AUTOHYDROLISIS/KRAFT PULPING AS A PRETREATMENT FOR BIOETHANOL, FURFURAL AND ACETIC ACID PRODUCTION

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1 AUTOHYDROLISIS/KRAFT PULPING AS A PRETREATMENT FOR BIOETHANOL, FURFURAL AND ACETIC ACID PRODUCTION María Noel Cabrera, Melissa Bariani, Juan Guarino, Leonardo Clavijo, Mairan Guigou, Mauricio Vique, M.Daniel Ferrari, Claudia Lareo, Norberto Cassella. Universidad de la República, Engineering School, Chemical Engineering Institute Montevideo, Uruguay

2 OBJECTIVE Optimization of autohydrolysis and Kraft pulping of Eucalyptus sawdust as pretreatments to obtain a liquid rich in hemicelluloses compounds and a solid phase feasible to produce bioethanol, respectively.

3 SCHEME OF THE PROPOSED PROCESS Eucalyptus sawdust Liquid phase Furfural production Acetic acid production Autohydrolysis Solid phase Kraft pulping Mechanical Refining Enzymatic hydrolysis Fermentation Bioethanol

4 MOTIVATION OF THE WORK 100% oil imported Motivation to produce biofuels 2 (3) new big mills: Adt/year, processing eucalyptus Mechanical transformation wood mills in the north of the country processing 700,000 m 3 of Eucalyptus grandis and 720,000 m 3 of Pinus.

5 AUTOHYDROLYSIS OF EUCALYPTUS SAWDUST Temperature (ºC) Time (min) 60, 90, , 300, 420, , 90, 120, , 90, 120, , 45, 60, 90, 105, 120, 150, , 90, 120, , 60, 90, 120

6 Chemical component Weight percent (o.d. basis) Ash 0.92 ± 0,01 Extractives a 3,4 ± 0,7 Glucans 44,6 ± 0,4 Xylans 15,5 ± 0,3 Arabinose < 1% Klason Lignin 26,0 ± 0,3 Acid soluble lignin 2,6 ± 0,1 Acetyl Groups 3,7 ± 0,2 a Acetone g/100g o.d.wood Total xylose in the liquor time (min) 80ºC 100ºC 140ºC 160ºC 165C 170ºC Xylan extracted T=170ºC g/100g o.d.wood 12,0 10,0 8,0 6,0 4,0 2,0 0, time (min) Xylooligosaccharides (Xos) Xylose Furfural Total xylose

7 AUTOHYDROLYSIS/KRAFT PULPING: Eucaliptus spp. pinchips from the screening of a pulp mil. Chemical component Weight percent (o.d. basis) Ash 0.92 Extractives a 1.1 Glucans 45.9 Xylans 14.0 Arabinose < 1% Klason Lignin 25.4 Acid soluble lignin 3.1 Acetyl Groups 2.8 a Acetone

8 AUTOHYDROLYSIS/KRAFT PULPING: EXPERIMENTAL DESIGN Draper Lyn Design with 24 assays and 7 replicates of the central point Temperature ( C) So % AA (% Na 2 O) Time at max. temp. (min) (153 and 186) (3.4 and 3.9) (8 and 13) (40 and 140)

9 AUTOHYDROLYSIS LIQUOR 5,0 ph 4,0 3,0 ph 2, P-factor % Yield 30,0 25,0 20,0 15,0 10,0 Yield (%wood after ext./ o.d.wood) time (min) T=160 T=153 T=170 T=187 T=180

10 % xylose Xylose (% Xyl/ o.d.wood) 10,0 8,0 6,0 4,0 2,0 0, tiempo (min) T=160 T=170 T=180 T=153 T=187 % xylose Total xylose (%xylose/ o.d.wood) time (min) T=160 T=170 T=180 T=153 T=187 15,0 13,0 11,0 9,0 7,0 5,0 3,50 3,00 2,50 2,00 1,50 1,00 0,50 0,00 Furfural (%furfural/ o.d.wood) time (min)

