Dr. Mario EdenDepartment ChairAuburn University

Liquid Transportation Fuels and High Value Co-Products from

Integrated Biomass Fractionation and Catalytic Conversion

Mario R. Eden1, Christopher B. Roberts2, Steven E. Taylor3

1Department of Chemical Engineering2Samuel Ginn College of Engineering

3Department of Biosystems EngineeringAuburn University

Inaugural SEC SymposiumFebruary 11, 2013

Overview

AU Biorefinery Platforms

Center for Bioenergy & Bioproducts

Includes Facilities For: Feedstock processing and

analysis

Biomass fractionation

Biomass pretreatment and fermentation

Biomass gasification, gas conditioning, and gas-to-liquids conversions

Transesterification

Fractionation LabTechnology to separate biomass into basic chemical constituents

Cellulose, hemicellulose, and lignin

Process Development Unit

Lignin-free cellulose for biochemical conversion to alcohols

Low molecular weight, sulfur-free lignin for use in higher value products

Biomass

Cellulose Pellets

Lignin

Center for Bioenergy & Bioproducts

Gasification LaboratoryCollaborating with Gas Technology Institute and Conoco Phillips

Fluidized bed gasifier Air or oxygen blown

650 psi design pressure for gasifier

1300 – 1900 F temperature

100 lb/hr biomass feed

150 lb/hr gas output (36 scfm)

Future phase will add coal in feed

Warm gas cleanup (1000 F)

Downstream Fischer-Tropsch reactors

Operational Spring 2013

Center for Bioenergy & Bioproducts

Mobile gasification and power generation unit

Collaborating with Alabama Power and Community Power Corporation

Downdraft gasifier

Air blown

Atmospheric pressure

1300 – 1650 F temperature

50 lb/hr biomass feed

25 kWe generation capacity

Capable of field deployment

Operational since January 2008

Center for Bioenergy & Bioproducts

Bench-Scale Fluidized Bed Reactor

Atmospheric pressure

600-700˚C temperature

Air equivalence ratio = 0.25

Analysis systems

• NDIR based gas analyzer*

• CO, CO2, CH4, H2, O2

• FTIR based gas analyzer*

• NH3, HCN, HCl

• Impinger train tar analysis**

*Online ** Offline

Center for Bioenergy & Bioproducts

XTL Technologies

Fischer-Tropsch Synthesis

Gasoline + Diesel + Wax

CnH2n and CnH2n+2 + CO2, H2O, oxygenates

COH2

H H C O

Catalyst Surface: Cobalt, Iron, Ruthenium, etc

H

CH

CH

HH

OH

H

Hans Tropsch

FTS Product Distribution

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 310%

2%

4%

6%

8%

10%

12%

14%

Carbon Number

Sele

ctivi

ty(%

)

Diesel Range Wax Range

Jet Fuel Range

Gasoline Range

FTS Product Upgrading

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 310%

2%

4%

6%

8%

10%

12%

14%

Carbon Number

Se

lecti

vit

y(%

)

Traditional FTS

Upgrade light FTS products by oligomerization

Hydrocracking & isomerization

Catalyst: Fe based FT Catalyst

Temp: 240 °C

Pressure: 17 - 77 bar

Catalyst: Amorphous Silica

Alumina (ASA)

Temp: 200 °C

Pressure: 17 - 77 bar

Catalyst: 1 Wt% Pd/ASA

Temp: 330 °C

Pressure: 17 - 77 bar

Inlet

Outlet

FT

HC

O

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 300%

2%

4%

6%

8%

10%

12%

14%

Carbon Number

Se

lecti

vit

y (

%)

Alternative FTS Operation

• Supercritical Phase FTS– SCF-FTS reaction conditions allow for vapor like transport

properties while maintaining liquid like heat transfer and solubilities.

– Results in reduced methane production, enhanced middle distillate yield.

