molecular-level kinetics in chemical engineering: from

9/9/2015

1

Molecular-level Kinetics in Chemical Engineering: From Chemical to

Mathematical ModelingKRG

University of Delaware [email protected]

Outline

• Chemical Modeling

• Elements of Chemical Modeling

Structure

Reaction Paths and Kinetics

Detailed Kinetic Modeling Approaches

• Computational Tools

• A Practical Hybrid Approach

• Conclusions

2

9/9/2015

2

Chemical Modeling Complements Real System Experiments

3

• Generally Whole-feed (e.g., Resid, Coal, Lignin) Experiments

• Pilot Plant or Lab Scale• Global feed, Global Product Measurements• Lumped Model

The direct and practical approach to obtaining chemical information:

Real Experiment

Real

System

Real

Results

Chemical Modeling

Limitations of Lumped Models

• Absence of chemical structure

• Consequence: absence of properties beyond definition of lump

• Conflict: new questions of unprecedented molecular detail

performance

environmental

reactivity

• Motivates molecular-level modeling

4

9/9/2015

3

Chemical Modeling Complements Real System Experiments

5

Accurate Chemical Modeling Requires Rigorous Mapping Steps

MS and RSbetween sdifference theaddress toTransform Modeling Chemical Inverse

domains Model and Real common to kinetics intrinsic procure todesigned Experiment System Model

MS and RSbetween sdifference theaddress toTransform"" Modeling Chemical

1

CM

ME

CM

Chemical Modeling

Elements of Chemical Modeling

6

CM• Simulation of Structure: CME• Optimization of 10K+ Molecular Composition: CME

ME• Network Analysis: DelPlots• LFER Analysis: Organization of 10K+ Rate, Adsorption and Thermodynamic Parameters• Extrinsic Effects: Kinetic Coupling; Solvent Effects; Phase Behavior, Transport• Novel Reactors

CM-1

• 10K+ Multifunctional Molecules: Implicit Equations via Monte Carlo Simulation of Kinetics• Equation Generation: NetGen, OdeGen• Kinetic Coupling: Accounting for Interactions; Optimal System Design• Transport: Molecule vs. Moiety; Size and Matrix Effects• ARM: Modeling N molecules with fewer than N equations

9/9/2015

4

Basic DelPlot Analysis (9/8/15)

7

A A, B, C, D, ...

Object is to determine the rank* of each product

y

x

i

A

xA

r > 1

non-zero intercept 1o

0 1

*Generations removed from reactant

Basic DelPlot Exposes Primary Products

8

0.60.50.40.30.20.10.00.0

0.2

0.4

0.6

0.8

X

Y/X

1 B 3 C; A 2 DA

-1k1 /min -1 = 1, k 2 /min = 2, and k 3 /min -1 = 4.

D

B

C

9/9/2015

5

Second-rank DelPlot Exposes Generations

9

k1/min -1 = 1, k1/min -1 = 2, and k3/min -1 = 4.

0.60.50.40.30.20.10.0.1

1

10

100

X

Y/XD

B

C

2

1 B 3 C; A 2 DA

Extended DelPlot Analysis

10

•

R = r

R < r

R > r

yi

XA

r

XA

9/9/2015

6


11



CM-1


Reaction Families Organize Pathways and Kinetics*

12

• Reaction Families:– Allow for computer-generated reaction paths

– Allow for massive parameter reduction via LFER organization

• Reaction Family: a set of reactionshaving similar transition states

index reactivity is where,ba = ln

H G

or 0

RIRIk

HSS

RI

lnk

ln k = a + b RI

*9/22/15

9/9/2015

7

Geometric Rationalization of LFER

13

• Physical picture of hypothetical reaction:Na + RCl NaCl + R•

• Variation of R gives Reaction Family

E*

q

BDE+Ip-Ae

†1

†2

Na+, Cl-, R•

Na, Cl•, R•

Na + RClR• + NaCl

BDE (R-Cl)

