【作者】 邢文国；

【导师】 张长桥； 冯圣玉； 李国平；

【作者基本信息】 山东大学 ， 高分子化学与物理， 2010， 博士

【摘要】 由于全球对经济可持续发展的要求和对“洁净能源”的呼唤,天然气需求量与日俱增。天然气作为一种清洁高效的能源,已成为世界各国改善环境和促进经济可持续发展的最佳选择,也是我国改善能源结构、寻找煤炭替代资源的主要途径。当前,天然气的普及率和耗用量已成为评价一个国家、一个地区或一座城市的经济及社会发展水平的标志之一,这表明21世纪天然气将在能源结构中扮演越来越重要的角色。管道输送是世界上五大运输工具之一,目前,天然气的主要运输方式为管道输送,为了提高输量,长运距、大管径和高压力管道是当今世界天然气管道发展的主流。在天然气管道输送方面存在着：长距离大管径输送管道能耗大的突出问题；对长期服役已出现腐蚀老化管道,采用原设计压力输送甚至用增压等措施来维持原输气量,将带来的重大安全事故隐患问题；由于油气田开采产量自身规律和经济发展的各个时期需求量不同,要求同一口径管道的输送设备应具有经济合理的弹性调节能力的问题；同时在开发海上、沙模、沼泽、高寒等自然条件恶劣地区的油气田时,占总成本比例极大的油气输送动力、能耗问题也是构成能否经济合理开发的关键问题之一。解决上述问题的最好方法是使用减阻技术。对于天然气管道运输而言,减阻技术可方便地提高管道的输量,降低管线的压力,节约能源,提高管线运行的安全系数等,其功能主要有两方面：一方面是在恒定输量的情况下,降低管道两点间的摩阻,在保持两点压力降不变的情况下,增加输量,从而节省大量的人力、物力消耗；另一方面是提高天然输量弹性,以满足不同气田、不同地区的需要。在天然气实际管道输送过程中使用减阻技术,可提高管道的输量弹性,使管道由“刚性”变为“弹性”,并能很好的解决长距离大管径输送管道能耗大的突出问题。同时对长期服役已出现腐蚀老化管道,应用减阻技术在维持原输气量条件下,能够降低管道压力,提高管线运行的安全系数。目前,国内外普遍采用管道内涂层减阻技术来解决上述问题,并取得了很好的技术效果和良好的经济效益,但管道内涂层减阻方法施工设备复杂、费用较高,特别是随着输气时间的延长和不定时清管,管道内涂层不断脱落,减阻效果逐渐降低,若进行二次修补,则必须停产、拆装和清理,这在工程和技术上都将造成极大的困难。更重要的是,目前国内外管道内涂层减阻技术随着使用年限的增长,其暴露出来的致命缺陷日益显现,即管道内涂层脱落残片直接影响燃气轮压缩机高速运转的叶片寿命,严重时可使叶片损坏,造成供给输送天然气动力的燃气轮压缩机停运。针对内涂层减阻技术存在的缺陷,20世纪90年代,美国率先提出了天然气减阻剂减阻技术的概念。该概念主要技术内容是将具有表面活性剂性质的被称作天然气减阻剂的化学品定期注入天然气管道中,通过极性端对钢铁表面的吸附,形成弹性分子薄膜,达到降低管壁粗糙度实现减阻的目的。依据该概念其研究与开发思路为：合成对钢铁表面具有强吸附性能,同时具有抗高速运动气体牵拉作用的化合物,利用该化合物可在钢铁表面形成弹性分子薄膜特性,从而达到降低管壁粗糙度实现减阻的目的。对于这种全新的天然气减阻技术方案,目前在国外还处于实验室研究阶段,而国内则是完全空白。本课题在总结国内外研究现状及技术发展趋势的基础上,针对国际上天然气减阻剂工业产品尚属空白,但国外研发已出现由实验室向工业化开发萌芽的现状,依据我们前期“输油管道α-烯烃系列减阻剂开发及其制备工艺”积累的经验与相关研究仪器设备,同时迅速开展天然气减阻剂减阻理论和产品研发与应用技术两方面的研究。天然气减阻剂的研制及其减阻性能的研究其科学与技术的意义为：作为油气储存与运输工程二级学科,特别是对运输工程而言,由于石油能源工业的特殊性,世界各国其输送装备技术均可通过引进、消化和吸收方法加以解决,因而就技术水平而言,全世界基本上处于同一水平。但是减阻增输技术因其具有战略意义,各国仅出售产品不出售技术,并且研发资料严格保密相互封锁,因此减阻增输技术被公认为该学科的技术制高点,代表了一个国家该学科在国际上的学术理论与工程技术地位。在油品减阻剂的开发方面,“输油管道α-烯烃系列减阻剂开发及其制备工艺”获2008年国家技术发明二等奖,标志着我国在油品减阻剂研制与工程应用技术方面处于世界领先水平。在天然气减阻剂开发方面,我国在研发起步阶段已落后于国外,我们只有强化研发力度,采用超常规研发思路开展该方面的研究,使我国天然气减阻剂研发赶上和超过国外先进水平,从而使我国在减阻增输高技术领域占有一席之地。正是基于上述情况,促使我在前期参加“输油管道α-烯烃系列减阻剂开发及其制备工艺”基础上,继续从事天然气减阻剂的研制及其减阻性能的研究。经过五年多的努力,取得了以下成果：1、利用流体力学、量子力学及分子动力学模拟等手段,在分析天然气输送过程中能量损失产生的原因及水力摩阻的基础上,结合我们对于原油减阻剂积累的经验,对天然气减阻剂的减阻机理进行了研究。研究表明含氨基、酰胺基、咪唑等极性基团的化合物或聚合物由于与铁具有较高的结合能,而具备了作为天然气减阻剂的先决条件,这为天然气减阻剂的分子设计奠定了理论基础。2、在对天然气输送过程中能量损失分析的基础上,结合油品减阻剂室内评价系统设计开发积累的经验,模拟实际天然气管道输送情况,设计完成了国内唯一一条天然气减阻剂室内评价系统,该评价系统基本稳定可靠,具有良好的可操作性及重复性。该评价系统的设计完成,为天然气减阻剂的筛选与研制打下了坚实的基础。3、在分析天然气减阻剂减阻机理的基础上,实验室合成了硬脂酸咪唑啉、巯基三氮唑及乙烯基咪唑—乙烯基三甲氧基硅烷共聚物三种天然气减阻剂,并利用扫描电子显微镜、电化学方法对其成膜性能进行研究,研究表明三种物质在钢铁表面均具有良好的成膜性能,表现出了良好的可实际工业化应用前景。4、利用设计完成的天然气减阻剂室内评价系统对所合成的三种天然气减阻剂进行了减阻性能的研究,探讨了各种工艺条件对减阻性能的影响,确定了最佳减阻工艺条件。研究结果表明：在最佳减阻工艺条件下,硬脂酸咪唑啉减阻率可达8.4%,AAMT减阻率可达10.03%,而VI-VTMS共聚物减阻剂,其减阻率最大可达22.72%,达到了国际领先水平,并且聚合过程操作工艺简单,为工业化生产应用打下了基础。更多还原

【Abstract】 The natural gas was growing in demand because of the needing on the economic sustainable development and the calling on the clean energy. As the green high efficiency energy, natural gas had become the optimum selection to improve environment and promote economic sustainable development for all over the world. It was also a main way to improve the energy structure and seek the coal replacement energy of China. At present, the popularization rate and the consumption of natural gas had became the mark of the economic and social development level to evaluate one country, one zone, or one city.Pipeline was one of five major forms of transportation in the world. At present, almost all of natural gas produced in the world were transported by pipeline. The long-distance, big-diameter and high-pressure pipeline was the main developing flow of gas pipeline in the world in order to