Babcock-hitachi Kabushiki Kaisha

Hitachi Power Systems America, Ltd

Takanori Nakamoto

Hirofumi Kikkawa

Hiroshi Ishizaka

Shigehito Takamoto

Toshio Katsube

Masakatsu Nishimura

Shigeru Nozawa

Fumito Nakajima

Hiroyuki Kaku

Atsushi Katagawa

Hiroyuki Nosaka

Takayuki Saitou

Kouji Muramoto

Hiroshi Kuroda

Naoki Oda

Takuro Ueda

Tomoyuki Konishi

Hiromichi Shimazu

Yasuyoshi Kato

Naomi Imada

Jun Shimamura

Song Wu

Hajime Okura

Yoshinori Taguchi

Nobuo Morimoto

Takashi Muramoto

Udo Zirn

Mitsuharu Kon

Masayuki Yamamoto

Kunikatsu Yoshida

An object of the present invention is to provide an exhaust gas treatment system that effectively use heat recovered from an exhaust gas without any limitation in a COchemical absorption equipment that requires enormous heat energy, and thus enabling reduction in running cost of the COchemical absorption equipment. Disclosed is an exhaust gas treatment system with a COchemical absorption equipment, which is provided with a heat recovery device that recovers exhaust heat from an exhaust gas discharged from a boiler; and a COchemical absorption equipment that absorbs COin the exhaust gas by bringing the exhaust gas into contact with an amine absorbing solution in a carbon dioxide (CO) absorption column, heats the absorbing solution that have absorbed COthereby releasing COinto a COregeneration column, heats the absorbing solution after release of COvia a reboiler, and then circulates the absorbing solution in a COabsorption column; the exhaust gas treatment system comprising a heat exchange unit that applies heat recovered by the heat recovery device to the absorbing solution that is delivered to the reboiler from the COregeneration column of the COchemical absorption equipment.

Exhaust gas treatment system with carbon dioxide chemical absorption equipment

In an absorbing tower including an absorption unit of relatively small diameter capable of absorption and removal by an absorbent slurry for exhaust gas purification and a tank unit of relatively large diameter for temporarily storing the absorbent slurry flowing down from the absorption unit, the tank unit and the absorption unit are joined together by a conical member. By disposing an entrance flue at the conical member, a distance from an upper portion of the conical member to a spray header is shortened, and a height of the absorbing tower can be reduced accordingly. By extending a front end of the entrance flue to the absorption unit into which droplets of the absorbent slurry fall, a high-temperature exhaust gas from a boiler, etc., that has passed through the entrance flue, is made to pass through a circumference of the conical member so that an inexpensive material can be used in the conical member.

Wet flue-gas desulfurization equipment

An absorbing tower is provided in its side wall with a gas entrance for introducing a combustion exhaust gas into the absorbing tower, and an absorbing liquid is sprayed from the nozzles of a spray header into the exhaust gas introduced to rise from the gas entrance. A trough is arranged in the side wall of the absorbing tower and above the gas entrance, and a nose having a horseshoe shape in a top plan view and extending into tower is disposed in the tower side wall portion of the gas entrance other than the portion arranging the trough and at the same or at substantially the same height as the portion of the trough. The absorbing liquid, which is sprayed from the nozzle and drops along the absorbing tower wall portion, is rescattered to the center portion of the absorbing tower excepting the entrance of the absorbing tower, so that the gas-liquid contact efficiency is improved while suppressing an increase in pressure loss, thereby to prevent the drift of the gas at the tower wall portion.

Wet-type exhaust desulfurizing apparatus

A system is provided that prevents inhibition of adsorption of Hg and other heavy metals by activated carbon or other heavy metal adsorbent due to prior adsorption of sulfur trioxide (SO) in an exhaust gas containing SO. As it has been found that while SOis adsorbed, the adsorption of SOprecedes the adsorption of Hg and other heavy metals onto activated carbon, a basic substance injection system is disposed along an exhaust gas flow channel at an upstream side of an activated carbon injection system, thereby attaining effective removal of Hg and other heavy metals from the exhaust gas by adsorption thereof onto surface pores of the activated carbon. The SOconcentration after removal by basic substance conversion is computed from the SOconcentration before removal, and the activated carbon injection rate can be controlled based on the concentration after removal.

