Catalytic Processes Directed Towards Lignin Derived Commodity Chemicals for Polymer Synthesis

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2 Catalytic Processes Directed Towards Lignin Derived Commodity Chemicals for Polymer Synthesis Xiaojuan Zhou, Pradeep Agrawal and Christopher W. Jones Georgia Institute of Technology School of Chemical & Biomolecular Engineering Atlanta, GA IPST Members Meeting Wednesday, April 11, 2012

3 Outline Mariefel Valenzuela Olarte Xiaojuan Zhou Previous work: catalytic phenol hydrogenation fuels Current work: catalytic phenol hydrogenation - chemicals

4 Mariefel Valenzuela Olarte University of the Philippines, Los Baños B.S. Chemical Engineering, 2001 Georgia Institute of Technology M.S. Paper Science and Engineering, 2006 Thesis Title: Batch Aqueous-phase Reforming of Woody Biomass Georgia Institute of Technology Ph.D. Chemical Engineering, 2011 Depolymerization of Lignin and Catalytic Hydrogenation of Lignin-derived Model Compounds Current: Research Engineer, Catalytic Biorefining, Pacific Northwest National Laboratory, Richland, WA.

5 Xiaojuan (Roxy) Zhou Zhejiang University Major: Material Science and Engineering Miami University (Oxford) Major: Chemical Engineering with concentration in Paper Science Degree: B.S. in Engineering

6 Motivation Most hydrodeoxygenation studies have focused on sulfided CoMo and NiMo-based catalysts. A significant fraction of fast pyrolysis and other bio-oils is a mixture of phenol compounds (20~30%). However, most of the phenolic fragments will be 6-9 carbons in mass, and after deoxygenation and ring saturation, the hydrocarbons formed will be of lower molecular weight and thus of only moderate value as a fuel. To this end, an important goal in biomass upgrading is often molecular weight enhancement, producing molecules of appropriate molecular weight for use as gasoline or diesel fuels. OH Bifunctional Catalysis Pt/Zeolite H 2 (4 MPa), 473 K + Hydrogenation/ Hydrogenolysis Hydrogenation/Hydrogenolysis & Coupling

7 Experimental: Preparation of catalysts Impregnation of the solution of Pt(NH 3 ) 4 (NO 3 ) 2 onto Y zeolites Calcination: 500 o C for 4 in air. Catalytic activity measurement Continuous fixed bed reactor Reduction: H 2 flow (50 ml/min; atmospheric pressure), 500 o C for 1h (b =1 o C/min). Temperature = K H 2 pressure = 40 bar WHSV = 5-20 h -1 H 2 flow rate = 50 ml/min Product analysis: On-line GC equipped with FID and TCD, GC/MS Characterization of catalyst XRD, H 2 chemisorption, N 2 physisorption, 27 Al NMR, TGA, FT-IR

8 Products identified using GC/MS Major products OH ( 60 ~ 95%) ( ~ 8%) ( ~ 15%) Minor products O OH O ( ~ 5%) ( ~ 5%) ( ~ 1%) ( ~ 3%) ( ~ 1%) ( ~ 1%) OH Trace ( < 0.5%) OH O OH O HO * Parentheses show the maximum selectivity Products were identified by Shimadzu GC/MS and Varian GC/MS.

9 Selectivity (%) Selectivity (%) Monocyclic Product Selectivity versus Phenol Conversion Methyl cyclopentane Benzene Cyclohexane Cyclohexene Cyclohexanone Cyclohexanol Conversion of phenol (%) 0 Temperature, 473 K; H 2 pressure, 4.0 MPa; Catalyst loading, 100 mg; Catalyst, 0.5 wt% Pt/HY (SiO 2 /Al 2 O 3 = 12), WHSV, 5-20 h -1 ; H 2 O content, 5 wt%.