increase the pipeline throughput. But there were several problems for the natural gas pipeline transportation. Firstly, high energy consumption was the outstanding problem for long-distance, big-diameter pipeline. Secondly, it took the hidden trouble of vital safety accident when using the design pressure or pressurization to maintenance the throughput for aging pipeline. Thirdly, it was required that the same diameter pipeline conveyer should have the economic and reasonable elastic adjusting ability because of the law of gas field exploitation and the various demand at different period. Fourthly, one of the key problems for the economic and rational exploitation was the transportation dynamics and energy consumption with high proportion to the total cost when exploitation the gas filed was in the hash natural conditions region, including offshore, desert, swamp, and alpine region.The best way to solve these problems was using drag reducing agents(DRAs). Using DRAs could improve the throughput, decrease the pipeline pressure, save energy, and improve the safety, etc. It had two main functions:On the one hand, the friction was decreased keeping the throughput invariant and the throughput was improved keeping the pressure drop invariant. Thus, the labor and material were saved. On the other hand, the elastic throughput was improved in order to meet the different gas fields and area. The elastic throughput was improved and the rigid pipeline changed into elastic when DRAs were used in the practical pipeline transportation. It also solved the outstanding problem of high energy consumption for long-distance, big-diameter pipeline. At the same time, the operating pressure of pipeline was reduced and the running safety coefficient was improved when using DRAs to maintain the throughput for the aging pipeline.At present, the inner-coated drag reduction technology was adopted to reduce the pipe wall roughness, which obtained excellent results and better economical benefits. But, for the inner-coated drag reduction technology, the construction equipments were complex and the cost was high. Especially, the drag reduction efficiency reduced and the inverse effect happened because of the runaway coating after long-time transportation and irregular pigging. It must stop production, dismount, and clean in order to repair. It was very difficult in the engineering technology. More important, the inner-coated drag reduction technology had fatal weakness that the exfoliated inner-coatings directly affected the high speed operation blade of compressor, on the severe case, blade was damaged causing the compressor outage.In 1990s, the concept of gas DRAs technology was firstly introduced according to the fatal weakness of inner-coated technology. The content of this concept was that the chemicals with surface activity said as gas DRAs were periodically injected into gas pipeline, the polar terminal was adsorbed onto the pipe iron wall surface to form the elastic film, so the pipe wall roughness was accordingly reduced and the drag reduction was obtained. The general idea of research and development according to the concept was that synthesis of compounds having high adsorption properties with iron and resistant to draw-off of high speed gas. At present, this technology was in developing phase abroad, but it was blank home.This paper overviewed the technology state and trend of gas pipeline development. According to the state that the natural gas DRAs was blank, and it was showed the industrial