Evaluation of the correlation between wax type and structure/behavior of the pour point depressant

Oliveira, Lize M. S. L.; Nunes, Rita C. P.; Melo, Isis C.; Ribeiro, Ygor L. L.; Reis, Leidiane G.; Dias, Júlio Cesar; Guimarães, Regina C. L.; Lucas, Elizabete F.

doi:10.1016/j.fuproc.2016.04.024

Cited by 48 publications

(24 citation statements)

References 22 publications

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“…This section first analyzes the pour point results promoted by the action of the unmodified EVA copolymers de EVA: EVA10, EVA9.7, and EVA6.5. As expected and reported in a previous study regarding model systems of commercial paraffins in toluene, the pour points of oils with low pour points were more easily reduced: the pour point of sample AP04 was reduced from +6 to −9 °C with the addition of only 100 ppm of EVA10. Also having a similar result to that obtained for the model system, the copolymer EVA10 presented the best performance.…”

Section: Resultssupporting

confidence: 87%

“…An interesting comparison can be made between samples EVA9.7(7.7VAc/0.4OH/1.6C10) and EVA10(8.0VAc/0.7OH/1.3C10), which differ in molar mass (EVA10 having higher molar mass than EVA9.7), as well as hydrolysis degree and content of C10 incorporated, since EVA10 has almost twice the hydrolysis content as EVA9.7. The modified EVA10, even though having a higher molar mass, as indicated by the results with the model paraffin systems that contributes to better performance, produced much less pronounced reductions in the pour point than the modified EVA9.7. This suggests that the reduction of the content of pendant hydrocarbon chains associated with an increase in the hydrophilic part diminishes the performance of the additive.…”

Section: Resultsmentioning

confidence: 83%

“…The assays were carried out in triplicate. The error calculated for these analyses took in account also the uncertainties of the thermometer (0.6 °C) and the balance (0.0002 g) …”

Section: Methodsmentioning

confidence: 99%

“…These structures have in common relatively long hydrocarbon chains (the hydrophobic segment can interact better with the hydrocarbon chains of the paraffin) and polar groups, OCO, (responsible for inhibiting the aggregation of the wax crystals formed). Although it is already known that the performance of the polymeric additive is related to wax content and molar mass, the correlation between polymer performance and its chemical structure is not established yet.…”

Section: Introductionmentioning

confidence: 99%

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Influence of the chemical structure of additives poly(ethylene‐co‐vinyl acetate)‐based on the pour point of crude oils

Oliveira

Nunes

Pessoa

et al. 2020

J of Applied Polymer Sci

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One of the methods to prevent wax precipitation, during petroleum production, transport, and refining, is the use of polymer additives that can reduce the oil pour point. However, no single additive work for all types of crude oil and this relation is not yet well known. In this study, a family of polymers based on poly(ethylene-co-vinyl acetate), containing hydroxyl groups and long pendant hydrocarbon chains (from C6 to C18), were synthesized and characterized by H 1 nuclear magnetic resonance and solubility test. Four crude oil samples containing different amounts and size distribution of the wax were used. The additive's action is favored by higher contents of iso + cycloalkanes and lower contents of n-paraffins with larger chain sizes. The presence of the CH 3 COO group in the copolymers promoted the lowering of the pour point, supported by a low OH concentration and the presence of a long pendant hydrocarbon chain: the best results were obtained with C10 and C12 chain lengths.

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Section: Resultssupporting

confidence: 87%

Section: Resultsmentioning

confidence: 83%

“…The assays were carried out in triplicate. The error calculated for these analyses took in account also the uncertainties of the thermometer (0.6 °C) and the balance (0.0002 g) …”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Influence of the chemical structure of additives poly(ethylene‐co‐vinyl acetate)‐based on the pour point of crude oils

Oliveira

Nunes

Pessoa

et al. 2020

J of Applied Polymer Sci

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“…Majority of existing flow improvers are high molecular weight polymeric compounds [30]. However, high cost of pour point depressant formulations, selectivity of pour point depressants to crude oils and negative environmental impact of oil additives have led to increased interest in developing cheaper eco-friendly flow improvers [32,34,36].…”

Section: Introductionmentioning

confidence: 99%

Pour point depression and flow improvement of waxy crude oil using polyethylene glycol esters of cashew nut shell liquid

et al. 2021

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Wax crystallization and deposition is a major flow assurance problem in production and transportation of waxy crude oil. Conventional flow improvers are mainly high molecular weight synthetic polymers, many of which are eco-toxic. Bio-based flow improvers derived from natural products are promising as inexpensive, eco-friendly alternatives to existing products. In this study, natural cashew nut shell liquid (CNSL) extracted from waste shells of Anacardium occidentale was esterified with polyethylene glycol (PEG). CNSL derivative reduced the pour point of waxy crude oil by 12 °C at 1000 ppm. The effects of CNSL derivatives on wax crystal morphology and micro-structure were studied by cross-polarized microscopy. Micrographs were processed and analyzed with ImageJ software. Addition of CNSL derivatives to oil resulted in changes in wax crystal morphology and micro-structure evidenced by a reduction in average crystal Feret diameter and aspect ratio and increase in boundary fractal dimension, indicative of formation of increasing number of smaller, rounder crystals. Effect of the additives on flow properties of the waxy oil was determined using a co-axial cylinder rotational viscometer. Dynamic viscosity of oil at shear rate of 17 s−1 was reduced by 79.7–90.5%. CNSL-PEG esters show good prospects as low-cost additives for production, storage and pipeline transportation of waxy crude oil.

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The effect of monoethylene glycol on the stability of water‐in‐oil emulsions

et al. 2021

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It is important from both a strategic and economic standpoint to study the mechanism of formation of water/oil emulsions, to predict their increase of viscosity with respect to that of the crude oil, and to obtain information about the stability vs separation of these substances (since their presence can impair oil processing and distribution). The objective of this work was to ascertain the influence of monoethylene glycol (MEG) on these parameters and its action mechanism. The addition of MEG in different proportions in the oil emulsions significantly changed the flow curve of the emulsion, passing from a quasi‐Newtonian one to a shear thinning behaviour. Besides this, when MEG was present at low concentrations, the demulsification process was slow and an increase in concentration made the emulsions more stable than samples containing the same aqueous phase proportion. Under the conditions studied, the addition of MEG did not reduce the quantity of the aqueous phase separated compared to the emulsions free of MEG, but significantly delayed the demulsification process. Rheology provided important information regarding the phase separation process of the aqueous phase in oil phase emulsions, and dynamic testing suggested that the most relevant effect of the addition of MEG is an increase of the emulsion elasticity that can be correlated with the increase in the emulsion stability observed by bottle test and Turbiscan.

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Evaluation of the correlation between wax type and structure/behavior of the pour point depressant

Cited by 48 publications

References 22 publications

Influence of the chemical structure of additives poly(ethylene‐co‐vinyl acetate)‐based on the pour point of crude oils

Influence of the chemical structure of additives poly(ethylene‐co‐vinyl acetate)‐based on the pour point of crude oils

Pour point depression and flow improvement of waxy crude oil using polyethylene glycol esters of cashew nut shell liquid

The effect of monoethylene glycol on the stability of water‐in‐oil emulsions

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