E*=q = ' RI


14



CM-1


9/9/2015

8

DBE Pyrolysis Mechanisms*

15

Free-Radical Mechanism Concerted Mechanism

k1 +

+k2 +

+k2’ +

k3 +

+k4 products

O

HH

O

H

RDS

+

+

‡

‡

b

c

RDS

*11/17, 19

The kinetics of hydrogen abstraction provide the probe of the mechanism

16

The options for hydrogen abstraction:

+ A H + '

X'+ A XH +

Consequences:

+ XD D + X'

D favored as XD/A D/(D + H) = DI 1.0 as XD/A Kinetics analysis shows XH = D

Hydrogen Abstraction Kinetics

9/9/2015

9

Free-Radical Pyrolysis of PDD

171/R (Moles PDD/Mole tetralin - d )12

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.0

0.0 0.2 0.4 0.6 0.8 1.0

DI

Experimental Example of Kinetic Coupling

18

DBE enhanced with PPE PPE impeded with DBE

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 20 40 60 80 100time / min

Mo

lar

Yie

ld D

BE DBE Neat

5:1 DBE:PPE

1:1 DBE:PPE

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 20 40 60 80 100

time / min

Mo

lar

Yie

ld D

BE

PPE Neat

1:1 PPE:DBE

9/9/2015

10

Two-Component Rice-Herzfeld Pyrolysis

19

A1 2 1 A2 2

1 + A1 P1 1 2 + A2 2 + P2

1 1 + Q1 2 2 + Q2

1 + A2 2 + P1

2 + A1 1 + P2

1 + 1 i + j 2 + 2

1 + 1 i + j 2 + 2

1 + 1 i + j 2 + 2

k11

k1

1

''11

11

'11

k22

k2

2

''22

22

'22

k12

k21

ij

' ij''ij

Rate Laws for Coupled Binary Systems

20

12

12

1 1111 1 1 2 2 2

111 1 2

11 1

211 1 51 22 21 1 22 1 1 2 3 2 2 2 12 3

2

22 1

12

1 122 2 2

11

2 1 2

1 1

,1

1 1 1 11

1

,

Ak A k S S

r A AN

Nk S

M k S k S M k SN

Nk S

Ak A k

r A A

1

1 222 11 2 2 2 1 2

1 21 2 2 1

11 1

21 1 1 51 22 21 1 22 1 1 2 3 2 2 2 1

2 32

22 1

1 1 1

1

1 1 1 11

N NS S k S N N

k S k SN

Nk S

M k S k S M k SN

Nk S

9/9/2015

11

Chain Transfer Limiting Case

21

One Component Pyrolysis

A1 21

1 + A 1k11 1H +1 1 + A2

k12 1H + 2

1 k1 1 + Q1 2 + A1

k'21 A2 + 1

2 1t

Products1 + 2

t

1 + 2t Products

Additional Reactions with Solvent

Volcano Curve for Pyrolysis with Chain Transfer Solvent

22

120110100908070

0

1

2

Bond Dissociation Energy µ2-H [kcal/mol]

E

Fixing species 1 [d°(1-H) and d°(1-H)]

Pyrolysis with Chain Transfer Solvent

9/9/2015

12

Coal Liquefaction Efficiency

23

0

10

20

30

40

50

60

70

80

90

100

70 80 90 100

An-H2

Py-H2 Phen-H2

AceN

TetInd

Me-N

Bond Dissociation Energy / kcal mol

Coa

l Con

vers

ion

toT

HF

Sol

uble

s

UD Computational Tools*

• Develop usable approaches and software tools for molecule-based kinetic modeling of complex feeds

• Maintain fundamental chemistry as the primary focus

• Link quantum and engineering levels

• Produce models that are compatible across a process (e.g., refinery)

