利用疏水性觸媒去除水中氨及酚之研究

Removal of Ammonia and Phenol by Using Hydrophobic Catalyst

黃冬梨(Tung-Li Huang) ； 許世雄(Shih-Hsiung Sheu)

《石油季刊》 37卷1期 (2001/03) Pp. 17-27

https://doi.org/10.30128/JP.200103.0003

摘要

石化煉油製程常有含高濃度氨及酚之特殊廢液產生，此股廢液具有高溫、高生物毒性特性，不易逕自排入廢水處理場處理，必需先行前處理，本研究乃探討利用疏水性觸媒，結合汽提及氧化方法以去除水中氨及酚之可行性。
以批式反應器進行可行性研究，得知水中氨及酚於120℃及氧氣分壓0.3MPa之溫和反應條件，可有效被疏水性觸媒(Pt/SDB)去除。同時汽提及觸媒氧化去除水中氨之操作模式，則利用滴流式反應器(Trickle bed reactor)進行，顯示疏水性觸媒具有極佳之去除效率及觸媒操作壽命。反應液中少量硝酸根、亞硝酸根離子之存在，係來自於氣態氮氧化物為水相吸收所致。
為瞭解影響水中氧去除效率之重要操作變數及探討各操作變數間之交互作用，乃利用統計試驗設計法之二水準全因子設計(TLFD, two-level factorial design) 進行反應條件探討，得知反應溫度、氧氣分壓及水中酚之存在等三項為重要影響因素，而溫度和酚之存在間則有交互作用，酚會降低溫度對於水中氨去除效率之影響程度。統計試驗設計是快速確認重要操作變數之有力工具，一旦確認後，則將有助於進一步的製程最佳化。

關鍵字

氨 ； 酚 ； 疏水性觸媒 ； 二水準全因子設計 ； 觸媒氧化 ； 滴流式反應器

並列摘要

The streams of ammonia and phenol containing wastes produced in petrochemical refineries are usually characterized by high concentration and high temperature, and are not treatable by biological methods directly. A chemical or physical pretreatment is required before subsequent biological processing. In this study, a combined process of stripping and catalytic oxidation to remove ammonia and phenol from water has been successfully developed using a hydrophobic catalyst.
The initial feasibility study was done in a batch reactor. Ammonia and phenol were converted to N 2, CO 2 and H2O under a mild reaction condition of 120℃ and PO2 0.3 MPa. Both stripping and catalytic oxidation by using hydrophobic Pt/SDB catalyst were carried out simultaneously in a single trickle-bed reactor, possessing a high removal rate and long reaction time in comparison with that using hydrophilic Pt/ r -A12O3 catalyst. Small amounts of nitrites and nitrates were detected in the resultant reaction solution, resulting from the aqueous absorption of gaseous nitrogen oxides.
A statistically based experimental design method, Two-Level Factorial Design (TEFD), was applied to identify the critical factors that affect process efficiency and to uncover the interaction between the factors. The results showed that temperature, PO2 and the presence of phenol are the critical factors, and the presence of phenol adversely affects the temperature dependence of the ammonia oxidation.
The statistically based experimental design is a powerful tool to more quickly identify the key factors affecting the process and to understand the interactions between factors. Once these critical elements have been determined, optimization the process performance can be approached effectively.

並列關鍵字

ammonia ； phenol ； hydrophobic catalyst ； two-level factorial design ； catalytic oxidation ； trickle bed reactor