– Better catalyst activity maintenance due to in-situ extraction of heavy products from the catalyst pores with the supercritical fluid solvent.

– Recycling light products into the FTS feed provides simultaneous product upgrade (longer chain length products) and improved reaction media.

Co-Products from SCF-FTS

Supercritical FTS(CO Conversion = 45%)

Gas Phase FTS(CO Conversion = 45%)

0%

20%

40%

60%

80%

100%

8 9 10 11 12 13 14 15 16 17 18 19 20Carbon Number

Sel

ecti

vity

0%

20%

40%

60%

80%

100%

8 9 10 11 12 13 14 15 16 17 18 19 20 21

Carbon Number

Car

bon

Sel

ecti

vity

0%

20%

40%

60%

80%

100%

8 9 10 11 12 13 14 15 16 17 18 19 20 21

Aldehyde m-Ketone Alcohol Olefin Other Paraffin

• Aldehydes and other Oxygenates– Fe catalyst for SCF-FTS results in selectivity towards diesel-length

aldehydes and methyl-ketones

– Residence time studies indicate aldehydes are primary products that are converted to olefins

3-Bed FTS Reactor System

GP-FTS with Product Upgrading

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 330%

2%

4%

6%n-ParaffinBranched ParaffinOlefinAromatics

Carbon Number

Sele

ctivi

ty (%

)

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 330%

2%

4%

6% n-ParaffinBranched ParaffinOlefinOxygenates

Carbon Number

Sele

ctivi

ty (%

)

Conversion & Selectivity

0 10 20 30 40 50 60 70 80 90 1000%

20%

40%

60%

80%

100%

GP FTSC FTGP FTOCSC FTOC

Time on Stream (hr)

CO

Conv

ersio

n (%

)

TOS CO Conversion

0 20 40 60 80 100 1200

4

8

12

16

20

GP FTSC FTGP FTOCSC FTOC

Time on Stream (hr)

CH4

Sel

ecti

vity

(%

)

TOS CH4 Selectivity

TOS CO2 Selectivity

0 20 40 60 80 100 1200

10

20

30

40GP FTSC FTGP FTOCSC FTOC

Time on Stream (hr)

CO2

Sel

ectiv

ity

(%)

Liquid Products GP & SC FTS

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 330%

2%

4%

6% n-ParaffinBranched ParaffinOlefinOxygenates

Carbon Number

Sele

ctivi

ty (%

)

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 330%

2%

4%

6% ParaffinOlefinAldehyde

Carbon Number

Sele

ctivi

ty (%

)

GP - FT

SC - FT

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 350%

2%

4%

6% ParaffinBranched ParaffinCyclo ParaffinOlefin

Carbon Number

Sele

ctivi

ty (%

)

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 330%

2%

4%

6% ParaffinOlefinAldehyde

Carbon Number

Sele

ctivi

ty (%

)SC FTS with Upgrading

SC - FT

SC - FTOC

Gas-Phase FTS Simulation

Model Specification

• Fischer-Tropsch Reactor– Based on ARGE reactor (Ruhrchemie and Lurgi)– 2050 tubes, 5 cm ID and 12 m length (48.3 m3)– Recycle of tail gas (ca. 1/3)– Production requires 70.5 gmole CO/sec– CO consumption 1.46 gmole CO/m3-sec– Heat of Rxn = 170,000 J/gmole CO– Volumetric heat generation= 248 kW/m3

– Packed bed thermal conductivity= 4.49 W/m-K– ΔTmax=SeR2/4k, ΔTmax= 8.6°K (average)

Fischer-Tropsch Technology (2004), Studies in Surface Science and Catalysis 152, A. Steynberg and M. Dry (Editors), Elsevier

Supercritical Phase FTS

*Enhanced Incorporation of α-Olefins in the Fischer-Tropsch Synthesis Chain-Growth Process over an Alumina-Supported Cobalt Catalyst in Near-Critical and Supercritical Hexane Media, Ind. Eng. Chem. Res. (2005), 44, 505-521