11 Acetic acid (%HAc/ o.d.wood) 5,00 4,00 3,00 2,00 1,00 0, time (min) T=160 T=170 T=180 T=153 T=187 LIQUID-LIQUID EXTRACTION WITH ETHYL ACETATE Acetic acid extraction (%) :1 1:2 1:3 1:4 0 2,00 2,50 3,00 3,50 4,00 ph

12 KRAFT PULPING Pulping conditions: 155 C, % AA and time at Tmax: Variable 120,0 Kappa number vs time at Tmax 100,0 kappa 80,0 60,0 40,0 20,0 0, time (min) %AA=8 %AA=9 % AA=10.5 %AA=12 %AA=13

13 KRAFT PULPING NREL/TP (adapted) Kappa number vs glucans in pulp 100,0 90,0 80,0 % glucans/pulp 70,0 60,0 50,0 40,0 30,0 20,0 10,0 0,0 0,0 20,0 40,0 60,0 80,0 100,0 120,0 kappa number

14 ENZYMATIC HYDROLYSIS Enzyme dose: 25 FPU/g glucan Enzyme: Cellic Ctec 2 (Novozymes), ph = 4.8 T = 48 C, 150 rpm Liquid/solid ratio: 6.67g liquid/gds

15 ENZYMATIC HYDROLYSIS D9 D13 D15 D5 Eficiency(%) D6 D2 D14 D7 D16 D17 D10 D12 20 D19 D D1 Time (h) D3 D18

16 FERMENTATION D9 was selected to adjust the fermentation process Extraction conditions Temp (C) 170 So 3,65 Time(min) 40 Liquor Yield (%o.d. wood) Pulping conditions ph Total xilose (%o.d. wood) Xilose (%o.d. wood) Furfural (%o.d. wood) P-factor 630 Acetic acid (%o.d. wood) Temp (C) 155 Time(min) 140 Pulp Yield (%o.d. wood) 51.5 (38.3) Kappa number Total glucose (%o.d. wood) AA (%Na 2 O) Total xilose (%o.d. wood) 10,5 H-factor: 650 Lignin (%o.d. wood) < LOD 3.5

17 FERMENTATION PSSF Prehydrolisis: 24 hours Enzyme dose: 25 FPU/g glucan Enzyme: Cellic Ctec 2 (Novozymes), ph = 4.8, 150 rpm Liquid/solid ratio: 7g liquid/gds Fermentation: Saccharomyces cerevisiae PE-2 24 hours, 120 rpm, ph = 4.8, Temp=35 C Results: 57g EtOH/L (81% yield) Global conversion 32% EtOH/ Theo EtOH (glucose in saw dust)

18 FURFURAL PRODUCTION TUBES ASSAYS Extraction conditions Temp (C) 170 So 3,65 Time(min) 40 Liquor Yield (%o.d. wood) ph Total xilose (%o.d. wood) Xilose (%o.d. wood) Furfural (%o.d. wood) P-factor 630 Acetic acid (%o.d. wood) Variables Levels Temperature (ºC) 150,160,170,180 Time(min) 5,13,22,30 (60-240) Conc. H 2 SO 4 (%) 0.75, 1.5, 3, 3.75

19 % furfural 3,0 2,5 2,0 1,5 1,0 0,5 0,0 180 ºC Time (min) 0,75% 1,5% 3% % furfural 30 min 2,5 2,0 1,5 1,0 0,5 0, Temperature 0,75% 1,5% 3% 3,74%

20 CONCLUSIONS 70 85% of Eucalyptus hemicellulose could be feasible to pre-extract by autohydrolysis pretreatment in the range of temperature and time studied. Kraft pulping increases the susceptibility of lignocellulose structure for enzymatic hydrolysis, resulting in yields above 80% after 48 hours. The fermentation time is deeply reduced, obtaining 80% efficiency in 24 hours. It is possible to produce bioethanol, furfural and acetic acid using eucalyptus saw dust as raw material.

21 ACKNOWLEDGEMENTS Financial support provided by the National Agency of Innovation and Research (ANII- FSE , Uruguay) is greatly appreciated. UPM-Fray Bentos and Novozymes Inc.

22 Thank you!!!!