Camilo A. Franco

Adsorptive removal of oil spill from oil-in-fresh water emulsions by hydrophobic alumina nanoparticles functionalized with petroleum vacuum residue

Oil spills on fresh water can cause serious environmental and economic impacts onshore activities affecting those who exploit freshwater resources and grassland. Alumina nanoparticles functionalized with vacuum residue (VR) were used as a low-cost and high hydrophobic nanosorbents. The nanomaterial resulting showed high adsorption affinity and capacity of oil from oil-in-freshwater emulsion. The effects of the following variables on oil removal were investigated, namely: contact times, solution pH, initial oil concentrations, temperature, VR loadings and salinity. Kinetic studies showed that adsorption was fast and equilibrium was achieved in less than 30 min. The amount adsorbed of oil was higher for neutral system compared to acidic or basic medium. Increasing the VR loading on nanoparticle surface favored the adsorption. Results of this study showed that oil removal for all systems evaluated had better performance at pH value of 7 using nano-alumina functionalized with 4 wt% VR. Adsorption equilibrium and kinetics were evaluated using the Polanyi theory-based Dubinin-Ashtakhov (DA) model, and pseudo-first and pseudo-second order-models, respectively.

Removal of oil from oil-in-saltwater emulsions by adsorption onto nano-alumina functionalized with petroleum vacuum residue

Formation water from oilfields is one of the major environmental issues related to the oil industry. This research investigated oil adsorption onto nanoparticles of hydrophobic alumina and alumina nanoparticles functionalized with a petroleum vacuum residue (VR) at 2 and 4wt% to reduce the amount of oil in oil-saltwater emulsions at different pH values (5, 7 and 9). The initial concentration of crude oil in water ranged from 100 to 500mg/L. The change in oil concentration after adsorption was determined using a UV-vis spectrophotometer. The results indicated that all of the systems performed more effectively at a pH of 7 and using Al/4VR material. The oil adsorption was higher for neutral and acid systems compared with basic ones, and it was improved by increasing the amount of VR on the surface of the alumina. Additionally, the amount of NaCl adsorbed onto nanoparticles was estimated for different mixtures. The adsorption equilibrium and kinetics were evaluated using the Dubinin-Astakhov model, the Brunauer-Emmet-Teller model, and pseudo-first- and pseudo-second-order models, with a better fitting to the Brunauer-Emmet-Teller model and pseudo-second-order model.

Water Remediation Based on Oil Adsorption Using Nanosilicates Functionalized with a Petroleum Vacuum Residue

Discharging water from oilfields has become one of the major environmental issues related to the oil industry. This work presents a study on the adsorption of oil onto nanoparticles of hydrophobic silica and silica nanoparticles functionalized with a petroleum vacuum residue (VR) at 2 and 4 wt% to reduce the amount of oil in oil–brine and oil–water emulsions at different pH values (5, 7 and 9). The initial concentration of crude oil in water ranged from 500 to 1500 mg/l. The change in oil concentration after adsorption was determined using a UV–VIS spectrophotometer. Experimental data on the adsorption kinetics were fitted to pseudo-first-order and pseudo-second-order models, with better results being obtained for the latter. Results of the study showed 100% oil removal for all the systems studied and a better performance was achieved for oil-saltwater emulsions than the experiments performed using oil-saltwater emulsions. In addition, the adsorption equilibrium was achieved faster for the oil–water emulsion using the salty medium. Adsorption velocity was higher for neutral and basic systems compared with acid ones, and it was improved by increasing the amount of VR on silica surface.