• Deliver in a user-friendly format

24*10/13, 15, 20 and 11/22

9/9/2015

13

UD Software Tools

Total Molecular Footprint

Feedstock Mole Fractions

Feedstock MoleculesMolecule Reactivity

Experimental Data on Feedstock

Interactive Network

Generator• Automatically builds reaction

network based on feedstock molecules, reaction chemistries, and reaction rules

Kinetic Model Editor• Builds and solves kinetic model

• Optimizes kinetic parameters using reactor experimental data

Composition Model Editor• Optimizes mole fractions

using experimental data

Experimental Data on Reactor

25

Interactive Network Generator

Kinetic Model EditorComposition Model Editor

UD Software Tools

26

9/9/2015

14

Composition Model

Editor

Interactive Network

Generator

Kinetic Model Editor

UD Supporting Apps and Tools

CoreGen• Creates core structures

HOUGen• Creates molecular identities of general hydrocarbon mixtures

PropGen• Estimates physical properties of molecules

Universal Sampling Builder• Sampling protocol between structural attribute pdfs and molecular compositions

Composition Model Visualizer• Bulk

Properties

Molecular Weight

CME‐Plastics• Light‐weight CME

applied to linear polymers

27

Interactive Network Generator

Kinetic Model EditorComposition Model

Editor


INGen Network Merge• Merges reaction networks, removes duplicates

Reaction NetworkVisualizer

File Converters• Molecule file conversion between BE matrix, adjlists, SMILES code, CML, MOPAC, CT, and images

28

9/9/2015

15

Kinetic Model Editor

Interactive Network

Generator

Composition Model

Editor


KME Results Analyzer• Visualize details of kinetic model solution

Reactions producing propane

TGA Simulator• Kinetic model for ThermogravimetricAnalysis

CodeGen• Converts reaction list to differential equations

KME Flowsheet• multiple reactors• simple separation

Milano Script Gen• Generates Milano‐style equations for a model

29


INGen Network Merge• Merges reaction networks, removes duplicatesReaction

NetworkVisualizer

KME Results Analyzer• Visualize details of kinetic model solution

Reactions producing propane

TGA Simulator• Kinetic model for ThermogravimetricAnalysis

CodeGen• Converts reaction list to differential equations

CoreGen• Creates core structures

KME Flowsheet• multiple reactors• simple separation

HOUGen• Creates molecular identities of general hydrocarbon mixtures

PropGen• Estimates physical properties of molecules

File Converters• Molecule file conversion between BE matrix, adjlists, SMILES code, CML, MOPAC, CT, and images

Universal Sampling Builder• Sampling protocol between structural attribute pdfs and molecular compositions

Composition Model Visualizer• Bulk

Properties

Molecular Weight

CME Express• Fast local optimization for similar compositions

Milano Script Gen• Generates Milano‐style equations for a model

CME‐Plastics• Light‐weight CME

applied to linear polymers

30

9/9/2015

16

Molecular-level Modeling Requirements

1. Composition Models: CME– Measurements (GS-MS, NMR, etc.)

– Modeling: Properties -> Molecular Structure

2. Reaction Network Modeling: INGen– N < NC: “Conventional” deterministic methods

– N > NC: Hybrid methods, e. g., The Attribute Reaction Model

3. Reaction Modeling: KME– Model parser and solver in various engineering modes

– Order 10 [O(10)] LFER’s for every process chemistry

4. Property Estimation: CME– Molecular Structure -> Properties

– End-use and internal-use properties

CCCCc1c2ccc(Sc3cc4cc(C)c5cc(CC)cc6cc(Sc7ccc(CCC)c(c7)c7cccc(CCCCCC)c7)c(c3)c4c56)cc2cc2sc3cc(C)ccc3c12

