埋地管道防腐技术浅析

埋地管道输油是目前原油的主要输送方式之一,但管道腐蚀严重影响其使用寿命和所输油品质量,甚至造成泄漏污染环境。进行分析埋地管道的腐蚀机理和影响因素以及相关防腐技术,针对不同的腐蚀类型采取相应的防腐技术。针对某输油管道应用阴极保护技术,用数据科学有效地进行了防腐控制。     

埋地输油管道防腐技术的研究现状

主要探讨了国内外输油管道在埋地铺设后,遭受土壤腐蚀而引起的严重事故及目前防腐方法的研究现状。本文在目前防腐方法调研的基础上阐述了土壤腐蚀影响、控制问题、腐蚀措施等方面,分析了不同情况下的影响因素,并提出了相应的防腐措施。对于埋地土壤中输油管道应根据实际铺设环境应采取涂层保护、缓蚀剂保护、电化学保护、阴极保护等手段因地制宜相结合,使输油管线得到最大的保护。     

航空燃料埋地输送管道的腐蚀与防护

随着航空事业的发展,管输方式成为航空燃料又一广泛运用的运输方式,但腐蚀穿孔成为埋地管道的重要安全隐患。文章从腐蚀的分类分析了航空燃料埋地输送管道腐蚀的原因、影响因素,并重点从外防腐涂层和阴极保护两方面论述了当前对管道腐蚀防护的技术。     

阴极保护技术在站外埋地钢质管道上应用效果分析

阴极保护技术是控制埋地钢质管道腐蚀行之有效的手段之一,阴极保护技术分强制电流阴极保护和牺牲阳极保护两类。当阴极保护设施不能够不能给埋地钢质管道提供足够的阴极保护电位时、管道外防腐层缺陷处会发生腐蚀,针对阴极保护电位不达标的问题,通过开展阴极保护技术应用现状调查、对现场测试数据进行分析、归纳和总结,找出阴极保护方面存在的问题,提出了解决建议。     

石化厂区埋地金属结构物阴极保护技术应用

某石化厂埋地金属结构物包括:埋地钢质管线、铜包钢接地网和地上石油储罐的罐底.由于地处滨海滩涂,土壤腐蚀性较强,加之电偶腐蚀、细菌腐蚀和杂散电流腐蚀等各种电化学腐蚀电池的综合作用,将给正常生产带来巨大的隐患.在建设之初,青岛双瑞公司承担了厂区埋地金属结构物阴极保护项目的设计、供货和施工任务(EPC 总承包),经过3年多的建设,目前阴极保护系统运行状态良好,保护效果达到设计要求,阴极保护技术将使埋地金属结构物的使用寿命平均提高了30年以上,消除了安全生产的一大隐患.     

埋地金属管道腐蚀机理及防护研究进展

腐蚀是困扰埋地金属管道的重要难题之一,更是造成管道事故的重要原因。文章综述了埋地金属管道的电化学腐蚀、微生物腐蚀、杂散电流腐蚀等主要机理,介绍了国内外利用缓蚀剂防腐、特殊涂层防腐、金属管道表面改性、阴极保护等几种主要的防护措施,并指出金属管道表面改性对于埋地金属管道防腐具有良好的作用,其应用前景非常广阔。     

望城输气管道阴极保护的设计

为保护埋地输气管道不受电化学腐蚀影响,应对其进行阴极保护。本文采用强制电流法和牺牲阳极法进行了管道阴极保护的设计和计算;综合比较后,确定采用牺牲阳极法对管道进行阴极保护。     

浅谈沿海埋地输油管道腐蚀与防护

随着我国输油管道的规模化建设,管道输送的可靠性也逐渐被社会所关注。对于铺设于地下的输油管道,除了受到管内油品介质的腐蚀,还会受到外部环境的腐蚀而发生腐蚀穿孔,从而引发油品泄漏事故。本文介绍了埋地输油管道的内外腐蚀机理,主要分析了沿海埋地输油管道外腐蚀因素,针对埋地输油管道的腐蚀特点,提出对埋地输油管道的内、外腐蚀保护措施,以保证管道的长期安全运行。     

石化管道杂散电流腐蚀的防护措施研究

输油气化工管道杂散电流腐蚀的发生必须具有杂散电流源,从源头上防止杂散电流的产生显得尤为重要;在钢轨侧增大轨地过渡电阻、减小钢轨纵向电阻及设置排流收集网可以有效降低杂散电流对管道的影响;管道表面涂覆绝缘防腐层可对埋地输油管道起到绝缘屏蔽保护作用,因此电气化铁路附近埋地输油管道表面必须涂覆绝缘防腐层。同时采用阴极保护及管道排流保护的方法均可有效抑制电流腐蚀的作用。     

