硫醇、硫醚类化合物在白油中对环烷酸腐蚀性的影响

Effects of Mercaptans and Sulfides on Naphthenic Acid Corrosion in White Oil

采用静态失重法研究了不同烷基结构和含量的硫醇、硫醚和二硫醚类化合物在工业白油体系中对环烷酸腐蚀性的影响。实验结果表明,当硫醇含量小于9.0μmo/g时对环烷酸的腐蚀性有一定的抑制作用,反之,则促进环烷酸腐蚀,不同结构硫醇腐蚀速率快慢的顺序为:环己硫醇>正丁硫醇>十二硫醇>苄硫醇;当硫醚含量小于19.7μmol/g时加剧了环烷酸的腐蚀,随硫醚含量的增加,腐蚀速率减慢,抑制了环烷酸的腐蚀,含量大于98.6μmol/g后腐蚀速率基本趋于不变,固定硫醚的一个烷基改变另一烷基的结构,其腐蚀速率快慢的顺序为:丁基苄基硫醚>丁基十二烷基硫醚>丁基环己基硫醚>二丁基硫醚;二硫醚中的二环己基二硫醚、二丁基二硫醚及双十二烷基二硫醚加剧了环烷酸腐蚀且随含量的增加腐蚀速率加快,而二苄基二硫醚对腐蚀的影响表现为没有促进也没有减弱腐蚀。

The effects of mercaptans,sulfides and disulfides with different alkyl groups on the corrosiveness of naphthenic acid in white oil were studied by a static weight-loss method.The results show that the naphthenic acid corrosion is inhibited when the concentrations of mercaptans are less than 9.0 μmol/g,otherwise the corrosion is promoted.The corrosiveness of mercaptans with different alkyl groups lowers in the order,namely cyclohexyl mercaptan,butyl mercaptan,dodecyl mercaptan and benzyl mercaptan.When the concentration of sulfides is less than 19.7 μmol/g,the corrosion is promoted;and the corrosion is inhibited when the concentration is from 19.7 μmol/g to 98.6 μmol/g.The corrosiveness of sulfides with different alkyl groups decreased in the order,i.e.butyl benzyl sulfide,butyl dodecyl sulfide,butyl cyclohexyl sulfide and dibutyl sulfide.The corrosion rate of naphthenic acid was promoted by dicyclohexyl disulfide,dibutyl disulfide and didodecyl disulfide,and the rate increased with the increase of the concentration of the disulfides,while the effect of dibenzyl disulfide on the corrosion is little.