Insights into the Self-Aggregation of Porphyrins and Their Influence on Asphaltene Aggregation

Abstract

Despite the studies on asphaltene aggregation throughout few decades, the formation of asphaltene aggregates and subsequent deposition are still the biggest challenges in the oil industry. Especially, the role of porphyrins existing in oil naturally on asphaltene aggregation is not completely understood due to asphaltene’s and porphyrin’s special structures. Herein, we investigated the influence of tetraphenylporphyrin (TPP), nickel tetraphenylporphyrin (NiTPP), and vanadium tetraphenylporphyrin (VOTPP) on asphaltene aggregation by a multiscale approach, which provides an in-depth understanding of the role of porphyrins on asphaltene aggregation. UV–vis spectroscopy and fluorescence spectroscopy were performed to examine the self-aggregation of TPP, NiTPP, and VOTPP and the influence of porphyrins on the aggregation of asphaltene. The changes of stacking structures, microscopic structures, and particle size distributions of co-aggregates of asphaltenes with porphyrins were analyzed in detail via X-ray diffraction, inverted fluorescence microscopy, and granulometric distribution, respectively. The characterization results indicated that the aggregation ability of the porphyrins (TPP, NiTPP, and VOTPP) was stronger than that of asphaltene and porphyrins can promote the aggregation of asphaltene, which leads to the increase of the average aromatic sheet number, aggregation morphology, and particle size of asphaltene aggregates. Based on experimental analysis, the possible mechanism by which porphyrins promoted asphaltene aggregation was elucidated. This research provided new insights into the aggregation and disaggregation of asphaltenes.

Porphyrin Catecholate Iron-Based Metal–Organic Framework for Efficient Visible Light-Promoted One-Pot Tandem C–C Couplings

“…6,7 However, outside of the biological systems, self-aggregation tendencies and/or selfdestructive effects are well-known in porphyrins. 8,9 It has been approved that porphyrin formulation in a porous structure can remarkably stabilize the structure and inhibit the drawbacks mentioned above.…”

“…Porphyrins and their analogues (such as chlorophyll and hemoproteins) are frequently observed in nature, which perform various important biological processes. As a result, they have been enormously investigated in the artificial synthesis and application of porphyrins as attractive materials in different arrays such as drug delivery, medical, electronics, optoelectronics, and photonics. , However, outside of the biological systems, self-aggregation tendencies and/or self-destructive effects are well-known in porphyrins. , It has been approved that porphyrin formulation in a porous structure can remarkably stabilize the structure and inhibit the drawbacks mentioned above.…”

Fine-Tuning Simulation of the ESR Spectrum─Sensitive Tool to Identify the Local Environment of Asphaltenes In Situ

“…It is known that, at concentrations of 5 wt %, most asphaltenes are present in the toluene solution as part of aggregates . A number of studies have shown that vanadyl porphyrins affect the formation of aggregates; , however, it is still not entirely clear due to which interactions this occurs. In another paper, it has been shown that π–π stacking interaction between vanadyl porphyrins and nonpolar aromatic molecules does not lead to the formation of their stable associates.…”

Resin–Paraffin Aggregation Processes in Waxy Oil Revealed by Vanadyl Porphyrin Spin Probe

“…Vanadyl porphyrins can either promote or inhibit the self-assembly of asphaltene nanoaggregates depending on their size and the presence of peripheral functional groups. 8,34 The degree of such an influence depends on how compact the monomer packing is in the initial asphaltene aggregates. 8 Thus, the formation of asphaltene−resin−paraffin deposits in the presence of metal-porphyrins is a complex all-inclusive problem.…”

“…The content of vanadium can reach almost 0.2 wt % and nickel 0.02 wt %, the presence of which in feedstock is a serious challenge for oil refining. , Issues related to their distribution in resin and asphaltene fractions and the impact on the processes of asphaltene aggregation and paraffin crystallization are important for developing an optimal strategy not only for oil refining technologies but also for minimizing the damage associated with the formation of deposits during oil production and transportation. Vanadyl porphyrins can either promote or inhibit the self-assembly of asphaltene nanoaggregates depending on their size and the presence of peripheral functional groups. , The degree of such an influence depends on how compact the monomer packing is in the initial asphaltene aggregates …”