Effects of resin I on the catalytic oxidation of n-C7 asphaltenes in the presence of silica-based nanoparticles

This study aims to evaluate the effects of resin I on the n-C7 asphaltene thermal decomposition under an oxidative atmosphere in the presence of hybrid nanoparticles (SNi1Pd1) of NiO and PdO supported over fumed silica nanoparticles. Resin I and n-C7 asphaltenes were characterized by elemental analyses, thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR). The adsorption of resin I and n-C7 asphaltenes was evaluated using heavy oil model solutions through a combined method of thermogravimetric analysis and softening point measurements. Adsorption isotherms were measured for individual resin I and n-C7 asphaltene samples as well as for different n-C7 asphaltene to resin I ratios of 7 : 3, 1 : 1 and 7 : 3. For the first time, competitive adsorption of n-C7 asphaltene and resin I on functionalized nanoparticles with NiO and PdO is assessed. The oxidation tests were carried out in an air atmosphere for a specific n-C7 asphaltene loading in each sample (ca. 0.20 ± 0.02 mg m−2). In this order, for samples adsorbed from different A : R ratios of 7 : 3, 1 : 1 and 3 : 7, the amounts of resin I adsorbed were 0.06, 0.10 and 0.20 ± 0.01 mg m−2, respectively. Hence, the A : R ratios in the adsorbed phase were 10 : 3, 2 : 1 and 1 : 1. The catalytic effect was measured through thermogravimetric analysis coupled to Fourier transform infrared spectroscopy, which evaluated the effluent gases of the catalytic oxidation process. The adsorption isotherms were modeled using the solid-liquid-equilibrium (SLE) model, and the effective activation energies for the oxidation process of the adsorbate were calculated through the non-linear integral method of Vyazovkin (NLN). As a result, it was observed that the temperature of n-C7 asphaltene decomposition did not vary significantly with the inclusion of resin I in the system. Rate of mass loss curves showed that the main peak temperatures of n-C7 asphaltenes and resin I decreased drastically from approximately 500 °C to 250, 260 and 270 °C for resin I loadings over SNi1Pd1 nanoparticles of 0.20, 0.10 and 0.06 mg m−2, respectively. However, the catalytic effect of the nanoparticles was indeed affected, as revealed by the increase in the estimated effective activation energy as the amount of resin I in the system increased. It is expected that this work opens a better outlook about the use of catalytic nanoparticles in the oil and gas industry, mainly in improved (IOR) or enhanced oil recovery (EOR) processes for heavy and extra-heavy oil upgrading.

Anomalous Heavy-Oil Rheological Thinning Behavior upon Addition of Nanoparticles: Departure from Einstein's Theory

Heavy and extra-heavy oils generally exhibit high viscosity, which is detrimental to their production, transport, and refining. The oil & gas industry has thoroughly investigated the use of chemical agents to improve the mobility of these types of low-quality crude oils at the surface as well as under reservoir conditions for many years. In this sense, the main objective of this paper is to provide unexpected experimental evidence of heavy oil and extra-heavy crude oils viscosity reduction resulting from the presence of nanoparticles (NPs) of different chemical natures (SiO2, Fe3O4, and Al2O3), particle size, surface acidity, and concentration at low-volume fractions. The viscosity of the enhanced fluids was measured using a rotational rheometer at shear rates varying between 1 and 75 s−1. Upon addition of NPs, viscosity reduction was observed in all cases evaluated. The maximum viscosity reduction of roughly 52% was obtained at a concentration of 1000 mg/L with 7 nm SiO2 NPs at low shear rate, below 10 s−1, contrary to expectations from Einstein’s viscosity theory in particulate systems. A mathematical model based on a modification to the Pal and Rhodes Model for the viscosity of suspensions is proposed in this work. The said model was validated successfully using experimental data, as evidenced by RSME% values lower than 10%. The importance of our findings lies in the lack of previous experimental and theoretical data in the open literature showing heavy crude oils viscosity reduction in the presence of NPs.

Viscosity reduction of extra heavy crude oil by magnetite nanoparticle-based ferrofluids:

The main objective of this work is to synthesize and evaluate magnetite (Fe3O4) nanoparticle-based ferrofluids for reducing the viscosity of an extra heavy crude oil. The carrier fluid of the nanoparticles was synthesized using an engine lubricant recycled from the automotive industry and hexadecyltrimethylammonium bromide as a surfactant. Fe3O4 nanoparticles were synthesized by coprecipitation method. The effect of the concentration of nanoparticles in the viscosity reduction degree was determined for dosages between 0 and 50,000 mg/L. Different dosages of carrier fluid were evaluated between 0 and 10% v/v. The effects of the amount of brine emulsified, temperature, time, and shear rate were assessed. Overall, the results showed that viscosity and shear stress of extra heavy crude oil could be reduced up to 81 and 78% in the presence of ferrofluid, respectively. The rheological behavior of extra heavy crude oil in the presence and absence of ferrofluid was assessed by Cross, Ostwald-de Waele, and Herschel-Bulkley models.

