含H_2S/CO_2脱硫胺液中Cl^-对20#钢腐蚀的影响  

Effect of Cl^- concentration on the corrosion of 20# steel in MEDA environment at the presence of H_2S/CO_2

作　　者：曾德智[1] 王哲[1] 商剑峰[2] 刘元直[2] 龙德才 张乃艳 ZENG De-zhi WANG Zhe SHANG Jian-feng LIU Yuan- zhi LONG De-eai ZHANG Nai-yan(State Key Laboratory of Oil ＆ Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China Sinopec Zbongyuan Oilfield, Puyang 457000, Henan, China CNOOC-Fujian LNG Co. , Ltd. , Fuzhou 350000, China)

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室,成都610500 [2]中石化中原油田分公司,河南濮阳457000 [3]中海福建天然气有限责任公司,福州350000

出　　处：《安全与环境学报》2016年第6期129-133,共5页Journal of Safety and Environment

基　　金：国家科技重大专项项目(2011ZX05017-005);西南石油大学中青年骨干教师培养计划项目

摘　　要：为评估Cl^-累积作用对脱硫净化装置安全运行的影响,利用高温高压釜在室内对20#钢材质进行5组不同Cl^-质量浓度(465~40 000 mg/L)条件下的腐蚀试验,并采用扫描电子显微镜(SEM)和X射线衍射(XRD)分析了腐蚀产物的微观形貌与组成。结果表明,在110℃条件下,随Cl^-质量浓度增加,20#钢在脱硫胺液环境中基体表面腐蚀产物膜的形态发生变化,腐蚀速率先增大后减小,当Cl^-质量浓度为20 000 mg/L时,腐蚀速率达到峰值0.801 mm/a,腐蚀产物主要由FeS、FeCO_3和FeS_2组成。研究表明,Cl^-通过加速金属阳极的溶解、破坏腐蚀产物的完整性、降低酸性气体的溶解度3方面作用影响腐蚀过程。在脱硫装置高温工况下,20#钢存在较大的腐蚀安全隐患,建议甲基二乙醇胺(MDEA)溶液中Cl^-质量浓度控制在500 mg/L以内,而酸气负荷大的单元和设施不宜采用20#钢材质。The given article is inclined to study the effect of Cl- accumulation on the working safety of the equipment and facilities for desulphurization in the purification plants by using high temperature （HT） autoclaves. For the aforementioned purpose, we have conducted the corrosion tests with 20# steel at five different Cl- mass concentrations, that is, 465 mg/L, 10 000 mg/L, 20 000 mg/L, 30 000 mg/L, 40 000 mg/L. What is more, we have done detailed analysis over the corrosion products by using the scanning electron microscope （SEM） and X-ray diffraction （XRD） devices. The results of our study demonstrate that the a- mine solution could absorb the acid gases of H2S/CO2 dissolved in MDEA solution in the co-existence system in a form of RNH2 - H2 S - CO2 - H20 corrosion environment. In addition, the solution can also reverse the chemical reaction at the high tempera- ture zone. The weight-reducing experiments indicate that the corrosion rate of 20# steel accounts for 0. 310 1 mm/a in MDEA de- sulphurization solution containing 465 mg/L Cl-. And, then, it would be possible for the steel to reach its peak value （0. 801 0 mm/a） when the mass concentration of Cl- goes up to 20 000 mg/L whereas the corrosion rate of 20# steel tends to decrease on the condition that the mass concentration of Clexceeds 20 000 mg/L. And, finally, the corrosion rate of 20# steel gets to its minimum value, that is, 0. 122 9 mm/a in MDEA desulphurization solution of 40 000 mg/L Cl-. XRD results may show that 20 # steel is likely going to change its morphology of the corrosion product with the increase of the Cl- mass concentration in MDEA desulphurization solution at the temperature of 110 ~E. And, it is in such a kind of condition that it can be found that the corrosion products of 20# steel mainly consist of FeS, FeCO3 and FeS2 at different Cl- concentrations as well. Thus, as combined with the current water quality and process conditions, CI- can help to ac- celerate the dissolve of the metal anode or destroy the integrity of

关 键 词：安全工程 净化厂 甲基二乙醇胺(MDEA) 20#钢 Cl- 腐蚀速率 腐蚀产物膜 

分 类 号：X937[环境科学与工程—安全科学]