Development Of New High-efficiency Aluminum Anode For Separator

The gas gathering station metering separator is a key equipment in the gas field surface system.Before the raw natural gas is dehydrated,it contains a certain amount of condensate water or formation water,which will cause corrosion damage to the inner wall of the separator and pose a certain threat to gas field production.At present,the gas field mainly adopts the cathodic protection method of sacrificial anode to prevent the inner wall of the separator,and has achieved good results;however,there are still problems such as low current efficiency,easy block loss,and uneven corrosion.For this reason,this article has fully investigated the use of sacrificial anodes and the current research status at home and abroad,and according to the national current efficiency test standards,taking Al-Zn-In-Mg-Ti anode materials as the research object,through alloying,heat treatment and Finite element simulation and other methods,using orthogonal experiment,fine melting,electrochemical performance testing,macroscopic morphology analysis,metallographic analysis and other methods,carried out research on the development and application of new sacrificial anodes,and clarified the influence of various alloy elements on the current of the sacrificial anode.The influence law of efficiency and corrosion uniformity has formed a sacrificial anode formula that dissolves more uniformly,does not lose lumps,and has a current efficiency of more than 90%.At the same time,the finite element method is used to simulate and analyze the influence of the number and distribution of sacrificial anodes on the protection potential and current density.The research content of this article mainly includes the following three parts:(1)Research on alloying formula.This article first selects 4 kinds of alloying elements and 3 levels of conditions to formulate orthogonal experiments according to the research situation,and prepares 9 sets of new sacrificial anode ingots using fine smelting technology.Then the electrochemical standard samples were prepared by machining methods,and the current efficiency test of each group of samples was carried out in accordance with the national standard.A set of anode formulations with the highest current efficiency and good corrosion uniformity were screened out,and at the same time as a comparison,a set of anode formulations with poor performance were selected.On this basis,the two groups of anode formulas were added with different contents of Ga element,and the influence of Ga element on current efficiency and corrosion uniformity was discussed.The results show that Mg element has the greatest influence on the anode current efficiency,followed by Zn element,and In and Ti elements have less influence.The optimal anode formula is0.5%Mg-4%Zn-0.035%In-0.045%Ti.Adding a certain amount of Ga element can effectively improve the corrosion resistance of the new sacrificial anode.When the content of Ga element is 0.03%,its self-corrosion potential is the highest.(2)Research on the influence law of heat treatment.The 2# sample and the worst 5#sample with the best performance were selected from 9 groups of orthogonal experimental samples,and the influence laws of different heat treatments such as air cooling,furnace cooling and water cooling were carried out respectively.Research shows that the current efficiency of 2# and 5# sacrificial anodes are basically the same after heat treatment.Except for the water-cooling heat treatment process,the overall current efficiency has been improved.After air-cooled and furnace-cooled heat treatment,the corrosion morphology of the 2# anode sample is relatively uniform;but the surface of the 2# anode sample that has been water-cooled has local corrosion problems,and there is a phenomenon of local blockage.The surface corrosion of the heat-treated 5# anode sample is relatively uniform,which is greatly improved compared with the unheated sample,and the corrosion is more uniform.(3)Finite element simulation analysis.The COMSOL finite element simulation method was used to analyze the influence of the number and distribution of sacrificial anodes on the protection potential and current density of the inner wall of the separator.The results show that as the number of anodes increases,the protection potential will decrease,reaching-1.04V?-1.02V;the current density on the anode surface also shows a significant downward trend,and the protection effect has been significantly improved;at the same time,the protection The uniformity of the potential distribution is also significantly improved as the number of anodes increases.