METHOD AND PLANT FOR REDUCING NITROGEN OXIDE EXISTING IN BURNT FUME OF PYROLYSIS GAS

摘要

PROBLEM TO BE SOLVED: To provide a method by which the discharge of nitrogen oxides (NO_x) existing in a burnt fume produced by pyrolyzing a feed that is rich in organic matters, such as biomasses, industrial wastes, domestic wastes, etc., can be reduced substantially at a low cost.;SOLUTION: This method of reducing nitrogen oxides includes a step (a) of pyrolyzing the feed in a substantial oxygen-free state, a step (b) of burning the gaseous part generated by the pyrolysis, and a step (c) of cooling the high- temperature fume obtained by the combustion so that the fume may fall within a temperature range which makes the non-contact reduction by means of a reducing agent advantageous. This method also includes a step (d) of injecting a solution containing the reducing agent or the precursor of the agent into the fume from the step (c), a step (e) of recovering at least part of the heat value of the fume from the step (d). The step (c) of cooling the high-temperature fume is performed at least partially by recycling at least part of the low- temperature fume from the step (e).;COPYRIGHT: (C)2003,JPO