# Presentation: 770353

## NIST Real Fuels Chemical Kinetic 

**Combustion Model Database**
- D.R. Burgess, Jr., T.C. Allison, J.A. Manion, and W. Tsang
- Physical and Chemical Properties Division
*National Institute of Standards and Technology*
**Real Fuels**
-  Transportation, Aviation fuels – gasoline, diesel, jet
-  Mixtures of n-paraffins, iso-paraffins, olefins, naphthenes, aromatics
-  Individual component composition: Gas(C4-C11), Diesel/Jet (C9-C15)
**Model Complexity**
-  Methane/O2 : 	several dozen species	100 some reactions
-  Heptane/O2:	100’s of species		1000’s of reactions
**Problem**
-  for small molecules – keeping track of data is not too difficult
-  for large, complex systems - efficient data management is problematic

## Information Overload means

- _Time Consuming “Bookkeeping Chores”_ just don’t get done
- _Compromised Quality_ in results
- _Data Management is a “rate-limiting step_” in the development of robust, validated models

## State of the Art for Combustion Modeling

**State of the Art for Combustion Modeling**
_**High Performance Tools and Advances**_
-  Advanced Comput. Fluid Dynamics (CFD)
-  Quantum Chemical Methods
-  Master Equation Analysis
-  Automated Mechanism Generation
-  Mechanism Reduction Tools
-  Understanding details of PAH formation
-  etc.

## State of the Art for Combustion Modeling

**State of the Art for Combustion Modeling**
_**High Performance Tools and Advances**_
-  Advanced Comput. Fluid Dynamics (CFD)
-  Quantum Chemical Methods
-  Master Equation Analysis
-  Automated Mechanism Generation
-  Mechanism Reduction Tools
-  Understanding details of PAH formation
-  etc.

_**Archaic Data Management**_** **
-  19th century (computer-wise) paradigms
-  Flat text files
-  Formats traceable to ANSI Fortran (1977)
-  Minimal error checking procedures
-  Minimal electronic “pedigree” documentation
-  *Ad hoc* symbolic species/reactions notation
-  etc.

## Miller, J. A.; Klippenstein, S. J.; J. Phys. Chem. A. 107,  2680-2692 (2003)

- Miller, J. A.; Klippenstein, S. J.; *J. Phys. Chem. A. ***107**,  2680-2692 (2003)

## C2H6              L 8/88C   2H   6   00   00G   200.000  3500.000  1000.000    1

-  1.07188150E+00 2.16852677E-02-1.00256067E-05 2.21412001E-09-1.90002890E-13    2
- -1.14263932E+04 1.51156107E+01 4.29142492E+00-5.50154270E-03 5.99438288E-05    3
- _-7.08466285E-08 2.68685771E-11-1.15222055E+04 2.66682316E+00 1.18915940E+04    4_
- C6H8              H6W/94C   6H   8    0    0G   300.000  3000.000              1
-  0.28481979E+02-0.15702948E-01 0.26771697E-04-0.11780109E-07 0.16573427E-11    2
-  0.93346445E+04-0.12500226E+03 0.15850439E+01 0.40215142E-01 0.78439543E-05    3
- _-0.38761325E-07 0.18545207E-10 0.17949613E+05 0.19112625E+02                   4_
- i-C4H5            H6W/94C   4H   5    0    0G   300.000  3000.000              1
-  0.10229092E+02 0.94850138E-02-0.90406445E-07-0.12596100E-08 0.24781468E-12    2
-  0.34642812E+05-0.28564529E+02-0.19932900E-01 0.38005672E-01-0.27559450E-04    3
-  _0.77835551E-08 0.40209383E-12 0.37496223E+05 0.24394241E+02                   4_
- HCCHCCH            82489C   4H   3          g  0300.00   4000.00  1000.00      1
-  0.01075274e+03 0.05381153e-01-0.05549638e-05-0.03052266e-08 0.05761740e-12    2
-  0.06121419e+06-0.02973025e+03 0.04153882e+02 0.01726287e+00-0.02389374e-05    3
- _-0.01018700e-06 0.04340505e-10 0.06338071e+06 0.06036507e+02                   4_
- c.ccho    11/12/97      c   3h   5o   1    0g   300.000  5000.000 1371.000     1
-  9.97669730e+00 1.15899378e-02-3.93593247e-06 6.08601507e-10-3.52246874e-14    2
- -3.71966345e+03-2.42959564e+01 2.95202753e+00 2.48297051e-02-1.23487153e-05    3
- _ __2.49449869e-09-8.44820686e-14-9.23323349e+02 1.46236244e+01                   4_
- meCy14pd3 bozzelli      C   6H   7    0    0g   300.000  5000.000 1352.000     1
-  1.64509401e+01 1.80104599e-02-6.44365088e-06 1.03095614e-09-6.10814842e-14    2
-  1.54366624e+04-6.72601234e+01-9.87511632e-01 4.83156342e-02-2.09426592e-05    3
-  6.71221112e-10 1.09340225e-12 2.25173499e+04 3.00704019e+01                   4

