Abstract: The technique of the present invention enhances the separation efficiency and the production efficiency of hydrogen in a hydrogen production system for fuel cells, while reducing the size of the whole fuel gas production system. In the fuel gas production system of the present invention, a hydrocarbon compound is subjected to multi-step chemical processes including a reforming reaction, a shift reaction, and a CO oxidation to give a hydrogen-rich fuel gas. Gaseous hydrogen produced through the reforming reaction is separated by a hydrogen separation membrane having selective permeability to hydrogen. The residual gas after the separation of hydrogen has a low hydrogen partial pressure and undergoes the shift reaction at the accelerated rate. The hydrogen-rich processed gas obtained through the shift reaction and the CO oxidation joins with the separated hydrogen and is supplied to fuel cells.

Abstract: A compression ignition type engine, wherein a first combustion where the amount of the inert gas in the combustion chamber is larger than the amount of inert gas where the amount of production of soot peaks and almost no soot is produced and a second combustion where the amount of inert gas in the combustion chamber is smaller than the amount of inert gas where the amount of production of soot peaks are selectively switched between. The second combustion is performed after the engine operation is started until a catalyst arranged in the engine exhaust passage has become activated and, the first combustion is performed after the catalyst has become activated.

Abstract: An NOx absorbent is arranged in an engine exhaust passage absorbs NOx when the air-fuel ratio of inflowing exhaust gas is lean and discharges absorbed NOx or SOx when the oxygen concentration of inflowing exhaust gas decreases. When the air-fuel ratio of the exhaust gas flowing into the NOx absorbent is rich, previously absorbed NOx or SOx is discharged from the NOx absorbent. When NOx or SOx is to be discharged from the NOx absorbent, oxygen is left in the exhaust gas flowing into the NOx absorbent and the oxygen concentration of this exhaust gas is maintained within a predetermined range.

Abstract: An exhaust emission control system of an internal combustion engine desorbs SOx by reversing a flow of an exhaust gas through an NOx storage-reduction catalyst, of which a structure is simplified as follows. A first exhaust pipe connected to an engine is connected to a first port of an emission switching valve having four ports. A second exhaust pipe 10, through which the exhaust gas is discharged into the atmospheric air, is connected to a second port, a third exhaust pipe connected to an inlet of a catalytic converter is connected to a third port. A fourth exhaust pipe connected to an outlet of the catalytic converter 30 is connected to a fourth port. When the emission switching valve is set in a forward flow position, the first exhaust pipe is connected to the third exhaust pipe, and the second exhaust pipe is connected to the fourth exhaust pipe, whereby the exhaust gas flows toward the outlet from the inlet within the catalytic converter.

Abstract: The invention is related to fuels having a high laminar flame speed and particular distillation characteristics. More particularly, the invention is directed towards fuels containing at least one species having a laminar flame speed greater than isooctane's laminar flame speed and specific distillation characteristics including T50, FBP, IBP.

Abstract: A compression ignition type engine, wherein a first combustion where the amount of the recirculated exhaust gas supplied to the combustion chamber is larger than the amount of recirculated exhaust gas where the amount of production of soot peaks and almost no soot is produced and a second combustion where the amount of recirculated exhaust gas supplied to the combustion chamber is smaller than the amount of recirculated exhaust gas where the amount of production of soot peaks are selectively switched between and where the second combustion is switched to the first combustion when the temperature of the catalyst arranged in an engine exhaust passage is about to fall below the activation temperature.

Abstract: An exhaust gas purifying catalyst in which catalytic activation particles 3 composed of a catalytic element or its compound are carried on a carrier 1. The catalytic activation particles 3, as carried on the carrier 1 and exposed to the outside of the carrier 1, are coated with the carrier 1 by 20 to 90% of their whole surface area. Also disclosed is a process for producing the exhaust gas purifying catalyst.

