Mitsubishi Heavy Industries Limited

Mitsubishi Jukogyo Kabushiki Kaisha

The Kansai Electric Power Co., Inc.

Ohji Rubber & Chemicals Co., Ltd.

Toru Takashina

Susumu Okino

Naohiko Ukawa

Masakazu Onizuka

Eiji Ochi

Kiyoshi Okazoe

Atsushi Tatani

Kazuaki Kimura

Shintaro Honjo

Taku Shimizu

Koichiro Iwashita

Takeo Shinoda

Kenji Inoue

Masao Hino

Takashi Haruki

Shinichiro Kotake

Makiichi Ishihara

Masaki Iijima

Tsuyoshi Oishi

Kozo Iida

Shigeo Hasegawa

Tsumoru Nakamura

Yasuyuki Yagi

Naoyuki Kamiyama

Hiroshi Tanaka

Tomio Mimura

Yasuhiro Takeuchi

Kouki Ogura

Yukio Kita

Yoshikazu Endo

Toyoshi Nakagawa

Kenichi Okada

Kouichiro Iwashita

Takakazu Sunada

Kousuke Yamashita

Junji Ozaki

Kaname Kaneshige

Takuya Hirata

Satoshi Nakamura

Hiromitsu Nagayasu

Tatsuto Nagayasu

Masashi Yoshikawa

Naoharu Shinoda

Yoshihiro Okamoto

Hiroshi Fujita

Hiroyuki Katayama

Yoshihiro Shiraishi

Tsuyoshi Ohishi

Atsushi Yoshioka

Tokuma Arai

Satoshi Yajima

Tamotsu Higuchi

Shoichi Onishi

Yoshimitsu Kawanishi

Heiji Tanaka

Kouzou Takano

Kouji Ikeda

Kenichiro Kawamichi

Takao Sodeshita

Kazumitsu Suzuki

The present invention provides a method for removing mercury in exhaust gas, in which mercury in exhaust gas discharged from combustion equipment is removed, characterized by including a mercury oxidation process in which mercury in the exhaust gas is converted to mercury chloride in the presence of a catalyst; a contact process in which the exhaust gas is brought into contact with an absorbing solution in a scrubber to absorb and remove mercury components from the exhaust gas; and a control process in which blowing of air or addition of an oxidizing agent into the scrubber is accomplished, and the amount of blown air or the added amount of oxidizing agent is regulated to control the oxidation-reduction potential of the absorbing agent, and a system for removing mercury in exhaust gas. According to the mercury removing method in accordance with the present invention, a phenomenon that mercury chloride is reduced into metallic mercury by SOetc. and the metallic mercury scatters in the exhaust gas can be prevented, and mercury in the exhaust gas can be decreased effectively.

Method for removing mercury in exhaust gas and system therefor

A COrecovery apparatus according to the present invention includes: an absorber () that brings CO-containing flue gas (A) into counter-current contact with COabsorbent () to reduce CO, and a regenerator () that regenerates rich solution () that has absorbed CO, in which lean solution () having COreduced in the regenerator () is reused in the absorber (). The absorber () further includes a COabsorbing unit () that recovers COcontained in the flue gas (A), and the COabsorbent () that has absorbed COis extracted from a rich side of the COabsorbing unit () to exterior, cooled, and then supplied to a position nearer to a lean side of the absorber () with respect to the position at which the COabsorbent () is extracted.

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An absorbing solution according to the present invention is an absorbing solution that absorbs COor HS in gas or both of COand HS. The absorbing solution is formed by adding desirably 1 to 20 weight percent of tertiary monoamine to a secondary-amine composite absorbent such as a mixture of secondary monoamine and secondary diamine. Consequently, it is possible to control degradation in absorbing solution amine due to oxygen or the like in gas. As a result, it is possible to realize a reduction in an absorption loss, prevention of malfunction, and a reduction in cost. This absorbing solution is suitably used in an apparatus for removing COor HS or both of COand HS.

A liquid column type exhaust gas treatment apparatus comprising a spray header () for injecting an absorbing solution upward in an absorption tower (), wherein exhaust gas introduced from a lower part of the absorption tower () and the absorbing solution injected from the spray header () are brought into gas-liquid contact with each other, by which desulfurization of exhaust gas is accomplished, characterized in that drift preventing plates (and) are provided in a liquid top portion of a liquid column () formed by the absorbing solution and/or at the installation position of the spray header ().

