|Date Upgrading of Pyrolysis Oil with Catalytic Hydrotreatment Agnes Ardiyanti Erik Heeres

|Date Lignocellulosic biomass (“woody biomass”) ›Source: wood, grass, sawmill dust ›Composition (in wt-%) 1 : ›Potential: 13 EJ (minimum) in WUR; 2 van Dam, 2007

|Date Lignocellulosic biomass – valorisation pathways

|Date | 4 Fast Pyrolysis Oil Lignocellulosic biomass Fast Pyrolysis Condensables, Fast Pyrolysis Oil Char Volatiles o C, 1-2 s BTG, Enschede Bridgewater et al, Org. Geochem, 30,1999

|Date Fast pyrolysis oil 5 › High oxygen content (up to 50%) › Immiscible with petroleum products › Unstable upon heating and storage (coke formation, repolymerization) Pyrolysis oil composition C (wt%)40.1 H (wt%)7.6 O (wt%)52.1 Moisture (wt%)23.9

|Date | 6 Objective: Deoxygenation of Pyrolysis Oil Fast pyrolysis oil Deoxygenation Co-feedstock for refineries (FCC, hydrocracking) Catalyst, P, T Fast pyrolysis oil H2H2 Upgraded Oil Gas Water Selected process: Catalytic Hydrotreatment -(CH x O y )- + c H 2  -(CH x )- + (H 2 O, CO 2, CH 4, CO)

|Date Desired product ›Low oxygen content ›Low viscosity ›Low molecular weight ›High aliphatic content ›Low coking tendency 7

|Date Catalytic hydrotreatment Oxygen content H/C, O/C ratio Viscosity Molecular weight Coking tendency Catalyst Heating route Reactor design Upgraded oil properties:Process variables:

|Date Heating route 9

|Date Why heating route? ›Polymerization is very common!  sticky, gooey paste is produced, instead of a nice and liquid oil ›Pyrolysis oil contains 30 wt% sugar  when heated: charring 10 Which condition should we apply to suppress this reaction?

|Date | 11 Pyrolysis Oil › Thermal cracking releases O mainly as H 2 O and CO 2 › Repolymerisation occurrs › O is released as H 2 O, H 2 is consumed › Further consumption of H 2 saturates the C-C double bonds and cracks the large molecules (similar to coal liquefaction) HPTT HDO Low H/C, High M w High H/C, Low M w o C >250 o C, H 2, catalyst Hypothesis 1,2 1 Gagnon, Ind. Eng. Chem. Res 27, Venderbosch, et al, J. Chem. Tech & Biotech, 85, 2009

|Date | 12 Experimental set-up ›4 fixed-bed reactors in-series ›Feed: forest residue pyrolysis oil (VTT, Finland) ›Catalyst: Ru (5%)/C ›H 2 pressure: 200 bar ›Variables: T, WHSV ›Analysis:  Elemental composition, TGA, GPC, viscosity BTG, The Netherlands

|Date Effect of process conditions, visual observations › High T in all 4 reactors  Phase separation, clogging after 25 min › Low T in all 4 reactors (‘Stabilization’)  Phase separation at 225 o C or higher › Low T in first reactors, high T at the end (‘Mild Hyd’)  Phase separation, run for 3 days without clogging › ‘2-stage Hyd’ (Hydrotreatment on ‘Mild Hyd’ organic product)  Top organic layer formed, no clogging observed Py-oi l Mild Hyd 2-stage Hyd

|Date Van Krevelen plot Py-oil (dry) Stabilization 175 o C Stabilization 225 o C Hydrogenation  dehydration  hydrogenation Mild hydrotreatment 2-stage

|Date Why H/C and O/C? 15 HDO Coke formation H/C = 0.5 O/C = 0 H/C = 1 O/C = 1/6 H/C = 1 O/C = 0 H/C = 1.7 O/C = 0

|Date | 16 Physical properties during further hydrotreatment stabMild2-stage M w and TGA Correlation between M w and residue weight (TGA) Py-oil MwMw residue (TGA)

