Development of a technology of dehydration of glycerol to acrolein, from catalyst to reactor and process

Transcription

1 Workshop on Glycerol Marketing, Uses and Chemistry Development of a technology of dehydration of glycerol to acrolein, from catalyst to reactor and process Franck Dumeignil a Unité de Catalyse et de Chimie du Solide - UMR CNRS 8181 Université Lille Nord de France Villeneuve d Ascq Cedex France

2 2 Introduction: The glycerol problem RO OR + 3 CH 3 RO Cat. Triacylglycerol (TAG) O HO 3 OCH 3 + R HO oil crop vegetable oil Biodiesel + Glycerol Acrolein acts: EU aims 7% biodiesel by kg glycerol for 90 kg biodiesel 10³ me etric tons EU US European Biodiesel Board 0

3 3 Introduction: Acrolein synthesis and application Current production process + O 2 Cat. O + H 2 O Gas phase oxidation of propene ( t/year worldwide) Applications O + CH 3 SH S O H 3C Acrolein Methanethiol + HCN + Na 2 CO 3 H 3 C HN 2 S CO DL-methionine H 3 C S H N O N H Hydantoin O Acrolein O +O 2 cat. CO Acrylic acid +Na COO Na n Sodium polyacrylate

4 4 Introduction: Gasphase dehydration Target: Acrolein from biomass derived glycerol gy HO Cat. O + 2 H 2 O Reaction requires acid catalyst Zeolites Supported Inorganic acids Various Metal-oxides β-zeolite H 3 PO 4 /α-al 2 O 3 Nb 2 O 5 MCM-22 H H-MFI 4 SiW 12 O 40 /SiO 2 WO 3 ZSM-11 H 3 PW 12 O 40 /SiO 2 Sm 4 (P 2 O 7 ) 2

5 5 Introduction: Catalytic properties - acidity Critical parameter: Acid strenght Catalyst TOS=1-2h TOS=9-10h Carbon amount C S C S deposits (g) (%) (mol%) (%) (mol%) (mg/g Cat ) Group-3 (-8.2 H 0-3) HZSM-5 (Zeolite) Nb 2 O wt% WO 3 /ZrO wt% H 3 PO 4 / a -Al 2 O wt% H 3 PW 12 O 40 /a Al 2 O 3 Group-4 (H 0-8.2) 5 wt% SO 2-4 /ZrO SiO 2 Al 2 O Nb 2 O S-H. Chai, H-P. Wang, Y. Liang, B-Q. Xu, Green Chem., 2007, 9, Strong acid catalyst show increased cok formation

6 Results: STA on SBA-15 Conditions of the catalytic tests: Active phase amount 20 wt.% Catalyst mass 0.3 g Reaction temperature 275 C Glycerol flow 1.5 ml/h Glycerol concentration 10 wt.% Helium flow 30 ml/min. Advantage High Selectivity in Acrolein Disadvantage Quick deactivation Solution Tuning of the acidic force 6

7 7 Tuning of the acidic force I Grafting with SBA-15 Zr(OiPr) 4 in Et Washing & Calcination Catalyst H 4 SiW 12 O 40 Strong interaction (Al, Zr): strong distortion of Keggin-unit > important t decrease in acidity Weak interaction (Si): low distortion of Keggin-unit > low impact on acidity

8 Tuning of the acidic force II TPD NH 3 ZrO 2 decreases acidic force T Total sample acidity Weak Medium Stron [mmol [%] [%] [%] NH 3 /g cat. ] a Bare SBA b ZrO 2 /SBA c STA / SBA d STA /ZrO 2 /SBA T desorp : Weak C; Medium C; strong > 450 C ZrO 2 increases number of acid sites Lewis acidity 8

9 9 Results: STA on ZrO 2 grafted SBA-15 Conditions of the catalytic tests: Active phase amount 20 wt.% Zirconia amount 20 wt.% Calcination temperature 650 C Catalyst mass 0.3 g Reaction temperature 275 C Glycerol flow 1.5 ml/h Glycerol concentration 10 wt.% Helium flow 30 ml/min. Advantage Increased long-term performance????? Disadvantage Increased formation of Acetol Slow activation

10 Critical parameter: Acid type a HO Reaction mechanisms: 2 + HO + O! glycerol Bronsted-site -H 3 O O HO -H 2 O O -H 2 O 2 acrolein Bronsted-site b HO glycerol + M O M Lewis-site H HO H O M O M M M + pseudo- Bronsted-site Increased formation of Acetol HO O -H 2 O M O M Activation period Alhanash et al., Appl. Catal A, 378 (2010) acetol Lewis-site 10

11 Critical parameter: Acid type Influence of different ZrO 2 amounts: Constant amount of 20wt.% H 4 SiW 12 O 40 (SBA-15 support) 2 Increasing ZrO 2 amoun less acrolein formation giving rise to increasing acetol TOS: 0-5 h Confirms the mechanism over Lewis-acid id sites 11

12 Conclusion - Catalyst Supported Heteropoly acids are highly selective in Glycerol dehydration Deactivation ascribed to coke deposition limits it long-term performance and necessitates regeneration Decreasing the acidity is supposed to reduce the formation of coke Acidity can be tuned via the support due to electronic interactions with HPA Increased long-term performance for zirconia supported HPA Deactivation still observed Regeneration possible? Increased formation of Acetol and significant activation period due to Lewis-acid character of ZrO 2 12