germination. Based on our experience and equipments on the studying process of "development and preparation technology of oil pipeline a-olefin", the natural gas DRAs drag reduction theory and the research and application of DRAs production were studied in this paper. The scientific and technical significance of synthesis of natural gas DRAs and its drag reduction performance studying was:Oil & gas storage and transportation was the grade-2 subject. Its transportation equipment can be solved by introducing, digesting, and adsorbing for all over the world. So, it was ranged in the same level. But the technology of drag reduction and throughput increasing possess a strategic significance, so only the products was for sale and the technique was keeping secret. The technology of drag reduction and throughput increasing was considered as the commanding point in this subject. It was representative for academic theory and engineering technology status of a county in the word. The "development and preparation technology of oil pipeline a-olefin" has won the second state technological innovation prize which mark a international leading level of China in the oil DRAs. Because the development of natural gas DRAs was drop behind in China compared to abroad, it was necessary to study energetically in order to catch up with and exceed the advanced level to take a place in the technology of drag reduction and throughput increasing field.For the above reasons, the author was engaged in development of natural gas DRAs and its drag reduction performance studying on the basis of taking part in "development and preparation technology of oil pipeline a-olefin". The following creative achievements were obtained after five years efforts.1. The drag reduction mechanism was studied using the methods of fluid mechanics, quantum mechanics, and molecular dynamics simulation on the basis of the experience of oil DRAs. The results showed that the compounds or polymers including amino, amide, and imidazole with high bond energy with iron had the preconditions to become natural DRAs. It was laying a solid foundation for the molecular design of natural gas DRAs.2. The natural gas drag reduction evaluation system was designed simulating the actual natural gas pipeline under the conditions of analyzing the energy loss in the transportation and the experience of the oil DRAs drag reduction evaluation system. The system was stable, reliable, maneuverability, and repeatable. The system was laying a solid foundation for the screening and development of natural gas DRAs.3. Three natural gas DRAs including stearic imidazole, AAMT, and VI-VTMS copolymers were designed and synthesized according to the drag reduction mechanism. The SEM and electrochemical methods were employed to study the property of film-forming. The results showed that three materials had better film-forming properties on the iron surface and the industrial application background.4. The drag reduction efficiency of three synthetic materials were studied using the natural gas drag reduction evaluation system. The technological conditions effect on the drag reduction efficiency were discussed and the optimum technological conditions were determined. The results showed that the drag reduction efficiency of stearic imidazole was 8.4%, AAMT was 10.03%, VI-VTMS was 22.72%. The drag reduction efficiency of VI-VTMS was international leading level and the polymerization process was simple. It was laying a solid foundation for the industrial development.更多还原