Download pdf - 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

IR In

tens

ity (A

rb. U

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)

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

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ity (A

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)

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

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ity (A

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)

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

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ity (A

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)

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

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ity (A

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)

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