## NIST Chemical Kinetic Combustion Model Database

- This unified Web site will provide the combustion community with detailed chemical
- kinetic models, along with supporting information, used in modeling applications.
_**Chemical Kinetic Models**_ used for combustion simulations
**Thermochemical Data** for fuel components & reaction intermediates
**Elementary Rate Coefficients** for chemical reactions relevant to combustion
- The primary focus of the Web site is to provide a centralized source of information where _well-documented, annotated reaction sets_ can be downloaded or uploaded.
- Particular emphasis is given towards promoting standards for _nomenclature, notation, traceability, and communication_ in the modeling community.
- This includes providing _systematic classification schemes_ for molecular species and chemical reactions.
- NIST not developing models – just centralized source for data
- Database will NOT warehouse ALL data – will provide links for some information

## NIST Chemical Kinetic Combustion Model Database

- _Current site is working prototype_
- Main current tasks are collecting and organizing data
- _NIST is seeking input and guidance_ from the combustion community with regard to its development in order to improve its content and capabilities.
- http://kinetics.nist.gov/CKMech                http://kinetics.nist.gov/realfuels

## One of a Set of Tools under Development in the Community

**The intent for this site and database is**
**To be complementary** to other mechanism, modeling, and data analysis tools under development
**To target areas** not being substantially addressed elsewhere such as standards, nomenclature, notation, traceability, etc.
**To collect and organize data** to be used eventually in community wide data evaluation process (akin to IUPAC, JPL atmospheric eval’s, but electronic)
**To facilitate collaboration** among the community with regard to process modeling
**To be integrated** into developing infrastructure in the chemical sciences

## Related Complementary Efforts

**EVALUATION**
- JPL Chemical Kinetics and Photochemical Data for Use in Atmospheric Studies
- IUPAC Subcommittee for Gas Kinetic Evaluation
**TOOLS**
- _PrIMe – Process Informatics Model_
- CMCS – Collaboratory for Multi-Scale Chemical Science
- RIOT – Range Identification and Optimization Tool for Kinetic Modeling (MIT)
- MECHMOD (Leeds)
**DATA**
- Burcat’s Thermochemical Database
- Chemkin Thermochemical Database (Sandia/Reaction Design)
- GRI-Mech Combustion Model
- SNL High Temperature Thermodynamics Database
- LLNL Combustion Chemical Kinetic Mechanisms
- Cal Tech Reaction Mechanism Library compilation
- NIST Chemistry Webbook
- NIST Chemical Kinetics Database

## NIST Detailed Chemical Kinetic Combustion Model Database

**Overview**** **
- _Chemical terminology_, definitions, etc.
- Links to related effort, etc
**Models**
- _Archival "flat file" listings_ of detailed chemical kinetic models with brief descriptions
- _Dynamical "relational" datasets_ of detailed chemical kinetic models with links to species, reaction, and bibliographic information
**Bibliography**
- _Supporting documentation_ for models, reactions, and species
**Species**
- _Molecular identifiers_ such as CASNO, chemical names, etc
- _Molecular structures and chemical information_ such as structural/chemical formulae, SMILES strings, NIChI identifiers, MDL mol files, chemical classes, etc.
**Reactions**
- _Tools_ to search, manipulate, and compare individual reactions or reactions by class for specific detailed kinetic models or among models or build a model based on recommended values

## Implementation Issues

- Most commonly employed models, thermochemical & chemical kinetic datasets, and databases are “**FLAT**” with regard to chemical speciation and reaction typing.
- One species
- One reaction
**...** after another
**Issue**:	Common employed chemical databases are not “chemical” in nature
**Problem**: 	Architecture hampers searches based on chemical properties
_**Need to Identify Species by Chemical Functionality**_ (e.g.)
- CH3CH2CH2CH3 (n-Butane) is a _normal alkane_
- CH2=CH-CH=CH2 (1,3-Butadiene) is a _conjugated alkadiene_
- CH3CH2CH2CH2O (n-Butoxy) is an _alkoxy radical_

