Mitsubishi Jukogyo Kabushiki Kaisha

Mitsubishi Heavy Industries Limited

Hokkaido Electric Power Company, Inc.

Atsushi Tatani

Susumu Okino

Taku Shimizu

Masakazu Onizuka

Naohiko Ukawa

Toru Takashina

Kazuaki Kimura

Naoharu Shinoda

Kiyoshi Okazoe

Eiji Ochi

Masao Hino

Kenji Inoue

Takashi Haruki

Makoto Susaki

Setsuo Omoto

Koichiro Iwashita

Masumi Atsukawa

Toshikuni Sera

Yoshio Nakayama

Hiroshi Fujita

Kenichi Yoneda

Shinichiro Kotake

Yoshihiro Shiraishi

Takayoshi Hamada

Tokuma Arai

Masaki Iijima

Shigeo Hasegawa

Yoshihiro Okamoto

Nobutaka Maeda

Toyoshi Nakagawa

Tsumoru Nakamura

Tsuyoshi Ohishi

Katsuhiko Yamada

Masato Miyake

Satoshi Yajima

Michio Oshima

Kenzo Muramatsu

Tsutomu Ueno

Hiroaki Tsuchiai

Yukio Kitamura

Koso Tao

Tsutomer Kabumoto

Yasuyuki Inoue

Sadaichi Shigeta

Shintarou Honjo

Yutaka Kitayama

A gas refining method for adsorbing a reducing gas obtained by pressure gasification of coal or oil comprises introducing a reducing gas stream into an adsorbing and removing zone where it contacts an adsorbent. Sulfur-containing compounds are adsorbed onto the adsorbent and a first oxygen-containing gas stream is introduced into the adsorbing and removing zone in order to form a regeneration gas containing sulfur dioxide. The regeneration gas is contacted with a second oxygen-containing stream and a calcium-containing liquid slurry to effect absorption of sulfur dioxide by the slurry and precipitation of a gypsum compound. The temperature of the slurry is varied to cause selective precipitation of 60 -gypsum hemihydrate or gypsum dihydrate.

Gas refining system

Five combustion exhaust gas treatment systems capable of removing dust and selenium (Se) in combustion exhaust gas and making harmless are proposed: (1) combustion exhaust gas is cooled to 350&deg; C. or less, dust is separated, Se is transformed into insoluble compound, and Se is separated; (2) combustion exhaust gas is cooled to 350&deg; C. or less, dust is separated, Se elution preventive agent is added, and dust is formed into scale; (3) dust in combustion exhaust gas is collected by dust collector, dust is formed into slurry by making use of part of circulation liquid in desulfurization apparatus, and tetravalent Se in dust slurry is transformed into insoluble compound, which is separated into solid and liquid; (4) dust is separated from combustion exhaust gas by dust collector, and it is heated to gasify Se, and is led into desulfurization apparatus, etc., and formed into slurry, and Se is made into insoluble compound; and (5) a treating agent for making tetravalent Se insoluble is added to part of circulation liquid in desulfurization apparatus, and it is sprayed into combustion exhaust gas to make Se insoluble.

Combustion exhaust gas treatment system

A liquid extracting apparatus in accordance with the present invention is configured so that a connection pipe (suction-side pipe) of a pump for extracting slurry liquid content is connected to the upper end side of a liquid content introduction path to which slurry in a tank can be introduced to attain the precipitation and separation of solid content, and a number of tubes are packed at the lower end portion of the liquid content introduction path . The present invention can provide a simple liquid extracting apparatus that can effectively extract only liquid content in the slurry (suspension) moving in the tank.

Liquid extracting apparatus

Five combustion exhaust gas treatment systems capable of removing dust and selenium (Se) in combustion exhaust gas and making harmless are proposed: (1) combustion exhaust gas is cooled to 350.degree. C. or less, dust is separated, Se is transformed into insoluble compound, and Se is separated; (2) combustion exhaust gas is cooled to 350.degree. C. or less, dust is separated, Se elution preventive agent is added, and dust is formed into scale; (3) dust in combustion exhaust gas is collected by dust collector, dust is formed into slurry by making use of part of circulation liquid in desulfurization apparatus, and tetravalent Se in dust slurry is transformed into insoluble compound, which is separated into solid and liquid; (4) dust is separated from combustion exhaust gas by dust collector, and it is heated to gasify Se, and is led into desulfurization apparatus, etc., and formed into slurry, and Se is made into insoluble compound; and (5) a treating agent for making tetravalent Se insoluble is added to part of circulation liquid in desulfurization apparatus, and it is sprayed into combustion exhaust gas to make Se insoluble.

This invention relates to a gasification power generation process wherein a product gas A1 obtained by the gasification of coal or petroleum is used as the fuel of a gas turbine 4 for electric power generation, the process comprising the steps of dedusting product gas A1, introducing product gas A1 directly into gas turbine 4 as the fuel thereof to effect electric power generation, and subjecting the exhaust gas A2 discharged from gas turbine 4 to a gas purification treatment including at least desulfurization. This invention can provide a gasification power generation process which is more suitable for practical use from an economic point of view in that a high degree of exhaust gas purification and a marked improvement in thermal efficiency can be achieved and, moreover, the construction of the equipment for carrying out a gas purification treatment including desulfurization can be highly simplified.

