廢液於渦旋式流體化床焚化爐中氧化亞氮排放之研究

Emissions of Nitrous Oxide in Vortexing Fluidized Bed Incineration of Waste Liquid

楊宗翰(Chung-Han Yang)

指導教授 ： 錢建嵩

中原大學/工學院/化學工程研究所/碩士(2003年)

https://doi.org/10.6840/cycu200300548

摘要

近年來，氧化亞氮的排放引起多方注意，因為N2O已在1997年的京都議定書中，列入六種溫室氣體之一，因其會造成溫室效應，使得地球溫暖化。N2O的另一危害是當其上升至臭氧層時，會與臭氧(O3)發生反應，使得臭氧層減少，而讓紫外線直射地球表面，造成危害。在流體化床燃燒爐(FBC)中，因其燃燒溫度比其他型式燃燒爐的燃燒溫度低，故N2O的生成量較高，因此降低N2O排放便成為一大課題。本研究最主要目的係探討各操作變數及燃料性質與N2O生成之關係。

本研究係於0.8 m × 0.4 m之方形床，高4.6 m之渦旋式流體化床焚化爐中進行，以焚化含氮之混合溶液為主，混合溶液之組成為甲醇、乙醇及丙酮，並加入尿素、苯胺、硝基苯與吡啶等含氮物質，輔助燃料為木炭與柴油，矽砂為床質，改變操作參數來探討渦旋式流體化床焚化爐中各區段之N2O及CO之濃度變化。操作參數包括：床溫、爐出口溫度及過量空氣等效應。

研究結果顯示，床溫、爐出口溫度及過量空氣等效應及不同燃料氮之結構式對N2O之生成皆無明顯影響。推測因揮發物在爐內溫度高於850℃環境中，有較長之平均滯留時間，故其對於N2O濃度之影響性，較床溫、爐出口溫度及過量空氣等效應為顯著。此外，於相同最小流體化速度下，當空床氣速增加時，則揮發物亦隨氣流向上至乾舷區而點燃。

關鍵字

氧化亞氮 ； 渦旋式流體化床焚化爐

並列摘要

All experiments are carried out in a cross surface of bed of 0.8 m × 0.4 m pilot scale vortexing fluidized bed incinerator. This waste liquid of organic compounds containing nitrogen were incinerated in a laboratory fluidized bed incinerator at temperatures ranging from 700 to 850℃, and wood coal and diesel oil were assistant fuel. The waste liquid contained methanol, ethanol, acetone, aniline, pyridine, nitrobenzene and urea. Silica sand was employed as the bed materials. The objective of the study was to investigate the formation of N2O in the vortexing fluidized bed incinerator of operating parameters and properties of fuel.

The effects of various operating parameters, such as bed temperature, outlet temperature, and excess air ratio on N2O and CO emissions had been investigated. The experimental results showed that the N2O emission was almost independent of the bed temperature, outlet temperature of incinerator, and excess air ratio. It was inferred that the influence of the mean residence time on N2O emissions was stronger than other operating parameters. In addition, Since Umf was constant; the results showed that increase in the inlet superficial gas velocity leaded to the volatiles were ignited front moving away from the distributor.

並列關鍵字

vortexing fluidized bed incinerator ； nitrous oxide

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