10 -3

10 -2

10 -1

1

Mol

e fr

actio

n

CO2

TiCl4ClCO

TiOCl2

Cl2

TiCl3

500 1000 1500 2000 2500 3000 3500Temperature (K)

N2

TiCl2

TiOClTi

TiCl O

(a) Industrial chlorinator.

10 -3

10 -2

10 -1

1

Mol

e fr

actio

n

CO2

TiCl4

Cl

CO

TiOCl2

Cl2

TiCl3

OH

TiOCl3

O

TiCl3OH

O2

TiOCl

H

500 1000 1500 2000 2500 3000 3500Temperature (K)

HClTi2O2Cl4

Ti5Cl6O8Ti3O4Cl4

TiO2Cl3

Ti2O2Cl2(OH)2

TiCl2OHTiOClOH

(b) Methane flame.

10 -3

10 -6

1

Mol

e fr

actio

n

500 1000 1500 2000 2500 3000 350010 -9

Temperature (K)

ClC(=O)O[Ti](Cl)(Cl)Cl

OC(O)Cl

(c) Industrial chlorinator, low concentrations.

10 -3

10 -6

1

Mol

e fr

actio

n

Temperature (K) 500 1000 1500 2000 2500 3000 3500

OC(O)Cl

ClC(=O)O[Ti](Cl)(Cl)Cl10 -9

(d) Methane flame, low concentrations.

Figure 3: Computed equilibrium compositions. Figure a) shows equilibrium compo-sitions in a rutile chlorinator based on an initial composition containing33.2 mol % TiCl4, 22.9 mol % CO2, 30.5 mol % CO, and 13.4 mol % N2 at3 bar. Figure b) shows equilibrium composition in a methane flame based onan initial composition of 48.5 mol % TiCl4, 3 mol % CH4, and 48.5 mol % O2 at1 bar. The industrially relevant conditions are highlighted in both figures by thegrey region. Figures c) and d) show compositions for the same simulations butshowing lower concentrations and with all species apart from the new speciesshown in grey.

11

Ti

Cl

O

Cl

OC O

O

Ti

Cl

OCl

OC O

OCl

[Ti]1(OC(=O)O1)(OCl)(Cl)Cl

Ti

Cl

OC

O

O

OC

Cl

1NewComb-0-1COCl

C

Cl

Cl OC O

O

C

Cl

ClCl

1NewComb-13-1CCl3

C

Cl

Cl

1NewComb-14-1CCl2

C

Cl

1NewComb-15-1CCl

C

Cl

O O

Cl

C

Cl

Cl OC

O ClC

Cl

Cl OC

O Cl

Cl

C

Cl

O OC O

O

Cl

OC

Cl

O

Cl

C

Cl

Cl OC

O

O

O

Cl

C

Cl

O O

OCl

Ti

Cl

O

Cl

OC

OCl Cl

Cl

C

Cl

CCl4Cl

ClClO

C

Cl

COCl2

Cl

CClCl Cl

O

OC

O

Cl

Ti

Cl

ClO

CO

Cl

Cl

Ti

O

ClO

CCl

ClCl

Ti

ClO

CCl

OCl

Cl

Ti

Cl

Cl OC

OO Ti

OO

CO

Cl

Cl

Ti

ClO

CCl

OO

Ti

OO

CO

O

Ti

Cl

O C

Cl

ClCl Cl

Cl

COO

CO

O

Cl[C]12(Cl)O[Ti]2(Cl)(Cl)O1 OC12O[Ti]2(Cl)(Cl)O1 O[Ti]12O[C]2(Cl)(Cl)O1

Cl[Ti](=O)OC(Cl)(Cl)Cl ClC(=O)O[Ti](Cl)(Cl)Cl ClC(=O)O[Ti](=O)Cl ClC(Cl)(Cl)O[Ti](Cl)(Cl)Cl

O=C1OC(=O)O1

OC(Cl)(Cl)Cl

ClO[C]12(O)O[Ti]2(Cl)(Cl)O1

[Ti]1(OC(O1)(Cl)Cl)(Cl)(Cl)OCl

ClC1OC(Cl)(Cl)O1 ClC1(Cl)OC(Cl)(Cl)O1

ClOC1(Cl)OC(=O)O1

ClOC1(O)OC(Cl)(Cl)O1ClOC(=O)Cl

ClOC1(Cl)OO1 ClC1(Cl)OO1

Ti

Cl

C

Cl

Cl[Ti](Cl)(Cl)C(Cl)(Cl)Cl

Cl

ClCl

Cl

Ti

O

C

[Ti]([C][O])(Cl)(Cl)[O]

Cl

O

ClTi

Cl

C

[Ti]([C][O])(Cl)(Cl)(Cl)Cl

Cl

OCl

Cl

Ti

O

C

ClCl

Cl

Cl

[Ti]([C](Cl)Cl)(Cl)(Cl)[O]

Cl

O Cl

ClO[Ti]12(Cl)OC2(O)O1 O[Ti]12OC2(O)O1

O=C1OC(Cl)(Cl)O1

OC(O)Cl

Ti

Cl

Cl OTi

O

Cl

Cl

Ti2O2Cl4

Ti

Cl

Cl OC

O

Cl

Cl

C

Cl

Cl OC

O

Cl

ClC

OO

CO

Cl

Cl

COO

CO

OTi

OO

CO

Cl

ClTi

Cl

Cl OC

OO Ti

O OC

OO

First-principles thermochemistry for gas phase species in an industrial rutile chlorinator

Raphael Shirley, Weerapong Phadungsukanan, Markus Kraft, Jim Downing, Nick Day, and Peter Murray-Rust

http://como.cheng.cam.ac.uk

CoMoGROUP

Many thanks to St Edmund’s College, Cambridge and The Cambridge Commonwealth Trust.

