Role of the porphyrins and demulsifiers in the aggregation process of asphaltenes at water/oil interfaces under desalting conditions:a molecular dynamics study

Breaking water-in-oil emulsions during the refining of crude oils is an important step before any upgrading process is started.Asphaltene molecules are incriminated as playing an important role in this phenomenon.Unraveling the mechanisms behind the affinity between them and water is a key step to understand how to break these emulsions more easily and require lower amounts of demulsifiers.Choosing which demulsifier molecule(s)to use is also primordial,but to do so rationally,one needs to know which are the molecular interactions in place between asphaltenes,porphyrins and water so that demulsifiers are chosen to destabilize a specific physical–chemical interaction.In this paper,we study the interactions arising between asphaltenes and porphyrins and six different molecules potentially displaying a demulsification action in the presence of water/oil interfaces.We demonstrate that the ionic demulsifier molecules present an interesting potential to either interact strongly with water,replacing asphaltenes in this interaction,or to interact with the active sites of asphaltenes,deactivating them and avoiding any asphaltenic interfacial activity.Finally,we also found that although asphaltenes do not migrate spontaneously toward the water/oil interfaces,porphyrins do so rather easily.This indicates that porphyrins do have an important activity at the water/oil interface.

Commercial Test of Two Diesel Demulsifiers

PetroChina Lanzhou Petrochemical Company conducted commercial tests for application of two types of diesel demulsifiers, the HPL-2 and GX-02 demulsifiers, in order to solve the emulsion problem arising from caustic washing of straight-run diesel fraction obtained from atmospheric and vacuum distillation unit at the Lanzhou refinery. After addition of each demulsifier into the diesel fraction the oil content in caustic residue was apparently decreased, and discharge of waste caustic was reduced, resulting in the elimination of emulsification and a significant increase of economic benefits. When 70 ppm of the HPL-2 demulsifier was added to diesel fraction, the oil content in waste caustic exiting the second-stage caustic wash settling tank was reduced to 2.45% from 7.90 %, whereas this value was reduced to 2.81% from 5.96% with addition of the GX-02 demulsifier.

Experiment Study of Reverse Demulsifier on Simulated Water Sample Treatment at Different Oscillation Time and Different Concentrations of Drugging

In recent years, the water content of oilfield production fluid is high and there is a large amount of oily sewage. In order to improve the capability of sewage treatment, usually using demulsifier for oily sewage processing. This article uses simulated water sample to test the treatment effect of the optimized reverse demulsifier at different oscillation time. As the increase of action time and oscillation, the average size of droplets increases and the amount of the droplets under 1 μm decreases.

基于密度泛函理论研究聚醚类破乳剂的构效关系

油田采出液处理工艺中化学破乳剂的使用能够大大提升工作效率并且节约成本,其中聚醚类破乳剂的应用最为广泛,研究聚醚类破乳剂的构效关系对于新型破乳剂的研发及应用至关重要。本文首先对几种聚醚类破乳剂和反相破乳剂的破乳效果进行了评价和比较,然后根据沥青质分子的结构特点及现有聚醚类破乳剂和反相破乳剂的类型,选取了相应的模型分子,通过密度泛函理论(DFT)中B3LYP/6-31G基组得到其最优分子几何构型和静电势分布图,并利用泛函M062X/6-31G基组计算了聚醚类破乳剂模型分子分别与沥青质模型分子和水分子之间的相互作用能。结合聚醚类破乳剂和反相破乳剂的破乳性能评价结果,进而分析了聚醚类破乳剂的构效关系。结果表明,由理论化学计算结果所推测的破乳剂的破乳性能差异与其实际破乳效果相一致:具有支状结构、聚合度较高的聚醚类破乳剂的效果优于线型结构、聚合度较低的聚醚类破乳剂;酚醛树脂聚醚的破乳效果优于酚胺树脂聚醚,而反相破乳剂中则是多元醇聚醚类反相破乳剂的效果较优。该工作的开展表明采用密度泛函理论进行破乳剂的构效关系研究是可行的,能够为未来新型破乳剂的制备及选用奠定重要的理论基础和提供参考依据。

破乳剂存在下两亲聚合物对乳状液的影响研究

从体相和界面两个方面开展了破乳剂存在下两亲聚合物对乳状液的影响研究。结果表明:具有两亲性的聚合物易于吸附在油水界面上参与界面成膜,溶液中加入一定质量浓度破乳剂后,虽然破乳剂可以部分取代吸附在界面膜上的两亲聚合物分子,减弱界面膜强度,但随着溶液中两亲聚合物质量浓度的增加,体系界面活性增加,溶液中两亲聚合物分子伸向油相的疏水基团增多,同时伸向油相的两亲聚合物分子中的部分疏水基团与体相两亲聚合物疏水基团的缔合作用也增强,所形成的油水界面膜黏度增大,界面膜弹性特征增强,界面膜的强度随着两亲聚合物质量浓度的增加而增大。

