Hitachi, Ltd.

Babcock-hitachi Kabushiki Kaisha

Mitsubishi Petrochemical Company Limited

Babcock-hitachi K.k.

Hitachi, Ltd. and Babcock-hitachi Kabushiki Kaisha

Fumito Nakajima

Masato Takeuchi

Shimpei Matsuda

Akira Kato

Shigeo Uno

Shinpei Matsuda

Yasuyoshi Kato

Yukio Hishinuma

Hirofumi Kikkawa

Jinichi Imahashi

Shigehito Takamoto

Takanori Nakamoto

Hiroshi Ishizaka

Hiroyuki Kaku

Hideo Okada

Hidetoshi Akimoto

Toshikatsu Mori

Shigeru Nozawa

Masakatsu Nishimura

Makoto Imanari

Yoshihisa Watanabe

Hiroshi Kawagoshi

Tomoichi Kamo

Hisao Yamashita

Kohki Tamura

Kunihiko Konishi

Sigeru Okabe

Youichi Sakuta

Hideo Yusa

Yoshijiro Arikawa

Toshiaki Matsuda

Kunio Kamiya

Ryuichi Kaji

Ikuhisa Hamada

Takahiro Tachi

Teruo Kumagai

Munehiko Tonami

Masahiro Nitta

Hirosi Tobita

Yutaka Fukui

Ryoichi Sasaki

Osamu Kuroda

Hiroshi Kuroda

Ryo Hiraga

Toshiki Kahara

Yasushi Muranaka

Norio Arashi

Seiji Takeuchi

Toshio Sawa

Seizi Takeuchi

Kazunori Fujita

Zensuke Tamura

Hiroyuki Miyagi

Kenichi Gomi

Yasuyuki Nishimura

Sadao Takahashi

Nobue Teshima

Atsushi Katagawa

Mutsuo Yamada

Nobuyoshi Ishida

Hideo Kikuchi

Hiroshi Tobita

Hiroshi Akama

Fumio Hataya

Kenzo Ishii

Isato Morita

Kouji Otani

Naomi Yoshida

Hitoshi Yamasaki

Takeo Komuro

Tokuji Iijima, Deceased

Tadaaki Mizoguchi

Hiroshi Terada

Otane Hitomi

Hiroshi Kagabu

Kazumi Murakami

Nobuo Matsuo

Mitsuharu Kon

Masayuki Yamamoto

Kunikatsu Yoshida

Masato Tekeuchi

A wet-type flue gas desulfurization method and plant making use of a solid desulfurizing agent in which exhaust gas exhausted from a combustion apparatus such as a boiler is brought into contact with absorbing liquid to absorb sulfur oxide from the exhaust gas into the absorbing liquid followed by neutralization of the absorbing liquid containing the sulfur oxide thus absorbed. The solid desulfurizing agent is selectively retained in an absorbing liquid neutralizing zone and the absorbing liquid, containing water as a main constituent and solid products formed from the absorbed sulfur oxide, is selectively removed from the neutralizing zone. In the neutralizing zone the upward flow of the absorbing liquid, optionally augmented by an upward flow of air or water, forms a fluidized bed of limestone particles, thereby preventing coating of the limestone by gypsum and thereby retaining reactivity of limestone. According to the present invention, coexistence of Al and F in the absorbing liquid seldom deteriorates the desulfurizing performance. Further, it is possible to reduce power and cost required to grind limestone and to achieve a higher desulfurizing performance.

Wet-type flue gas desulfurization plant and method making use of a solid

Wet-type flue gas desulfurization plant

A catalyst for purifying an exhaust gas includes a first component having activity for reducing nitrogen oxides with ammonia and a second component having at least one of activity for forming nitrogen oxide from ammonia and activity for forming carbon dioxide from carbon monoxide. The first component is a composition containing an oxide of at least one member selected from titanium, vanadium, tungsten and molybdenum and the second component is a composition containing a salt of a noble metal selected from platinum, palladium and rhodium or any one of these noble metals supported on a porous material selected from zeolites, alumina and silica. The invention further provides a method for purifying an exhaust gas containing NOx, CO and leak NH.sub.3 using the catalyst.

Catalyst for purifying exhaust gas

A process for producing carbamic acid esters (N-phenyl carbamate) which comprises reacting an amino group-containing compound (aniline), oxygen, a nitro group-containing compound (nitrobenzene), a carbon monoxide-containing gas and a hydroxyl group-containing organic compound (ethyl alcohol) in the presence of a compound of a transition metal belonging to Pt group of VIII group (Pd) of the Periodic Table as catalyst, a non-metal halide (HCl) and water. ##STR1##

Process for producing carbamic acid esters

A catalyst or a catalyst structure for removing nitrogen oxides contained in exhaust gases, having a small pressure loss and hard to cause ash deposition, and a process for producing the same are provided, which catalyst comprises a mixture of a catalyst composition of titanium oxide and at least one member of oxides of vanadium, molybdenum and tungsten, and inorganic fibers, the clearances of the inorganic fibers are filled with said catalyst composition; the ration by weight of said catalyst composition to said inorganic fibers is 3 or more; and the apparent density of said catalyst is 0.8 g/cm.sup.3 or more; and which process comprises providing a composition containing titanium oxide and at least one member of oxides of vanadium, molybdenum and tungsten, calcining said composition at 500.degree.-650.degree. C., crushing the calcined material so that powder of 20.mu. or less can occupy 90% by weight or more of the crushed material, adding water to the crushed material to form a slurry, impregnating an inorganic fiber sheet with the above slurry, placing the resulting sheet between porous molds, drying and molding it, and clacining the resulting molded material at 300.degree.-650.degree. C.