There is very little chemical interaction between Ti and C in industrial rutile chlorinators.

1. 2. 3.These new species also play no role in the flame synthesis of TiO2. Water is the only important reactant.

Using an RDF database for the dissemination of thermochemical data offers significant advantages.

The Combustion synthesis of TiO2 nanoparticles requires pure TiCl4. This is manufactured by ‘chlorinating’ impure TiO2:

Improving the thermochemistry distribution system is a sec-ondary aim of this work:

Automatic molecule screening

Equilibrium

Carbon species new carbon containing spe-cies are investigated.

Methane flameThe new thermochemistry presented here is used to investigate other reactive systems.

Triplestore databaseThe new distribution system allows easy open access to the data.

Species highlighted in red are found at highest con-centrations at industrially relevant conditions.

TiO2(s) + 2 Cl2(g) + C(s) → TiCl4(g) + CO2(g)

Algorithm builds new species from old set New species are considered by going through all origi-nal TixOyClz species (West et. al., Comb. Flame, 2009) and trying all possible combinations of replacement of Ti with C.

Over 100 species were filtered down to 22 All species manually checked for physically unreason-able geometries.

Geometry optimized with B97-1/6-311+G(d,p) Gaussian03 software package used throughout

e.g.

Triplestore Pattern matching

Results:

?compchem

?cmlurl

?formula (= CiCl

jOkTi

l)

cmlrdf

:repre

sented

By

chemid:EmpiricalFormula

PREFIX cmlrdf:<http://www.xml-cml.org/rdf-schema#>PREFIX chemid:<http://www.xml-cml.org/chemid#>SELECT DISTINCT ?cmlurlWHERE { ?compchem cmlrdf:representedBy ?cmlurl; chemid:EmpiricalFormula ?formulaFILTER regex(str(?formula),"(C[0-9]*)(Cl[0-9]*)?(O[0-9]*)?(Ti[0-9]*)?$","i")}

SPARQL Protocol and RDF Query Language SPARQL can be used to query the database by matching graph patterns.

We provide example Python scripts to retrieve thermochemical data in cantera form for the re-sulting speices.

A SPARQL que-ry and the corre-sponding graph pattern

As well as match-ing the graph pat-tern one can also filter the nodes

Industrial rutile chlorinator New species are present at extremely low con-centrations. They will play no role in industrial re-actors

Methane flameAgain new species are present at extremely low concentrations.

Storing chemical data with CML and RDF CML makes machine access to the data easy.

Querying CML is difficult.

We store data as subject object predicate sentenc-es or ‘triples’. This allows sophisticated queries.

Open accessDatabase is available online:

http://como.cheng.cam.ac.uk/thermodatabase/

The database is extremely flexible...

<?xml version="1.0" encoding="UTF-8"?><cml xmlns="http://www.xml-cml.org/schema"> <module role="joblist"> <identifier convention="chemid:EmpiricalFormula" value="C2Cl4O2"/> <identifier convention="chemid:InChI" value="InChI=1/C2Cl4O2/c3-1(4)7-2(5,6)8-1"/> <identifier convention="chemid:CanonicalSmiles" value="ClC1(Cl)OC(Cl)(Cl)O1"/> <module role="job" title="job1"> <module role="init"> <parameterList> <parameter dictRef="cmlqm:cmd.geom"> <scalar dataType="xsd:string">Geometry optimization</scalar> </parameter> <parameter dictRef="cmlqm:qm.basis"> <scalar dataType="xsd:string">6-311+G(d,p)</scalar> </parameter>

</parameterList> <molecule formalCharge="0" spinMultiplicity="1"> <atomArray> <atom id="a1" elementType="C" x3="-1.663" y3="-1.148" z3="-0.058"/>

</atomArray> <bondArray> <bond atomRefs2="a1 a2" order="S" id="a1_a2"/>

</bondArray> </molecule> </module> <module role="final"> <molecule formalCharge="0" spinMultiplicity="1"> <atomArray> <atom id="a1" elementType="C" x3="-1.662" y3="-1.151" z3="-0.058"/>

</atomArray> <bondArray> <bond atomRefs2="a1 a2" order="S" id="a1_a2"/>

</bondArray> <propertyList> <property dictRef="cmlqm:property.hf298"> <scalar units="units:kcal.mol-1" ataType="xsd:double"> -58.4476055698 </scalar> </property>

</propertyList> </molecule> </module> </module> </module></cml>

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Chemical Markup Lan-guage (CML) CML has a hierarchical structure.

Multidimensional graph structure We turn the CML into a graph.

We use the Resource Description Framework (RDF) to store it.

CML