Gasification power generation process and gasification power generation

An uncondensed gas in steam discharged from a turbine in a geothermal power plant and separated from water with a condenser is treated by a desulfurization method comprising the combustion step of combusting the uncondensed gas in the steam to convert hydrogen sulfide in the uncondensed gas to a sulfurous acid gas and the absorption reaction step of bringing a combustion gas coming from the combustion step into gas-liquid contact with an absorbent slurry and further bringing air into air-liquid contact with the absorbent slurry to allow the absorbent slurry to absorb the sulfurous acid gas and undergo oxidation and neutralization to exhaust desulfurized gas and to convert the absorbent slurry to a sulfate slurry, whereby detrimental hydrogen sulfide is removed from the steam exhausted after the use of the steam for power generation in the geothermal power plant.

Desulforization method and desulfurization apparatus in geothermal power

This invention relates to a gas refining system wherein a high-temperature and high-pressure reducing gas is introduced into a fixed-bed desulfurizer packed with an adsorbent by which sulfur compounds contained in the high-temperature and high-pressure reducing gas are adsorbed and removed in the form of a sulfide, and the adsorbent having the sulfide adsorbed thereon is regenerated by roasting it with a regenerating gas containing oxygen, characterized in that the gas refining system is equipped with oxygen concentration control means for controlling the oxygen concentration in the regenerating gas introduced into the desulfurizer so as to keep the internal temperature of the desulfurizer during the regeneration reaction within the allowable temperature range of the adsorbent. This invention includes an embodiment in which the exhaust gas obtained after the regeneration reaction gas is brought into contact with a calcium compound-containing slurry to recover gypsum is recycled to the desulfurizer for use as the regenerating gas for the adsorbent. Thus, the adverse effect of the heat of regeneration reaction on the adsorbent used in the fixed-bed desulfurizer can be avoided positively and easily.

A corrosion preventive method and an apparatus for preventing corrosion of stainless steel components in an exhaust gas desulfurizing apparatus of an exhaust gas treatment system comprising the exhaust gas desulfurizing apparatus for removing at least sulfur dioxide by bringing exhaust gas into contact with absorbing solution, wherein specific means is employed to maintain the Cl.sup.- concentration and SO.sub.4.sup.2- concentration at a corrosion preventive side of the corrosion resisting limit of stainless steel.

Method and apparatus for preventing corrosion of exhaust gas treatment

A wet flue gas desulfurization process wherein sulfur dioxide present in flue gas is absorbed into a slurry containing a calcium compound, the slurry having sulfur dioxide absorbed therein is oxidized to form a gypsum slurry, and gypsum is separated and recovered from the gypsum slurry, which comprises the steps of dipping a part of a circulating filtering surface of a suction filter into the gypsum slurry so as to cause gypsum to adhere the filtering surface, carrying the gypsum-bearing filtering surface above the surface of the gypsum slurry, sucking out the liquid phase through the filtering surface to form a dehydrated gypsum layer thereon, and removing the gypsum layer from the filtering surface, as well as an apparatus for carrying out this process.

Wet flue gas desulfurization process and system

A flue gas desulfurizer having an absorption tower for bringing untreated flue gas into gas-liquid contact with an absorbent slurry, wherein there is provided heat recovery means for recovering heat from the flue gas passing through the flue gas inlet section of the absorption tower prior to gas-liquid contact, and to boiler equipment including heat release means for releasing the recovered heat to heat utilization equipment. This invention also relates to thermal electric power generation equipment including extraction feedwater heaters for heating boiler feedwater with steam from steam turbines, a flue gas desulfurizer using an absorbent slurry, and means for recovering heat from the flue gas passing through the flue gas desulfurizer and/or the absorbent slurry within the flue gas desulfurizer, whereby boiler feedwater is preheated by the recovered heat and then introduced into the extraction feedwater heaters.

Flue gas desulfurizer, boiler equipment and thermal electric power

A wet flue gas desulfurization system for removing sulfur dioxide present in flue gas by absorption into an absorbent slurry includes an absorption tower having at a bottom thereof a tank for holding an absorbent slurry; a circulating pump for feeding the absorbent slurry within the tank to a flue gas inlet section in an upper part of the absorption tower and bringing the absorbent slurry into contact with flue gas; and a slurry preparation compartment provided on one side of the tank of the absorption tower and separated from a flue gas passage section by a partition wall having its lower end submerged below a surface of the absorbent slurry, whereby an absorbent and water constituting the absorbent slurry are directly introduced into the slurry preparation compartment.

Wet flue gas desulfurization system

A gas refining system for adsorbing a reducing gas includes a reduced gas stream, a section for adsorbing and removing sulfur-containing compounds in the reducing gas, an adsorbent which contacts the reduced gas stream, an oxygen-gas containing stream which enters the adsorbing and removing section, a calcium-compound containing stream, and a reactor which receives the above streams and allows for the adsorption of sulfur dioxide and precipitation of a gypsum compound.

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Tokyo, Japan

Atsushi Tatani