Development Of Corrosion Inhibitors Using Solid Cleaning Agent At High Temperature

Carbon steel is not only cheap but also has good mechanical properties,so it is widely used in petrochemical,marine,aerospace and many other fields.The equipment of carbon steel will produce a lot of rust and scale during the long-term used.How to remove rust and scale of carbon steel equipment is a very worthy of study,in which the pickling is a very effective method for cleaning.In practical engineering applications,since pickling environment is very complex,it need high performance requirements for the corrosion inhibitor.This paper filter out better corrosion inhibitors that resistance high temperature through selecting from a large number of one-component corrosion inhibitors,A composite and excellent corrosion inhibitor was composed by orthogonal method.Eventually JLL-1,JLL-2 and JLL-3 as three kinds of corrosion inhibition that resistance high tempearture are developed.Each corrosion inhibitor had conducted at the amino acid,citric acid,EDTA in high temperature system in the way of weight loss method.Experiments have determined concentration-metal corrosion rate curve,acid concentration-metal corrosion rate curve,temperature-metal corrosion rate curve and time-metal corrosion rate curve of the three compound corrosion inhibitors.The experimental data showed that carbon steel in 5%citric acid at 90? conditions,when JLL-1 corrosion inhibitor in an amount of O.lg,the corrosion rate of carbon steel decreased to 0.65 g·m-2·h-1,and this fully demonstrates the inhibition performance of JLL-1.Further experimental studies have shown that JLL-1 corrosion inhibitors can be used in the system for amino acid-carbon steel,citric acid-carbon steel,EDTA-carbon steel,EDTA-aluminum,citric acid-aluminum citrate at high temperature conditions.JLL-2 corrosion inhibitors can be used in the system for citric acid-carbon steel,EDTA-carbon steel,amino acid-carbon steel,citric acid-aluminum,EDTA-aluminum.JLL-3 corrosion inhibitors can be used in the system for amino acid-stainless steel,amino acid-aluminum,citric acid-aluminum,EDTA-aluminum.JLL-1,JLL-2 and JLL-3 corrosion inhibitor has been studies in the aspect of electrochemistry at different cleaning agents and different temperatures and the study using a three-electrode system.Experimental data show that:JLL-1 corrosion inhibitor is a mixed type corrosion inhibitor.JLL-2 corrosion inhibitor is a cathode type corrosion inhibitor.JLL-3 corrosion inhibitor is a anode type corrosion inhibitor.After many experiments show that these corrosion inhibitor is non-toxic,inexpensive,efficient and environmentally friendly these corrosion inhibitor has broad market prospects.