输油管道的防腐技术应用现状

输油管道防腐技术的发展与应用对油气的安全运输起关键作用,目前输油管道防腐技术快速发展,石油运输中管道发生腐蚀有多种原因,包括管道内壁腐蚀及外环境的腐蚀,当前应用较为广泛的防腐技术有管道外涂覆绝缘层、添加缓蚀剂、管道内涂层及衬里技术、阴极保护技术等。合理运用各种防腐技术有利于经济发展与环境友好。     

佛山市顺德新城区降水中污染物的监测和分析

为掌握佛山市顺德新城区降水中污染物的情况,2015年7月至8月,文章作者分别在雨天进行了降水取样,对降水中的pH、电导率、常见阴离子(F-、Cl~-、NO_3~(2-)、SO_4~(2-))及部分重金属(铅和镉)进行监测分析。选择有相关数据的珠江三角洲和石家庄、厦门等地的降水中污染物的情况进行对比。结果表明,顺德新城区降水中的p H和部分阴离子浓度优于珠江三角洲平均值,酸雨类型属于硫酸和硝酸混合型;其水体洁净程度略差于石家庄;铅和镉的浓度也高于厦门,甚至部分超出了人体能直接接触的安全范围。     

Metabolism of trideuterated iso-lignoceric acid in rats in Vivo and in human fibroblasts in culture

Saturated very long chain fatty acids (fatty acids with greater than 22 carbon atoms; VLCFA) accumulate in peroxisomal disorders, but there is little information on their turnover in patients. To determine the suitability of using stable isotope-labeled VLCFA in patients with these disorders, the metabolism of 22-methyl[23,23,23-²H₃]tricosanoic (iso-lignoceric) acid was studied in rats in vivo and in human skin fibroblasts in culture. The deuterated iso-VLCFA was degraded to the corresponding 16- and 18-carbon iso-fatty acids by rats in vivo and by normal human skin fibroblasts in culture, but there was little or no degradation in peroxisome-deficient (Zellweger’s syndrome) fibroblasts, indicating that its oxidation was peroxisomal. Neither the 14-, 20-, and 22-carbon iso-fatty acids nor the corresponding odd-chain metabolites could be detected. In the rat, the organ containing most of the iso-lignoceric acid, and its breakdown products, was the liver, whereas negligible amounts were detected in the brain, suggesting that little of the fatty acid crossed the blood-brain barrier. Our data indicate that VLCFA labeled with deuterium at the ω-position of the carbon chain are suitable derivatives for the in vivo investigation of patients with defects in peroxisomal β-oxidation because they are metabolized by the same pathways as the corresponding n-VLCFA. Moreover, as iso-VLCFA and their β-oxidation products are readily separated from the corresponding n-fatty acids by normal chromatographic procedures, the turnover of VLCFA can be more precisely measured. A preliminary report of part of this work (Reference 18) was presented at the 5th International Symposium on the Synthesis and Applications of Isotopes and Isotopically Labelled Compounds, Strasbourg, France, June 20–24, 1994.     

Denitrification in shallow groundwater in a coastal agricultural area in Japan

In a coastal agricultural area in the central part of Japan (Shizuoka), we found decreasing nitrate concentration with depth in a shallow groundwater, where the depth to water table varied between 0.6 and 1.2 m below ground surface. High nitrate concentrations (5–29 mg N L^–1) were often observed in the upper layer (0–2 m) of the groundwater, but the concentration decreased to less than 1 mg N L^–1 in the deeper layer. Ammonium was scarcely detected, and the concentration of dissolved oxygen was usually low (< 1 mgO₂ L^–1) in the groundwater. Nitrate in the groundwater often had very heavy nitrogen stable isotope ratios (>20{}). There was a negative relationship between nitrogen stable isotope ratio of nitrate and its concentration. When nitrate was injected into the groundwater with acetylene and bromide (a conservative tracer), nitrate concentration decreased to 20% of the initial level within 5 days, accompanied by the increase in nitrite and nitrous oxide concentration and a little change in bromide concentration. These results indicate that microbial denitrification plays a potential role in the decrease of nitrate in shallow groundwater at the study site.     

我国硝酸工业生产技术新进展

系统叙述了我国硝酸工业2000-2007年生产现状及主要技术成果,尤其指出了国产"四合一"机组的成功投运,使我国硝酸国产化装置取得较大的进步,表现在吨酸的铂耗、氨耗和能耗等方面接近国外引进装置水平,同时介绍了国外双加压法硝酸生产技术的进展.我国已成为硝酸生产大国,仍需以先进的技术改造和发展我国硝酸工业,确保我国硝酸工业健康有序地发展,加快从硝酸生产大国向强国迈进的步伐.     

高效液相色谱法分析化妆品中微量成分的研究进展

综述了高效液相色谱法在化妆品中防腐剂、防晒剂中紫外线吸收剂以及性激素的检测等几个方面的应用;同时,介绍了分析所用的色谱柱、流动相、使用的检测手段以及样品的提取方法;最后针对目前存在的问题,提出了高效液相色谱用于化妆品中微量成分分析的研究方向和发展前景。