Ngk Insulators, Inc.

Nobuhiko Mori

Toshiyuki Nakamura

Taku Okamoto

Akira Takahashi

Toshihiro Tomita

Masaaki Kawai

Aya Satoh

Hitoshi Sakai

Yuichiro Kondo

Kenichi Noda

Takayuki Sekiya

Yuki Nakayama

Kosuke Monna

Osamu Sakai

Aya Miura

Daichi Ichikawa

Takashi Ina

Koichi Katsurayama

Koki Hamada

Mariko Takagi

A first gas sensor having a first sensor element includes a first protective cover that protects the first sensor element, and a second gas sensor having a second sensor element includes a second protective cover that protects the second sensor element. The first protective cover is coated with an oxidation catalyst for one target component from among a plurality of target components, and the second protective cover is coated with an inert catalyst for the one target component.

Gas sensor set and method of measuring concentrations of a plurality of target components within a gas to be measured

In a gas sensor, which measures a measurement pump current Ipof a measurement chamber, while switching a preliminary pump cell of a preliminary chamber ON or OFF at a constant period, there are formed in communication with each other sequentially from a gas introduction port in the interior of a structural body made from a solid electrolyte, a preliminary chamber, an oxygen concentration adjustment chamber, and a measurement chamber. The gas sensor rapidly determines a steady-state value of a measurement pump current Ip, based on a peak value of a rate of change over time dIp/dt of the measurement pump current Ip, thereby hastening an ON/OFF switching period of the preliminary pump cell.

Gas sensor and gas concentration measurement method

A sensor element includes a NOx sensor part, a NHgas sensor part, and a single common electrode shared by the both parts. The former has a pump cell including a measurement electrode facing an internal space, a pump electrode formed on a surface of the element, and a solid electrolyte therebetween. The latter includes a sensing electrode formed on a surface of the element and having catalytic activity inactivated for a NHgas. The common electrode is located to be in contact with a reference gas. The NOx concentration is determined based on a potential difference occurring between the sensing electrode and the common electrode, and a current flowing through the pump cell in a state of controlling a voltage applied across the electrodes to maintain a potential difference between the measurement electrode and the common electrode constant.

Gas sensor

Provided is a gas sensor having simpler configuration than a conventional multi-gas sensor, and being capable of measuring NOx and NHsimultaneously. In the gas sensor determining a NOx concentration in a measurement gas based on a pump current flowing between a NOx measurement electrode and an outer pump electrode, the outer pump electrode has catalytic activity inactivated for NHso that a sensor element further includes a NHsensor part having a mixed potential cell constituted by the outer pump electrode, a reference electrode, and a solid electrolyte between these electrodes, and determination of a NHconcentration based on a potential difference occurring between the outer pump electrode and the reference electrode and determination of a NOx concentration based on the pump current and the NHconcentration can be performed simultaneously or selectively when the sensor element is heated to 400&#xb0; C. or higher and 600&#xb0; C. or lower.

A slope &#x394;in a linear area of sensor output characteristics for a mixed atmosphere of CO and THC and a slope &#x394;in the linear area of the sensor output characteristics for NHare specified in advance at a time when a time thas elapsed since a start of use of an engine. In performing calibration of an NHsensor when a time t(greater than the time t) has elapsed, a slope &#x394;in the linear area of the sensor output characteristics for the mixed atmosphere is specified, a value &#x394;is calculated from an equation &#x394;=&#x394;/(&#x394;/&#x394;), and the calculated value &#x394;is determined as a new slope in the linear area of the sensor output characteristics for an NHgas.

Ammonia sensor calibration method

A method for manufacturing a silica membrane filter includes performing, at least once, a fired membrane forming operation having a membrane forming step of applying, to a porous substrate, a precursor sol which is a sol of a silicon alcoxide including a p-tolyl group to form a precursor sol membrane, a drying step of drying the precursor sol membrane formed in the porous substrate to form a dried membrane, and a firing step of firing the dried membrane formed in the porous substrate to form a fired membrane, thereby preparing the silica membrane filter including the porous substrate and a silica membrane which is the fired membrane formed in the porous substrate, and a ratio of a total mass of the silica membrane to a total mass of the dried membrane is 38 mass % or more and 85 mass % or less.

Method for manufacturing silica membrane filter, and silica membrane filter

There is provided a silica membrane filter having performance of selectively separating an aromatic compound and performance of selectively separating an alcohol. The silica membrane filter is provided with a porous substrate and a silica membrane. The ratio of a He gas permeation amount to an Ngas permeation amount (He gas permeation amount/Ngas permeation amount) is 7 or less, and the ratio of the Ngas permeation amount to a SFgas permeation amount (Ngas permeation amount/SFgas permeation amount) is 1.5 or more.