RI

lnk

ln k = a + b RI

31

GasolineNaphtha

Kerosene LGO HGO VGO

MW(g/mol) 83.2 130.5 168.5 211.5

345.1

469.0

H/C ratio 1.97 1.46 1.62 1.64 1.77 1.63

Distillation

IBP(K) 297 376 476 545 594 696

10BP(K) 302 437 479 546 633 705

30BP(K) 310 460 498 546 653 723

50BP(K) 318 460 517 559 669 743

70BP(K) 326 461 517 572 677 791

90BP(K) 334 461 532 584 690 805

EBP(K) 358 461 544 588 693 810

CME Converts Measurements to Molecules

CME

AttributePDFs

SimulatedCompositions

AvailableMeasurements

Molecules

SimulatedProperties

Adjust

32

9/9/2015

17

XH

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

Attribute Probability Distribution to Generate Molecular Species

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

Pro

babi

lity

XX

XXX

X

XO

X

XS

SX

X XO

H

X

O

OH

X

2. Optimization of Probability Distributions:• Initially uniform probability• Minimization of objective function

Cores Inter-unit Links Side Chains

33










34

9/9/2015

18

Equivalent Computational Representations

Bond Electron Matrix Adjacency List

C(C(C(H3)H2)C(C(H3)H2)H2)String Code

CCCCCSMILES Code

35

Chemical Reaction as a Matrix Operation

+

C1 C2 H1 H2

C1 0 1 0 0

C2 1 0 0 0

H1 0 0 0 1

H2 0 0 1 0

C1 C2 H1 H2

C1 0 0 1 0

C2 0 0 0 1

H1 1 0 0 0

H2 0 1 0 0

C1 C2 H1 H2

C1 0 ‐1 1 0

C2 ‐1 0 0 1

H1 1 0 0 ‐1

H2 0 1 ‐1 0

+ =

Reduced Reactant Matrix

Reaction MatrixReduced

Product Matrix

+

MA MR MB

36

9/9/2015

19

Structure/Reactivityparameters

Rate law parameters

InputGraph of reactant molecule

Determine species type

Determine connected components

Determine products uniqueness (isomorphism)if unique, add to unreacted species list

Add reaction expression to the list

Obtain species from unreacted list

Determine reaction sites and apply reaction matrices

Determine Reactivity Index(CQC, GA, Data Base, etc.)

Network Building Algorithm

37

INGen Output: Species Analysis

38

9/9/2015

20

INGen Output: Network

KME Compatible

Network

Reaction Family

39

Co-Processing of BPO & HGO

Pyrolysis Unit

BiomassBPO

(Biomass Pyrolysis

Oil)

HGO (Heavy

Gas Oil)

HydrotreatingUnit

Commodity Chemicals

& Fuels1-α

α

Hydrogen

Water Water

9/9/2015

21

Lignin Monomers

41

Freudenberg Lignin Model as a String

Substituents: 39 Attributes

Cores : 19 Attributes

63 Connections:

CML Input from ChemDraw

O=CC=Cc1cc(OC)c(c(c1)c1cc(cc(c1O)OC)C1OCC2C1COC2c1ccc(c(c1)OC)OC(C(c1cc(OC)c(c(c1)Oc1ccc(cc1OC)C(C(Oc1ccc(cc1)C(C(Oc1ccc(cc1OC)C(C(Oc1ccc(cc1)C(C(CO)C)C)CO)Oc1ccc(cc1OC)C(c1cc(ccc1O)CC(=O)CO)C(CO)C)CO)O)CO)O)O)C)CO)OC(C(c1ccc(c(c1)OC)O)Oc1c(OC)cc(cc1c1cc(cc(c1O)OC)C1C2C(=O)OCC2C(c2c1cc(OC)c(c2)OC)O)C(C(Oc1ccc(cc1OC)C(c1cc(O)c(cc1C1Oc2c(C1CO)cc(cc2OC)CC(=O)CO)OC)C(Oc1c(OC)cc(cc1OC)C(C(CO)C)O)CO)CO)O)CO

