Asphaltene and smaller aromatic molecules tend to form linear nanoaggregates in bitumen. Over the years bitumen undergoes chemical aging and during this process, the size of the nanoaggregate increases. This increase is associated with an increase in viscosity and brittleness of the bitumen, eventually leading to road deterioration. This paper focuses on understanding the mechanisms behind nano...

We study chemical aging in "Cooee bitumen" using molecular dynamic simulations. This model bitumen is composed of four realistic molecule types: saturated hydrocarbon, resinous oil, resin, and asphaltene. The aging reaction is modelled by the chemical reaction: "2 resins → 1 asphaltene." Molecular dynamic simulations of four bitumen compositions, obtained by a repeated application of the aging ...

formation of asphaltene deposition during oil production, processing and synthesis is known as a fundamental problem of petroleum reservoir worldwide. asphaltene is a petroleum fraction that can lead to increasing the operating costs in these industries. variations in operational pressure, temperature and fluid composition are generally the significant cause of asphaltene precipitation. in this...

asphaltene instability is one of the major problems in gas injection projects throughout the world. numerous models have been developed to predict asphaltene precipitation; the scaling equation is an attractive tool because of its simplicity and not involving complex properties of asphaltene. in this work, a new scaling model is presented to account  for asphaltene precipitation due to gas inje...

Despite recent advances in spectroscopic techniques, there is uncertainty regarding the nature of the carbonyl groups in the asphaltene and resin fractions of crude oil, information necessary for an understanding of the physical properties and environmental fate of these materials. Carbonyl and hydroxyl group functionalities are not observed in natural abundance 13C nuclear magnetic resonance (...

Flocculation can be used in turbulent environments resulting in floc breakage due to shearing. The degree of re-flocculation relates directly to product quality and process efficiency. This study aimed at looking for alternatives to improve the re-flocculation ability of aggregates when polyelectrolytes (PEL) are used as flocculation agents. Moreover, because branched PEL have proved previously...

Formation of asphaltene deposition during oil production, processing and synthesis is known as a fundamental problem of petroleum reservoir worldwide. Asphaltene is a petroleum fraction that can lead to increasing the operating costs in these industries. Variations in operational pressure, temperature and fluid composition are generally the significant cause of asphaltene precipitation. In ...

Asphaltene instability is one of the major problems in gas injection projects throughout the world. Numerous models have been developed to predict asphaltene precipitation; The scaling equation is an attractive tool because of its simplicity and not involving complex properties of asphaltene. In this work, a new scaling model is presented to account  for asphaltene precipitation due to gas ...

In this study, asphaltene deposition from crude oil has experimentally and theoretically been studied using a test loop and an accurate temperature monitoring during a laminar flow. The effects of oil velocity and surface temperature on the thickness of asphaltene deposition were investigated. The results show that asphaltene deposition thickness increases by increasing surface temperature. As ...

during estuarine mixing of fresh water with saline water and due to the flocculation process, aportion of dissolved metals come into particulate phase, and the dissolved load decreases. this process plays an important role in self-purification of heavy metals in rivers. in this study, flocculation of cu, mn, ni, pb and zn during mixing of cheshme-kileh river water with caspian sea water has bee...