Silica film filter and process for producing silica film filter

There is provided a zeolite separation membrane-provided article having gaps or pores larger than pores inherent to zeolite crystals and controlled within an appropriate range and being capable of achieving both high permeability and high separability for components with small difference in adsorption properties or a component having a smaller molecular diameter than the diameter of the pores, a method for producing the same, a method for separating mixed fluids, and a device for separating mixed fluids. The zeolite separation membrane-provided article is provided with a zeolite membrane having an Ngas permeation speed at room temperature of 1.0&#xd7;10mol&#xb7;m&#xb7;s&#xb7;Paor more and a permeation speed ratio of 1,3,5-trimethylbenzene/Nat room temperature of 0.17 or more and being free from dyeing caused by the impregnation with Rhodamine B.

Structure provided with zeolite separation membrane, method for producing same, method for separating mixed fluids and device for separating mixed fluids

A method for producing a carbon membrane of the present invention is a production method where a carbon membrane obtained by subjecting a carbon-containing layer to thermal decomposition in an oxygen inert atmosphere while sending a gas mixture containing an oxidizing gas thereinto is thermally heated. The carbon membrane is subjected to a heating oxidation treatment with controlling the ratio of the flow rate of the gas mixture to the areas of the carbon membrane to 0.5 cm/min. or more to control (temperature &#xb0; C.)&#xd7;time (h)/10000, which is the relation between the temperature of the gas mixture and the flow time, to 9 to 32. This enables to obtain a carbon film which selectively separates alcohols having 2 or less carbon atoms from a liquid mixture of the alcohols having 2 or less carbon atoms and organic compounds having 5 to 9 carbon atoms.

Method for producing carbon film, carbon film and separator

There is disclosed a permselective membrane reactor which efficiently forms hydrogen by use of a water-gas shift reaction and which is excellent in an aspect of manufacturing cost. In a permselective membrane reactor, a permselective membrane is a Pd membrane or a Pd alloy membrane, and a catalyst layer includes a first catalyst layer on the side of the permselective membrane and a second catalyst layer disposed apart from the permselective membrane. The first catalyst layer has a noble metal-based catalyst, and the second catalyst layer has an iron-based catalyst.

Permselective membrane type reactor

A selectively permeable membrane type reactor including a catalyst for promoting a chemical reaction, a selectively permeable membrane which selectively allows a specific component to pass therethrough, and a carrier for disposing the catalyst and the selectively permeable membrane the carrier being a tubular body having two or more gas passage cells partitioned and formed by a partition wall formed of a porous body, the catalyst being individually disposed in some of the cells of the carrier, the selectively permeable membrane being individually disposed in the remainder of the cells, and the cell in which the catalyst is disposed and the cell in which the selectively permeable membrane is disposed being adjacently disposed with the partition wall positioned therebetween.

Selectively permeable membrane type reactor

A permselective membrane reactor is provided, including a reactor tube having a gas inlet at one end and a gas outlet at the other end thereof. A separator tube is disposed in the reactor tube and has a permselective membrane selectively permeable to hydrogen on a surface thereof and a discharge outlet for passing separated gas through the permselective membrane. The permselective membrane reactor also includes a layer comprising a reforming catalyst that promotes reforming of ethanol, so that &#x3b2;, defined by the following equation, is in a range of 0.05 to 20:&#x3b2;=a/b

Process for producing hydrogen with permselective membrane reactor and permselective membrane reactor

A selectively permeable membrane reactor includes a reaction tube including a supply port as an inlet port for a raw material gas and a discharge port as an outlet port for an unseparated gas, and a separation tube inserted into the reaction tube. The separation tube includes a selectively permeable membrane exhibiting selective permeability for a specific component on a surface facing the internal space of the reaction tube, and a process port as an outlet port for a separated gas which has passed through the selectively permeable membrane, and a catalyst for promoting a chemical reaction is provided in the reaction tube excluding the separation tube. A catalyst is carried by a foamed body having porous structure to form a foam-molded product and suppresses physical and chemical deterioration in the selectively permeable membrane and allows a mixed gas produced by a catalytic reaction to be efficiently separated.

Reactor of selective-permeation membrane type

A process is provided for reforming a hydrocarbon with carbon dioxide using a selectively permeable membrane reactor including a catalyst for accelerating a chemical reaction and a selectively permeable membrane exhibiting selective permeability, wherein a carbon dioxide reforming reaction of the hydrocarbon is accelerated by the catalyst to produce reaction products, and a specific component among the reaction products is allowed to pass through the selectively permeable membrane so specific component is selectively separated. The process includes the steps of adding steam to a raw material gas containing the hydrocarbon and the carbon dioxide and supplying the raw material gas mixture to the selectively permeable membrane reactor.

Process for reforming hydrocarbons with carbon dioxide by the use of a selectively permeable membrane reactor

A laminated zeolite composite is provided, including a MFI membrane constituted by a MFI type zeolite having a SiO/AlO(molar ratio) of 40 to 100, and a porous substrate constituted by a MFI type zeolite having a SiO/AlO(molar ratio) of 20 to 400, wherein the MFI membrane is formed on the porous substrate. The composite has high separation characteristics and high permeability.

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Nagoya, Japan

Nobuhiko Mori