An Enhanced-Solvent Deasphalting Process: Effect of Inclusion of SiO2 Nanoparticles in the Quality of Deasphalted Oil

In this work, the effect of nanoparticles in deasphalting heavy oil and extra-heavy oil process at laboratory-scale based on the conventional solvent deasphalting process was studied and named enhanced-solvent deasphalting (e-SDA) process. This work evaluated the effect of the nanoparticles of SiO2 in the separation efficiency based on deasphalted oil (DAO) fraction quality compared to the conventional process of deasphalting (SDA). Different effects have been assessed such as solvent to oil ratio, operating temperatures, type of solvent, and SiO2 nanoparticles dosage. The DAO quality was based on the asphaltene and sulfur contents, API gravity, distillable fraction, and rheological properties. The improvement of the process from the use of nanoparticles was confirmed with important reductions in the asphaltene and sulfur contents in the DAO of up to 24% and 23%, respectively, in comparison with the SDA process. Also, the API gravity can be increased by approximately 14% with the e-SDA process. The rheological properties of the DAO were improved by the inclusion of nanoparticles showing reductions in the viscosities of the DAO greater than 50% in comparison with the conventional process. These results lead to the conclusion that the e-SDA process improves the DAO quality when compared with the typical deasphalting process.

Adsorption-desorption of n-c7 asphaltenes over micro- and nanoparticles of silica and its impact on wettability alteration

espanolResumen En este trabajo, se desarrollo un estudio de la adsorcion/desorcion de asfaltenos a bajas y altas concentraciones (100 - 30000 mg/L) incluyendo el efecto del tamano de particula del adsorbente (nano y microsilice), efecto de la presion, de la temperatura y el tipo de solvente. Las pruebas de adsorcion/desorcion en las diferentes superficies de silice se realizaron mediante pruebas por lotes usando espectrofotometria UV-vis y analisis termogravimetricos. Debido a sus especiales caracteristicas de alta area superficial y dispersabilidad, las nanoparticulas de silice adsorben una mayor cantidad de asfaltenos que la silice microparticulada. Ademas, se observo que la desorcion de los asfaltenos de las nanoparticulas de silice fue significativa, mientras que para el sistema microparticulado fue insignificante, sugiriendo un mayor potencial de adsorcion para la silice microparticulada. La cantidad de asfaltenos adsorbidos aumento al incrementar la presion, al mismo tiempo que disminuye al aumentar la temperatura del sistema. Tambien, los resultados obtenidos demuestran que el tipo de solvente juega un papel importante en el proceso de desorcion de los asfaltenos. Adicionalmente, se realizaron pruebas de humectabilidad para las nanoparticulas de silice en presencia y en ausencia de asfaltenos adsorbidos y se evidencio que incluso a altas cantidades adsorbidas, las nanoparticulas mantienen su condicion humectable al agua. EnglishAbstract In this work, a study of the adsorption/desorption of n-C7 asphaltenes at low and high concentrations (100 - 30000 mg/L) was performed for which the effects of adsorbent particle size (nano and microsilica), pressure, solvent, and temperature were evaluated. Adsorption/desorption tests on different silica surfaces were performed in batch-mode using UV-vis spectrophotometry and thermogravimetric analyses. Owing to its high surface area and dispersibility, nanosilica adsorbed higher quantities of n-C7 asphaltenes than microsilica. Asphaltene desorption from nanosilica surface was significant, while the desorption from microsilica surfaces was insignificant, suggesting a higher adsorption potential for the latter. Asphaltene adsorption increased with pressure and decreased with temperature. Type of solvent plays a significant role on the asphaltene desorption. The wettability tests for virgin nanosilica and nanosilica contained adsorbed asphaltenes showed that even at high asphaltene loading, the nanoparticles maintained its water-wet nature. portuguesResumo Neste trabalho foi realizado um estudo sobre a adsorcao/dessorcao de asfaltenos n-C7 em concentracoes altas e baixas (100 - 30000 mg/L) no intuito de avaliar os efeitos do tamanho da particula adsorvente (nano e microsilica), pressao, solvente e temperatura. Testes de adsorcao/dessorcao em diferentes superficies de silica foram realizados em serie utilizando analises termogravimetricos e de espectrofotometria UV-vis. Vista sua grande area de superficie e capacidade de dispersao, a nanosilica adsorveu maiores quantidades de asfaltenos n-C7 do que a microsilica. A dessorcao de asfalteno da superficie da microsilica foi insignificante, isso sugere a existencia de um maior potencial de adsorcao para a microsilica. A adsorcao de asfalteno aumentou com a pressao e diminui com a temperatura. O tipo de solvente tem um papel preponderante na dessorcao de asfalteno. Os testes de molhabilidade para nanosilica virgem e asfaltenos adsorvidos com conteudo de nanosilica mostraram que mesmo durante uma carga alta de asfaltenos, as nanoparticulas preservaram sua natureza de humidade-agua.