10 Reaction pathway of phenol to monocyclics O H 2 H2 H 2 H 2 OH OH OH 2H 2 H 2 H + H 2 -H 2 O Reaction pathway of phenol to monocyclics in the catalytic hydrogenation treatment. Phenol appears to be hydrogenated to cyclohexenol as an intermediate product in the initial steps, and then this species is rapidly converted to cyclohexanol and/or cyclohexanone through two parallel pathways. Hong et al., Chem. Commun. 2010, 46, 1038;

11 Selectivity (%) Bycyclic Product Selectivity versus Phenol Conversion Cychlopentyl Methyl cyclohexane Bicyclohexyl 2-Cyclohexyl cyclohexanone 2-Cyclohexyl phenol 4-Cyclohexyl phenol Tricyclohexyl Conversion of phenol (%) Temperature, 473 K; H 2 pressure, 4.0 MPa; Catalyst loading, 100 mg; Catalyst, 0.5 wt% Pt/HY (SiO 2 /Al 2 O 3 = 12), WHSV, 5-20 h -1 ; H 2 O content, 5 wt%.

12 Reaction pathway of phenol to bicyclics OH OH OH OH H + 3H 2 2H 2 2H 2 2H 2 O O O O H 2 H + Proposed reaction pathway of phenol to bicyclics in the catalytic hydrogenation reaction Cyclohexyl phenol formation is dominant in the presence of cyclohexanol as an alkylating agent Kallury, et al., Can. J. Chem., 1984, 62, 2540; Anand et al.,catal. Lett., 2002, 81, ; 2002, 81, cyclohexyl cyclohexanone can be produced from cyclohexanone by aldol condensation over the acidic zeolite Xu et al., J. Am. Chem. Soc., 1994, 116, 1962; J. Huang, W. Long, P. K. Agrawal and C. W. Jones, J. Phys.Chem. C, 2009, 113,

13 Conversion of phenol (%) N 2 adsorbed (ml/g, STP) N 2 adsorption over spent catalysts with different on-stream times 100 Conversion of phenol h 1h 5h 8h 10h Time-on-stream (h) Relative Pressure (P/Po) Samples were pretreated in vacuum at 473 K for 12 hr Reaction conditions: Temperature, 473 K; H 2 pressure, 40 bar; Catalyst loading, 100 mg; Catalyst, 0.5 wt% Pt/HY (SiO 2 /Al 2 O 3 = 12); WHSV, 5 h -1 ; H 2 O content, 10 wt%. Sample S BET (m 2 /g) TPV (cm 3 /g) V micro (cm 3 /g) Vol * (cm 3 /g) 0 h h h h h

14 Summary Pt-HY catalyst effectively hydrogenates phenol to produce saturated hydrocarbons. Hydrogen use significant (high P); catalyst expensive (Pt). Catalyst deactivates due to coking stability too limited for practical use. Bicyclic products in good molecular weight regime for fuels, cyclohexane of limited value.

15 Recent Work: Slow Deactivation, Tune Product Selectivity Replace Pt with Ni (lower metal cost) Replace microporous zeolite with large pore, mesocellular foam (improved transport, lower acid strength, less impact of carbon deactivation) Experiment with reactor configuration: -- bifunctional catalysts -- intermixed acid and hydrogenation catalysis -- dual beds - acid and hydrogenation catalysis Ni/SiO 2 is a known catalyst for phenol hydrogenation. Shin, E. J.; Keane, M. A., Ind. Eng. Chem. Res. 2000, 39, Pina, G.; Louis, C.; Keane, M. A., Phys. Chem. Chem. Phys. 2003, 5, ; Mahata, N.; Raghavan, K. V.; Vishwanathan, V.; Keane, M. A. React. Kinet. Catal. Lett. 2001, 72, ; Shin, E. J.; Keane, M. A., Appl. Catal. B. Env. 1998, 18,

16 Silica and Aluminosilicate Mesocellular Foams Mesocellular foams (MCF): hydrothermally-synthesized mesoporous silicates* formed by adding a swelling agent (1,3,5-trimethylbenzene) to the surfactant-templated SBA-15 synthesis mix Because of the pore expansion, a higher surface area is achieved promising support for catalysts dealing with large molecules as substrate, such as fatty acids and possibly lignin Progression of morphological transition of P-123-templated materials as TMB content is increased Lettow, et. al. Langmuir 2000, 16, Liu, et. al. Catal. Lett. 2008, 125,

17 Ni-MCF as a Hydrogenation Catalyst Ni-MCF: Still complete conversion of phenol in 15 hrs with 80% less H 2 Main product: cyclohexanol Conditions: NiMCF, 6.7 bar, 200 o C, 5 h -1 sv, 100 mg catalyst, 10% H 2 O, No deactivation over 16 hrs.