|Date TG residue, as a function of H/C and O/C TGA residual weight [%] = – H/C O/C 17 Estimation of physical properties is possible

|Date Change of composition: solvent fractionation ›Sugar, HMM decreases after reaction, leaving the apolar, low molecular weight components behind! 18

|Date H-NMR (organic phase) ›Groups: aldehydes, aromatics, carbohydrates, methoxy, aliphatics 19 Pyrolysis oil Stabilization 175 o C Mild hydrotreatment 2 nd hydrotreatment

|Date Upgraded oil as co-feeding ›Comparable yields are found for the petroleum feed (Long Residue) and mixture of Long residue+upgraded oil de Miguel Mercader, App. Cat. B 96, 2010 In catalytic cracking

|Date Summary on heating route › Van Krevelen plot indicates the occurence of three subsequent processes:  hydrogenation,  dehydration,  hydrogenation › During hydrotreatment, the M w, viscosity, and TGA residue-weight of product oil increase during the stabilization step, then decrease at more severe conditions. › High H/C and low O/C of the organic product is desired › The change of composition can be followed by e.g. solvent fractionation and 1 H-NMR. › Upgraded oil can be used as co-feeding in refinery units 21

|Date Catalyst 22

|Date What type of catalyst? ›No specific reaction  homogeneous is not an option ›Heterogeneous catalyst: Which support, active metal, preparation? 23

|Date Support ›Regenerable ›Stable in water, acid, high temperature:  ZrO 2, SiO 2  potential ›High specific surface area (less important) 24 Active metal ›Any metal with hydrogenation activity ›Interesting: noble metals (Ru, Pd, Rh), Ni (usually promoted)

|Date Noble metal vs cheaper transition metal ›Noble metal: high activity, easy maintenance, very high price ›“cheaper” transition metal: lower activity, prone to deactivation, cheap 25

|Date Van Krevelen: comparison of activity 26 Ru/C Pd/C

|Date Potential catalyst: NiCu ›δ-Al 2 O 3 as support (better stability than γ- Al 2 O 3 ) ›Various Ni/Cu ratio 27 CatalystcNi (wt%) Cu (wt%) A BET (m 2 /g) 24.5Cu Ni18.2Cu Ni11.8Cu Ni6.83Cu Ni2Cu Ni

|Date Hydrogenation activities ›Van Krevelen plot is used to calculate the hydrogenation activities, blank experiment as the reference 16Ni2Cu and 13.8Ni6.83Cu are the most active

|Date Why is Cu needed? ›Ni is a catalyst for CNT (carbon nanotube) formation  produces “carbon whiskers”, decrease the activity ›CNT formation is structure sensitive  needs adjacent active sites ›Cu makes Ni x Cu 1-x alloy, and reduce the crystallite size  the carbon formation is reduced ›Cu also helps the reduction 29

|Date XRD analysis 13.8Ni6.83Cu 20.8Ni NiO Ni No Ni(0) was found at 20.8Ni after reduction at 300 o C (reduction temperature of Ni is > 500 o C) Ni(0) was formed on 13.8Ni6.83Cu after reduction Cu does not have HDO activity, but supports the reduction of Ni Reduction was performed at 300 o C and 10 bar of H 2

|Date What about the stability? HRTEM Active metal particle size: 10 nm (fresh)  100 nm (spent). ICP showed leaching of Ni, Cu, and Al Fresh 16.8Ni6.83CuSpent 16.8Ni6.83Cu Dissolution and recrystallisation of NiCu seem to occur

|Date Next? Find other supports … ›Carbon, ZrO 2, TiO 2, etc ›Ongoing research

|Date Summary on catalyst selection ›A good support selection is a good start ›Noble metal vs “cheaper” transition metal ›Bimetallic catalyst: effect of composition 33 Heterogeneous catalysts, SϋdChemie

|Date Acknowledgement: Robbie Venderbosch, Vadim Yakovlev, Sofia Khromova, Jelle Wildschut, Anja Oasmaa, Jelmer Westra UIC Boreskov Institute of Catalysis – SB RAS