Hits:

Affiliation of Author(s):能源与动力工程学院

Journal:Process Safety and Environmental Protection

Key Words:Urea; Selective non-catalytic reduction (SNCR); Nitric oxide (NO); Additive

Abstract:An experimental study on the nitric oxide (NO) reduction through the NOxOUT Process has been conducted on a drop tube furnace experimental system. At 1223 K, when stoichiometric ratio of urea to NO (beta) is fixed at 1.5 and 2, the maximum NO reduction efficiency of 70.19% and 78.89% could be achieved, respectively. The efficiency curve is presented as a reversed "V" as a function of temperature and the corresponding "temperature window" is 108 K and 154 K at beta = 1.5 and 2. Also, these two beta values are preferable to determine injected urea quantity. As oxygen concentration is increased from 1.5% to 4.5%, efficiency is continuously depressed from 68.35% to 55.37% at beta = 1.5 and from 77.87% to 62.76% at beta = 2. At the same time, residence time (tau) should be guaranteed at least 0.61 s for thorough NO reduction. When 50 ppm of NaOH, 25 ppm of Na2CO3 or 50 ppm of CH3COONa is injected as promoted additive, the maximum NO reduction efficiency is, respectively, heightened to 82.07%, 81.36% and 81.81% at beta = 1.5 and these values are even higher than the ones which are achieved at beta = 2 if no additive is injected. For both beta = 1.5 and 2, efficiency improvement becomes slow when NaOH is increased to 20 ppm. Meanwhile, when NaOH is injected at beta = 2, efficiency of above 90% could be achieved and this value is comparable to the one achieved in advanced reburning.

First Author:Shengli Niu

Indexed by:Journal paper

Correspondence Author:Chunmei Lu*

Document Code:lw-100397

Discipline:Engineering

First-Level Discipline:Power Engineering and Engineering Thermophysics

Document Type:J

Volume:89

Issue:2

Page Number:121-126

Translation or Not:no

Date of Publication:2011-02-01