Praxair Technology, Inc.

Other

Weitung Wang

Hancun Chen

Jack C Chen

Terry Joseph Mazanec

Prasad Shrikrisnna Apte

A method of producing a green form for use in manufacturing a composite, ceramic ion transport membrane is provided in which first and second ceramic powder mixtures are used to produce first and second layers of the green form. The first and second ceramic powder mixtures have ceramic particles and a pore former. After formation of each of the first and second layers or after formation of the second layer, heat is applied to burn out the binder and form pores. This heating is completed prior to application of a dense layer to prevent production of defects within the dense layer. The dense layer contains an ion transport material. Defects are also prevented by grading particle size from the first layer to the dense layer. This allows the second intermediate layer to fill in larger pores of the first layer and to present a smooth surface to the dense layer. Additionally, the second ceramic powder mixture contains in part material used in forming the dense layer for thermal expansion compatibility purposes.

Ceramic manufacture for a composite ion transport membrane

A method of making an electrolytic cell in which an electrolyte layer of an intermediate sintered form is coated with a pre-coat layer containing electrically non-conductive particles of less than about one-tenth of a micron in size to fill in defects existing within the electrolyte layer. The pre-coat layer is removed so that the electrically non-conductive particles remain within the defects of the electrolyte layer. The cathode layer is then applied to the electrolyte layer with the electrically non-conductive particles in place within the defects. The intermediate sintered form is fired with the applied cathode layer to produce the electrolytic cell.

Method of making an electrolytic cell

A method of manufacturing an electrolytic cell in which an intermediate sintered form is produced that comprises a porous anode layer and an electrolyte layer having a prespecified shape of the electrolytic cell. The electrolyte layer has defects extending through the electrolyte layer. A substance by way of a pressure, a solvent, particle suspended in a solvent or particles introduced by way of thermal spray are introduced into defects within the electrolyte layer. Thereafter, a green cathode layer is applied to the electrolyte layer while the substance is in place, within the defects. The intermediate sintered form with the applied green cathode layer is then fired to produce the electrolytic cell.

Method of manufacturing an electrolytic cell

A wall construction for an electrolytic cell to separate oxygen from an oxygen containing gas in which an electrolyte layer of less than 200 microns and a cathode layer of less than 500 microns are supported by an anode that can have a sufficient thickness to also contain the separated oxygen at pressure. The cathode is formed from the same material as the electrolyte and also a noble metal or noble metal alloy and a mixed conductor. The cathode contains a sufficient amount of the noble metal or noble metal allow and the mixed conductor that the total resistance thereof is not greater than about 70 percent of the total resistance of the anode and the cathode. In a preferred embodiment, first and second porous interfacial layers are situated between an anode layer and the electrolyte and the electrolyte and a cathode layer, respectively. The first and second porous interfacial layers increase thermal compatibility between the anode and cathode and the electrolyte, improve the three-phase boundary and allow thinner electrolytes to be employed with fewer manufacturing defects.

Wall construction for electrolytic cell

The present invention provides an ion conducting ceramic membrane selectively permeable to a gas, for instance oxygen and a method of treating such a membrane to improve permeation through the membrane. The membrane is formed by a mass of a substance through which ions of the gas migrate. The mass has two opposed surfaces where dissociation and ionization of the gas occurs and gas ions release electrons and recombine to form molecules of the gas, respectively. At least one of said two opposed surfaces is treated by a removal of surface material to produce surface irregularities of increased area and therefore an increase in total surface area of a treated surface to in turn increase permeation of the gas. Preferably, both surfaces of the membrane are treated by chemical etching techniques, although sand blasting and ion etching are other possible surface treatments in accordance with the present invention.

Growing community of inventors

East Amherst, NY, United States of America

Weitung Wang