Abstract: An engine comprising an exhaust gas recirculation system, wherein a first combustion where the amount of the recirculated exhaust gas supplied to the combustion chamber is larger than the amount of recirculated exhaust gas where the amount of production of soot peaks and almost no soot is produced and a second combustion where the amount of recirculated exhaust gas supplied to the combustion chamber is smaller than the amount of recirculated exhaust gas where the amount of production of soot peaks are selectively switched. The exhaust gas recirculation rate is caused to be changed in a step-like manner when switching from the first combustion to the second combustion or from the second combustion to the first combustion.

Abstract: According to the present invention, there is provided an exhaust gas purification device for an engine having an exhaust passage, the device comprising a catalyst arranged in the exhaust passage and having an upstream end and a downstream end, a purification ratio of exhaust gas by the catalyst becoming more than a predetermined ratio when a temperature of the catalyst is within a predetermined temperature range, cooling means for cooling the upstream end of the catalyst, heating means for heating the downstream end of the catalyst, and control means for controlling the cooling means and the heating means to maintain the temperature of a portion of the catalyst, which portion is positioned between the upstream end and the downstream end, in the predetermined temperature range.

Abstract: According to the present invention, there is provided an exhaust gas purification device for an engine having an exhaust passage, the device comprising a catalyst arranged in the exhaust passage and having an upstream end and a downstream end, a purification ratio of exhaust gas by the catalyst becoming more than a predetermined ratio when a temperature of the catalyst is within a predetermined temperature range, cooling means for cooling the upstream end of the catalyst, heating means for heating the downstream end of the catalyst, and control means for controlling the cooling means and the heating means to maintain the temperature of a portion of the catalyst, which portion is positioned between the upstream end and the downstream end, in the predetermined temperature range.

Abstract: A method for purifying an exhaust gas by simultaneously removing carbon monoxide, hydrocarbons, and nitrogen oxides contained in the exhaust gas, comprising bringing the oxygen rich exhaust gas into contact with an exhaust gas purifying catalyst comprised of at least one noble metal selected from the group consisting of platinum and palladium, at least one alkaline earth metal selected from the group consisting of barium, magnesium, calcium, and strontium, and at least one alkali metal selected from the group consisting of iron, nickel, and cobalt, supported on a carrier composed of a porous substance.

Abstract: A catalyst for purifying an exhaust gas for simultaneously removing carbon monoxide, hydrocarbons and nitrogen oxides contained in the exhaust gas under an oxygen rich atmosphere, comprising a carrier composed of a porous material, and barium oxide, lanthanum oxide and platinum supported on the carrier, and a method for purifying an exhaust gas by bringing the exhaust gas under an oxygen rich atmosphere into contact with the above-mentioned catalyst.

Abstract: A catalyst for purifying exhaust gases includes a porous support, at least one catalyst ingredient selected from Pt and Pd, and additional ingredients including (1) at least two rare-earth elements including La, (2) at least one rare-earth element including La and at least one transition element selected from Fe, Ni, Co and Mn, (3) at least two alkali metals, (4) at least one alkali metal and at least one rare-earth element including La, (5) at least one alkali metal and at least one transition element selected from Fe, Ni, Co and Mn, (6) at least two alkaline-earth metals, (7) at least one alkaline-earth metal and at least one rare-earth element including La, or (8) Ba, Li, La, Ce and Zr. A process for purifying an exhaust gas, by contacting the catalyst with an exhaust gas, is also provided.

Abstract: A compression ignition type engine, which switches between a first combustion where the amount of the inert gas in the combustion chamber is larger than the amount of inert gas where the amount of production of soot peaks and almost no soot is produced and a second combustion where the amount of inert gas in the combustion chamber is smaller than the amount of inert gas where the amount of production of soot peaks. The second combustion is provided instead of the first combustion when a catalyst is not activated.

