Extraction of pyridine using systems based on water-soluble polymers

In the process of using hydrocarbon fractions containing a large amount of nitrogenous compounds, nitrogen oxides are released into the atmospheric air, which have a negative impact on the environment and human health. The traditional cleaning method is treatment with a 25% sulfuric acid solution and subsequent hydrotreating. However, this process becomes disadvantageous due to its inability to achieve ultra-low concentrations of nitrogen-containing compounds (<10 ppm). Extraction using non-toxic and environmentally friendly water-soluble polymers is a promising alternative compared to traditional methods. This work presents the dependence of the interphase distribution of pyridine on the composition of extraction systems based on water-soluble polymers. According to the results of the study, it was found that polyethylene glycol-400, polypropylene glycol-425 and methyl ether of polyethylene glycol-350 exhibit effective extraction properties in relation to pyridine and extract it by 90.95%, 90.33% and 87.82% in one extraction stage, respectively. It was also found that the use of two-phase aqueous systems based on water-soluble polymers in the process of extracting pyridine is promising.

Achieving optimal micro-explosions in stable emulsions by adding water-soluble polymers

The emulsified feedstock technique is to improve the performance of products by using the micro-explosion phenomenon of emulsion. However, an obstacle to some applications of this technology is the contradiction between emulsion stability and micro-explosion intensity. For the first time, adding water-soluble polymers was proposed to solve this problem. Two polymers of xanthan gum (XG) and nonionic polyacrylamide (NPAM) were investigated and the results show that micro-explosions have five forms. As one of these five forms, the intensity of optimal micro-explosion is three orders of magnitude higher than other forms, and adding 0.5% XG increases the probability of optimal micro-explosion from 0% to 60% due to the low surface activity, strong thickening and pseudoplasticity of XG solutions. By contrast, NPAM does not promote micro-explosion because of its strong surface activity. Finally, a new mechanism for micro-explosions related to surface tension, interfacial tension and viscosity is proposed.

Improved Release of a Drug with Poor Water Solubility by Using Electrospun Water-Soluble Polymers as Carriers

In an attempt to improve the solubility of valsartan, a BCS II drug, fibers containing the drug were prepared from three water-soluble polymers, hydroxypropyl-methyl-cellulose (HPMC), polyvinyl-pyrrolidone (PVP), and polyvinyl-alcohol (PVA). Fiber spinning technology was optimized for each polymer separately. The polymers contained 20 wt% of the active component. The drug was homogenously distributed within the fibers in the amorphous form. The presence of the drug interfered with the spinning process only slightly, the diameters of the fibers were in the same range as without the drug for the HPMC and the PVA fibers, while it doubled in PVP. The incorporation of the drug into the fibers increased its solubility in all cases compared to that of the neat drug. The solubility of the drug itself depends very much on pH and this sensitivity remained the same in the HPMC and PVP fibers; the release of the drug is dominated by the dissolution behavior of valsartan itself. On the other hand, solubility and the rate of release were practically independent of pH in the PVA fibers. The different behavior is explained by the rate of the dissolution of the respective polymer, which is larger for HPMC and PVP, and smaller for PVA than the dissolution rate of the drug. The larger extent of release compared to neat valsartan can be explained by the lack of crystallinity of the drug, its better dispersion, and the larger surface area of the fibers. Considering all facts, the preparation of electrospun devices from valsartan and water-soluble polymers is beneficial, and the use of PVA is more advantageous than that of the other two polymers.

