co2 fixation in polymers - cat catalytic center · 2015-06-18 · »energy balance of co 2...
TRANSCRIPT
»
ACS Spring Meeting, New Orleans, 8 April 2008
Thomas E. Müller CAT Catalytic CenterRWTH AachenGermany
CO2 Fixation in Polymers
» Agenda
Current options concerning CO2 » Trend in CO2 Emission» CCS Technologies» Substitution potential
CO2 as C1 building block» Activation of CO2» Energy balance
Synthesis of building blocks for polymers» Reduction of CO2» Cyclic carbonates» Acrylic acid
Direct synthesis of polymers» Polycarbonates
Conclusions and outlook
» Current trend in CO2 emissions
Current status» Global CO2 emissions 28 192 Mio t/a (2005)» Tendency increasing» Correlation with global warming appears likely
Possible measures for reduction» Avoid CO2 production (regenerative energies)» Development and introduction of CCS technologies» Use of CO2 as building block in chemical industry
0
5.000
10.000
15.000
20.000
25.000
30.000
1980 1990 2000 2010
YearC
O 2 E
mis
sion
/ M
io t/
ahttp://www.eia.doe.gov/iea/carbon.html
http://www.cutco2.org/
» CCS Technologies (Carbon capture and storage)
Industrial uses
Mineral carbonation
Geological storage
Ocean storage
» Substitution potential for CO2 in chemical industry
Pharmaceutics (Aspirin)Solvent
Fertilizer, melamine, Formaldehyde, acetic acid
Food industry, cleaning, extraction, inert gas
Use
2000178Substitution potential0.070.0812730
Mio t/a
(2005)0.03Salicylic acid(2005)0.04Cyclic carbonates200472Urea20053Methanol2005~80Raw material
200220Industrial gas
200528 192CO2 Emissions Anthropogeneous
YearMio tCO2/a
C&EN June 26 (2000) 48
BTXGasoline Lightalkenes
MethanolAmmonia
Prod
uctio
n (m
illio
n t/a
)
230 Mio t/a (2005)Shift to oxidized
materials required
PPPELD PEHD PVC PS PA PC PET PUR
10
0
20
30
40
60 in Mio t/a
» Sources of clean CO2
Amine based adsorption» Monoethanolamine» Methyldiethanolamine
CO2 rich stream
CO2 poor stream
» Properties of CO2
Colorless and tasteless gasNon-toxic Low supercritical pointUnique properties as solvent
Pre
ssur
e p
Temperature T
solid
gaseous
liquid
Tc = 31.0 °Cpc = 73.75 bar
Critical point
supersuper--criticalcritical
GasViscosity
Mass transfer
LiquidSolvent
Heat capacity
scCompressibility
Adjustable
Courtesy of Prof. Leitner
» Activation of CO2
T. Sakakura et al. Chem. Rev. 107 (2007) 2365
J. E. Gready et al, JACS 123 (2001) 10821
Ribulose bisphosphate carboxylase (RubisCo)• One of the most abundant enzymes on this planet.• This enzyme takes solar energy. • Converts carbon dioxide into carbohydrate.
Lewis base
π-Complexes
Lewis acid
Reactive positions
MgO
MgO
M. Chiesa, E. GiamelloChem. Eur. J. 13 (2007) 1261
Oxidative cycloaddition
Reaction with nucleophiles
» Energy balance of CO2 conversion
Sakakura et al. Chem. Rev. 107 (2007) 2365
CO2 is the energetic end product of combustion
»Use high-energy starting materials, such as H2, alkenes, strained rings, organometallics
Note: Reduction requires more energy than released by combustion of the products so produced
»Choose oxidized low-energy synthetic targets
»Shift equilibrium to products
»Supply physical energy, such as light or electricity
Konuma, React. Func. Polym. 67 (2007) 1129
» Synthesis gas
Dry reforming of methane
Base chemical for synthesis of»Olefines»Paraffins»Methanol»Dimethylcarbonate
CH4 + CO2 2 CO + 2 H2 ΔH0298= +247 kJ/mol
endothermal
» Hydrogenation
Methanol (20 Mio t/a in 2000)
Formic acid (0.4 Mio t/a in 2000)
CO + 2 H2 CH3OH ΔH0298= -90,8 kJ/mol
CO2 + 3 H2 CH3OH + H2O ΔH0298= -49,6 kJ/mol
CO + H2O CO2 + H2 ΔH0298= -41 kJ/mol
CO + CH3OH HC(O)OMe HC(O)OH + CH3OH
CO2 + H2 HCO2H ΔH0298= -31.6 kJ/mol
NaOMe H+
Source of H2 ?
» Hydrogenation
Methanol (20 Mio t/a in 2000)CO + 2 H2 CH3OH ΔH0
298= -90,8 kJ/mol
CO2 + 3 H2 CH3OH + H2O ΔH0298= -49,6 kJ/mol
CO + H2O CO2 + H2 ΔH0298= -41 kJ/mol
Source of H2 ?
I. Chorkendorff, J. W. Niemantsverdriet, Concepts of Modern Catalysis and Kinetics, Wiley-VCH, 2003
Commercial catalyst Cu/ZnO/Al2O3
H2 H2 : H2O = 1 : 3 H2 : CO = 95 : 5
» Methanol synthesis
formate
Cu
Cu
Cu
Cu
CO2
OC
O
H
O
CO
H2
H2
H HH2
H
H3C
O H
CH3OH
O H H
methoxy
I. Chorkendorff, J. W. Niemantsverdriet, Concepts of Modern Catalysis and Kinetics, Wiley-VCH, 2003
Microkinetic model Adsorption• H2(g) + 2* 2H*• CO (g) + * CO*• CO2 (g) + * CO2*Surface reaction• CO2* + H* HCOO* + *• HCOO* + H* H2COO* + *• H2COO* + H* H3CO* + O*• H3CO* + H* CH3OH* + *• H3CO* + H* CH3OH + *Regeneration of catalyst• CO* + O* CO2* + *• 2H* + O* H2O* + 2*
r.d.s.
Cu(100)
r.d.s. = Hydrogenation dioxomethylener.d.s. = Hydrogenation formateExperiment
» Synthesis of cyclic carbonates
Bimetallic catalyst for reaction of propylene oxide with CO2
R. Eberhard, M. Allmendinger, M. Zintl, C. Troll, G. A. Luinstra, B. Rieger, Macromol. Chem. Phys. 205 (2004) 42
Bu4N+Br- as co-catalystSelective reaction at 0-25°CTOF 18 h-1 at 0°CE. K. Noh, S. J. Na, S. Sujith, S.-W. Kim, B. Y. Lee, JACS 129 (2007) 8082
T. Sakakura et al. Chem. Rev. 107 (2007) 2365
CatCO2
Review on use of CO2: D. Walther, Nachrichten Chemie 55 (2007) 1188
» Synthesis of carbonates
Direct methoxylation of CO2
D. Ballivet-Tkatchenko, Appl. Cat. A: Gen. 255 (2003) 93
To be solved: removal of water
Mechanism
D. Walther, Nachrichten Chemie 55 (2007) 1188
Cat
» Synthesis of acrylates
Synthesis of acrylic acid from ethene and CO2
» Hypothetical cycle based on known model compounds
Red: isolated model compoundsBlue: fast reacting intermediates
D. Walther, Nachrichten Chemie 55 (2007) 1188
» Synthesis of aliphatic polycarbonates
Inoue et al. Macromol. Chem. 130 (1969) 210Macromol. Chem. C21 (1981) 135
Heterogeneous Zn-salts» Diethylzinc-water» Zn-glutarates
Soga et al. Polym. J. 13 (1981) 407
Darensbourgh et al. J. Mol Cat. A 104 (1995) L1Zheng et al. Z. Kristallogr. 215 (2000) 535Rieger et al. Chem. Eur. J. 11 (2005) 6298
Cat
» Synthesis of aliphatic polycarbonates
Zn-ß-diiminato complexes
Coates et al JACS 120 (1998) 11018; JACS 124 (2002) 14284; JACS 125 (2003) 11911; Angew. Chem. Int. Ed. 43 (2004) 6618
Bimetallic mechanism
Rieger et al. Chem. Eur. J. 11 (2005) 6298
» Synthesis of aliphatic polycarbonates
Cr, Co, Zn - Salen complexes
Darensbourgh et al. Coord. Chem. Rev. 153 (1996) 155; JACS 121 (1999) 107; Coord. Chem. Rev. 107 (2007) 2388
Rieger et al. Chem. Eur. J. 11 (2005) 6298
D. Walther, NachrichtenChemie 55 (2007) 1188
Cocatalyst:Imminium saltsPropyleneoxideTOF (22°C) 1100/h
Cocatalyst:Imminium saltsPropyleneoxideTOF (22°C) 1100/h
No cocatalyst:Selective alternatingPolymerisationTOF (80°C) 3500/h
No cocatalyst:Selective alternatingPolymerisationTOF (80°C) 3500/h
No cocatalyst:SelectiveBlock-Copolymerisation
No cocatalyst:SelectiveBlock-Copolymerisation
» Status of CO2 as building block
Thermal energy requiredlow yields, not efficientHet. (Pd, Rh)+MethaneAcetic acidC-C
Low yields, slow reactionElectron donors, hνCO, MeOH, CH4, …---First applicationsHom. (Co, Zn, Cr)-EpoxidePolycarbonates
No solution for economic removal of waterHom. + het.~0MethanolDimethylcarbonate
C-OC-N
C-H
--
-
-
ΔH
Commercial productionTechnical productionOnly stoichiometric
High TON and TOFnot competitive
Technical productionExcellent selectivity
Evaluation
EpoxideAmmoniaEthylene
Hydrogen
Hydrogen
Starting compound
Hom.Cyclic carbonatesNoneUreaHom. (Mo, Ni)Acrylic acid
Hom. (Ru, Rh)Formic acid
Het. (Zn-CuO)Methanol
CatalystProducts
Table adapted from D. Walther, Nachrichten Chemie 55 (2007) 1188
Chemical energy source
Artificial photosynthesis with Ru(bpy)3
2+
H. Arakawa et al, Chem. Rev. 2001, 101, 953-996Light as energy source
» Conclusions and outlook
The use of CO2 is an attractive option in global CO2 management
» C1 building block for chemical syntheses» Fixation in polymers particularly attractive» Energetically low level
» Reaction with reactive molecules» Equilibrium limited reactions» External energy source
» Inert molecule requiring activation The use of CO2 can not provide a single solution for the reduction of CO2 emissionsOverall energy balance needs to be considered
» Acknowledgements
Walter Leitner
Johannes LercherHerui Dou
EU TOPCOMBIDeutsche ForschungsgemeinschaftFonds der Chemischen IndustrieDr. Ing. Leonhard Lorenz Stiftung