Babcock-Hitachi Kabushiki Kaisha

Hitachi, Ltd.

Noriyuki Imada

Tomoichi Kamo

Masahiro Komachiya

Kazutoshi Higashiyama

Hiroyuki Kaku

Naoki Oda

Hidehisa Yoshizako

Kiyoshi Hiyama

Tetsurou Okano

Yoshiaki Mitsui

In an exhaust gas treatment device provided with: an exhaust gas treatment unit in which an oxygen combustion boilerusing coal as fuel, a denitration device, an air preheater, a dust-collection device, a desulfurization device, and a carbon dioxide recovery deviceare sequentially arranged from the upstream side to the downstream side of an exhaust gas duct; and an exhaust gas circulation unit which branches off from the exhaust gas duct at an outlet of the dust-collection deviceor an outlet of the desulfurization deviceand through which the exhaust gas is preheated by the air preheaterand returned to the oxygen combustion boiler, a heat-recovery heat exchangerthat adjusts a gas temperature at an inlet of the dust-collection deviceto be not greater than an acid dew point of SOand not lower than a water dew point is provided between the air preheaterand the dust-collection device, a reheating heat exchangerthat adjusts a gas temperature to be not lower than the acid dew point of SOis provided in the vicinity of a branch of the exhaust gas circulation unit, adjusting the gas temperature at the inlet of the dust-collection deviceto be not greater than the acid dew point of SOmakes it possible to prevent corrosion of pipes in the exhaust gas circulation unit and to avoid a decrease in fluidity or combustibility of the pulverized coal in the pipes in the mill.

Exhaust gas treatment device for an oxygen combustion system

For the stabilization of the reaction, especially, for maintaining reaction temperature, the feedback control by the feedback unit is performed for to the supply of air (, oxygen, or oxidizing agent), whereas other materials are supplied by the open-loop control according to the instruction of the flow selection unit which indicates a preset value depending on the required hydrogen production volume. In addition, the continuous flow setting unit capable of changing the flow continuously is employed for the supply system of the air, whereas the flow control of the other materials is performed by use of the discrete flow setting units each of which provides the discretized flow by use of the on-off combination of two or more on-off valves.

Hydrogen producing apparatus and power generating system using it

Growing community of inventors

Kure, Japan

Noriyuki Imada