海上超稠油高温脱水技术研究

某海上超稠油富含胶质和沥青质,原油密度大、黏度高、油水密度差小、原油流动性差,并且油水乳化严重,导致热化学沉降脱水速度慢、脱水周期长。因海上平台空间受限和缺少稀油资源,该超稠油脱水不能采用陆上油田掺混稀油和长时间大罐沉降脱水的常规方法。开展了超稠油高温脱水技术研究,优选出耐高温破乳剂,破乳剂加剂量400 mg/L,在150℃高温、0.6~0.7 MPa压力下沉降4 h,含水15%~65%超稠油的原油含水率均达到<1%,实现了较好的脱水效果。根据室内脱水实验结果,获得海上超稠油高温脱水工艺参数,确定最佳破乳剂加药量、脱水温度和沉降时间,推荐了海上超稠油二段热化学脱水工艺方案。

响应面法优化老化油破乳脱水工艺条件及油水界面的分子动力学模拟

采用不同相对溶解常数的破乳剂对某油田老化油进行破乳脱水,考察了破乳剂种类和用量、助剂种类和用量、温度等因素对脱水率的影响,利用响应面法优化了工艺条件,并通过分子动力学模拟分析了破乳剂对油水界面的作用机制。在单因素实验的基础上,通过响应面法得到老化油破乳脱水的最优工艺条件为破乳剂C用量130 mg/L、温度75℃、助剂NaOH用量0.3%(w),该条件下老化油脱水率达86.57%。主要工艺参数对脱水率的影响从大到小依次为温度、破乳剂用量、助剂用量。分子动力学模拟结果表明,相对溶解常数最大的破乳剂C与老化油体系的界面生成能最高,在油水界面上的扩散系数最大,对老化油的破乳脱水效果最佳。

化学破乳/超声协同处理气田废弃油基泥浆

气田废弃油基泥浆是气田钻井过程中产生的一种成分复杂的乳状液体系,组成复杂且性质稳定、处理难度大,未经处理直接外排对环境危害大。采用化学破乳-超声-离心方法对其进行处理,结果表明:当化学破乳段的体系pH值为5—6,温度为60℃,200 r/min下搅拌时间40 min,AR36型破乳剂的加量8 mg/L;超声强化段的频率25 kHz,功率30 W,超声时间11 min;混凝及离心处理段的阳离子PAM加量60 mg/L,混凝后搅拌时间15 min,离心机转速3000 r/min,离心时间20 min时,油回收率和减量化率均达到94%以上,回收油中含水率降低至0.5%以下,底泥中含油率降低至5%以下。扫描电镜分析表明,在破乳剂/超声的协同作用下,油水固稳定的乳化状态可被打破。

某作业区乳化油的破乳研究与应用

某作业区在生产运行中产生了大量乳化油,多次加药处理的效果不佳,导致乳化油存量积压,严重影响了生产运行和经济效益。本文分析了乳化油的成分和影响因素,发现胶质、沥青质和固体颗粒是导致乳化油的稳定性强的主要原因。为此进行了药剂筛选、反应条件优化以及药剂复配等实验,结果表明,SW-30和乳化油处理剂对该区乳化油的处理效果较好。用SW-30破乳剂进行处理,脱水量最高达到40.5%。将SW-30与杀菌剂复配使用,可进一步提高破乳效果,脱水量从40.5%增加到47%。现场处理乳化油110m^(3),获得了30.47t净化油,有效解决了乳化油的处置问题。

气田废弃油基钻井泥浆处理及循环利用技术研究

对延长气田钻井过程产生的废弃泥浆进行固液分离、油/水循环利用、底泥的固化等处理。研究表明,废泥浆固液分离后,减量化率达82.11%,油回收率和回收油中的含水率分别为94.50%,0.43%;分离出水经过化学氧化—絮凝—过滤处理后,透光率可达98.5%以上,可用于油田工作液的再配制;底泥中的含油率为4.56%,经固化处理后,抗压强度可达15.977 MPa,可用于油气田现场铺设井场或道路,固化体浸出液满足《污水综合排放标准》中的水质要求。

高效破乳剂混凝剂去除兰炭废水中COD的研究

考察破乳剂种类、投加量、pH值以及混凝剂种类、投加量、pH值对兰炭废水COD去除率的影响。结果表明,破乳剂采用脂肪氨聚氧乙烯醚类破乳剂,最佳投加量为3 g/L,pH值为6,COD去除率为34.2%,含油量去除率为62.3%,混凝剂为有机胺混凝剂,最佳投加量为5 mg/L,pH值为6,COD去除率为52%。

