March 2016 NAS Workshop
The Changing Landscape of Hydrocarbon
Feedstocks for Chemical Produc<on – Implica<ons for Catalysis
• Today’s prac<ces, challenges, and opportuni<es
• Why not oxygen
• Lots of interes<ng fundamental and prac<cal ques<ons.
• Combining reac<on engineering and catalysis to make wise use of our methane resources.
Ac3va3on of Natural Gas Using Nontradi3onal Oxidants
The
Changing Landscape
of HydrocarbonFeedstocks for Chemical Produc<on – Implica<ons for Catalysis
What’s Changing ?
Vola<lity in price ?
Or
Natural Gas 2016
~ 0.5‐1 ton CO2/ton C
O= C =O
C
‐4
O
‐2
It has not proven possible to parVally oxidize alkanes with oxygen at high rates and low cost
without producing CO2.
The Future of Methane Conversion ?
Our challenge
:
low CO
2release in electricity and transporta3on
and ………… more sustainable chemical produc6on
get value from our resources
HC’s + Cx + H2
catalysis
Need New Catalysts for
DecarbonizaVon of our Shale Gas !
NH
3
SelecVve ParVal OxidaVon and OxidaVve Coupling
of Methane: free energy and enthalpy of reacVon
Oxidant
Reac<on
ΔG
r°
ΔH
r°
O
22CH
4+ O
2
C
2H
4+ 2H
2O
‐295
‐281
NO
22CH
4+ 2NO
2
C
2H
4+ 2H
2O + 2NO
‐221
‐165
Cl
22CH
4+ 2Cl
2
C
2H
4+ 4HCl
‐219
‐169
SO
32CH
4+ 2SO
3
C
2H
4+ 2H
2O +2SO
2‐153
‐83
Br
22CH
4+ 2Br
2
C
2H
4+ 4HBr
‐57
‐3
NO/N
22CH
4+ ½ NO+ ¼ N
2
C
2H
4+ ½ H
2O +NH
3‐8
‐31
I
22CH
4+ 2I
2
C
2H
4+ 4HI
131
183
heat
2CH
4
C
2H
4+ 2H
2170
202
CO
22CH
4+ 2CO
2
C
2H
4+ 2H
2O + 2CO
219
287
S
22CH
4+ S
2
C
2H
4+ 2H
2S
235
332
2CH4 + 4 S2 2CS2 + 4H2S
2CH
4+2CO
2
4CO + 4H
22CO + 4H
2
C
2H
4+ 2H
2O
2CH
4+ 2CO
2
C
2H
4+ 2H
2O + 2CO
Andrussow Process
Andrussow Process
CH4 + NH3 + 1.5 O2 → HCN + 3 H2O
300 microsecond residence Vme, Pt catalyst or else, COx
NO2
Hg (III) Pt (IVII)
ΔH/ΔG 400 C H2O + ½ C2H4
I
2 (94/36kJ/M)H2 + ½ C2H4
(106/60kJ/M)
Heat
Par<al Oxida<on of CH
4Without CO
22H2 + C
2HBr +2HI+ C
(‐34/‐128kJ/M)
I
24HI + C (60/‐34 kJ/M)
2HCl+2HI + C
I2
Benchmark SMR + CCS
O
2BUT To Suppress Complete OxidaVon
Halogens
: flame retardants:
1) Oxida6ve dehydrogena6on +
2) Suppresses oxycombus6on
‐CH
2‐CH
Br
‐CH
2‐ ‐ ‐ ‐ ‐‐‐ ‐ ‐ CH
2‐CH
2‐CH
2‐
Fredrick Rust, Industrial & engineering chemistry 1949 vol:41 iss:11 pg:2595
This is well known
Oxyhalogena6on/Dehydrohalogena6on for Par6al Oxida6on
Oxychlorina<on (OCL) almost on parity with SMDS for methane
Oxyhalogena<on and
dehydrohalogena<on in one step with I
2Well Known Process (many fundamental ques<ons)
Cl
Polychlorides, CO
xFront. Chem Sci Eng 2013, Vol. 7 Issue (3) : 279‐288
AlF3~ 1000 C 200 kta faciliVes
MgCl2~750 C
Heat, MX
z,X
2,XY
XY= I, Cl, Br
+
H
X/Y
Our Approach Preserva<on of Methane Chemical Poten<al in
an Op<mally Efficient Chemical Processing Plaoorm
C
H
4
‐(C
H
2)‐
C
H
2
Q/eV
H
2
O +
Q
/
eV
O
2,Ox
React for Show, Separate for Dough
CH
4+ XY
H
3C‐X/H
nC
m+ HY
XY
HY
O
2CH
4N
2, CO
xCH
yO
xH
2O
S
CH
4CH
3SH
CS
2H
2S
NO
xCH
4N
2, NO, CO
xH
2O
SO
xCH
4SO
2CH
3SO
3H
H
2O SO
2H
2SO
41981 Jack Kilby, Texas Instruments
HI/HBr/O2 Fuel Cells
HBr
Br2 out
HBr Br2
H
X
has a carrier role in “an electron world”;
it has value!
