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Solvent deasphalting of the bottom of vacuum distillation columns (vacuum residue, VR) is a process practiced worldwide. In Northern Alberta, a solvent deasphalting plant was designed to process up to 4000 tons/day of the asphaltenic pitch. Asphaltenes oxy-cracking in liquid phase could be a new approach to asphaltenes upgrading and conversion into valuable chemicals. Oxy-cracking is a combination of oxidation and cracking in basic aqueous media at moderate temperatures (170–225 °C) and pressures (300–500 psi). This process could act very selectively producing smaller amounts of greenhouse gases like CO2, thus being considered environmentally friendly. In this work, a mild oxy-cracking treatment of C5-asphaltenes solid from Athabasca vacuum residue was investigated. The reaction kinetics and possible reaction mechanism for C5-asphaltenes oxy-cracking in water under alkali conditions were studied. Products solubilized under different severities were characterized using Fourier transform infrared and nuclear magnetic resonance spectroscopies, simulated distillation, elemental analysis, and ultraviolet–visible spectrophotometry to investigate the structure of solubilized products and changes in asphaltenes structures after the reaction. A model based on sequential-parallel reactions from the asphaltenes to water-soluble products and CO2 was found to describe the process successfully. Products of oxidized functionalities like carboxylic acids, their salts, methyl ethers and esters, and sulfur-oxidized forms plus phenolics were determined as the most significant fractions soluble in water. Solubilization of asphaltenes in water could also decrease challenges regarding facilities and pipelines plugging.

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Removal of asphaltenes and heavy metals, using asymmetric ceramic monolith membranes with pore sizes of 0.2 μm and 50 nm, was investigated for three Iranian crude oils. The experiments were conducted in a batch filtration unit at a pressure gradient of 200 kPa and temperature range of 75−190 °C based on the amount of crude oil asphaltene contents. The investigated crude oils consisted of 1−10 wt % asphaltene contents. During heating of crude oils to specified temperatures, nanometer particles of asphaltene aggregated to micrometer size and then micrometer particles were separated smoothly using the membranes. The obtained results illustrated that asphaltene separation reached 60−87 wt % based on the asphaltene content of crude oils. In addition, the separation of asphaltene and heavy metals, such as nickel and vanadium, increased using the membrane of a smaller pore size. Besides, densities and viscosities of crude oils showed a sufficient decline after filtration through the membrane.

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Asphaltenes surplus production in northern Alberta facilities as a result of heavy oil upgrading incentivizes searching for alternative processes to coking or gasification, with less environmental footprint and/or lower costs. Oxy-cracking of asphaltenes in liquid phase under alkali conditions could be a new approach to creating higher value products. In the present study, asphaltene particles/drops were solubilized in water with the ultimate intention of reducing their molecular weight, converting them to analogs of humic substances with potential applications as soil cofertilizers or other industrial applications. For evaluating the feasibility of solubilizing asphaltene particles by oxy-cracking, experiments were done in a batch reactor to study the parameters maximizing the solubilization toward liquid products: temperature, residence time, pressure, base effect, asphaltenes mass, and stirring speed. The results showed that temperature and residence time are the two parameters affecting reaction the most, being the optimum values 180−210 °C and 1−2 h, respectively. The intermediate product of asphaltenes oxycracking reaction is water-soluble asphaltenes (WSA), and the final product is CO 2 . The water solubilized products were found to contain organic carboxylic, carbonyl, phenolic, and sulfonic functions, responsible for their dissolution in water. At less severe conditions, WSA had characteristics similar to humic analogs; but with increasing reaction severity, products aromaticity increased and lower molecular weight components (fulvic analogs) were formed.

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As early as 1992, proline was examined as a potential chiral selector for high-performance liquid chromatography. In recent years, brush-type selectors with up to 10 proline units have been examined, and the longer peptides were found to be competitive with commercial chiral stationary phases (CSPs). In this article, we report on a comprehensive examination of a t-butoxycarbonyl- (t-Boc-) terminated monoproline selector. This selector was grafted through an amide linkage to an aminopropyl siloxane-terminated Si(111) wafer and to a silicon atomic force microscopy tip. Chemical force spectrometry measurements were performed for interaction forces between two d- or l-monoproline monolayers in water and in the presence of various amino acid solutions. When exposed to amino acids, the adhesion forces measured between the proline layers were reduced. Amino acids containing hydrophilic side chains were found to exhibit a selectivity opposite to that seen for those containing hydrophobic side chains. Molecular dynamics simulations of the monoproline interfaces in the presence of racemic alanine and serine identified the importance of hydrogen-bonding interactions between the amino acids and the monoproline selectors. We found that, when amino acids are bound to the proline selector, their side chains protrude into the bulk solution, explaining the strong impact of side-chain hydrophobicity on the selectivity. Taken together, the experiments and simulations show that hydrogen-bonding interactions are key to effective chiral discrimination for proline-based CSPs.