university of colorado at boulder biomass crackingweb.mit.edu/icck/posters/icck53poster.pdfocho...
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![Page 1: University of Colorado at Boulder Biomass Crackingweb.mit.edu/ICCK/posters/ICCK53poster.pdfOCHO products! [radicals] ≅ 10 pulse-1! τ (nozzle) ≅ 30-50 µsec! 1 mm SiC tube @ 300–1700](https://reader036.vdocuments.us/reader036/viewer/2022081623/61491f8c9241b00fbd675b07/html5/thumbnails/1.jpg)
IR In
tens
ity (A
rb. U
nits
)
3500 3400 3300 3200 3100 3000 2900Wavenumber (cm-1)
! 1 CH3CCH
!
2 C
H3C
CH
C4 H 3O -CHO at RT = BLACK C4 H 3O -CHO at 1300C = RED CH3CCH at RT = BLUE
! !!!
Biomass Cracking
AnGayle Vasiliou1,2, Kimberly Urness1, Krzysztof Piech1, M.R. Nimlos2, J.W. Daily1* and G.B.Ellison1
!
!!
!!
!!!
!
Pyrolysis of Furfural
!!!
1University of Colorado at Boulder *(Mechanical Enginnering )
->Next 20 years energy consumption in the U.S is !!projected to rise by 30% with energy ! ! !!production only to grow 25%.!
!- Biofuels via Biomass (Cellulosic Ethanol).!
!- Reduce the Price of EtOH per gallon by 2012!
!- 30 x 30 – Produce enough EtOH to displace ! 30% of our !current gasoline consumption by ! the year 2030.!
!!
Gasification! CO, H2
“aromatics” → Tars! Clean Up Alcohols! EtOH $$
Sugars!Anhydrous Sugars
Furans, Furfural !5-Hydroxymethylfurfural
CO, H2, Tars
Experimental Apparatus
Ethanol Production
Thermochemical Decomposition
O
OOH
OH
OH
!OCH2OH CHO O CHO O
5-hydroxymethyl furfural!
Levoglucosan dehydrates to furans; mech ?!
Consider thermal fragmentation of furfural.!!!
furan!furfural!levoglucosan!
O
O H
•
• :C
H2C
OH2C
:C
O
H + CO + HCCCH2 CH2=C=O + HCCH CH3C!CH + CO
vinyl carbene "-carbene #-carbene
trace minor major !
HC
HC CH
CHO CH2=C=CH
CHO
CH3C!CH + CO
HCCCH2• + •HCO
H2C
:C CH
CHO
:C
H2C CH
CHO
O=C=CH2 + HC!CH
"-carbene#-carbene
furan
65 kcal mol-169 kcal mol-1
27 kcal mol-1
$rxnH298 = 54.0 ± 0.8 kcal mol-1
$rxnH298 = 52.5 ± 0.7 kcal mol-1
$rxnH298 = 143 ± 3 kcal mol-1
HC
•HC CH
CH•O
HC!CCH2CHO
84 kcal mol-189 kcal mol-1
Adapted from G2(MP2) calculations of Sendt et al., J. Phys. Chem. A, 104, 1861 (2000)
28 kcal mol-1
39 kcal mol-1
HC
HC CH
C• + •HO122 kcal mol-1
• Biomass is plant material: agricultural crops, trees, and grasses. !! Structural polymers — cellulose, hemicellulose, and lignin !!• Thermochemical processing converts solid biomass ⇒ clean liquid fuels and chemicals. ! All from local sources in a way that reduces dependence on carbon stored over geological times.!!• All thermal methods use heat to break the chemical bonds of large ! structural biopolymers ⇒ smaller semi-volatile or volatile units & “char”.!
+
• Furfural thermally initially cracks to produce furan!Further thermal cracking of Furan produces:![CH3CCH + CO] + [CH2=C=O + HC≡CH] !!•Matrix IR of: !
Conclusions/Future
Objectivities for Thermal Chemical Research
+
Hyperthermal Nozzle cracking:!
!
!
Supersonic Jet of Radicals/He into 10-5
Torr!
118.2 nm VUV Photoionization Laser (10.487 eV)!
furfural entrained in He carrier gas behind pulsed valve!
HC
HC CH
CO CHO
products!
[radicals] ≅ 1013 pulse-1!
τ (nozzle) ≅ 30-50 µsec!
1 mm SiC tube @ 300–1700 K!
C4H3O-CHO+!TOF detection
Contact Information:!
AnGayle Vasiliou!
University of Colorado at Boulder!Department of Chemistry and Biochemistry !Boulder, CO [email protected]!
!HC
HC CH
CO CHO
HC
HC CH
CHO
CH3C"CH + COCH2=C=O + HC"CHCH2CCHCO
Appears that furfural decarbonylates to product furan.!
HC
HC CH
CO CHO
products!
C5H4O2 m/z: 96
HC
HC CH
CHO
C4H4O m/z 68
HC
HC C:
CHO CHO
O
H
H
H
CO
H••
O
H
H H
H
HC
HC CH
CHO
CO
!
•
•
"-carbene
Mechanism ?!
118
.2 n
m P
hoto
ioni
zatio
n M
S Si
gnal
100908070605040 m/z
300K
1100K
1300K
1400K
1600K
96
95
40
42 39
68
HC
HC CH
CO CHO
products!
Chemical Formula: C5H4O2m/z: 96.021 (100.0%), 97.024 (5.4%)
118
.2 n
m P
hoto
ioni
zati
on M
S Si
gnal
100908070605040 m/z
300K
900K 1100K
1300K
1400K
1600K
97
95
69
41
42 40
39 43
HC
HC CH
CO CDO
products!
C5H3DO2 m/z: 97
IR In
tens
ity (A
rb. U
nits
)
1100 1050 1000 950 900Wavenumber (cm-1)
! 18 C
4 H 3O
-CH
O
! 7 C
4 H 3O
-CH
O
! 8 C
4 H 3O
-CH
O
! 20
C4 H
3O -C
HO
IR In
tens
ity (A
rb. U
nits
)
1800 1780 1760 1740 1720 1700 1680 1660 1640Wavenumber (cm-1)
!3 C4 H 3O -CHO (rot)
!3 C4 H 3O -CHO (rot)
IR In
tens
ity (A
rb. U
nits
)
1150 1100 1050 1000Wavenumber (cm-1)
!16 C4 H 4O
!6 C4 H 4O !7 C4 H 4O C4 H 3O -CHO at RT = BLACK C4 H 3O -CHO at 1300C = RED C4 H 4O at RT = BLUE
IR In
tens
ity (A
rb. U
nits
)
2200 2180 2160 2140 2120 2100 2080 2060Wavenumber (cm-1)
12 CO
13 CO
! 2
CH
2 CO
C4 H 3O -CHO at RT = BLACK C4 H 3O -CHO at 1300C = RED
HC
HC CH
CO CDO
products!
C5H3DO2 m/z: 97
HC
HC CH
CHO
from → Vasiliou, Nimlos, Daily, & Ellison, “Thermal Decomposition of Furan Generates Propargyl Radicals”, J. Phys. Chem. A 113, 8540-8547 (2009).!
3n-6=Vibrational modes =27 modes in Furfural
1.0
0.8
0.6
0.4
0.2
0.0
Mas
s Fra
ctio
n
10-7 10-6 10-5 10-4 10-3 10-2 10-1 100
Time (sec)
Cellulose 'Active Cellulose' Char Volatiles Stables Tar
τ (Colorado Experiments) !
τ ≅ 50 — 100 µsec!
2