Abstract: A fuel injection control device for a direct injection type engine having an exhaust passage and a NO.sub.x catalyst arranged therein to purify NO.sub.x in exhaust gas discharged from the engine comprises fuel injectors for injecting fuel into a cylinder. The injecting operation of the fuel injectors is controlled to carry out a main fuel injection at the latest at the beginning of a power stroke of the engine. The injecting operation of the fuel injectors is controlled to carry out a sub fuel injection at one of a power stroke and an exhaust stroke of the engine after the main fuel injection is completed to increase an amount of hydrocarbon in the exhaust gas. The injecting operation of the fuel injectors is controlled to carry out an additional sub fuel injection after the main fuel injection is completed and before the sub fuel injection is carried out.

Abstract: An exhaust gas purification device of an engine providing a NO.sub.x absorbent arranged in the exhaust passage. An O.sub.2 sensor is arranged in the engine exhaust passage downstream of the NO.sub.x absorbent. The degree of deterioration of the NO.sub.x absorbent is detected from the output signal of the O.sub.2 sensor. The cycle for making the air-fuel ratio of the air-fuel mixture rich for causing the release of the NO.sub.x from the NO.sub.x absorbent and the rich time at that time are shortened the greater the deterioration of the NO.sub.x absorbent.

Abstract: In the exhaust gas purification device of the present invention, a NO.sub.x absorbent is disposed in the exhaust gas passage of a diesel engine. At the time when NO.sub.x should be released from the NO.sub.x absorbent, a control circuit of the engine reduces the excess air ratio of the engine, and switches the combustion mode of the engine from the normal diesel combustion, in which diffusive combustion is dominant in the combustion chamber of the engine, to the combustion mode in which pre-mixture fuel combustion is dominant. By doing this, it is possible, even in a diesel engine, to reduce the excess air ratio in combustion to thereby make the air-fuel ratio of the exhaust gas lower than or equal to the stoichiometric. Thus, the regeneration of the NO.sub.x absorbent can be performed even when it is applied to a diesel engine.

Abstract: An exhaust purification device of an engine providing a NO.sub.x absorbent arranged in the exhaust passage. An O.sub.2 sensor generating a current proportional to the air-fuel ratio is arranged in the engine exhaust passage downstream of the NO.sub.x absorbent. The amount of NO.sub.x actually absorbed in the NO.sub.x absorbent at the time of release of the NO.sub.x is calculated on the basis of the output signal of this O.sub.2 sensor. On the basis of this calculated amount of NO.sub.x, correction is made so that the estimated amount of NO.sub.x represents the actual amount of absorption of NO.sub.x. When this corrected estimated amount of NO.sub.x reaches a set value, the action of releasing the NO.sub.x from the NO.sub.x absorbent is carried out.

Abstract: A device for detecting deterioration of a NO.sub.x absorbent arranged in the exhaust passage of an engine. An O.sub.2 sensor generating a current proportional to the air-fuel ratio is arranged in the exhaust passage downstream of the NO.sub.x absorbent. When the amount of NO.sub.x absorbed in the NO.sub.x absorbent is almost zero or after the amount of NO.sub.x absorbed in the NO.sub.x absorbent is made almost zero, the air-fuel ratio of the air-fuel mixture is changed from lean to rich, and the amount of oxygen stored in the NO.sub.x absorbent is detected from the output signal of the O.sub.2 sensor at this time. Further, the NO.sub.x absorbing capability is found by using this detected oxygen amount.

Abstract: A catalyst for purifying exhaust gases, which is composed of a catalyst substrate, a first porous support layer supporting barium as a NOx-occluding material and palladium, which is formed on the catalyst support, and a second porous support layer supporting platinum, which is formed on the first porous support layer. Platinum efficiently oxidizes nitrogen monoxide to be converted into nitrogen dioxide. Palladium is supported in a highly dispersed state even after endurance to act as inlet and outlet of barium for nitrogen dioxide or the like, whereby absorption and emission of nitrogen oxides can be performed smoothly, and accordingly, the purification performance for nitrogen oxides is improved.