芳香性聚氨基酸破乳剂的制备及性能评价

以芳香族氨基酸苯丙氨酸为疏水单体、脂肪族氨基酸天冬氨酸为亲水单体,通过氨基酸N-羧基环内酸酐(NCA)单体的开环聚合(ROP),制备了一系列强极性、高芳香度的聚氨基酸类高分子破乳剂聚苯丙氨酸-聚天冬氨酸苄酯(PPA-b-PBAA),并对产物进行了结构表征和相对分子质量测定。采用瓶试法评价了PPA-b-PBAA的破乳性能,结果表明PPA-b-PBAA具有优秀的低温破乳效率,室温下2 min内能高效分离pH=6.0~11.0、含油量1.0%~10.0%(质量分数)的稀释沥青乳状液。其中,PPA-b-PBAA对1.0%(质量分数)的含油乳化废水的最佳脱水效率达到了99.98%,相应脱出水中残余油含量低至8.50 mg/L。破乳机理研究表明,PPA-b-PBAA加入油水乳状液后能快速迁移到达油水界面,通过与形成油水界面膜的沥青质、胶质相互作用,促使分散油滴絮凝聚并,实现油水分离。量子化学计算和弱相互作用分析表明,破乳剂PPA-b-PBAA分子与形成油水界面膜的主要成分沥青质之间产生的强相互作用有利于加速油水界面膜破裂和分散油滴聚并,是助推PPA-b-PBAA低温高效快速破乳脱水的关键。

改性超支化聚酰胺-胺的合成及高效破乳能力研究

本文通过合成超支化聚酰胺-胺(HPAMAM)作为大分子骨架,使用棕榈酰氯接枝的方式对其进行改性,得到了具有疏水基团的超支化聚酰胺-胺(CPAMAM)。破乳实验结果表明,温度为60℃、沉降时间40min、添加量为120mg·L^(-1)时,CPAMAM比冀东油田目前所用聚醚型破乳剂的破乳效率高20%,且破乳速度更快。对CPAMAM的破乳机理分析结果证明,经过疏水化改性的CPAMAM可通过电荷吸附与大分子增溶剂作用对乳状液中油滴进行聚并,使CPAMAM具有更高的破乳效率。

交联聚醚破乳剂对胜利油田二元驱采出液破乳性能研究

针对胜利油田二元驱采出液存在的破乳困难问题,将脱水型聚醚破乳剂(BP01,TA01和PA08)与清水型聚醚破乳剂(PEI01)交联,制备出交联聚醚破乳剂D-BP,D-TA和D-PA,研究了交联聚醚破乳剂的界面活性和对油水界面膜强度的影响,以及对二元驱采出液的破乳效果。结果表明,在三种交联聚醚破乳剂中,具有超支化结构的D-PA在油水界面上的吸附作用力最强,界面活性最高;D-PA对稀释原油与采出水油水界面膜的影响最大,其吸附在油水界面后形成的界面膜的扩张模量最低。D-PA破乳剂对W/O乳状液的脱水率达到94.4%,对O/W乳状液的除油率达到98.1%。更为重要的是,其能同步处理含W/O和O/W复杂乳状液。D-PA对含W/O和O/W复杂乳状液的综合脱水率高于98%,处理后污水含油低于30 mg/L,游离态聚合物保留率达到了94.8%,油水界面整齐,无乳化中间层,表现出良好的破乳效果。

Sustainable production of high-energy-density jet fuel via cycloaddition reactions

Developing an energy supply-chain based on renewable biomass holds great potential to build a low carbon society.High-energy-density(HED)jet fuel,featuring unique fused/strained cycloalkanes,is of great significance for volume-limited military aircrafts,as their high density and combustion heat can extend flight duration and increase the payload.Therefore,the exploration of biomass-based routes towards HED fuel has drawn much attention over the past decade.Cycloaddition reaction features rapid construction of various carbocycles in an atom-and step-economical fashion.This elegant strategy has been widely applied in the manufacture of sustainable HED fuel.Here we carefully summarize the progress achieved in this fascinating area and the review is categorized by the cycloaddition patterns including[4+2],[2+2],[4+4],and[2+1]cycloadditions.Besides,the energy densities of the as-prepared biofuels and petroleumbased fuels(conventional Jet-A and advanced JP-10)are also compared.This review will provide important insights into rational design of new HED fuel with different ring-types/sizes and inspire the chemists to turn those literature studies into practical applications in military field.