Catalyst for removing nitrogen oxides and a process for producing the

A catalyst for removing nitrogen oxides contained in exhaust gases, particularly those containing vapor-form catalyst poisons, by catalytic reduction with ammonia, while retaining a high denitration performance for a long time, which catalyst comprises titanium oxide as a first component, molybdenum oxide and/or tungsten oxide as a second component and vanadium oxide and/or sulfate as a third component, the atomic ratio of the respective elements being Ti:Mo and/or W:V=80-96.6:3-15:0.5-5, and the size of the crystallite of the titanium oxide according to Sherrer's equation being in the range of 185 .ANG. to 300 .ANG. in the direction of a plane (101) (interplanar spacing: d=3.52 .ANG.).

Catalyst for removing nitrogen oxides

A process for removing nitrogen oxides from exhaust gases containing volatile metal compounds with good efficiency by contacting the gases with a catalyst comprising TiO.sub.2, difficulty reduced by the compounds, in the presence of ammonia, and such a catalyst are provided, which process is characterized in that the average pore diameter of the TiO.sub.2 is 10,000 .ANG. or less and the proportion of the volume of pores having pore diameters of 400-5,000 .ANG. to the total pore volume is 50% or more; a denitration-active component is supported on the TiO.sub.2 ; a catalyst carrier precursor comprising an aqueous slurry sol of TiO.sub.2 or Ti hydroxide prepared by hydrolyzing a Ti salt is precalcined at 150.degree.-700.degree. C., followed by adding a denitration-active component and then normally calcining the mixture; and a polymer compound having a thermal decomposition temperature of 110.degree. to 300.degree. C. is added in 1-20% by weight to the catalyst carrier precursor, followed by precalcining the mixture at the thermal decomposition temperature or higher.

Process for removing nitrogen oxides

A process for removing nitrogen oxides from exhaust gases containing at least nitrogen oxides and volatile metal compounds by the use of a catalyst having prevented activity reduction due to the volatile metal compounds and having a superior durability is provided, which process comprises contacting the exhaust gases with a catalyst containing TiO.sub.2, a compound active to nitrogen oxides-removing reaction such as oxides of V, Cr, Mo, W, Fe, Co, Ni, Cu, Ce, etc. and/or sulfates thereof and a metal sulfate containing water of crystallization such as those of Al, Mg or Mn, in the presence of ammonia at 150.degree. to 600.degree. C.

A fuel cell provided with an electrolyte retaining plate made of electrical insulating long fibers such as lithium aluminate long fibers which have preferably a length of 100 to 400 .mu.m and a diameter of 1 to 4 .mu.m, are interlocked each other and have vacant spaces for filling an electrolyte can be constructed and operated safely without damaging the electrolyte retaining plate for a long period of time.

Process for producing an electrolyte retaining matrix of electrical

A waste gas generated in the reprocessing of used nuclear fuel is at first subjected to removal of explosive, gaseous substances such as hydrocarbons and nitrogen oxides, and materials capable of forming the explosive gaseous substances, such as oxygen, and condensible substances such as carbon dioxide, water and ammonia from the waste gas, and then to cryogenic distillation, thereby separating and recovering Kr-85 from the waste gas. As the separation and recovery of Kr-85 is carried out by cryogenic separation after the removal of the substances having a possibility to explode in a cryogenic distillation apparatus and also the removal of condensible substances having a possibility to clog a piping system of the apparatus, the operation of the apparatus is ensured. It is also disclosed that the oxygen and nitrogen oxides can be completely removed by catalytic hydrogen reduction.

Process for treating waste gas in reprocessing of used nuclear fuel

Mineral impurities can be effectively removed from coal by introducing oil droplets into an aqueous slurry of pulverized coal. Coal, which is lipophilic, attaches to the surface of the oil droplets and floats upwardly along with the oil droplets utilizing their buoyancy. On the other hand, mineral impurities, which are hydrophilic, are left in the aqueous slurry.

Process for removing ash from coal

In a molten carbonate fuel cell, an anode or cathode is made of a sintered material containing a nickel oxide and/or cobalt oxide and a rare earth element oxide. This anode or cathode has a high activity and is stable at high temperatures.

Molten carbonate fuel cell

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Hitachi, Japan

Fumito Nakajima