柠檬酸根对Ba^(2+)、Ca^(2+)的阻垢性能研究

Research about Scale Inhibition of Citrate on Ba^(2+) and Ca^(2+)

柠檬酸及柠檬酸钠含有丰富的羧基基团,可对金属阳离子产生络合包结作用。由于酸效应的存在,柠檬酸对BaSO_4的阻垢效果较差,调节pH为7.0,使其成为柠檬酸钠后,对BaSO_4具有较好的阻垢效果,并且对已经成垢的BaSO_4具有较好的分散除垢作用。结果表明,柠檬酸钠与阻垢剂2-磷酸基-1,2,4-三羧酸丁烷(PBTCA)相复配,在处理CaCO_3垢上具有较好的协同阻垢效果。与聚环氧琥珀酸钠相比,在处理油田含Ba^(2+)注水时,柠檬酸钠具有一定的经济优势。

Citric acid and sodium citrate contain are rich in carboxyl groups, which can be used to coordinate and package metal cations. Because of the effect of H＋ , the scale inhibition of citric acid on BaSO4 was poor. After the pH was adjusted to be 7.0 and citric acid became sodium citrate, its scale inhibition performance on BaSO4 was better. Meanwhile, sodium citrate had a good effect on dispersing and removing the formed BaSO4. The experimental results showed that, sodium citrate had synergistic effect on descaling CaCO3 when it was compounded with PBTCA. Compared with polyepoxysuccinic acid, sodium citrate had economic advantage in dealing with oilfield water injection which contains Ba2＋.