The computer “knows” Lignin as its SMILES code

42

9/9/2015

22

Pyrolysis Reaction Chemistry

β-O-4 Ether Cleavage Reactions β-O-4 Ether Dehydration α -O-4 Ether Cleavage Vinyl Degradation Pathways

Virk, Michael T. Klein and Preetinder S. "Model Pathways in Lignin Thermolysis. 1. Phenethyl Phenyl Ether." Industrial Engineering Chemistry Fundamentals, 1983: 35-45.John B. McDermott, Cristian Libanati, Concetta LaMarca, and Michael T. Klein. Ind. Eng. Chem. Res., 1990: 22-29.

43

Model Results

• INGen Results: beta and alpha linkage reactions on adapted molecule• 1851 reactions • 295 species

• Kinetic Model Solution Time• C#=30, 2‐3 minutes• C#=60, 1 hour

44

9/9/2015

23

Attribute Reaction Modeling

45

Reducing the Freudenberg Lignin into its Attributes

O

O OH

O HO

O

OHO

OH

O

OH

OHO

HO

O

O

OH

OH

O

HO

O

OH

O

O

O

OOH

O

O

O

O

OH

O

O

O

OH

HOO

OH

OH

OO

O

O

OH

OH

O

O

HO

OH

O

O

OH

OOH

OH

O

O

O

Core Identity IL Identity SC Identity

O

O

O H

O

O H

CoresInter-core Linkages (IL)Side Chains (SC)

46

9/9/2015

24

Attribute Reaction Model Equations

47

Juxtaposition Tracks Molecules

XH

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

Pro

babi

lity

XX

XXX

X

XO

X

XS

SX

X XO

H

X

O

OH

X


9/9/2015

25

Model Results

• Parity plot comparison with literature data

• Once-through solution time: 5 seconds

0

0.05

0.1

0.15

0.2

0.25

0.3

0 0.05 0.1 0.15 0.2 0.25

Predicted values

Observed Values

Data Set 4

Data Set 11

Data Set 2

Data Set 3

Data Set 12

Data Set 13

Data Set 14

Data Set 15

y=x

49

Computational Issues

• Conventional Model

– More than 2000 species (equations) and 10,000 reactions

– Solution time: minutes to hours depending on complexity

• Attribute Reaction Model

– Less than 100 equations and hundreds of reactions

– 5 second solution time

50

9/9/2015

26

Co-Processing of BPO & HGO

Pyrolysis Unit

BiomassBPO

(Biomass Pyrolysis

Oil)

HGO (Heavy

Gas Oil)

HydrotreatingUnit

Commodity Chemicals

& Fuels1-α

α

Hydrogen

Water Water

511

HGO Composition

• Aromatic species

– Cores

– Substituents

• Substituents are further divided into side chains and inter-core linkages

• Paraffins

– C5-C25 n-Paraffins

– C4-C15 2-methyl and 3-methyl Paraffins

52

9/9/2015

27

Hydrotreating Reaction Families*

Reaction Family log A E0*

C‐O Hydrogenolysis 10 21 H2 + →

Dealkylation 10 25 H2 + → +

Decarbonylation 12 6 → + CO

Decarboxylation 14 31 → + CO2

Denitrogenation 10 25 2H2 + → + NH3

Desulfurization 20 36 2H2 + → + H2S

Hydrogenation 10 20 H2 + →

Saturation 2H 10 25 H2 + →

Saturation 4H 10 25 2H2 + →

Saturation 6H 10 18 3H2 + →

Water Gas Shift 10 11 H2O + CO → H2 + CO2

S

53*10/22/15

Hydrotreating Reaction NetworkReaction Family BPO HGO Sum of Models Combined Model

