油溶性非离子咪唑啉的开发与性能评价

Development and Performance Evaluation of Oil Soluble Non-ionic Imidazoline

为满足海上天然气管线集输及腐蚀防护要求,解决在用的水溶性阳离子咪唑啉9H长期加注后在高温条件下或后续处理工况下缓蚀剂的有效成分经常析出而造成海管堵塞等问题,先以油酸、二乙烯三胺、二甲苯为原材料合成了中间体油酸咪唑啉,再通过中间体与环氧丙烷、环氧乙烷在设定温度下反应及复配得到了非离子咪唑啉缓蚀剂。采用动态挂片失重法、SEM和电化学、光学分析等方法研究了缓蚀剂的缓蚀性能及缓蚀机理。研究结果表明:以油酸二乙烯三胺咪唑啉与环氧丙烷、环氧乙烷质量比为1∶0.1∶0.05合成的产物与5%的硫脲复配得了缓蚀剂HS-006,药剂加注浓度为20 mg/L时,在温度95℃、硫化氢加注浓度50 mg/L、CO_2分压0.4 MPa、N2总压1.0 MPa的腐蚀环境下,HS-006对X65碳钢的缓蚀率可达95.03%,缓蚀效果优于现场在用药剂9H。该药剂主要抑制试片的阴极反应,且具有良好的成膜性。

The effective components of the water-soluble corrosion inhibitor 9 H contained cationic imidazoline often separate out after long-term injection,which results in that the sea pipe is blocked in high temperature condition or the following processing. In this paper,oleic acid,divinyl three amine and xylene,as raw materials,were used to synthesize oleic acid imidazoline,which was be used in accordance with the requirements of anti-corrosion of pipelines in offshore exploitation. The imidazoline inhibitor was further modified by adding different ratio of epoxy ethane and epoxy propane. Dynamic weight loss method,SEM,EDS and optical profiler was applied to evaluation the inhibition efficiency of the inhibitor,the surface morphology and the influence of inhibitor on film-forming were also analyzed. The optimum inhibitor HS-006 was composed of 5% thiourea and imidazoline which was synthesized by oleic acid imidazoline,epoxy ethane and epoxy propane（mass ratio was 1∶0.1∶0.05）. The inhibition efficiency of the corrosion inhibitor HS-006 to X65 steel sheet could reach 95.03% in the corrosion environment with H2 S concentration of 50 mg/L under CO2 partial pressure of 0.4 MPa and the total pressureof 1.0 MPa at the temperature of 95℃,which was higher than that of the inhibitor 9 H. The corrosion inhibitor HS-006 mainly inhibit the corrosion caused by cathode reaction and the HS-006 could form a excellent protect film on the surface of the steel sheet.