Advances in Ceramic-Carbonate Dual-Phase Membrane Reactors for Direct CO2 Separation and Utilization

Abstract

Excessive (carbon dioxide) CO₂ emissions are a primary factor contributing to climate change. As one of the crucial technologies for alleviating CO₂ emissions, carbon capture and utilization (CCU) technology has attracted considerable global attention. Technologies for capturing CO₂ in extreme circumstances are indispensable for regulating CO₂ levels in industrial processes. The unique separation characteristics of the ceramic-carbonate dual-phase (CCDP) membranes are increasingly employed for CO₂ separation at high temperatures due to their outstanding chemical, thermal durability, and mechanical strength. This paper presents an overview of CO₂ capture approaches and materials. It also elaborates on the research progress of three types of CCDP membranes with distinct permeation mechanisms, concentrating on their principles, materials, and structures. Additionally, several typical membrane reactors, such as the dry reforming of methane (DRM) and reverse water-gas shift (RWGS), are discussed to demonstrate how captured CO₂ can function as a soft oxidant, converting feedstocks into valuable products through oxidation pathways designed within a single reactor. Finally, the future challenges and prospects of high-temperature CCDP membrane technologies and their related reactors are proposed.

Keywords: CO2 separation; ceramic–carbonate dual-phase membranes membrane reactor; mixed ionic–electronic conducting; post-combustion.

Figure 3

Membrane separation technology. (a) The preparation scheme of the crosslinked polymer membrane [58]. (b) The palladium-based metal membrane for H₂ separation [60]. (c) The activation mechanism of the N-doped CNTs membrane [61]. (d) The illustration of the homogeneous hollow-fiber membranes [62]. (e) The structure of a metal–organic framework membrane [64]. (f) The schematic drawing of the setup and CCDP membrane for CO₂ permeation [67]. (g) The schematic illustration of the CCDP membrane for CO₂ separation [68].

Figure 6

(a) Illustration of CO₂ permeation through a dense mixed ionic–electronic-conducting (MIEC) carbonate dual-phase membrane [100]. (b) Schematic drawing of preparation of thin SDC layers on SDC/BYS supports by co-pressing method [101]. (c) Schematic diagram of the ALD chamber and the relationship between the surface grain size of the selective layer and the number of ALD cycles. (d) Schematic diagram of pore size tailoring of ceramic membranes of sintered nanoparticles by ALD. (e) High-magnification SEM images of the layer and the correlation between the thickness of the layer and the number of ALD cycles. (f) Microstructure of a porous Ag matrix overcoated with ZrO₂. (g) Schematic diagram of conventional infiltration method and new two-step coating method [71]. (h) Schematic representation for making dead-end tubes by CIP method [67].

Figure 7

(a) Microstructures of Ag50Al50 and 48 h-Ag50Al50 [115]. (b) Schematic illustration of the proposed bi-pathway transport mechanism [113]. (c) The effect of H₂ concentration in the sweep gas on CO₂ and O₂ flux densities [115]. (d) The microstructure of a porous Ag matrix and a porous Ag matrix coated with 5% Al₂O₃ colloidal [117]. (e) A schematic illustration of the self-forming NiO-MECC membrane. (f) The CO₂ densities of the MECC membrane as a function of the reciprocal of thickness at 550 °C and 600 °C. (g) The CO₂/O₂ flux density and selectivity of the NiO–MC membrane measured at 850 °C [118].

Figure 8

(a) Effects of different gas flow directions on CO₂ permeation in LSCF hollow-fiber membranes and its schematic diagram. (b) Elemental mapping images of the cross-section before and after long-term stability testing [90]. (c) Structural schematic of La_1.5Sr_0.5NiO_4+δ. (d) CO₂ permeation flux at different temperatures [77]. (e) CO₂ flux under the MOCC model and the transmission ratio between MOCC and MECC pathways [122]. (f) Schematic diagram of SrFe_0.8Nb_0.2O_3−δ four-channel hollow-fiber membrane. (g) Thermal shock resistance [109]. (h,i) Conductivity of different GDC and LN ratios at varying temperatures and Nyquist plots of CG80-LN20 [123]. (j) Permeation mechanism of the SDC-SSFA-MC membrane. (k) CO₂ permeation of the SDC-SSFA-MC membrane [124].

Figure 1

A schematic summary of the main components in this review. Global carbon neutral pledge-related projects and pathways, CO₂ capture and utilization technologies, and membrane reactor-based materials for post-combustion technology.

Figure 2

(a) Flow sheet of the chemical absorption. (b) Mechanism diagram of adsorption. (c) Flow sheet of the cryogenic distillation. (d) Mechanism diagram of the membrane separation method.

Figure 4

Schematic diagram of CO₂ separation mechanism in (a) MOCC, (b) MECC, and (c) MEOCC.

Figure 5

(a) Schematic diagram of penetration of YSZ [80]. (b) Views of MC on the dense ScCeSZ pellet at a different temperature, reproduced from Ref. [56] with permission from the American Chemical Society, 2021. (c) The CO₂ permeability of Ce_1−xGd_xO_2−δ-MC (x = 0.00–0.30) dual-phase membranes at different temperatures [79]. (d) SEM-EDS image of SDC matrix and SDC-MC membrane [89]. (e) SEM of Ce_0.8Gd_0.2O_2−δ supports prepared using pore formers with different particle sizes, and the particle size distribution of the pore former [79]. (f) CO₂ flux of BZY-20C-MC membrane with different H₂O partial pressure [98]. (g) H₂O-enhanced CO₂ transport mechanism in the CCDP membranes under wet sweeping gas condition, reproduced from Ref. [56] with permission from the American Chemical Society, 2021. (h) CO₂ permeation stability of SDC–carbonate membranes with H₂/CO₂/N₂ feed containing various concentrations of H₂S at 750 °C [99].

Figure 9

(a) Schematic diagram of the CP-PSFC-MC membrane coupled with DRM. (b) DRM performance of the CP-PSFC-MC membrane at different temperatures [40]. (c) Schematic diagram of the SDC-NiO-MC membrane used in DRM. (d) Long-term stability test of the SDC-NiO-MC membrane coupled with DRM [125]. (e–g) Ethane-to-ethylene conversion using a GDC-MC membrane reactor: (e) mechanism diagram, (f) long-term stability, and (g) SEM image of the surface after testing [126]. (h) SDC-MC tubular membrane for hydrogen production via the WSG mechanism [127]. (i) Numerical simulation of ceramic–MC membrane for hydrogen production via WSG and the influence of membrane thickness [128].