Dr. Mario Eden Department Chair Auburn University

Liquid Transportation Fuels and High Value Co-Products from Integrated Biomass Fractionation and Catalytic Conversion Mario R. Eden 1, Christopher B. Roberts 2, Steven E. Taylor 3 1 Department of Chemical Engineering 2 Samuel Ginn College of Engineering 3 Department of Biosystems Engineering Auburn University Inaugural SEC Symposium February 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 Lab Technology 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 Laboratory Collaborating 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  ˚C temperature  Air equivalence ratio = 0.25  Analysis systems NDIR based gas analyzer* CO, CO 2, CH 4, H 2, O 2 FTIR based gas analyzer* NH 3, HCN, HCl Impinger train tar analysis** *Online ** Offline Center for Bioenergy & Bioproducts

XTL Technologies

Fischer-Tropsch Synthesis Gasoline + Diesel + Wax C n H 2n and C n H 2n+2 + CO 2, H 2 O, oxygenates CO H2H2 H H C O Catalyst Surface: Cobalt, Iron, Ruthenium, etc H C H C H H H O H H Hans Tropsch

FTS Product Distribution Diesel Range Wax Range Jet Fuel Range Gasoline Range

FTS Product Upgrading Traditional FTS Upgrade light FTS products by oligomerization Hydrocracking & isomerization Catalyst: Fe based FT Catalyst Temp: 240 °C Pressure: bar Catalyst: Amorphous Silica Alumina (ASA) Temp: 200 °C Pressure: bar Catalyst: 1 Wt% Pd/ASA Temp: 330 °C Pressure: bar Inlet Outlet FT HC O

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%) 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

Conversion & Selectivity TOS CO Conversion TOS CO 2 Selectivity

Liquid Products GP & SC FTS GP - FT SC - FT

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 m 3 ) –Recycle of tail gas (ca. 1/3) –Production requires 70.5 gmole CO/sec –CO consumption 1.46 gmole CO/m 3 -sec –Heat of Rxn = 170,000 J/gmole CO –Volumetric heat generation= 248 kW/m 3 –Packed bed thermal conductivity= 4.49 W/m-K –ΔT max =S e R 2 /4k, ΔT max = 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, *All the data is scaled in order to be comparable with Gas-Phase FTS

Process Integration

Simulation Results/Analysis Supercritical Phase FTS Model 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 H2H2 COH2OH2OCO 2 + Alcohol formation CO + H 2 → CH 3 OH + 91 kJ 2CO + 4H 2 → C 2 H 5 OH + H 2 O kJ Hydrocarbon formation CO + 2H 2 → (CH 2 ) + H 2 O kJ Water-gas-shift reaction CO + H 2 O → CO 2 +H kJ Highly exothermic Severe reaction conditions (T>=250 ̊ C, P >= 4 Mpa) Low selectivity towards higher alcohols

Liquid Product Distribution

SCF Effect on Productivity Catalyst: 0.5 wt% K doped Cu/Co/ZnO/Al 2 O 3 Temperature: 300 ºC Pressure: 4.5 MPa – 18 MPa H 2 /CO: 2 P Syngas : 4.5 MPa F Syngas : 50 sccm

Effect of H 2 /CO 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 H 2 /CO ratios under supercritical conditions Modeling and Optimization –Enables systems level analysis of performance potential

Acknowledgements

Dr. Mario Eden Department Chair Auburn University