Exhaust gas purifying method and apparatus

Methods and apparatus for pollution control which are well suited for use in a coal power plant are described. Ash is collected and injected into the flue gas stream at a location upstream of a cooling module. The ash acts as an absorbent and/or reactant material onto which condensate may condense. By re-introducing ash to keep the condensation forming wet areas within the system, lower cost materials which are less corrosion resistant than needed for wet operating conditions can be used. Mercury recovery and SO3 removal is facilitated by the cooling process and re-introduction of collected ash. Activated carbon and/or an alkali absorbent material may be added. Use of a dry ESP and/or fabric filter as opposed to a wet ESP for particulate collection leads to cost benefits. Energy recovered by the cooling of the flue gas may be re-used to heat turbine condensate leading to improved energy efficiency.

Methods and apparatus for performing flue gas pollution control and/or energy recovery

Flue gas of boiler is introduced through gas inlet part of flue-gas desulfurization apparatus, and absorbent liquid sprayed from spray nozzle is trapped in recirculation tank. There, agitation is performed by oxidation agitator to thereby oxidize SOabsorbed from the flue gas into gypsum. In the tank, oxidation air is fed from posterior air pipe and anterior air pipe behind and ahead of liquid propulsion by the propeller. Thus, even when the amount of oxidation air must be increased in accordance with an increase of boiler load, the oxidation efficiency can be enhanced without increasing the number of agitators. Then the apparatus with which even when the amount of oxidation air fed to the liquid trapping section is increased, highly efficient oxidation can be performed without increasing the number of agitators installed and the operating cost.

Wet flue-gas desulfurization apparatus and method of wet flue-gas desulfurization

An exhaust gas processing method using a device having an air preheater for preheating air for combustion in a combustion device by using an exhaust gas emitted from the combustion device; a gas-gas heater (GGH) heat recovery device composed of a heat transfer tube for recovering the heat of the exhaust gas to a heat medium; a dust collector; a wet-type desulfurization device; a gas-gas heater (GGH) re-heater composed of a heat transfer tube for heating the exhaust gas at its outlet by using the heat medium supplied from the gas-gas heater heat recovery device, which are installed in that order from the upstream to the downstream of an exhaust gas duct of the combustion device.

Exhaust gas treating method

An exhaust smoke processing system comprises air preheater for heating combustion air by exhaust smoke discharged from a boiler, a heat recoverer for heating a heat medium by exhaust smoke discharged from the air preheater, a dust collector for collecting soot and dust in exhaust smoke discharged from the heat recoverer, a wet-type exhaust smoke processing apparatus for processing exhaust smoke discharged from the dust collector, a reheater for heating exhaust smoke discharged from the wet-type exhaust smoke processing apparatus by the heat medium, and a heat medium circulation pipe passage for circulating the heating medium between the reheater and the heat recoverer. the system measures a heavy metal concentration in the exhaust smoke and adjusts the temperature of exhaust smoke at an outlet of the heat recoverer such that the measured value falls within a predetermined range.

Exhaust smoke-processing system

An exhaust gas processing device includes an air preheater for preheating air for combustion in a combustion device by using an exhaust gas emitted from the combustion device; a gas-gas heater heat recovery device composed of a heat transfer tube for recovering the heat of the exhaust gas to a heat medium; a dust collector; a wet-type desulfurization device; a gas-gas heater re-heater composed of a heat transfer tube for heating the exhaust gas at its outlet by using the heat medium supplied from the gas-gas heater heat recovery device, which are installed in that order from the upstream to the downstream of an exhaust gas duct of the combustion device.

Exhaust gas treating apparatus

Disclosed are a method and an apparatus for treating an effluent containing ammonia in which method and apparatus NO concentration in the gas at the outlet of a catalyst tower does not rise to a high level even when the NHconcentration in the effluent was reduced and the amount of hazardous substances formed is small; in the method and apparatus, an NH-containing effluent A and a carrier gas (steam C and combustion gas F) are contacted in stripping towerto transfer the NHfrom the NH-containing effluent to a gas phase, the gas containing the generated NHis heated with pre-heaterand then contacted with catalyst layerplaced in catalyst towerto decompose the NHinto nitrogen and water; and at that time, the oxygen concentration in the gas to be introduced into catalyst towerand the NO concentration in the gas discharged from catalyst towerare determined by measuring instrumentsand, respectively, and the oxygen concentration in the gas to be introduced into catalyst toweris adjusted by adjusting valveso that the NO concentration becomes within a prescribed range.

Method for treating amonia-containing effluent water

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

Growing community of inventors

Hiroshima, Japan

Takanori Nakamoto