Exhaust gas treatment apparatus

Provided is an exhaust gas treating tower in which exhaust gas flow velocity is increased more than a prior art case so that exhaust gas treating efficiency can be enhanced or the exhaust gas treating tower can be made compact if equivalent performance is to be maintained. Also, an exhaust gas treating tower ensuring a liquid recovery is provided. In an exhaust gas treating towerA, liquid columns C are generated and also a liquid drop generating memberis provided to thereby generate liquid drops M therearound to be floated. Also, liquid is spouted from spray nozzles to thereby generate liquid films F in area different from the liquid columns C. In an exhaust gas treating tower, a liquid drop eliminatoris provided upstream of a mist eliminator. Interval Pof collecting platesof the liquid drop eliminatoris made larger than interval Pof collecting platesof the mist eliminator. Thereby, liquid drops having larger particle diameter contained in the exhaust gas are collected by the liquid drop eliminator

Exhaust gas treating tower

A wet type exhaust gas desulfurization method includes sucking liquid in a liquid reservoir containing a sulphur compound formed from sulphur dioxide contained in exhaust gas so as to form a flow of the liquid, reducing the flow of the liquid in diameter to form a depressurized region in the flow, the reducing including passing the liquid through a reduction section which includes a reduction section plate having a reduction section hole and a peripheral portion surrounding the reduction section hole, the peripheral portion protruding toward the upstream side of the flow, introducing air into the depressurized region so as to generate a mixture stream of the air and the liquid, and spouting the mixture stream into the liquid reservoir. The reducing includes forming cavities in the flow, the forming cavities includes shearing the flow, and the shearing includes bringing the flow into contact with the peripheral portion.

Method and apparatus for wet type flue-gas desulfurization

The present invention provides a method for the treatment of mercury present in exhaust gas wherein, after a chlorinating agent is added to exhaust gas containing nitrogen oxides, sulfur oxides and mercury, the exhaust gas is subjected to a reductive denitration treatment in the presence of a solid catalyst and then to wet desulfurization using an alkaline absorbing fluid, the method being characterized by measuring the mercury concentration in the exhaust gas after the wet desulfurization; calculating a predicted value of the inlet mercury concentration before the reductive denitration treatment on the basis of the measured mercury concentration; and controlling the feed rate of the chlorinating agent added prior to the reductive denitration treatment, according to the deviation of the predicted value from a reference inlet mercury concentration, as well as a system for the treatment of exhaust gas. Thus, the present invention provides an exhaust gas treatment process permitting the removal of mercury, and this process makes it possible to achieve efficient operation of the system and maintain the performance thereof without exerting any adverse influence the units within the system.

Method for the treating in exhaust gas and exhaust gas treating system

The wet-gas desulfurizing apparatus according to this invention removes the oxides of sulfur, such as SO, from combustion exhaust gas by scrubbing the combustion exhaust with an absorption liquid which contains an alkali. It includes: 1) a branch pipe to circulate the absorption liquid which is inserted into a collection tank, of which the end discharges the absorption liquid into the collection tank, and the branch pipe having an internal diameter of D; and 2) an air-blowing pipe in inject air into the branch pipe, of which the end is inserted at an insertion point located between 3 D and 10 D from the discharge end of the branch pipe. The end of the air-blowing pipe is inserted into the branch pipe, and has an appearance of a semicircular trough facing downstream toward the collection tank.

Wet type flue gas desulfurization equipment

In a flue gas treating system, an absorption tower (), a reheating section () and a fan () are arranged in line on a vertical axis so as to function as at least a part of a stack for emitting the treated flue gas into the atmosphere. Moreover, in a flue gas treating process, the amount of ammonia injected in the denitration step (a denitrator ()) and/or the amount of ammonia at a point downstream of the denitration step are determined so as to be on such an excessive level that ammonia or ammonium salt will remain in the flue gas introduced into the desulfurization step (absorption tower ()). Thus, the size and cost of the equipment can be reduced.

Flue gas treating system and process

An oxygen-containing blowing device for use in a wet flue gas desulfurizer for removing SO from combustion exhaust gas by wet desulfurization includes a fluid reservoir for an absorbing fluid equipped with a delivery pipe for discharging the absorbing fluid so that its discharge end is open in said fluid reservoir, and an oxygen feed nozzle for injecting an oxygen-containing gas disposed in the area of the discharged stream in the discharge end of the delivery pipe.

Oxygen-containing gas blowing devices

A wet type exhaust gas desulfurization apparatus includes a liquid reservoir which reserves absorption liquid containing absorbent and sulfite, a desulfurizing system which removes sulphur dioxide from combustion exhaust gas and forms sulfite, and an air supplying and circulating device which has a reduction section and supplies air to said liquid reservoir using a negative pressure generated due to said reduction section to oxidize the sulfite.

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 method and system for desulfurizing flue gas in which desulfurization is effected by bringing absorbent slurry containing limestone into contact with flue gas. The method classifies absorbent slurry extracted from a desulfurization absorber, returns a fine-side fluid to the desulfurization absorber, and sends a coarse-side fluid to a solid-liquid separator. Supplied limestone powder is mixed to yield limestone slurry by a solid-liquid mixer, and the limestone slurry is classified, sending the small-particle fluid component thereof to the desulfurization absorber, and sending the large-particle fluid component thereof to a limestone fine grinder. And, limestone contained in the large-particle fluid component is finely ground by the limestone fine grinder and the finely ground limestone is sent to the desulfurization absorber. According to the desulfurization method and system, the concentration of limestone in the desulfurization absorber is increased while the concentration of residual limestone in by-product gypsum is kept low, whereby the desulfurization performance of the absorber can be enhanced, and the operation power for the whole system can be decreased.

Exhaust gas desulfurizing method and system therefor

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Hiroshima, Japan

Toru Takashina