Влияние полимеров и сополимеров олефинов на турбулентное течение углеводородных жидкостей

Drag reducing additives (DRA) are widely used to increase the pipeline capacity in oil and refined products transit. Introducing DRA at a rate of 1–5 ppm results in considerable lowering of pumping energy. To predict the capability of concerned polymer as a DRA we tried to give an effectiveness theoretical justification in terms of its chemical composition. It was shown that the most effective oil-soluble polymers relate to higher poly(1-alkenes) of superhigh molecular weight (M > 106). Additionally, the nature of the solvent is of importance. 1-Hexene polymerization in the presence of Zigler–Natta catalysts gives a super high molecular weight polymer which is the most effective drag reducer among the higher poly(1-alkenes). But if environment provide some limitation in poly(1-hexene) solubility, such as temperature lowering, or asphaltene content increasing the (co)polymers of 1-octene and 1-decene become the best. Для интенсификации перекачки нефти и нефтепродуктов по магистральным трубопроводам в настоящее время широко используют противотурбулентные присадки, при введении которых в турбулентный поток в предельно малой концентрации (C = 1–5 г/м3) наблюдается уменьшение энергетических затрат на транспортировку углеводородной жидкости. С целью прогнозирования перспективы промышленного использования присадки той или иной химической природы в настоящей работе представлено теоретическое обоснование и экспериментальное подтверждение эффективности различных полимеров. Установлено, что из всех нефтерастворимых полимеров наилучшими противотурбулентными свойствами обладают высшие поли-α-олефины со сверхвысокой молекулярной массой (Мr > 1·106). Также выявлено влияние компонентного состава и термодинамического качества растворителя на эффективность присадок, причем эти факторы следует рассматривать в совокупности. Например, цепь полимера, обогащенная гексеном, при прочих равных условиях синтеза имеет большую молекулярную массу, и такой полимер в хорошем растворителе снижает сопротивление лучше своих аналогов. Тем не менее, если превалируют факторы, ограничивающие растворимость полигексена (низкая температура, обилие асфальтенов в нефти), предпочтительными оказываются полимеры и сополимеры октена и децена, имеющие более низкую температуру стеклования.

Associative Microgels, New Self Adaptive Systems to Control Fluid Loss in Well Cementing

Fluid loss control additives are critical constituents in a cement slurry formulation to ensure even cement placement and ultimately satisfactory zonal isolation. Many technological options have been developed over the past decades to design fluid loss control additives for cementing. The most popular technologies as of today are either based on water soluble polymers or colloidal particles like latexes. As an alternative approach, in this paper we introduce a new technology based on associative or "sticky" microgels. These microgels are able to associate with one another at elevated concentration but, more surprisingly, are also able to associate under shear in the dilute regime during a filtration process. As a consequence these additives demonstrate outstanding performance as fluid loss control agents. This study focuses first on standard API filtration tests using sticky microgels, and on how their behavior in application differs from traditional systems, in particular water-based soluble polymers such as cellulosic derivatives or synthetic polymers. Our investigations then focus on the working mechanism of the microgel system by analyzing adsorption on the cement surface, rheology, and filter cake structure using Mercury Intrusion Porosimetry (MIP). Finally the behavior of sticky microgels in model filtration tests is explored with either filtration against porous ceramic discs or using microfluidic chips allowing a direct visualization of microgels during filtration. This study demonstrates that associative microgels are not controlling fluid loss through a simple size match between particles and pores within the filter cake but rather through shear-induced aggregation. Microfluidic observations reveal that aggregation occurs irreversibly as microgels are forced through the pores as the filtration process occurs. The shear-induced associated gels are particularly effective at reducing dramatically the filter cake permeability and allowing gas migration control. Interestingly the shear-induced aggregation of associative μgels seems to confer self-adaptive properties of the fluid loss additives with respect to the pore network to be clogged. Indeed, formation of shear aggregated gels larger than the individual microgels can be used to limit fluid loss even if the pore sizes are much larger than the individual microgels.

DEVELOPMENT OF AN EFFECTIVE TECHNOLOGY FOR OBTAINING A FASTENING BASED ON OXIDIZED STARCH AND SYNTHETIC WATER-SOLUBLE POLYMERS

In the article results of suitable the technology of reception of thickeners for use at stuffing of fabrics on the basis of natural and synthetic polymers received from local source of raw materials are shown. As have shown results of researches, use of polymeric systems on the basis of the oxidised starch as thickener leads to improvement operational and coloristic characteristics of stuffed fabrics.