Hierarchical CoFe@N-Doped Carbon Decorated Wood Carbon as Bifunctional Cathode in Wearable Zn-Air Battery

Rechargeable Zn-air batteries(ZAB)have drawn extensive attention due to their eco-friendliness and safety.However,the lack of high-performance and low-cost oxygen redox reactions(OER and ORR)catalysts has become one of the main stumbling blocks in their development.Herein,we successfully fabricate a CoFe nanobubble encapsulated in nitrogen-doped carbon nanocage on wood carbon support(CoFe@NC/WC)via pyrolysis of a novel Prussian blue analog(PBA)/spruce precursor.The hierarchical CoFe@NC/WC catalyst exhibits an excellent potential difference of 0.74 V between the OER potential at 10 mA cm^(-2)and half-wave potential of ORR in 0.1 M KOH,comparable to recently reported preeminent electrocatalysts.Further,CoFe@NC/WC shows outstanding electrochemical performance in liquid ZAB,with a peak power density of 138.9 mW cm^(-2)and a specific capacity of 763.5 mAh g^(-1).More importantly,a bacterial cellulose nanofiber reinforced polyacrylic acid(BC-PAA)hydrogel electrolyte shows ultrahigh tensile-breaking stress of 1.58 MPa.In conjunction with the as-prepared CoFe@NC/WC catalyst,BC-PAA-based wearable ZAB displays impressive rechargeability and foldability,and can power portable electronics,such as electronic timer and mobile phone,in bent states.This work provides a new approach toward high-activity and low-cost catalysts for ZAB.

GD油田采出液高效破乳剂研制及应用效果

GD油田开发进入中后期,伴随着弱碱三元复合驱的开采,采出液含水量、含药量不断升高,集输过程中油水易乳化,不易分离。针对这一问题,开展高效破乳剂的室内评价实验。基于正交设计实验,筛选出高效破乳剂,并依据筛选得出的最佳复配比、最佳处理温度区间,制定出适应GD油田弱碱三元复合驱采出液处理的工艺方案。结果表明,破乳剂DQZY-2C和LJZ-425对采出液具有良好的破乳效果,在50℃条件下沉降90 min脱水率均达90%以上;进一步复配后,在2∶1复配比时,二者协同作用的脱水率达93%以上;随着处理温度和体系含水率的升高,破乳效果逐渐增强;现场实施应用1年后,实现了脱水处理后净化油含水率≤1.0%,水中含油质量浓度≤1000 mg/L,有效解决了GD油田弱碱三元采出液破乳问题。

高酸原油选择适合破乳剂的实验分析研究

现有破乳剂均有一定的局限性,对于特高含水的水包油型乳状液,存在脱水率低、脱水温度高、脱水速度慢等缺点,因此,针对不同地区的不同原油选择适合的破乳剂有着重要意义。基于此,考察了影响破乳剂性能的各种反应条件,在实验温度90℃和用量为10×10^(-6)破乳剂的条件下,通过瓶试脱水法,考察评价石油磺酸盐对破乳剂的影响。研究表明,石油磺酸盐明显降低了破乳剂在高酸原油中破乳脱水作用。

海上石油生产过程中破乳剂自动化投加控制方法

破乳剂自动化投加控制是海上石油自动化生产核心,但是现行方法控制效果较差,在实际应用中不仅超投量比较高,而且石油生产合格率比较低,针对现行方法存在的不足和缺陷,提出海上石油生产过程中破乳剂自动化投加控制方法。结合FPSO现场仪表数据的特征,综合应用中位值滤波算法对石油生产数据滤波处理,利用学习模型估计油处理量及生产水量,利用专家经验模型确定破乳剂投加量,并对破乳剂投加时延控制,实现海上石油生产过程中破乳剂自动化投加控制。经实验证明,设计方法破乳剂超投量不足0.1%,海上石油生产合格率在99%左右,可以实现对破乳剂自动化投加精准控制。

铝盐破乳剂的优化及其对拉丝油乳化液破乳效果的研究

以单一硫酸铝作为破乳剂,对自配的不同含油量的拉丝油乳化液进行破乳,测定了破乳后水层的COD、浊度、pH,并计算了COD、浊度去除率。然后分别考察了单独使用硫酸铝以及使用硫酸铝-聚合氯化铝复合破乳剂对实际生产中得到的中、高含油量拉丝油乳化废液进行破乳的效果。结果表明:在几种破乳剂中,使用硫酸铝对自配的拉丝油乳化液进行破乳有较好的效果,在破乳后,COD、浊度去除率可以分别达到70%、60%。单独使用硫酸铝对中、高含油量的拉丝油乳化废液进行破乳的效果不佳,乳化废液的油水不分层,而硫酸铝-聚合氯化铝复合破乳剂在硫酸铝和聚合氯化铝同时加入时则具有较好的效果,在搅拌器转速为500 r/min,搅拌总时间为10 min,搅拌后静置时间为30 min的条件下,中含油量废液破乳后水层的COD、浊度去除率可分别达到98%、91%,高含油量废液的COD、浊度去除率可分别达到99%、97%以上。