Energy, Petroleum, and Bio Energy

A procedure was developed to calibrate the wavenumber (energy shift) axis in Raman spectrometers, and it was tested in both portable and laboratory-based instruments.

October’s AP column highlights a team of geochemists at the University of Houston who have been developing methods to streamline multi-element analysis for a more complete fingerprinting of oils by using one sample preparation method utilizing a single reaction chamber microwave digestion system and then analyzing these solutions for major, and minor elements by ICP-OES and low abundance trace elements by triple quadrupole (QQQ) ICP-MS. Results to date using this approach have shown that complete elemental recovery and removal of organic matrices can be achieved safely and that up to 57 elements can be determined in oils with good accuracy and precision. Removal of organic matrices during digestion not only helps to limit the formation of polyatomic spectral interferences, but improves instrument stability and reduces carbon build in the sample introduction and interface regions, which have traditionally plagued “dilute and shoot” methods.

The enhanced resolution of comprehensive two-dimensional gas chromatography (GCxGC) was combined with the increased resolving power, speed, and mass accuracy of the Pegasus® HRT's mass analyzer to confidently characterize molecules in light cycle oil (LCO) and vacuum gas oil (VGO). Optimized chromatographic and mass spectrometry parameters were implemented to improve data acquisition, processing, and heteroatomic speciation of these light to midlevel petroleum fractions. Software tools were utilized to process the data and facilitate robust compound identifications. GCxGC-HRT data was processed using comprehensive Peak Find and resulted in comprehensive characterization of molecules in LCO and VGO samples. Compound classes consisted of, but were not limited to alkanes, cycloalkanes, aromatics, benzothiophenes, and carbazoles. Selective processing of alkylbenzothiophenes and dibenzothiophenes was conducted by retrospectively processing data using rapid two-dimensional, accurate mass Target Analyte Finding (TAF).

Inductively coupled plasma (ICP) techniques, such as ICP coupled with mass spectrometry (ICP-MS) and ICP–optical emission spectroscopy (OES), have seen a lot of growth in recent years for the direct analysis of organic samples such as petroleum and biofuels. José-Luis Todolí, a professor at the University of Alicante in Spain, has conducted several studies in this area, including the elemental determination of metals in bioethanol using ICP-OES, and the use of a torch integrated sample introduction system as well as ICP-MS to analyze petroleum products and biofuels. He recently spoke to us about this work and other projects involving ICP techniques that his group is focused on.

Raman bands in the low energy region of the spectrum of crystals are attributed to so-called external lattice vibrational modes. The Raman bands from these external vibrational modes (low energy phonons) are very sensitive to crystal structure and orientation with respect to the incident laser polarization and to molecular interactions within the crystal. The low energy vibrational modes of many organic molecular crystals have very high Raman scattering cross-sections. Raman spectra and images of low energy phonons in so-called two dimensional (2D) crystals such as few-layer MoS2 reveal spatial variations in the solid state structure that are not evident in the higher energy bands.

The Mid-Infrared Technologies for Health and the Environment (MIRTHE) center hosted a workshop titled “Air Quality Monitoring Related to Energy Extraction†on Friday, August 9, 2013 at Princeton University (Princeton, New Jersey). The workshop was well attended and highlighted some of the key issues surrounding energy extraction.

The application of high-resolution TOF-MS to petroleomics is presented, and the basic theory of each type of ultrahigh-resolution mass spectral platform is briefly explained.

A new class of x-ray photoelectron spectroscopic microscope has been developed at the U.S. Department of Energy?s Brookhaven National Laboratory (Upton, New York) and will be used for advanced research on a wide range of technologically important materials systems.

A number of analytical methods make use of the X-ray region of the electromagnetic spectrum. Of these, the technique in widest use is energy-dispersive X-ray fluorescence (EDXRF).

Cellulosic feedstocks from biological harvests (such as timber, prairie grass, and corn stover) or industrial–urban waste have been proposed as a source for the production of energy in the form of fermentation-produced ethanol biofuel.

In this article, the authors evaluate the use of multiple mass defect filters on metabolite identification data from a hybrid mass spectrometer. The study also investigates the use of higher energy collisional dissociation for structural elucidation in metabolite identification experiments.