Luis S. Zamudio-Rivera

Boron-nitrogen macrocycles: a new generation of calix[3]arenes.

The simple condensation reaction of 3,5-di-tert-butyl salicylaldehyde and 3-aminophenylboronic acid leads to a trimeric macrocyclic compound. The ability of this molecule to include small organic molecules was in a first approximation analyzed by (1)H NMR spectroscopy and X-ray crystallography.

Structural relationship between a host included chain of spirocyclic water hexamers and bulk water – the role of water clusters in self assembly and crystallization processes

Infinite chains of spirocyclic water hexamers are included in the crystal lattice of a tin complex with a curved, hydrophobic surface and only weak intermolecular bonding interactions between the host molecules, so that the enclosed water clusters might be reminiscent of the solvation sphere in solution.

Effect of Asphaltenes and Resins on Asphaltene Aggregation Inhibition, Rheological Behaviour and Waterflood Oil-Recovery

This study presents an investigation about the influence of resins and asphaltenes, extracted from two Mexican crude oils (light and heavy oil samples), on the asphaltene aggregation inhibition, rheological behavior, and waterflood oil-recovery. Resins and asphaltenes were characterized by means of elemental analysis, metals analysis by atomic absorption, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, and electrospray ionization mass spectrometry (ESI-MS) in order to evaluate the effect of their structural parameters on the phenomena studied. Efficiency of the resins fraction as natural inhibitors of asphaltene aggregation was evaluated trough ultraviolet–visible (UV–vis) spectroscopy. Results showed better efficiencies of resins on asphaltene aggregation inhibition at resin/asphaltene (R/A) ratios close to unity and at high temperature. In addition, efficiencies were influenced by structural characteristics of the asphaltene–resin system. Rheological behavior of the heavy crude oil sample was significantly influenced by the presence of asphaltenes and resins. Finally, asphaltenes and resins played an important role on wettability and waterflood oil-recovery. GRAPHICAL ABSTRACT

Adsorption of zwitterionic surfactant on limestone measured with high-performance liquid chromatography: micelle-vesicle influence.

Herein is presented a new methodology to determine the static adsorption of a zwitterionic surfactant on limestone in three different aqueous media [high-performance liquid chromatography (HPLC) water, seawater, and connate water] with the use of HPLC at room temperature and 70 °C. The results showed that, in both HPLC water and seawater, the surfactant adsorption followed a monolayer Langmuir tendency. In contrast, for connate water, the surfactant presented a new adsorption profile, characterized by two regions: (i) At surfactant concentrations below 1500 mg L(-1), an increase of adsorption is observed as the amount of divalent cations increases in the aqueous media. (ii) At surfactant concentrations above 1500 mg L(-1), the adsorption decreases because the equilibrium, monomer ⇆ micelle ⇆ vesicle, is shifted to the formation of vesicles, giving as a result a decrease in the concentration of monomers, thus reducing the interaction between the surfactant and the rock, and therefore, lower adsorption values were obtained. The behavior of the surfactant adsorption under different concentrations of divalent cations was well-described by the use of a new modified Langmuir model: (dΓ/dt)ads = k(ads)c(Γ∞ - Γ) - k(cmc)(c - c(cmc))(n)ΓH(c - c(cmc)). It was also observed that, as the temperature increases, the adsorption is reduced because of the exothermic nature of the adsorption processes.

Strecker intermediates as non-pollutant scavengers for cyanides

Using a series of five bis(aminomethyl)ethers, a fast and efficient transformation of sodium cyanide to sodium N-2-hydroxyethylglycinates is reported, where the starting materials are prototypes for application in the mining and oil industries to diminish the pollution of the tailings derived from their processes.

Application of Multifunctional Agents During Enhanced Oil Recovery

During the application of enhanced oil recovery (EOR) processes, complex operational issues, such as the deposition of organic compounds (i.e., wax, resins, and asphaltenes, among others), reservoir formation damage, rock wettability alteration, and high fluids viscosity negatively affect oil recovery. This chapter presents the experimental evaluation of the multifunctional properties of two novel chemical agents recently developed: a zwitterionic surfactant (ZS) and a supramolecular complex (named here as AMESUS) for chemical EOR applications. The performance of the new multifunctional agents and the mechanisms in play on the removal/control of organic compounds deposition oil recovery, asphaltenes inhibition-dispersion activity, reduction in heavy crude oil viscosity, rock wettability modification, and relative permeability are discussed in this chapter.