A study of asphaltene-resin interactions

Abstract

Foi realizado um estudo para investigar a interação entre asfaltenos (em soluções de tolueno) e resinas (em soluções de n-heptano). Para entender melhor o tipo de interação entre essas frações, quantificou-se o consumo de resina quando asfaltenos (dissolvidos em tolueno) foram precipitados com uma solução de n-heptano contendo resina. Os resultados indicaram que a precipitação de asfaltenos ocorre juntamente com a redução na concentração de resina. Os perfis das isotermas de ligação indicaram que a saturação ocorreu em um caso, em quanto que o efeito cooperativo com posterior platô inicial foi observado para duas outras amostras. Estes resultados confirmaram a hipótese de que resinas podem adsorver em asfaltenos, mas não podem evitar floculação e precipitação de asfaltenos. Além disso, resultados de microcalorimetria sugeriram que a resina e asfalteno interagem por forças fracas de van der Waals. Estes resultados estão em contraste com a escola de pensamento predominante desde a década de 1940 que advoga que as resinas podem peptizar e estabilizar asfaltenos.A study was carried out to investigate the interaction between asphaltenes (in toluene solutions) and resins (in n-heptane solutions). To better understand the type of interaction between these fractions, it was quantified the resin uptake when asphaltenes (dissolved in toluene) were precipitated by a resin-containing n-heptane solution. These results indicated the asphaltene precipitation occurs together with a reduction in the resin concentration. The binding isotherm profiles indicated that saturation occurred in one case, while collective association following an initial plateau was observed for the other two samples. These results confirmed the hypothesis that resins can adsorb on asphaltenes but cannot prevent asphaltenes from flocculating and precipitating. Furthermore, microcalorimetric results suggested that the resin and asphaltene interact by weak van der Waals forces. These results are in stark contrast with the school of thought prevalent since the 1940s that resins can peptize and stabilize asphaltenes.

A theoretically modified PC-SAFT equation of state for predicting asphaltene onset pressures at low temperatures

“…Fluids 5 and 9 were also chosen to predict the sensibilities of AOPs to MWres. In this case, MWres values of 500, 600, 700, and 800 Da were used, which are consistent with measurements reported in the literature [156], [160].…”

“…The resin molecular weight (MWres) was initially set to 600 Da, while the asphaltene molecular weight (MWasph) was modified to study the AOPs´ sensibility, as predicted for both PC-SAFT models. Thereafter, for the same purpose, MWres was varied between 500 and 800 Da [156], [160]. did not eliminate MUCSTs but moved MUCSTs to lower temperatures.…”

Interfacial sciences in unconventional petroleum production: from fundamentals to applications

“…These components play a central and often contradicting role in the production and utilization of unconventional oils. [45][46][47][48][49][50] Recently, characterizing the chemistry of resins and asphaltenes as well as the interactions between these two fractions [51][52][53][54][55][56][57] has undergone a revitalization period, although many controversies and debates are yet to be resolved.…”

Mechanism of an asphaltene inhibitor in different depositing environments: Influence of colloid stability

“…Asphaltene inhibitors are typically amphiphilic surfactant or dispersant-type molecules. Reported inhibitors include mono-substituted esters of glycerol (Breen, 2001), esters of sorbitan (Spans) (Breen, 2001), alkylamines (Subramanian et al, 2018b), alkylphenols (Chang and Fogler, 1994;Goual et al, 2014;Rogel and León, 2001;Wei et al, 2015), alkylbenzene sulfonates such as dodecylbenzyl sulfonic acid (Benayada and Rahmani, 1999;Chang and Fogler, 1994;Goual and Sedghi, 2015;León et al, 1999;Liu et al, 2015;Wei et al, 2015) and polymeric dispersants such as polyisobutylene succinimides (PIBS) (Breen, 2001;Hashmi et al, 2010;Manek and Sawhney, 1996;Marques et al, 2012;Wang et al, 2017). It has been theorised that resins, which are naturally occurring in crude oil, can stabilise asphaltenes (Acevedo et al, 1995;Kawanaka et al, 1989;Leontaritis and Mansoori, 1987;Pfeiffer and Saal, 1939;Porte et al, 2003;Soorghali et al, 2014), hence chemists may look to utilise these chemistries by finding synthetic analogues or by recycling / reintroducing natural resins (Khvostichenko and Andersen, 2010;Speight, 2004).…”