No abstract

We identify water-soluble (23 degrees C) crude oil NSO nonvolatile acidic, basic, and neutral crude oil hydrocarbons by negative-ion ESI and continuous flow FD FT-ICR MS at an average mass resolving power, m/deltam50% = 550,000. Of the 7000+ singly charged acidic species identified in South American crude oil, surprisingly, many are water-soluble, and much more so in pure water than in seawater. The truncated m/z distributions for water-soluble components exhibit preferential molecular weight, size, and heteroatom class influences on hydrocarbon solubility. Acidic water-soluble heteroatomic classes detected at >1% relative abundance include O, O2, O3, O4, OS, O2S, O3S, O4S, NO2, NO3, and NO4. Parent oil class abundance does not directly relate to abundance in the water-soluble fraction. Acidic oxygen-containing classes are most prevalent in the water-solubles, whereas acidic nitrogen-containing species are least soluble. In contrast to acidic nitrogen-containing heteroatomic classes, basic nitrogen classes are water-soluble. Water-soluble heteroatomic basic classes detected at >1% relative abundance include N, NO, NO2, NS, NS2, NOS, NO2S, N2, N2O, N2O2, OS, O2S, and O2S2.

By means of electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) and automated field desorption/ionization (FD) FT-ICR MS, we identify nonvolatile nonpolar, polar acidic, and basic water-in-bitumen emulsion film stabilizers. Highly condensed aromatic basic, nonpolar, and acidic asphaltene multilayered films stabilize emulsions near or at critical bitumen concentration for asphaltene flocculation. Solvent diluent added beyond the critical dilution concentration precipitates highly condensed acidic, all basic, and most neutral species from the oil/water interface. The most abundant classes in high bitumen concentration emulsion films include neutral pure hydrocarbons and S, acidic O 2 and O 2 S, and basic N and NS heteroatom classes. Highly abundant low bitumen concentration emulsion film stabilizers include acidic O 2 , O 4 , and O 3 S classes.

By means of electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT−ICR MS), we identify nonvolatile polar acidic and basic emulsion stabilizers in nine geographically distinct light, medium, and heavy oils. Although oil class distributions are unique, oils of similar API specific gravity exhibit similar relative abundances for the O2 and O4S classes. Heavy oils are high in O2 and low in low in O4S. The light oils follow the opposite trend. However, independent of parent oil O2 and O4S class abundances, O2 and O4S species preferentially adsorb and are the two most abundant classes in the emulsion interfacial material. Negative-ion nitrogen-containing classes do not have a high affinity for emulsion interface adsorption. However all positive-ion nitrogen-containing species adsorb to the oil/water interface.