Synthesis And Performance Evaluation Of Water-soluble Imidazoline Amide As Corrosion Inhibitor

As the increase of sulfur content in the crude oil,the processing of sour crude oil cannot be safe and stable operation for a long period of time in refinery plant.The sulphate and chloride of sour crude can be decomposed and generated into H2S and HCl in the hydrolysis occurs at high temperature,and the severe corroding system can be formed by H2S、HCl and water with cooling down in the crude distillation tower.Adding corrosion inhibitors method are often used to inhibit the corrosion of metal.Imidazoline amide on HCl-H2S-H2O media have a good corrosion inhibit effect.Compared to oil-soluble imidazoline amide,water-soluble amide imidazoline with high efficiency,low-cost,environmentally friendly and wide application is an excellent corrosion inhibitor.This paper is using azelaic acid,acetic acid and tetraethylenepentamine as materials synthesized water-soluble fatty acid amide,and then closed-loop response to synthesy of water-soluble imidazoline amide.Then the effects of synthesis conditions such as density,temperature,time and having toluene or not during the reaction were studied to determine the appropriate process.The product was identified and analyzied by IR spectrum.Inhibition performance of the different amount of Water-soluble imidazoline amide for A3 was investigated using static weight-loss method,polarization curve and Scanning electron microscopy.The results show that the appropriate process of the synthesis of Water-soluble imidazoline amide is without toluene,the mass ratio of reaction raw materials n(tetraethylenepentamine):n(nonanoic acid):n(acetic acid)is 1:0.5:4;amidation reaction temperature is 120～130℃,reaction time is 3～5 hours;Closed-loop reaction temperature is 220～240℃,the closed-loop response time is 3～5 hours.Using infrared spectroscopy to analyze structural characterization of the product,it showed that the product is the substances of imidazoline amide.The mass fraction is 10%～50%solution of water-soluble imidazoline amide is transparentthe,and it is not hierarchical when it was long-term storage at room temperature.The properties of Different concentrations of water-soluble imidazoline amide can be conformed to requirement of the People’s Republic of China in the oil and gas industry standards SY/T5273-2000 of oil field with corrosion inhibitor on the spot.By Simulating the corrosion conditions of crude distillation tower condensing system,through the method of static coupon data from known that the water-soluble imidazoline amide in 1000mg/L,HCl-1000mg/L H2S corrosion medium,Temperature for 90±2℃ with 6h,when adding volume is 15mg/L,the inhibition efficiency will be over 85%.