The invention relates to a
flue gas desulphurization and denitration method as well as its apparatus, and especially relates to a desulphurization and denitration
technology system for
flue gas from large-scale mobile facilities such as ships. The method comprises the following steps:
flue gas is passed through a
heat pipe exchanger and a
heat pump in order for increasing temperature of
flue gas, and
flue gas is selectively passed through an electric heater for heating to the temperature of 340-350 DEG C, an
urea solution is used for preparing
ammonia gas in a
hydrolysis reactor,
ammonia gas is diluted by partial high temperature
flue gas at an outlet of a SCR reactor and then mixed for injecting flue gas which is undenitrated, the mixed flue gas enters into the SCR reactor for a flue gas denitration reaction, the flue gas after denitration is passed through the
heat exchanger, the
heat pump and the
hydrolysis reactor and cooled, and then enters into a desulfurization
tower, flue gas after desulphurization is directly discharged into
atmosphere, and an absorption liquid adds alkali and
seawater for regeneration and cycle usage. In the method, the
heat exchanger and the
heat pump are used for recovering
waste heat of flue gas, and the
energy consumption is greatly reduced. The
ammonia production method through
hydrolysis is capable of increasing the mixing degree of ammonia and flue gas, so that denitration efficiency can be further increased.