Synthesis Of N-containing Inhibitors And Research Of The Inhibition Performance Under High Temperature And In Alkaline Solution

A new amide corrosion inhibitor OMA and two quaternary ammonium imidazoline inhibitors OMS and OMC are synthesized in the laboratory. Their corrosion inhibition performances are compared in the alkaline environment of high-temperature and high-pressure, and their structure is affirmed by IR spectra. The DTA testing indicates the maximum temperature in the high-temperature and high-pressure experiment. The inhibition performance for carbon steel of the inhibitors under high temperature, high pressure and in alkaline solution is evaluated by autoclave quadrature experiment. The results show the optimum practical conditions of the vapor-phase, liquid-phase and the comprehensive optimum practical conditions. With scanning electron microscopy (SEM) testing, the surface analysis of the inhibitor film on the carbon steel surface is carried out and a compact protection film formed by OMA on the surface can be observed. From the research mentioned above, the results are showed as the following:(1) The results of differential thermal analysis (DTA) showed that the thermal discomposure temperature of OMA is 368.1℃. Combined with the maximum working temperature of the autoclave is 350℃, the maximum temperature in the high-temperature and high-pressure experiment is determined as 320℃.(2) The inhibition performance for carbon steel of OMA, OMC and OMS under high temperature, high pressure and in alkaline solution is evaluated by autoclave quadrature experiment. The optimum practical condition of the vapor-phase is: 320癈, concentration 60mg/L, pH 10, the inhibitor is OMA.The optimum practical condition of the liquid-phase is: 320 ℃, concentration 20mg/L, pH 12, the inhibitor is OMA.The comprehensive optimum practical condition is: 320癈, concentration 60mg/L, pH 12, the inhibitor is OMA.(3) With scanning electron microscopy (SEM) testing, the surface analysis of the inhibitor film on the carbon steel surface is carried out and a compact protection film formed by OMA on the surface can be observed.(4) A kind of amide, AM-C, is selected to conduct the farther high temperature and high pressure experiment on inhibition performance. This experiment showed that both OMA and AM-C have effective inhibition performance for carbon steel under high temperature, high pressure and in alkaline solution.With scanning electron microscopy (SEM) testing, the surface analysis of the inhibitor film on the carbon steel surface is conducted. By comparing the inhibition performance for carbon steel of OMA, OMC and OMS, OMA is found that it apparently surpass OMC and OMS in the inhibition performance. AM-C is also quite effective in protecting carbon steel surface against corrosion.