Methane conversion to syngas and hydrogen in a dual phase Ce_0.8Sm_0.2O_2-Δ-Sr₂Fe_1.5Mo_0.5O_5+Δ membrane reactor with improved stability

authored by

Wenyuan Liang, Hangyue Zhou, Jürgen Caro, Heqing Jiang

Abstract

Coupling of partial oxidation of methane (POM) with water dissociation in an oxygen transport membrane is a promising technology for methane utilization. However, cobalt-based membrane materials show poor stability under the above harsh conditions. In this work, a nominal 60 wt % Ce_0.8Sm_0.2O_2-δ-40 wt % Sr₂Fe_1.5Mo_0.5O_5+δ (CSO-SFMO) dual phase membrane is reported, which was synthesized by using a one-pot EDTA-citric acid complexing method. The phase structure and morphology of the CSO-SFMO membrane were characterized by XRD, SEM and EDXS. It was found that a uniform distribution of CSO phase with a fluorite structure and SFMO phase with a perovskite structure was achieved in the dual phase membrane. The CSO-SFMO membrane exhibited an improved stability compared with cobalt based perovskite Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ (BSCF) membrane under CO₂ or reductive gas atmospheres. The oxygen permeation flux of the dual phase membrane was investigated under different oxygen partial pressure gradients: air/He, air/CO₂, air/POM, and H₂O/POM. At 950 °C, the oxygen permeation fluxes of the CSO-SFMO membrane under air/POM and H₂O/POM gradients were 2.7 cm³ (STP) min⁻¹ cm⁻² and 0.75 cm³ (STP) min⁻¹ cm⁻², respectively, which were much higher than the oxygen flux of 0.1 cm³ (STP) min⁻¹ cm⁻² under air/He. Moreover, a CO selectivity of 98%, a CH₄ conversion of 97% on the POM side and a H₂ production of 1.5 cm³ (STP) min⁻¹ cm⁻² on the H₂O splitting side were achieved in CSO-SFMO membrane reactor under the oxygen partial pressure gradient of H₂O/POM, which was steadily run for 100 h before the measurement was intentionally stopped.

Organisation(s)

Institute of Physical Chemistry and Electrochemistry

External Organisation(s)

University of the Chinese Academy of Sciences (UCAS)
Chinese Academy of Sciences (CAS)

Type

Article

Journal

International Journal of Hydrogen Energy

Volume

43

Pages

14478-14485

No. of pages

8

ISSN

0360-3199

Publication date

02.08.2018

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Renewable Energy, Sustainability and the Environment, Fuel Technology, Condensed Matter Physics, Energy Engineering and Power Technology

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy

Electronic version(s)

https://doi.org/10.1016/j.ijhydene.2018.06.008 (Access: Closed)