MEMBRANES FOR SEPARATION OF CARBON DIOXIDE

摘要

Methods for separating carbon dioxide from a fluid stream at a temperature higher than about 200° C. with selectivity higher than Knudsen diffusion selectivity include contacting a porous membrane with the fluid stream to preferentially transport carbon dioxide. The porous membrane includes a porous support and a continuous porous separation layer disposed on a surface of the porous support and extending between the fluid stream and the porous support layer. The porous support comprises alumina, silica, zirconia, stabilized zirconia, stainless steel, titanium, nickel-based alloys, aluminum-based alloys, zirconium-based alloys or a combination thereof. Median pore size of the porous separation layer is less than about 10 nm, and the porous separation layer comprises titania, MgO, CaO, SrO, BaO, La₂O₃, CeO₂, HfO₂, Y₂O₃, VO_z, NbO_z, TaO_z, ATiO₃, AZrO₃, AAl₂O₄, A¹FeO₃, A¹MnO₃, A¹CoO₃, A¹NiO₃, A²HfO₃, A³ CeO₃, Li₂ZrO₃, Li₂SiO₃, Li₂TiO₃, Li₂HfO₃, A⁴N¹_yO_z, Y_xN¹_yO_z, La_xN¹_yO_z, HfN²_yO_z, or a combination thereof; wherein A is La, Mg, Ca, Sr or Ba; A¹ is La, Ca, Sr or Ba; A² is Ca, Sr or Ba; A³ is Sr or Ba; A⁴ is Mg, Ca, Sr, Ba, Ti or Zr; N¹ is V, Nb, Ta, Cr, Mo, W, Mn, Si or Ge; N² is V, Mo, W or Si; x is 1 or 2; y ranges from 1 to 3; and z ranges from 2 to 7.