POROUS TUBULAR SUPPORTED THIN OXYGEN MEMBRANES PREPARATION FOR OXIDATIVE COUPLING OF METHANE N B ADIOLA 1,3,4) , D. F RANK 2) , E. F ERNANDEZ 1) , M.A.L LOSA T ANCO 1) , P.L. A RIAS E RGUETA 4) , M. V AN S INT A NNALAND 3) , U. W ERR 2) , F. G ALLUCCI 3) , D.A. P ACHECO T ANAKA 1) 1) T ECNALIA , G ROUP OF M EMBRANE TECHNOLOGY (S PAIN ) 2) R AUSCHERT H EINERSDORF -P RESSIG G MB H (G ERMANY ) 3) TU E INHOVEN C HEMICAL P ROCESS I NTENSIFICATION G ROUP (T HE N ETHERLANDS ) 4) U NIVERSITY OF B ASQUE C OUNTRY , D EPARTMENT OF C HEMICAL AND E NVIRONMENTAL E NGINEERING (S PAIN ) This project is supported by the European Union’s HORIZON2020 Programme (H2020/2014 -2020) for the SPIRE Initiative under grant agreement nº 679933 Duration: 4 years. Starting date: 01-October-2015 Contact: nerea.badiola@tecnalia.com ; alfredo.pacheco@tecnalia.com The present publication reflects only the author’s views and the European Union is not liable for any use that may be made of the information contained therein. 05/12/2017 Page 1 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
Summary ▪ Motivation: Why OCM? ▪ Support preparation ▪ Membrane preparation ▪ CGO membranes ▪ BSCF membranes ▪ Conclusions 05/12/2017 Page 2 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
Motivation: Why OCM? High impact Feedstock cost Reduce the process and reduction and enviromental large market diversification impact share (Use of NG) OCM reaction(Oxydative coupling of methane) Allows the direct + + 2 2 production of ethylene Methane Oxygen Ethylene Water Limitations: • Very exothermic reactions. • With packed bed reactor the C 2 yield is low MEMBRANE REACTOR TECHNOLOGY Oxygen membranes introduces oxygen in ditributive way Increase the C 2 yield 05/12/2017 Page 3 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
MEMERE PROJECT OBJECTIVE Development of oxygen separation membranes for OCM membrane reactors with improved flux and selectivity, and thermal, chemical and mechanical stability under operating conditions (T=800-950ºC). CO2-TOLERANT OXYGEN MEMBRANES Two options in material selection: Not tolerant to CO2: • High flux perovskites (e.g. BSCF, LSCF) CO2 tolerant (lower O2 flux) : • Sr(Fe, M)O 3 ; M = Sb,Ta, Nb, … • Ce 0.9 Gd 0.1 O 2 (CGO) 05/12/2017 Page 4 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
MEMERE PROJECT Two possible configuration : 1. Capillary membranes High permeation but very fragile (self-supported) Alternative Advantages: • Easier sealing 2. Thin membranes supported • Better mechanical stability on porous ceramic tubes • Thin membrane allows high permeation MEMBRANE: Funtion: oxygen separation SUPPORT : Function : 1.Oxygen/Air ditribution 2.Mechanical stability 05/12/2017 Page 5 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
MEMERE PROJECT Need of CO 2 protective layer CO 2 Tolerant CGO BSCF No CO 2 Tolerant Al 2 O 3 Al2O3 Support • Asymmetric • Good surface quality • Commercially available (Rauschert RKV) CGO CO 2 Tolerant MgO MgO Support • Symmetric • Experimental development (Rauschert RHP) 05/12/2017 Page 6 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
Support preparation Porous MgO supports (Rauschert Heinersdorf-Pressig GmbH) Based on MgO-powder < 25 µm 2nd manufacturing of 14/7 mm tubes: 1st Manufacturing of 14/7 mm tubes: No more iron oxide Iron oxide impurities Cracks after firing impurities after fixing from the preparation unit the preparation unit No cracks due to reduced heating rate 05/12/2017 Page 7 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
Support preparation Porous MgO supports (Rauschert Koster Veilsdorf GmbH) Based on MgO-powder < 25 µm Tubes are usually fired on refractory supports, touching the outer surface 10/7 mm tubes have been fired on inserted alumina rods ▪ Smoother surface, closer to commercial surface quality ▪ Avoid bending 05/12/2017 Page 8 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
Membrane preparation Dip-coating technique Sintering Sintering Dry Dry T (ºC), t (h) T (ºC), t (h) T (ºC), t (h) T (ºC), t (h) Dip coating Dip coating Advantages of dip-coating: • Easy to perform • Cheap equipment required in comparison with other techniques • Good reproducibility of the membrane layers • Possibility of very thin layer deposition 05/12/2017 Page 9 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
CGO membrane 1 Coating CGO on MgO Membrane thickness: 1.76 µm ▪ The layer looks dense but there are still defects in the surface . So we proceed to do multiple coatings. 05/12/2017 Page 10 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
CGO membranes: Multiple coatings Coating 3 Coating 4 Coating 1+ Coating 2 Defects: 4,11-2,87µm Defects: 900nm-400nm Thickness: 2,93µm-627nm- Thickness: 1,21µm-840nm Thickness: 3,18-1,08µm 882nm 05/12/2017 Page 11 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
BSCF membrane 1 Coat BSCF on porous Alumina Membrane thickness: 9.72 µm EDX Ba Co Sr Fe Phase 1= Ba+Sr Phase 2= Fe+Co • Apparently there is a phase segregation of BSCF 05/12/2017 Page 12 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
BSCF membrane 21 16 11 6 1 Results observed with the Al 2 O 3 rod New layer Membrane layer synchrotron show that there BSCF - - × Al 2 O 3 × × × is an intermediate layer Ag × × × between alumina support Ba 0.717 Al 11 O 17.282 - - × BaAl 2 O 4 - - × and the BSCF. (Fe 0.868 Al 0.132 ) 8 (Fe 0.066 Al 0.934 ) 16 O 32 - - × Ba 0.5 Sr 0.5 CuAl 10 O 17 - - × CoAl 2 O 4 - - × Ag 2 O 3 - × Need of intermediate layer CuO - × - Ag 3 Al 22 O 34 - × - CuAl 2 O 4 - × - 05/12/2017 Page 13 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
Conclusions and future work ▪ MgO surface has been improved modify the mixture of the raw materials and sintering process. ▪ Develop new support of MgO with the goal of obtaining similar surface quality of commercial Al 2 O 3 asymmetric supports Obtain membranes without defects. ▪ Thin continuous BSCF coating onto Al 2 O 3 asymmetric support of Rauschert (RKV) and thin CGO coating onto MgO support symmetric support of (RHP) have been obtained by a simple dip coating technique . ▪ There is a chemical interaction between the Al2O3 support and the BSCF supports which caused a segregation of the BSCF material not making it oxygen permeable. ▪ A intermediate layer will be develop as a sacrificial layer to avoid the BSCF disaggregation. 05/12/2017 Page 14 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
Acknowledgements This project is supported by the European Union’s HORIZON2020 Programme (H2020/2014-2020) for the SPIRE Initiative under grant agreement nº 679933 Website: https://www.spire2030.eu/memere MEthane activation via integrated MEmbrane REactors We thank Finden for the support given us, carrying out the BSCF membrane analysis in the Synchrotron. 05/12/2017 Page 15 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
Thank you for your attention Contact info: Nerea Badiola: nerea.badiola@tecnalia.com 05/12/2017 Page 16 ( Disclosure or reproduction without prior permission of MEMERE is prohibited).
Recommend
More recommend
