Simple Functionalization of Asphaltene and Its Application for Efficient Asphaltene Removal

Asphaltene, the cheapest fraction of petroleum, was modified into a novel additive in order to facilitate a deasphalting process, such as paraffinic froth treatment. Asphaltene powder was oxidized by ozone, which is more powerful and less harmful to the environment than other oxidants. The ozonized asphaltene was characterized, and the reaction kinetics of ozonation was interpreted by the shrinking core model. Ozonized asphaltene was added to a water/<i>n</i>-pentane/bitumen emulsion to enhance the precipitation of asphaltene. Control of the properties of the precipitate was allowed by adjusting the ozonation degree and dosage of ozonized asphaltene. The removal of asphaltene was enhanced from 40% to a maximum of 70% by adding ozonized asphaltene under the same conditions. The boiling point distribution of deasphaltened oil indicates that a large amount of residue was removed using ozonized asphaltene. The dispersion behavior was checked by measuring the aggregate size in toluene and alkane solution. It was confirmed that asphaltene and ozonized asphaltene can interact with each other with high affinity

Evaluation of Laser Desorption Ionization Coupled to Fourier Transform Ion Cyclotron Resonance Mass Spectrometry To Study Metalloporphyrin Complexes

In this study, the applicability of positive-ion (+) laser desorption ionization (LDI) as an ionization method for metalloporphyrin complexes was evaluated. The evaluation was performed by analyzing standard compounds and a series of crude oils with various V⁴⁺ and Ni²⁺ contents by (+) LDI and (+) atmospheric pressure photoionization (APPI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The analysis of standard compounds showed that molecular ions were main ionic species in (+) LDI. Fragmented ions because of the loss of CH₃ were also observed. The analysis of crude oils showed that the sensitivity of (+) LDI toward metalloporphyrin complexes is greater than that of (+) APPI. Furthermore, five types of ion VO²⁺ and Ni²⁺ porphyrin complexes (etio, DPEP, rhodo-etio, rhodo-DPEP, and di-DPEP) were observed with (+) LDI, but only three types were observed with (+) APPI. Nickel porphyrins were observed in unfractionated oils by (+) LDI but not by (+) APPI. The summed relative abundance of peaks corresponding to VO²⁺ and Ni²⁺ porphyrins observed by (+) LDI was shown to be correlated with the V⁴⁺ and Ni²⁺ metal contents of the oils in general. However, the abundance of DPEP porphyrins did not correlate well with the metal content because it depends upon the maturity or state of biodegradation of oils. Also, 1 μL of oil sample was sufficient to perform (+) LDI FT-ICR MS analysis. Therefore, (+) LDI FT-ICR MS is a sensitive method to detect metalloporphyrins in petroleum using caution with respect to fragmented ions because of the loss of CH₃