*All the data is scaled in order to be comparable with Gas-Phase FTS

Process Integration

Process Integration

Simulation Results/Analysis

Supercritical Phase FTS Model

Syngas (kmol/hr)

Gasoline (kg/hr)

JP5 (kg/hr) Total Fuel

(kg/hr)D1 D2 Total D1 D2 Total

Gas-Phase FTS 1524 882 526 1348 1271 417 1688 3036

SCF-FTS

Same Syngas Feed 1524 508 1318 1826 1091 756 1848 3674

Same Fuel Product(based on gasoline)

1122 374 974 1348 806 558 1364 2712

Same Fuel Product(based on total

product)1259 420 1090 1510 903 623 1526 3036

Syngas (kmol/hr)

Gasoline (kg/hr)

JP5 (kg/hr) Total Fuel

(kg/hr)D1 D2 Total D1 D2 Total

Gas-Phase FTS 1524 882 526 1348 1271 417 1688 3036

SCF-FTS

Same Syngas Feed 1524 508 1318 1826 1091 756 1848 3674

Same Fuel Product(based on gasoline)

1122 374 974 1348 806 558 1364 2712

Same Fuel Product(based on total

product)1259 420 1090 1510 903 623 1526 3036

SCF-FTS is about 20% more expensive than Gas-Phase with the same syngas molar feed rate, but produces

about 50% more fuel!

Fuels Production Analysis

Energy Analysis

Higher Alcohol Synthesis

H2 CO

H2O CO2

+

Alcohol formationCO + H2 → CH3OH + 91 kJ

2CO + 4H2 → C2H5OH + H2O + 254 kJ

Hydrocarbon formationCO + 2H2 → (CH2) + H2O + 145 kJ

Water-gas-shift reaction CO + H2O → CO2 +H2 + 41.1 kJ

• Highly exothermic

• Severe reaction conditions (T>=250 C, P >= 4 Mpa) @

• Low selectivity towards higher alcohols

Liquid Product Distribution

0

4

8

12

C8 C9 C10 C11 C12 C13 C14 C15 C16 C17 C18Pro

du

ctiv

ity

(g/k

gC

at/h

)

n-paraffin productivity

Supercritical hexanes phase Gas Phase

0

4

8

12

16

Methanol Ethanol 1-propanol 2-propanol 1-butanol 2-butanol isobutanol 1-pentanol 1-hexanol 1-heptanol 1-octanolPro

duct

ivity

(g/

kgC

at/h

)

Alcohol productivity

Supercritical hexanes phase Gas phase

SCF Effect on Productivity

Catalyst: 0.5 wt% K doped Cu/Co/ZnO/Al2O3 Temperature: 300 ºC

Pressure: 4.5 MPa – 18 MPa H2/CO: 2PSyngas: 4.5 MPa FSyngas: 50 sccm

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0

11.5

23

Productivity(g/kgcat/h)

Hexanes/syngasmolar ratio

Effect of H2/CO Ratio

0.0

4.0

8.0

12.0

1.00

1.35

1.75

2.00

H2/COmolar ratio

Productivity (g/kgcat/h)

0.0

4.0

8.0

12.0

2.001.75

1.35

1.00

Productivity(g/Kgcat/h)

H2/COmolar ratio

Gas Phase

SCF Phase

Summary

• Biomass Fractionation & Gasification– Enables production of uniform commodity type

products– Targeted processing of each constituent

separately– Enables conversion of disparate feedstocks to

syngas

• Supercritical Phase FTS & Alcohol Synthesis

– Significant increase in fuel range products– Improved carbon utilization– Co-production of aldehydes and methyl ketones– Higher alcohol synthesis favored at lower H2/CO

ratios under supercritical conditions

• Modeling and Optimization– Enables systems level analysis of performance

potential

Acknowledgements

Dr. Mario EdenDepartment ChairAuburn University