18 Control Reaction Selectivity by Catalyst Configuration (a) Single Bed single catalyst type (b) Sequential Beds (c) Single Bed physical mixture

19 Control Reaction Selectivity by Catalyst Configuration Selectivity Phenol Conversion Reactant Reactor pressure Catalyst Major product after 4 after 15 after 4 after 15 NiMCF Cyclohexanol HY no reaction AlMCF no reaction Aqueous phenol (10% water) 100 psig (6.7 bars) NiMCF-HY sequential beds NiMCF/HY mixed bed Cyclohexene Cyclohexane NiMCF-AlMCF sequential beds Cyclohexene NiMCF/AlMCF mixed beds Cyclohexane C, 100 psig H 2, WSHV = 5hr -1

20 Control Reaction Selectivity by Catalyst Configuration Selectivity Phenol Conversion Configuration Reactor pressure Catalyst Major product after 4 after 15 after 4 after 15 NiMCF Cyclohexanol psig (6.7 bars) HY AlMCF NiMCF-HY sequential beds NiMCF/HY mixed bed NiMCF-AlMCF sequential beds NiMCF/AlMCF mixed beds no reaction no reaction Cyclohexene Cyclohexane Cyclohexene Cyclohexane C, 100 psig H 2, WSHV = 5hr -1

21 Control Reaction Selectivity by Catalyst Configuration Selectivity Phenol Conversion Configuration Reactor pressure Catalyst Major product after 4 after 15 after 4 after 15 NiMCF Cyclohexanol psig (6.7 bars) HY AlMCF NiMCF-HY sequential beds NiMCF/HY mixed bed NiMCF-AlMCF sequential beds NiMCF/AlMCF mixed beds no reaction no reaction Cyclohexene Cyclohexane Cyclohexene Cyclohexane C, 100 psig H 2, WSHV = 5hr -1

22 Control Reaction Selectivity by Catalyst Configuration Selectivity Phenol Conversion Reactant Reactor pressure Catalyst Major product after 4 after 15 after 4 after 15 NiMCF Cyclohexanol HY no reaction AlMCF no reaction Aqueous phenol (10% water) 100 psig (6.7 bars) NiMCF-HY sequential beds NiMCF/HY mixed bed Cyclohexene Cyclohexane NiMCF-AlMCF sequential beds Cyclohexene NiMCF/AlMCF mixed beds Cyclohexane High selectivities and yields of olefin, alcohol and alkane by adjusting catalyst configuration with no deactivation over 16 hrs. 200 C, 100 psig H 2, WSHV = 5hr -1

23 Summary Ni-MCF, combined with acidic catalysts such as H-Al-MCF or HY, can be used to give high yields and selectivities of cyclohexanol, cyclohexane or cyclohexene.

24 Summary Ni-MCF, combined with acidic catalysts such as H-Al-MCF or HY, can be used to give high yields and selectivities of cyclohexanol, cyclohexane or cyclohexene. New Project Tune catalyst and reactor configuration to produce high yields of cyclohexanols/cyclohexanones from mixed lignin-derived phenol streams. Investigate utility of lignin-derived cyclohexanols/cyclohexanones as components of renewable nylon polymers.

25 Nylon 6 Precursors from Lignin Fragments by Catalytic Hydrogenation Traditional Nylon 6 synthesis selective catalytic hydrogenation

26 Nylon 6 Precursors from Lignin Fragments by Catalytic Hydrogenation Proposed work Schedule: Year 1: Recruit student, use existing infrastructure (high pressure flow reactor) to study individual model compounds (phenol, catechol, guaiacol, 4-ethylguaiacol). Start with Ni/NiO/SiO 2 catalyst. Years 2-3: Tune catalyst structure and reaction conditions to target monomeric cyclohexanols. Year 4: Evaluate blending model compounds as simulated mixed phenol feedstock in catalytic experiments. Questions Primary: can we control hydrogenation selectivity of mulitiply-substituted phenols? [85% catalysis and reaction engineering] Secondary: if yes, can we make Nylon 6 from said precursors? What are properties of nylons? [15% polymer science]

27 Thanks to: IPST and IPST member companies.

28 Research Support: This Work Also thanked for financial support: