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HC C H 2 CH OH HC C H 2 CH OH CH 3 O OCH 3 CH 3 O O C 6 H 11 O 5 O C 6 H 11 O 5 Fig. 11: Lignin monomer; coniferine (left) and syringine (right). Lignins result from the oxidative polymerization of three phenolic alcohols. Biosynthesis of these alcohols is carried out in one sequence of enzyme-induced stages. From aromatic aminoacid (phenylalanine, PhAla) comes the double bond CH=CH and then, hydroxyl groups -OH are introduced into the aromatic nucleus. Lastly, transformation of these groups in methoxylic substituents supervenes. In the course of this process, three principal acids are formed, esterified, and reduced to phenolic aldehydes or alcohols. The formulae of these alcohols follow [Lin et al.]: CH 2 OH CH CH CH 2 OH CH CH CH 2 OH CH CH OMe MeO OMe OH OH OH 1 2 3 Fig. 12: Formulae of three principal lignin alcohols. 1: 3-(4-Hydroxyphenyl)-2-propen-1-ol (alcohol coumaryle), 2: 3-(3-methoxy-4-hydroxyphenyl)-2-propen-1-ol (alcohol coniferyle), 3: 3-(3,5-dimethoxy-4-hydroxyphenyl)-2-propen-1-ol (alcohol sinapyle). — 50 —
The first stage of lignin polymerisation consists in enzymatic dehydrogenation of these alcohols that gives phenoxy radicals characterised by four isometric forms. This degradation of alcohols takes place in the presence of peroxydase enzymes. CH 2 OH CH CH CH 2 OH CH CH CH 2 OH CH CH HC CH 2 OH CH C R1 O R2 R1 O C R2 R1 O R2 R1 O R2 Fig. 13: Lignin polymerisation. R 1 , R 2 = H or OCH 3 . The second stage of polymerisation consists in formation of random bonds between these radicals that give rise to the three-dimensional molecule of lignin. The nature of bonds originated in this procedure is varied, as is shown in Fig. 14 below: CH 2 OH CHO CH 2 C O C O CH 2 HO CH HO CH 2 C O A B C OH OH Fig. 14: Types of bonds that occur in lignine [Lin et al.] (See continuation on p. 52). A) Arylglycerol β-aryl ether, B) Glyceraldehyde 2-aryl ether, C) Noncyclic benzyl aryl ether. — 51 —
Page 1 and 2: N° d’ordre : 2283 THESE présent
Page 3 and 4: — 3 —
Page 5 and 6: Appendices Appendix A: FTIR working
Page 7 and 8: Appendix D Fig. D-1: Michelson inte
Page 9 and 10: Acknowledgements Firstly I must exp
Page 11 and 12: 1. Introduction Accumulation of var
Page 13 and 14: Oil is produced by condensation of
Page 15 and 16: There are 4 main techniques of recy
Page 17 and 18: 2.2 Thermal analysis A typical meth
Page 19 and 20: Tab. 1: Principal thermoanalytical
Page 21 and 22: a point of inflection at a faster h
Page 23 and 24: can react with porcelain or alumina
Page 25 and 26: The use of Arrhenius equation which
Page 27 and 28: their kinetic parameters are false.
Page 29 and 30: statistical analysis allows one to
Page 31 and 32: The ability to handle multi-step re
Page 33 and 34: The solution for avoiding these pro
Page 35 and 36: quantifying the experimental result
Page 37 and 38: 2.4 Polymers The word polymer has i
Page 39 and 40: - linear - branched - network Fig.
Page 41 and 42: * Hydrogen bonds (hydrogen bonding
Page 43 and 44: • Non-recyclable via standard tec
Page 45 and 46: Polymers formed via this process in
Page 47 and 48: [Mathias]: proteins, polypeptides,
Page 49: Fig. 10: Cut through a young black
Page 53 and 54: H 2 COH HC O HCOH OMe OMe HC CH CH
Page 55 and 56: Notwithstanding, lignins can be mad
Page 57 and 58: monomer CH 2 OH HC O HO CH second m
Page 59 and 60: Lignin Lignin CH 2 O, Na 2 SO 3 CH
Page 61 and 62: Cellulose is a component part ensur
Page 63 and 64: 1) Extrusion of films: food packagi
Page 65 and 66: HIPS or Impact polystyrene Commerci
Page 67 and 68: H * C C H n* 2 Fig. 23: Elementary
Page 69 and 70: 2.4.5 PVC PVC is the second most ut
Page 71 and 72: As a matter of fact, PVC is more an
Page 73 and 74: In all experiments, samples of EVA
Page 75 and 76: 3.2 Part A Kinetic study of the the
Page 77 and 78: Now, several experiments using vari
Page 79 and 80: Otherwise, its value would have to
Page 81 and 82: 3.2.2 Kinetic model in literature 3
Page 83 and 84: 3.2.2.2 Cellulose From the point of
Page 85 and 86: 3.2.2.3 Ethylene vinyl acetate At p
Page 87 and 88: HC H O H 2 H H 2 2 H 2 C C C C C C
Page 89 and 90: 3.2.2.4 Polystyrene The PS degradat
Page 91 and 92: formation of gases that add to thos
Page 93 and 94: naphtalene and anthracene) is forme
Page 95 and 96: them to find the third stage that w
Page 97 and 98: 3.2.3 Analysis of experimental resu
Page 99 and 100: degradation. Thus, the evaluation o
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3.2.3.3 Ethylene vinyl acetate The
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3.2.3.4 Polystyrene The pyrolysis b
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3.2.3.5 Polyvinyl chloride The pyro
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3.2.4 Discussion and conclusions In
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The thermal degradation consists of
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3.3 Part B Kinetic study of thermal
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Operating methods The type of ligni
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Tab. 16: Comparison of literature a
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Ad 1) Initialisation of parameters:
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77 Theoretical and experimental evo
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Reaction order as a function of tem
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Globally, results connected to acti
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3.3.2 Ethylene vinyl acetate Let us
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graph of mass loss rates of the sum
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parameters are the ones from the pa
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This equation and its coefficients
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Tab. 22: Calculation of VA percenta
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3.3.3 Study of the degradation kine
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Study of the mixture EVA/PS This ch
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EVA/PS mixture Here, three stages o
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Generally speaking, DTG value incre
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Let us remind the initial hypothesi
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The values of relative errors of fr
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The results concerning the order of
Page 149 and 150:
Study of the mixture EVA/PVC and EV
Page 151 and 152:
Tab. 33: Mass loss, DTG, and DTG pe
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dm1 : 30 % at 300°C dm2 : 20 % at
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Xa(T,i)*DTGa(i), (36) where Xa(T,i)
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Chart of PVC modelling: Fig. 50: Co
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dCellulose = k 0 .exp(-E a /RT) (1
Page 161 and 162:
The problem of incoherence between
Page 163 and 164:
Fig. 56: Comparison of experimental
Page 165 and 166:
Conclusion on MatLab simulation res
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Principle of infra-red spectrometry
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Analysis of results of FTIR for pur
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5. time = 1,419.01 s, T = 510°C. T
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2. time = 922.60 s, T = 344°C. The
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Weak peaks of acetic acid can be ob
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• In the pyrolysis of mixtures, n
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4. Discussion and conclusion In the
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5. References ACS, American Chemica
Page 183 and 184:
Day, M., Cooney, J. D., Touchette-B
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Lecomte, D., Bodoira, N., Mise au p
Page 187 and 188:
Oliveira, A. A. M., Kaviany, M., Hr
Page 189 and 190:
Turi, E. A., editor, Thermal charac
Page 191 and 192:
Cao, J., Mathematical studies of mo
Page 193 and 194:
Kissinger, H.E., Variation of peak
Page 195 and 196:
Poutsma, M. L., Fundamental reactio
Page 197 and 198:
Appendices Appendix A Working proto
Page 199 and 200:
are visualized. This tool is very p
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for EVA + EVA* stage 1, T d,max1 [
Page 203 and 204:
Appendix C Detailed description of
Page 205 and 206:
Furnace The furnace used within the
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The above mentioned data were obtai
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Tab. E-3: Cellulose pyrolysis frequ
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Tab. E-7: EVA 25 frequency factors,
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Tab. E-11: Temperatures at various
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Tab. E-15: Activation energies of t
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Tab. E-19: PVC pyrolysis frequency
Page 219 and 220:
Appendix F - Figures for PART A -
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Appendix G - Polymer generalities -
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Appendix H List of publications and
Page 261 and 262:
Appendix I - Notation used A Freque
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