臺灣博碩士論文加值系統

論文提要內容 :
隨著高科技電子產業發展，其所排放酸鹼廢氣量亦增加，而這些酸鹼廢
氣目前大多沒有受到有效控制。因此研發一套有效且經濟可行的控制設備，來處理其各產業產生之酸鹼廢氣排放是一重要課題。濕式洗滌塔是控制酸鹼廢氣的重要設備，如何增加其處理效率並減少設備規模降低處理成本是酸鹼廢氣是否能有效控制的關鍵，亦是濕式洗滌塔業者期望研發改善的重要工作。
本研究針對此任務，以模廠實驗進行洗滌塔中添加NaOCl及NaOH 去除H2S
的參數研究。在逆流式洗滌塔中考慮 pH值、液氣比、塔內氣體的停留時間及速度、氧化劑加藥量等參數對去除H2S效率及移轉高度Hoy的影響。
本研究結果歸納如下:
1.當pH值低於10.5以下，洗滌塔去除H2S效率就開始大幅下降。
2.當在相同pH值時，L/G比較大時，其去除率亦較高，但在L/G比為1.42~
2.28範圍時，其去除效率相當接近，此可做為設計洗滌塔的設計參數
參考。
3.氣體流率越大時，其轉移高度亦越大，但在氣體流率為1300~2100
lbs/ft2-hr範圍時，其轉移高度Hoy相當接近，此可能為化學反應動力
的限制上限。
4.當氣體質量流率在1300~2100 lbs/ft2-hr範圍時，對H2S去除效率相當
接近，但當氣體質量流率超過2100 lbs/ft2-hr時，對H2S去除效率則有
明顯下降趨勢。整個實驗結果可知，在適當的操作參數條件下去除率可
達96％∼99％
5.設計洗滌塔尺寸大小時，可訂氣體質量流率在2000 lbs/ft2-hr時，以
達最佳經濟效益成本。
6.建議日後可對NOX、SO2氣體做相同實驗，建立最佳操作條件及提供洗滌
塔尺寸大小設計之參考參數。

A pilot plant for the packed column has been used to study the absorption of hydrogen sulfide in aqueous mixed solutions of NaOCl and NaOH. These systems consist of wet scrubber which facilitate destruction of hydrogen sulfide gas and the related odor by continu-ously contacting the collected air counter-currently with a strong oxidizing solution of sodium hypochlorite. Hydrogen sulfide removal of up to 96~99% was obtained using a packed bed scrubber.H2S was found to be oxidized to NaSO4 and/or to elemental sulfur, and ClO- was reduced to Cl-. Experimental results indicate that hydrogen sulfide molecules instantaneously break down into hydrogen and sulfide ions,under the influence of the prevailing high pH. Absorption rates are reported in terms of overall reaction rates and heigh of transfer units for a packed bed scrubber.
The results of the research are as follows:
1. When pH value is smaller than 10.5, the H2S removal
efficiency% of the wet scrubber decreases dramatically.
2. When pH value is constant, the larger L/G, the higher the
removal efficiency%. However, when L/G ratio is between
1.42 and 2.28, the removal efficiencies% are very similar.
This can be the reference parameter for designing a wet
scrubber.
3. The higher the gas phase mass velocity, the bigger the HTU.
However, when the gas phase mass velocity is at the range
of 1300~2100lbs/ft2-hr, the HTU is approximately the same.
Thus, the range of 1300~2100lbs/ft2-hr could be the upper
limit of chemical reaction momentum.
4. When the gas phase mass velocity is in the range of 1300 to
2100 lbs/ft2-hr, the removal efficiencies% are similar.
But, when gas phase mass velocity is above 2100 lbs/ft2-hr,
the removal efficiencies% decrease greatly. Thus, it is
obvious that under suitable controlled condition, the
removal efficiency can reach 96% to 99%.
5. When contact time of the gas is at the range of 0.7~1.1 sec
and the velocity of the gas is at the range of 1.50~2.37m/sec within the scrubber, the removal efficiencies% are very similar. Thus, we recommend controlling the contact time of the gas and the velocity of the gas under above-mentioned range, and then many materials can be saved by using smaller wet scrubber.
6. Optimal economic effectiveness can be achieved by setting the gas phase mass velocity at 2000 lbs/ft2-hr.
7. We recommend doing similar experiments on NOx and SO2 to provide information about optimal operation conditions and about the design of wet scrubber.

目 錄
目錄…………………………………………………………………..…Ⅰ
圖目錄…………………………………………………………………..Ⅲ
表目錄…………………………………………………………………..Ⅴ
第一章 前言
1-1 研究背景…………………………………………...………..1
1-2 研究目的………………………………………………...……..3
第二章 文獻回顧…………………………………………………….….5
2-1 濕式洗滌塔原理……………………………………………….5
2-1-1 基本原理…………………………………………………5
2-2吸收原理……………………………………………………..9
2-2-1 質量均衡…………………………………………………..9
2-2-2 填充塔高度計算…………………………………………..11
2-3 酸性氣體去除影響因素…………….………………………..13
2-3-1 溶解度的影響…………………………………………….13
2-3-2 硫化氫的產生……………………………………………..14
2-3-3 化學反應的影響…………………………………………..16
2-4 理論…………………………………………………………...18
第三章 實驗設備與條件…..……………………………………...…...20
3-1 模廠實驗設備流程圖……………………………………….20
3-2 實驗設備…………………………………………..………….21
3-3 實驗步驟……………………….……………………………..31
3-4 試驗條件……………………………………………………..32
3-5氣體分析方法與處理效率表示法 ………………..………36
第四章 結果與討論…………..………………………………...….40
4-1 風機風量與填充層壓差率定………………………………40
4-1-1 變頻器頻率與風機風量率定關係……………………….40
4-1-2 不同液體、氣體質量流率與壓降關係……………………42
4-1-3 氣體質量流率與壓降率定關係…………………………...43
4-2 測試各參數對去除效率的影響……………………...…44
4-2-1入口硫化氫濃度改變與硫化氫去除率關係……………….44
4-2-2 pH值、液體質量流率改變與去除效率關係……………..45
4-2-3 pH值、氣體質量流率與去除效率關係………………..46
4-2-4 氧化還原電位(ORP)與H2S去除率關係……...………….47
4-3 液氣比改變對去除效率的影響……………………...…48
4-3-1 pH值與H2S去除效率關係….…………………………48
4-3-2 NaOCl濃度與去除效率關係……..…………………….48
4-3-3 液體質量流率與去除效率關係…..…………………….50
4-4 塔內氣體速度、氧化劑量對去除效率的影響…...………….51
4-4-1 塔內氣體速度與去除效率關係………………………….51
4-4-2 塔內氣體速度、NaOCl濃度與去除效率關係…………..52
4-5 塔內氣體接觸時間對去除效率的影響……………………..53
4-5-1 塔內氣體接觸時間與去除率的關係……………………..53
4-5-2 塔內氣體接觸時間、NaOCl濃度改變與去除效率關係..54
4-6 氣體質量流率對移轉單位高度的影響……………………...55
4-6-1 氣體質量流率、pH值改變與移轉單位高度關係………..55
4-6-2 氣體質量流率、NaOCl濃度改變與移轉單位高度關係…56
第五章 結論……………………………………….…...…………….58
參考文獻…………………………………………………………..……60
附錄A……….……………………………………………….……….63
附錄B……….……………………………………………….………….69

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