;
2
4 th EucheMs chemistry congress
P - 0 6 2 3
wAter oxidAtion By SinGLe-Site rutheniuM
CoMPLexeS – uSinG LiGAndS AS redox And
Proton trAnSfer MediAtorS
M. KärKäS 1 , t. AKerMArK 2 , e. JohnSton 1 ,
S. KAriM 1 , t. LAine 1 , B. L. Lee 1 , t. PrivALov 1 ,
B. AKerMArK 1
1 Stockholm University, Department of Organic Chemistry,
Stockholm, Sweden
2 Stockholm University, Department of Materials and
Environmental Chemistry, Stockholm, Sweden
The splitting of water into molecular oxygen and hydrogen
gas is an attractive option for the production of sustainable energy,
where mastering the process of oxidizing water is the key step for
the utilization of this potential. The possibilities are enormous,
where the later can be used as a fuel, stored for future demands,
or even to be used for the production of more complex fuels and
chemicals.
A serious problem is that most of the catalysts developed so
far require a powerful sacrificial oxidant, i.e. CeIV , to be able to
oxidize water. In a sustainable system, the oxidant needs to be a
light-absorbing component, a photosensitizer, which can be
regenerated. A major obstacle in light-driven water oxidation is
frequently the mismatch between the relatively high redox
potential at which a catalyst assumes its active state and the lower
potential attainable with a photosensitizer.
Comprising a redox and proton transfer mediator motif into
the WOC would facilitate the simultaneous transfer of electrons
and protons, thus avoiding high-energy intermediates and give
access to new reaction pathways. In order to both decrease the
redox potentials and permit coupled proton-electron transfer,
imidazole and carboxylate were introduced as mediators into the
ligands. Therefore the meridionally coordinating benzimidazole
based ligands 1 and 2 and their related single-site ruthenium
complexes 3 and4 were synthesized. Indeed, by introducing the
redox and proton transfer mediator motif (imidazole) the WOCs
were able to catalyze water oxidation, under neutral conditions,
both by pre-generated and photogenerated [Ru(bpy) ] 3 3+ .
Keywords: Water splitting; Sustainable chemistry; Ruthenium;
Photochemistry; Electrochemistry;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc