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改性双季铵盐的合成及其在油田水处理中的应用研究
Synthesis and Application of Modified Bis-quaternary Ammonium Salt in Oilfield Wastewater Treatment
【作者】 周娟;
【导师】 张宁生;
【作者基本信息】 西安石油大学 , 应用化学, 2010, 硕士
【摘要】 本文针对油田回注水中SRB、TGB等微生物对注水设备和管线造成严重腐蚀,又由于微生物产生耐药性导致常用杀菌剂投加量升高、处理成本攀升甚至处理后水质不能达标等问题,以环氧氯丙烷(ECH)、十二烷基二甲基胺(DMA12)和甲硝唑(MDZ)为原料,合成了一种新型杀菌剂——改性双季铵盐MHTD。本文对MHTD的合成工艺进行了研究,并对MHTD的杀菌性能、缓蚀性能、表面活性及其做为杀菌剂与其它水处理剂的配伍性进行了探讨。研究结果表明:合成MHTD分三步进行,首先DMA12和氯化氢反应生成叔胺盐酸盐(DMAH),然后ECH与DMAH反应制得中间体N-(3-氯-2-羟丙基)-N,N-二甲基十二烷基氯化铵(CHAC),最后CHAC与MDZ反应得MHTD。CHAC的最佳合成工艺条件为:n(DMAH): n(DMA12):n (ECH)=1:0.15:1.10.温度40℃, CHAC的最高收率达93.5%; MHTD的最佳合成工艺条件为:乙腈作溶剂、反应物物质的量之比n (MDZ):n (CHAC)=1.2:1、反应温度80℃、反应时间12 h,收率达82.4%,应用熔点测定和红外光谱分析方法证明合成的产物就是设计的目标产物甲硝唑改性双季铵盐MHTD。MHTD的杀菌性能研究表明:MHTD浓度越高杀菌率越高,当浓度为30 mg/L时,SRB和TGB的杀菌率分别为99.99%和99.14%,达到油田回注水水质要求,较同等浓度的常用杀菌剂1227分别提高了63%和99%,当浓度为40 mg/L时,SRB和TGB的杀菌率均达到100%;菌药接触时间在48 h内MHTD对SRB、TGB的杀菌率均保持在90%以上:MHTD对矿化度1×104~1×105 mg/L、温度30-60℃、pH 5.5到8.5的油田污水均有良好的适应性,与现场所应用的缓蚀剂和阻垢剂具有良好的配伍性。应用静态挂片法和动电位电化学法对MHTD进行了缓蚀性能评价,当浓度为50mg/L在矿化度为8.68×104 mg/L的模拟盐水中对A3钢的缓蚀率分别达77.2%和71.2%。测得MHTD的CMC值为0.77 mmol/L, CMC值下的表面张力为34.14mN/m。
【Abstract】 SRB, TGB and other microbes in oilfield reinjection water could cause corrosion of injection equipments and pipelines. However, the microbes would contain genes conferring resistance on biocide, resulting in increasing in MIC of common biocide and treatment costs and even that the treated water couldn’t meet the criteria. Aiming at solving this problem, one novel biocide, the modified bis-quaternary ammonium salt MHTD was synthesized by using epichlorohydrin (ECH), N,N-dimethyl dodecyl amine (DMA 12) and metronidazole (MDZ) as raw materials. In this paper, the synthesis process conditions, bactericidal properties, corrosion inhibition, surface activity of MHTD were studied, as well as compatibility with other wastewater treatment agents. The results show that:It took three steps to synthesis MHTD. First, DMA 12 combined with hydrogen chloride to form N, N-dimethyl dodecyl amine hydrochloride (DMAH). Second, DMAH reacted with ECH to produce the intermediate product of CHAC (N-(3-chloro-2-hydroxypropyl)-N, N-dimethyl dodecyl ammonium chloride). At last, MHTD was obtained from the reaction of CHAC and MDZ. The yield of CHAC could reach the best of 93.5% in the conditions of reaction temperature at 40℃and the molar ratio of reactants n(DMAH): n(DMA12):n(ECH) at 1:0.15:1.10. The best yield of MHTD reached 82.4% in acetonitrile with the conditions of the reaction temperature at 80℃, the molar ratio of reactants n(MDZ):n(CHAC) at 1.2:1 and reaction time of 12 h. The product structure of MHTD was detected by IR spectrum and melting point apparatus, the result was coined with the primary design.The results of the bactericidal properties study show that: the bactericidal rate is increasing with the concentration of MHTD; the bactericidal rates could reach 99.99% and 99.14% to SRB and TGB respectively when the concentration of MHTD is 30 mg/L, which meet to the water injection requirements and 63% and 99% more than 1227 at the same concentration; MHTD had a bactericidal rate up to 100% to SRB and TGB in the concentration of 40 mg/L. The bactericidal rate of MHTD to SRB and TGB maintained above 90% within the contacting time of bacterium and drug at 48 h. MHTD is perfectly adapted to oilfield wastewater with salinity from 1×104 mg/L to 1×105 mg/L, temperature of 30℃to 60℃and pH of 5.5 to 8.5. Furthermore, it has good compatibility with the corrosion inhibitor and scale inhibitor applying in oilfield.The corrosion inhibition of MHTD was evaluated by the static hanging experiments and potentiodynamic electrochemical test. The results demonstrate that MHTD with the concentration of 50 mg/L has corrosion rates of 77.2% and 71.2% respectively to A3 steel in 8.68×104 mg/L salinity simulated salt water. The CMC and ys(CMC) of MHTD are 0.77 mmol/L and 34.14 mN/m respectively.
【Key words】 Bis-quaternary ammonium salt; Metronidazole; Synthesis; Bactericide; Oilfield produced water;