COHydrogenolysis‐Oxygen 1,052 0 1,052 1,052

Dealkylation‐Aromatic 12 39 51 45

Dealkylation‐MultiRing 0 119 119 119

Dealkylation‐Nap6 12 39 51 45

Dealkylation‐Oxygen 269 0 269 269

Decarbonylation‐Oxygen 107 0 107 107

Decarboxylation‐Oxygen 21 0 21 21

HDN‐Nitrogen 1 4 5 4

HDS_4H‐Sulfur 0 4 4 4

Hydrogenation‐Aromatic 5 7 12 10

Hydrogenation‐IsoOlefin 0 1 1 1

Hydrogenation‐MultiRing 0 8 8 8

Hydrogenation‐Nap6 5 7 12 10

Hydrogenation‐NOlefin 2 3 5 3

Hydrogenation‐Oxygen 64 0 64 64

Saturation2H‐MultiRing 1 3 4 3


Saturation4H‐Nitrogen 0 2 2 2

Saturation4H‐Oxygen 8 0 8 8

Saturation6H‐Aromatic 18 45 63 51


Saturation6H‐Nitrogen 0 4 4 4

Saturation6H‐Oxygen 157 0 157 157

WaterGasShift‐Oxygen 1 0 1 1

Total 1,747 475 2,222 2,178

541

9/9/2015

28

Profile Plot of Major Species

0

10

20

30

40

50

60

70

80

90

100

0.E+00 2.E‐06 4.E‐06 6.E‐06 8.E‐06 1.E‐05

Molar Flow Rate (mol/s)

Reactor Length (dm)

0

2

4

6

8

10

12

14

0.E+00 2.E‐06 4.E‐06 6.E‐06 8.E‐06 1.E‐05

Molar Flow Rate (mol/s)

Reactor Length (dm)

water

methane

carbon dioxide

carbon monoxide

cyclohexane

methylcyclohexane

furan

1,3‐dimethylcyclohexane

oxepane

hexane

o‐cresol

2‐methoxyphenol

4‐hydroxy‐3‐methoxybenzaldehydephenol

6,8‐dioxabicyclo[3.2.1]octane‐2,3,4‐triol2‐methoxy‐4‐methylphenol

2,4‐dimethylphenol

formic acid

furan‐2‐carbaldehyde

2‐hydroxyacetaldehyde

acetic acid

hydrogen

PFR, 1,000 atm pressure, 800 K

551

Preliminary Status

• Quantitative organization of science and engineering knowledge base

• Identified some key technology gaps, science needs• Petroleum was inherently profitable, which allowed

for 100+ years of technology development• Biomass not inherently competitive, issues need to

be addressed• H2 consumption: expensive• H2 consumption: CO2 footprint• H2O release

• O rejection as H20 or CO2?• Energy density

56

9/9/2015

29

Conclusions

• Irreducible complexity, as measured by model parameters:

– Structure: O(10) 5-10 pdf’s 2-3 parameters each

– Reactivity: O(10) 10 LFER’s 2 parameters each

– Reaction Families:O(10) Reaction Matrices

• Rigorous kinetics can model interactions and competitions

• Net reduction of complexity: O(105 105) parameters reduced to

0(30)

• Combinatorial detail easily handled by

– INGen

– KME

– CME

57

CME Converts Measurements to Molecules

CME

AttributePDFs

SimulatedCompositions

AvailableMeasurements

Molecules

SimulatedProperties

Adjust

58

9/9/2015

30

XH

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

Attribute Probability Distribution to Generate Molecular Species

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

Pro

babi

lity

XX

XXX

X

XO

X

XS

SX

X XO

H

X

O

OH

X

2. Optimization of Probability Distributions:• Initially uniform probability• Minimization of objective function


59










60

9/9/2015

31

Lignocellulosic Biomass

[1] Yang H, Yan R, et al. Energy & Fuels. 2006. 20 (1), 388-393.[2] Freudenberg K, Neish AC. Science. 1969. 165 (3895), 784.