## Chemical Kinetic Data typically in “Flat” Format lacking Descriptive Info

- CH4 + H 	= H2 + CH3  	1.300E+04	3.00 	33600.
- CH4 + O     	= OH +CH3     	6.923E+08	1.56	35500.
- HO2 + CO	= OH+CO2     	1.500E+14 	0.0   	23600.
- C2H3O + OH  	= CH2CO + H2O	5.00E+12	0.0    	0.0  	! Estimated
- C4H6 + O  	= HCO + aC3H5	6.00E+08	1.45  	-860. 	! Fontijn
- CH3 + C2H 	= C3H3 + H     	2.41E+13	0.0   	0.0  	! Tsang-Hampson
- C2H5 + HCO	= C2H5CHO      	1.81E13    	0.0   	0.0 	! Tsang/Hampson 1986
- C4H4 + CH3 	= n-C4H3 + CH4	3.98E+11  	0.0	4972. 	! 85SCH/CLA
- C4H4 + C2H 	= n-C4H3 + C2H2	3.90E+13  	0.0   	0.0 	! 80TAN/GAR
- R4CH3 + R72C3H7 	= C4H10  	1.7E+13  	0.0  	0.0  	! CO 329 KB
- C4H10 + R1H     	= H2+R20C4H9	5.6E+07  	2.0  	7700.  	! ME 191 CW
- C*CC.C + H 	= C2H3 + C2H5	9.63E+32 `	-5.2	32320.  	! n51
- C*CC*C + CH4    	= C*CC.C + CH3	1.36E+14 	-0.04 	57100.  	! n55
- No **standard symbols** used for species
- No indicator of **reaction type** (*e.g.*, bond scission, abstraction)
- No links to **related reactions**
- No links to other **possible rate expressions**
- No indicator of **datatype** (expt, review, analogy) and **quality** (limited temp range, etc)
- No **standard reference** system, sometimes no references included
- References often not **original sources**
- No links to a bibliographic database

## Reaction Set in a Dynamic Linked Format

- Reaction String
- Standardized Symbols for Species
- Links to more information

- Reaction Classification
- -e.g. abstraction, bond fission
- -bond broken/formed
- -reaction sites

- Arrhenius parameters

- Reaction Datatype
- e.g., expt, review, est

- Citation

- Links to NIST Chemical Kinetics Database

## http://kinetics.nist.gov/CKMech

**http://kinetics.nist.gov/CKMech**

## Slide 16

## Slide 17

## Slide 18

## Slide 19

## Slide 20

## Species by Molecular Formula

## Species Chemical Class

## PAH Classification

## Slide 24

## Slide 25

## Slide 26

## Slide 27

## Reaction Set Input 

- Reaction Set Input
- Flat Text File

## Reaction Species Set

## Reaction Set in a Dynamic Linked Format

**Reaction Set in a Dynamic Linked Format**

## Species Images w/ Reactions

## All Reactions for a Species

## All Reactions for General Class

- C-H abstraction by O centered Radical

## All Reactions for a Specific Type

- From a R-CH=CH-H Site

## Compare Models

## Slide 36

## NIST Chemical Kinetic Combustion Model Database

- This unified Web site will provide the combustion community with detailed chemical
- kinetic models, along with supporting information, used in modeling applications.
_**Chemical Kinetic Models**_ used for combustion simulations
**Thermochemical Data** for fuel components & reaction intermediates
**Elementary Rate Coefficients** for chemical reactions relevant to combustion
- The primary focus of the Web site is to provide a centralized source of information where _well-documented, annotated reaction sets_ can be downloaded or uploaded.
- Particular emphasis is given towards promoting standards for _nomenclature, notation, traceability, and communication_ in the modeling community.
- This includes providing _systematic classification schemes_ for molecular species and chemical reactions.
- NIST not developing models – just centralized source for data
- Database will NOT warehouse ALL data – will provide links for some information

## NIST Chemical Kinetic Combustion Model Database

- _Current site is working prototype_
- Main current tasks are collecting and organizing data
- _NIST is seeking input and guidance_ from the combustion community with regard to its development in order to improve its content and capabilities.
- http://kinetics.nist.gov/CKMech                http://kinetics.nist.gov/realfuels