Kawasaki Jukogyo Kabushiki Kaisha

Electric Power Development Co., Ltd.

Chiaki Nagai

Yasuyuki Nakabayashi

Hayami Ito

Hayami Itoh

Kunihiko Mouri

Takashi Ikeda

Kihachiro Igarashi

A method of recovering fuel from coal ash containing non-combusted carbon in particulate form discharged from a pulverized coal fired boiler, a fluidized bed boiler or a coal gasification furnace together with exhaust gases. In this method, water and a binder and surfactant, if necessary, are added to the ash collected by the dust collecting device, and the mixture is agitated to form coarse particles of high carbon content. Then fine particles of high ash content are separated from the coarse particles, allowing the coarse particles separated from the fine particles to be dehydrated while tailing ash is turned white in color and the ash is put to use.

Method of recovering fuel from coal ash

When exhaust gas from a coal-burning boiler containing NO.sub.x as well as SO.sub.x is subjected to NO.sub.x removal by catalytic reduction of the NO.sub.x with ammonia and the coal ashes contained in the gas are separated, the coal ashes are contaminated by a certain quantity of ammonium compounds produced from the SO.sub.x and the ammonia excessively used. The ammonium compounds in the coal ashes are decomposed into ammonia and a sulfur compound by heating by the hot gas at a temperature in the restricted range, viz. 350.degree. to 700.degree. C., thereby to release ammonia into the gas preferentially to the sulfur compound. The ammonia thus released is recycled to the NO.sub.x removal step.

Removal of nitrogen oxides and sulfur oxides by ammonia

Growing community of inventors

Kobe, Japan

Chiaki Nagai