13 Regeneration of spent catalysts I O 40 20wt.% H 4 SiW 12 O on SBA-15 on 15 wt.% H 4 SiW 12 O 40 0wt.% ZrO 2 /SBA-1 20w 20 Air flow (30 ml/min) 275 C Significant decreas in selectivity it to acrolein alteration of the HPA? 13

14 14 Loss of cryst. H 2 O Regeneration of spent catalysts II H 2 O TGA Loss of constitutional water and thermal decomposition: H 4 SiW 12 O 40 SiW 12 O H 2 O SiW 12 O 38 SiO WO 3 Loss of const. H 2 O H 4 SiW 12 O 40 on ZrO 2 /SBA-15 and decomposition H 4 SiW 12 O 40 on SBA-15 Strong interaction (Al, Zr): > important increase in thermal stability Weak interaction (Si): > no impact on thermal stability

15 Regeneration of spent catalysts III O 40 20wt.% H 4 SiW 12 O on SBA-15 on 15 SiW 12 O 40 O 2 /SBA-1 wt.% H 4 S 0wt.% ZrO 20w 20 wet air flow (30 ml/min) 275 C 77% N 2 18 % O 2 5 % H 2 O Selectivity to acrolein slightly increased (66% vs. 50%) 15

16 16 Periodic regeneration of spent catalysts I Allows periodic switching etween Glycerol and Air flow nditions of the catalytic tests: talyst mass 0.2 g action temperature 275 C ycerol flow 1.5 ml/h ycerol concentration 10 wt.% lium flow 30 ml/min. flow 30 ml/min (dry) cle time 10 min. Gly 10 min. Air

17 Periodic regeneration of spent catalysts II 2O 40 20wt.% H 4 SiW 12 on SBA-15 No loss in selectivity it No thermal degradation due to short cycles 20 0wt.% H 4SiW 4 12 O 4 0 on 20wt.% ZrO 2 /SBA A-15 Low selectivity to acrolein Activation period 17

18 18 Concept: Two-Zone-Fluidized-Bed-Reactor Reaction conditions Feed: Glycerol 4.8 ml/h (20wt.%) Vector gas 5.5 L/h (275 C; N 2 ) Fluidizing gas: Temperature: 275 C 90 NL/h (275 C; N 2 or air) Catalyst: 20wt.% H 4 SiW 12 O 40 on CARiACT C (221 µm) 5 g catalyst + 76 g inert (silica) Permanent regeneration of the catalyst Isothermicity

19 19 Results: Two-Zone-Fluidized-Bed-Reactor Deactivation under N 2 flow Increasing conversion under air flow: - accompanied with increasing temperature - presence of CO 2 detected by Mass-Spec. Regeneration confirmed by back-switch to N

20 Conclusion - Regeneration Supported Heteropoly acids are highly selective in Glycerol dehydration Deactivation ascribed to coke deposition limits it long-term performance and necessitates regeneration Silicotungstic acid on ZrO 2 /SBA-15 Long-term performance Increased thermal stability facilitates the regeneration Increased formation of Acetol and significant activation period due to Lewis-acid character of ZrO 2 Silicotungstic acid on silica Rapid deactivation Low thermal stability (decomposition in hot-spots) No activation period Short cycle ng cycles 20

21 Acknowledgements (1) Special thanks to my colleagues and industrial partners who actively participated to these projects: Prof. Sébastien Paul (UCCS) Prof. Nouria Fatah (UCCS) Dr. Benjamin Katryniok (UCCS) Dr. Mickaël Capron (UCCS) Dr. Virginie Bellière-Baca (Rhodia) Dr. Patrick Rey (Adisseo) Dr. S. Pariente (Rhodia) Mr. Roger D. Melendez (UCCS) We gratefully acknowledge Adisseo for their financial supports 21

22 Acknowledgements (2) Thank you very much for your kind attention! Process for obtaining acrolein by catalytic dehydration of glycerol or glycerine S. Pariente, V. Bellière-Baca, S. Paul, N. Fatah WO 2012/05166A1 (2012) Method for Preparing Acrolein from Glycerol or Glycerines S. Paul, B. Katryniok, F. Dumeignil, M. Capron WO 2011/08325 (2011) Regeneration of silica-supported silicotungstic acid used as a catalyst for the dehydration of glycerol B. Katryniok, S. Paul, M. Capron, V. Bellière-Baca, P. Rey, F. Dumeignil ChemSusChem. 5 (2012), Synthesis and characterization of zirconia grafted SBA-15 nanocomposites B. Katryniok, S. Paul, M. Capron, S. Royer, C. Lancelot, L. Jalowiecki-Duhamel, V. Bellière-Baca, P. Rey, F. Dumeignil J. Mater. Chem. 21 (2011), Long-Life Catalyst for Glycerol Dehydration to Acrolein B. Katryniok, S. Paul, M. Capron, C. Lancelot, P. Rey, V. Bellière-Baca, F. Dumeignil GreenChem. 12 (2010), Glycerol Dehydration to Acrolein in the context of Glycerol new usages B. Katryniok, S. Paul, V. Bellière-Baca, P. Rey, F. Dumeignil GreenChem. 12 (2010) Towards the sustainable production of acrolein by glycerol dehydration B. Katryniok, S. Paul, M. Capron, F. Dumeignil ChemSusChem. 2 (2009),