0%

10%

20%

30%

40%

50%

Composition, m

ol%

C

H

O

CelluloseC6H10O5

HemicelluloseC5H8O4

Lignin2

C10H12O3

61

Adapted Freudenberg Structure

Formed from three monolignols Phenolic copolymer

linkages• α-O-4 linkages• β-O-4 linkages

There is a propensity toward the β-O-4 linkage forming with it comprising upwards of 50-70% of linkages of the lignin [1]

[1] Lewis, Laurence B. Davin and Norman G. "Dirigent Proteins and Dirigent Sites Explain the Mystery of Specificity of Radical Precursor Coupling in Lignan and Lignin Biosynthesis." Plant Physiology, 2000: 453 462

62

9/9/2015

32

Exhaustive Method Reaction Network

Seven degradation pathways and many reactive sites on the lignin macromolecule create a combinatorial problem

– Within INGen the amount of species reaches a computational limit due to the amount of memory required to store species information

Two separate reaction networks were created for linkage and vinyl cleavages respectively and merged to create an overall network.

63

Probability Distributions to Mole Fractions

Pro

babi

lity

Side Chains

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

0

0.1

0.2

0.3

0.4

0.5

Cores Inter-unit Links

XH

XO

X

XS

SXX

X

XXX

X

XX XO

H

X

O

OH

XH

XH

XX

64

9/9/2015

33

• Inter-core Linkages cleave to two side chains

• Side chains react to form smaller side chains and irreducible molecules

• Cores can break down to form smaller cores and irreducible molecules

• Char formation

Reactions between Attributes

65

BPO Composition: Major Species

# Major Species Name ChemDraw NameNetwork Species #

Mole Fraction

1 water water species2 0.566

2 acetic acid acetic acid species110 0.047

3 glycolaldehyde 2‐hydroxyacetaldehyde species42 0.047

4 furfural furan‐2‐carbaldehyde species129 0.030

5 formic acid formic acid species127 0.025

6 2,4‐dimethylphenol 2,4‐dimethylphenol species28 0.023

7 4‐methylguaiacol 2‐methoxy‐4‐methylphenol species48 0.022

8 levoglucosan 6,8‐dioxabicyclo[3.2.1]octane‐2,3,4‐triol species107 0.017

9 phenol phenol species154 0.015

10 vanillin 4‐hydroxy‐3‐methoxybenzaldehyde species94 0.015

11 2‐methylphenol o‐cresol species145 0.013

12 guaiacol 2‐methoxyphenol species52 0.013

Total 0.834

661

9/9/2015

34

Effect of Catalyst on BPO Composition

Fast Pyrolysis

# Species Name wt%

1 dimethylphenol 7.0

2 levoglucosan 5.0

3 acetic acid 5.0

4 glycolaldehyde 5.0

5 furfural 5.0

6 methoxytoluene 4.5

7 methylguaiacol 4.2

8 vanillin 4.0

9 methylphenol 3.5

10 guaiacol 2.8

~~~ ~~~~~~~~~~~~~~~~~ ~~~ ~~~~~~~

129 4‐ethyl‐2,6‐dimethylphenol

0.05

Catalyzed Pyrolysis

# Species Name wt%

1 toluene 7.1

2 ethylbenzene 3.4

3 2‐methylnaphthalene 3.3

4 naphthalene 2.8

5 dimethylnaphthalene 2.5

6 methylphenanthrene 2.3

7 xylene 2.1

8 dimethylphenol 1.6

9 benzene 1.6

10 trimethylbenzene 1.5

~~~ ~~~~~~~~~~~~~~~~~ ~~~ ~~~~~~~

70 phenanthrol 0.01

67

HGO Composition: Cores

Aromatic Cores Sulfur-containing Cores

Nitrogen-containing Cores

681

9/9/2015

35

HGO Composition: Substituents

X

Inter-Core LinkagesSide Chains

Attribute Juxtaposition DetailsMonomers & dimersCoordination number: 4

691

molecular-level kinetics in chemical engineering: from

Documents