1: Magnetic Particles: Preparation, Properties and Applications: M. Ozaki. 2: Maghemite (gamma-Fe2O3): A Versatile Magnetic Colloidal Material C.J. Serna, M.P. Morales. 3: Dynamics of Adsorption and Oxidation of Organic Molecules on Illuminated Titanium Dioxide Particles Immersed in Water M.A. Blesa, R.J. Candal, S.A. Bilmes. 4: Colloidal Aggregation in Two-Dimensions A. Moncho-Jorda, F. Martinez-Lopez, M.A. Cabrerizo-Vilchez, R. Hidalgo Alvarez, M. Quesada-PMerez. 5: Kinetics of Particle and Protein Adsorption Z. Adamczyk.

Surface and Colloid Science

Asphaltene adsorption at solid surfaces is a ubiquitous phenomenon that begins within the production well and continues through the entire production chain. It is generally an undesirable phenomenon that causes damage within reservoirs, fouling of pipelines and transportation equipment, and fouling of refining and upgrading equipment. However, by virtue of this phenomenon, problematic asphaltenes may also be selectively removed from petroleum streams to produce partially upgraded petroleum, which has significantly improved handling, processing, and upgrading qualities. This review covers many basic aspects regarding the chemical and physical nature of asphaltenes and sorbents related to asphaltene adsorption.

Asphaltene Adsorption, a Literature Review

Small inorganic particles strongly enhance water−crude oil emulsion stability when interactions with asphaltenes promote particle adsorption at the oil−water interface. A variety of particle types have been studied to investigate the controlling factors for particle-stabilization effectiveness. Emulsion stabilities were determined by the extent of water resolved after centrifugation and the electric field required for emulsion breakdown. All particles used were hydrophilic and stabilized oil-in-water emulsions if small enough to be interfacially active. When dried and exposed to asphaltene-containing oil phases, the particles stabilized water-in-oil emulsions. Decreased extents of preadsorbed water, decreased particle sizes, and increased particle concentrations enhanced water-in-oil emulsion stability. Investigations with model emulsions showed that an intermediate state of asphaltene aggregation, near the point of incipient precipitation, is required for particle modification and emulsion stabilization....

The Effects of Inorganic Solid Particles on Water and Crude Oil Emulsion Stability

The precipitation of asphaltenes in two Mexican crude oils was measured using a combination of high-pressure isothermal expansion and atmospheric titration with n-alkanes. Experiments were carried out from the live- and tank-oil type of samples of the same crude oils. For the oils investigated, compositional data, precipitation phase diagrams, and bubble point pressures are reported. A theoretical study for these systems was performed using the statistical association fluid theory for potentials of variable range (SAFT-VR) equation of state (EOS) in the framework of the McMillan–Mayer theory. By matching a single titration curve or two precipitation onset points with this EOS, a good prediction of asphaltene precipitation over wide temperature, pressure, and composition intervals is obtained. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2552–2570, 2004

Asphaltene Precipitation in Crude Oils: Theory and Experiments

This study investigates the adsorption and oxidation of asphaltenes onto nanoparticles. Six different metal oxide nanoparticles were employed, namely, Fe3O4, Co3O4, TiO2, MgO, CaO, and NiO. Batch adsorption experiments were carried out at different initial asphaltene concentrations. Asphaltene adsorption was evaluated by measuring the asphaltene concentration using thermogravimetric analysis, and adsorption kinetics and isotherms were obtained. For all the six nanoparticles, the isotherm data fitted well to the Langmuir model. Results showed that asphaltene adsorption is metal-oxide-specific and the adsorption capacities of asphaltenes onto the oxides followed the order CaO > Co3O4 > Fe3O4 > MgO > NiO > TiO2. Furthermore, oxidation of asphaltene was investigated after adsorption onto NiO nanoparticles. The oxidation temperature of asphaltene decreased by ∼140 °C in the presence of nanoparticles, showing their catalytic effect. The activation energies calculated by the Coats−Redfern method for asphaltene o...

Metal Oxide Nanoparticles for Asphaltene Adsorption and Oxidation

Asphaltene precipitation and deposition has been recognized to be a significant problem in oil production, transmission,and processing facilities. The precipitation of asphaltenes is cause by a number of factors including changes in pressure, temperature, chemical composition of the crude oil, mixing the oil with diluents or other oils, and during acid stimulation. The precipitated asphaltenes reduces the permeability of the reservoir near the well-bore region causing formation damage and can plug-up the well-bores and well tubings. Deposition of asphaltenic organic scales leads to operational problems, safety hazards and an overall decrease in production efficiency, thereby increasing the cost of oil production. This paper presents a review of the important factors which affect asphaltene precipitation in petroleum reservoirs and in processing facilities. The nature and characteristics of asphaltenes in the crude oil and their molecular and colloidal properties are discussed. A description of the asphaltene deposition problem manifestations in the reservoir, well bores and well tubings, processing and transportation equipment is presented. current research work in this area is also discussed.

Selim G. Sayegh

Papers

Asphaltenes: The Cholesterol Of Petroleum

Measurement And Correlation Of Asphaltene Precipitation From Heavy Oils By Gas Injection

Electrokinetic and adsorption properties of asphaltenes

Phase Behaviour And Physical Properties Of Lindbergh Heavy Oil/CO2 Mixtures

Phase behavior and physical properties of CO2-saturated heavy oil and its constitutive fractions: Experimental data and correlations