The interaction of waxes with pour point depressants

Paraffin wax deposition from crude oils at low temperature is one of the serious and long-standing problems in petroleum industry. Addition of pour point depressants (PPD) has been proved to be an efficient way to inhibit wax deposition. The influence of PPD on wax precipitation at low temperature was investigated. The amount and composition of wax precipitated from paraffin solutions with and without PPD at different temperatures were studied by high speed centrifuge and gas chromatography (GC), respectively. The interactions between waxes and PPD were investigated by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The results showed that PPD do not completely prevent the wax from precipitating, but just shift the precipitation toward a lower temperature. This conclusion was identified from the analysis of the amount and composition of precipitated wax as well as the transition temperatures and energies of wax. It was shown that this effect is due to the structure of wax is partly transformed from orthorhombic into hexagonal form by PPD.     

Some biosurfactants used as pour point depressant for waxy egyptian crude oil

Two bacteria (B1 and B2) were isolated from soil-contaminated sites. The surface properties of biosurfactants produced by these bacteria were determined. These bacteria were given a good resistance to NaCl concentration up to 20%. The surface activity was detected with maximum value at pH7 with B1, whereas B2 was not affected by the change pH (3–12). The biosurfactants of these bacteria were added as a mixture or individual to crude oil given the good result in reducing the pour point. The infrared spectrum of wax or asphaltene fractions of Egyptian crude oil untreated and treated with biosurfactants was detected.     

降凝剂乙烯-醋酸乙烯酯共聚物乳液的制备

采用适当溶剂溶解乙烯-醋酸乙烯酯共聚物(EVA),在复合乳化剂存在下进行乳化制备水包油乳液,最后加入转向剂反转,得到固液高度稳定的EVA分散体系。较佳工艺条件为:复合乳化剂为m(OP)∶m(AOS)=1∶5,m(EVA)∶m(乳化剂)=2∶1;乳化温度80℃,搅拌转数700r/min,乳化时间30min,冷却后加入一定量转向剂,静置分层,分出水后制得EVA乳液。该乳液具有稳定性高、分散性好的优点,在梁南混油上使用,持续降凝幅度为11℃。     

马来酸酐/苯乙烯/醋酸乙烯酯三元共聚衍生物的制备及对柴油低温流动性的影响

以马来酸酐、苯乙烯、乙酸乙烯酯、十八醇为原料，采用三元共聚，通过醇解，制备了马来酸酐／苯乙烯／醋酸乙烯酯三元共聚十八酯（OMSV）。将其作为柴油降凝剂，用于改善柴油低温流动性。通过对加入OMSV的燕山石化催化加氢0#柴油的凝点和冷滤点的实验室评价，考察了OMSV的降凝效果。结果表明，当OMSV在柴油中的质量分数为0．15％时，燕山石化催化加氢0#柴油的凝点降低31℃，冷滤点降低11℃。     

柴油降凝剂MAVA的合成与性能研究

以马来酸双酯和醋酸乙烯酯为单体,聚合制得二元聚合物MAVA。该聚合物作为柴油降凝剂可以降低几种柴油的冷滤点和凝点：0．09％MAVA可降低乌石化0号柴油冷滤点2℃,凝点7℃;可降低独石化0号柴油冷滤点3℃,凝点8℃;对吐哈0号、-10号、-20号柴油均有较好的降滤、降凝效果。     

原油降凝剂在齐-青输油管道上的应用

青岛石油化工厂 3Mt/a输油能力的原油管道 ,由于受输量、地温和首、末站储罐等条件的限制 ,不能采取长输管道热输的方式输送白虎、陆比等高凝点原油 ;BEM Q原油降凝剂在管道上应用后 ,原油凝点降低了 16～19℃ ,15℃时原油粘度仅 9.7～ 12mPa·s ;大大改善了原油的流动性 ,实现了高凝原油的降凝输送。     

Salen-Ni配合物催化合成聚甲基丙烯酸十二酯降凝剂

以甲基丙烯酸十二酯为原料、不对称Salen-Ni-Salicylaldehyde配合物/偶氮二异丁腈(AIBN)为催化体系,在甲苯溶剂中,通过溶液聚合,在Schlenk装置上合成了聚甲基丙烯酸十二酯(PLMA)。采用红外光谱、核磁共振氢谱表征了聚甲基丙烯酸十二酯的结构,利用凝胶渗透色谱(GPC)测定了聚合物的相对分子质量及其分布,并对其降凝性能进行了评价。结果表明：当助催化剂(偶氮二异丁腈(AIBN))与催化剂(Salen-Ni-Salicylaldehyde)的摩尔比为3∶1反应温度为110 ℃、反应时间为8 h、单体与催化剂的摩尔比为2400∶1时,催化剂的活性为4.087 ×10⁴ g/(mol·h)。合成的聚合物数均相对分子质量范围为2.563×10⁴~10.527×10⁴。当油品中PLMA加剂量为1.5%(质量分数)时,可将300~340 ℃柴油馏分和380~400 ℃润滑油馏分的凝点分别降低5~10 ℃和2~6 ℃。当300~340 ℃柴油馏分中添加2.0%(质量分数)的PLMA降凝剂时,凝点可降低12 ℃,降凝效果较好。     

高凝原油降凝剂的合成及复配性能研究

根据高凝原油组成以及降凝剂对原油的感受性确定了合成降凝剂的高碳醇的碳数,以丙烯酸和C18～C22混合醇为原料,合成丙烯酸高碳醇酯,得到三种聚合物:丙烯酸酯自聚物(AM),丙烯酸酯-醋酸乙烯酯(AMV)和丙烯酸酯-醋酸乙烯酯-苯乙烯(AVS)。比较了三种聚合物的降凝效果,选出AVS考察其合成条件并且与常用降凝剂EVA进行复配。实验结果表明:丙烯酸酯、醋酸乙烯酯、苯乙烯最佳配比为1∶1∶0.5,引发剂用量为1.2%,单体质量浓度30%,反应时间为7h时,三元共聚物AVS与EVA的复配物CPR可以使魏岗原油凝固点降低10℃,防蜡率达到40.62%。     

高效降凝剂的合成与改性

在氮气保护下,以摩尔比为9∶5∶1的丙烯酸十八酯、马来酸酐、苯乙烯为单体,甲苯为溶剂,过氧化二苯甲酰为引发剂,在80℃下合成了丙烯酸十八酯-马来酸酐-苯乙烯三元共聚物(降凝剂A);在甲苯溶剂中,120℃下分别用脂肪醇/脂肪胺对降凝剂A进行醇解/胺解,合成了降凝剂B/降凝剂C。考察了降凝剂A用于大庆原油降凝时所需的最佳引发剂用量;在大庆原油中分别加入0.5%(w)的降凝剂A,B,C,考察了不同降凝剂对大庆原油的降凝和降黏效果。实验结果表明,合成降凝剂A的最佳引发剂用量为1.0%(基于总单体质量);降凝剂C在降凝和降黏方面都优于降凝剂A和降凝剂B,使用降凝剂C时大庆原油倾点降幅最高达14℃、黏度最大降幅为56.78%;脂肪醇/脂肪胺的碳数影响降凝剂对原油的降凝和降黏效果。     

柿竹园萤石综合回收浮选抑制剂的研究

采用研制的组合新型萤石抑制剂NO3进行柿竹园多金属矿萤石浮选试验,对含CaF226.55%的强磁选非磁性产物,获得的萤石浮选精矿含CaF297.39%、SiO21.06%、CaCO30.68%,CaF2回收率72.41%。本文对NO3在萤石浮选中的抑制作用及其效果进行了讨论和比较。