應用於常壓蒸餾單元的鹽酸腐蝕抑制劑性能之比較研究

Comparative Study on the Corrosion Inhibition Efficiencies of Various Inhibitors for HCl Corrosion in CDU System

在煉油產業中，常壓蒸餾單元（CDU）經常遭受到鹽酸露點腐蝕的侵害。為了解決此問題，有許多腐蝕抑制劑被開發並應用。在本研究中針對三種不同腐蝕抑制劑的腐蝕抑制效果加以測試。腐蝕抑制效果以電化學以及浸泡試驗兩種方法加以評估，並利用掃描式電子顯微影像（SEM）和傅立葉轉換紅外線光譜儀（FTIR）來輔助分析。實驗結果顯示，在1 wt%鹽酸水溶液中，咪唑啉、環胺、羧酸和多胺反應之化合物，對於低合金鋼的腐蝕抑制效果明顯不同，其腐蝕抑制機制將加以探討。

In petroleum industry, the Crude Distillation Unit (CDU) suffered hydrochloric acid dew point corrosion. To mitigate this problem, corrosion inhibitors are commonly used to release or to minimize the impact of hydrochloric acid corrosion. In this study, the corrosion inhibition efficiencies of three different corrosion inhibitors used in CDU systems were evaluated and compared. The corrosion inhibition efficiency of each inhibitor was evaluated by performing electrochemical polarization and immersion tests. Scanning electron microscopy (SEM) for surface morphology examination and Fourier transform infrared spectroscopy (FITR) for corrosion product identification were used to assist the evaluation. The experimental results showed that imidazoline, cyclic amine and that the product formed by reacting carboxylic acid with polyamine had different corrosion inhibition efficiencies for low alloyed steel in 1 wt% HCl solution. The respective corrosion inhibition mechanisms are discussed.