Cataly<c Oxida<on HBr + O
2less well studied academically (than HCl, Deacon)
but proven in lab and pilot studies
(excess water equilibrium limit at high temp)
Can Make Heat or Electricity
2HX + ½ O
2
H
2O +
X
2Bromination
T~400 C
Catalytic Coupling
T~ 400 C
Br
22H
Br
Solid Oxide
Chem. Com. 2004, 2100
Catalysis Today 2004, 98, 317
Chem.Com. 2004, 566, 658
Phys. Chem.Chem.Phys. 2011, 13,2550
Bromine Mediated Dehydrogena6on in Two‐Phase Reactor System
keep HC away from O
229
Clarence Chang and Tony Silvetsri, Mobil 1970’s
CH3OH
-HBr -HBr -HBr -HBr
CH3Br
CH3Br CH3Br CH3Br CH3Br
Methane
Ethane
!
Propane
!
C6+
!
Methanol/DME"
Olefins! BTX+!
Ethanol" Glycol"
Ethylene!
BTX+!
Olefins"
Ethoxylates"
Propanol"
Propylene!
BTX!
O2/Electricity/Photons H2O / H2
GRT/UCSB Demonstrated Br
2
/HBr Plaoorm
Ethylbromide ethylene (99.5% selecVvity) Propylbromide propylene (99.2% selecVvity)
Butylbromide butene (99.1 % selecVvity)
Ac<va<on:
Methane
Aromatics
Light Olefins
2002: Bromine Mediated DehydrogenaVon
Regenerable Solid Reactant (Br carrier) NiBr2
NiO
•
Bromine Containing Components
Remain at Temperature
Unsolved (Unsolvable?) Issues
‐
Regenerability of solid reactants
sintering
‐
Capacity of supported solids
‐
Hydrocarbon stability over solids
Bromination
T~400 C
Catalytic Coupling
T~ 400 C
Br
22H
Br
Catalytic Oxidation
In The Absence Of A Regenerable Solid,
More Conventional Separations Were Used
34
Methane
Aromatics
Light Olefins Alkanes
Where Prior Methane/Br Work Stopped
Major Issues (that made capital too high):
0.0% 5.0% 10.0% 15.0% 20.0% 25.0% 30.0% 35.0%
Cost (ISBL) by Equipment Type
For Propane Dehydrobromination
Cost Dominated By Indirect Heat Exchange
Change Our Approach:
separa<on in molten salt: MO(H
2O)/MOH + HBr
MBr
2Halogens Remain Hot
Hydrogen as the ul<mate sustainable electron
acceptor CH
4
C + 2H
2
CH4 + 2O2 CO2 + 2H2O
CH4 C + 2H2 2H2 + O2 2H2O
Hydrogen as the ul<mate sustainable electron
acceptor CH
4
C + 2H
2
Barriers and Opportuni<es
~ 0.5‐1 ton CO2/ton HC@$100/ton CO2 ~ 10% inc feed
Enable New low C Fuels, H2, NH3 New routes to fix C
Process IntegraVon/Cost reducVon IntegraVon OpportuniVes (C e‐)