Development and Evaluation of Surfactant Nanocapsules for Chemical Enhanced Oil Recovery (EOR) Applications

The primary objective of this study is the synthesis of nanocapsules (NC) that allow the reduction of the adsorption process of surfactant over the porous media in enhanced oil recovery processes. Nanocapsules were synthesized through the nanoprecipitation method by encapsulating commercial surfactants Span 20 and Petro 50, and using type II resins isolated from vacuum residue as a shell. The NC were characterized using dynamic light scattering, transmission electron microscopy, Fourier transform infrared, solvency tests, softening point measurements and entrapment efficiency. The obtained NC showed spherical geometry with sizes of 71 and 120 nm for encapsulated Span 20 (NCS20), and Petro 50 surfactant (NCP50), respectively. Also, the NCS20 is composed of 90% of surfactant and 10% of type II resins, while the NCP50 material is 94% of surfactant and 6% of the shell. Nanofluids of nanocapsules dispersed in deionized water were prepared for evaluating the nanofluid—sandstone interaction from adsorption phenomena using a batch-mode method, contact angle measurements, and FTIR analysis. The results showed that NC adsorption was null at the different conditions of temperatures evaluated of 25, 50, and 70 °C, and stirring velocities up to 10,000 rpm. IFT measurements showed a reduction from 18 to 1.62 and 0.15 mN/m for the nanofluids with 10 mg/L of NCS20, and NCP50 materials, respectively. Displacements tests were conducted using a 20 °API crude oil in a quarter five-spot pattern micromodel and showed an additional oil recovery of 23% in comparison with that of waterflooding, with fewer pore volumes injected than when using a dissolved surfactant.

RETRACTED: Striking behavior of the rheology in heavy crude oils by adding nanoparticles:

At the request of the Publisher, the following article has been retracted for redundant publication. Taborda EA, Franco CA, Ruiz AM, Alvarado V, Cortés FB (2017) Striking behavior of the rheology in heavy crude oils by adding nanoparticles. Adsorption Science & Technology. Epub ahead of print 29 August 2017. DOI: 10.1177/0263617417727996. After publication, the Adsorption Science & Technology Editorial Office became aware that this article had been simultaneously submitted to Adsorption Science & Technology, and two other journals: Chemical Engineering Communications and Energy Fuels, which resulted in the redundant publication of the above article. The above article is near-identical to the following articles published by the same group of authors in Chemical Engineering Communications and Energy & Fuels. Taborda EA, Franco CA, Ruiz AM, Alvarado V, Cortés FB (2017) Anomalous Heavy-Oil Rheological Thinning Behavior upon Addition of Nanoparticles: Departure from Einstein’s Theory. Chemical Engineering Communications 204(6): 648–657. Taborda EA, Franco CA, Ruiz AM, Alvarado V, Cortés FB (2017) Experimental and Theoretical Study of Viscosity Reduction in Heavy Crude Oils by Addition of Nanoparticles. Energy Fuels 31(2): 1329–1338.