Using machine learning-based variable selection to identify hydrate related components from FT-ICR MS spectra

The blockages of pipelines caused by agglomeration of gas hydrates is a major flow assurance issue in the oil and gas industry. Some crude oils form gas hydrates that remain as transportable particles in a slurry. It is commonly believed that naturally occurring components in those crude oils alter the surface properties of gas hydrate particles when formed. The exact structure of the crude oil components responsible for this surface modification remains unknown. In this study, a successive accumulation and spiking of hydrate-active crude oil fractions was performed to increase the concentration of hydrate related compounds. Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) was then utilised to analyse extracted oil samples for each spiking generation. Machine learning-based variable selection was used on the FT-ICR MS spectra to identify the components related to hydrate formation. Among six different methods, Partial Least Squares Discriminant Analysis (PLS-DA) was selected as the best performing model and the 23 most important variables were determined. The FT-ICR MS mass spectra for each spiking level was compared to samples extracted before the successive accumulation, to identify changes in the composition. Principal Component Analysis (PCA) exhibited differences between the oils and spiking levels, indicating an accumulation of hydrate active components. Molecular formulas, double bond equivalents (DBE) and hydrogen-carbon (H/C) ratios were determined for each of the selected variables and evaluated. Some variables were identified as possibly asphaltenes and naphthenic acids which could be related to the positive wetting index (WI) for the oils.publishedVersio

Demonstration of a novel instrument for online monitoring of absorber emissions to air

A novel concept for online monitoring of nitrosamines, solvent amines and their degradation products in amine absorber emissions to air was demonstrated at the Tiller CO2-lab pilot facility. The monitoring concept is based on SINTEF patent No. PCT/EP2011/073557. The measurement method applies gas sampling by capture of analytes in a condensate stream from a single stage condensate collector unit. An improved design for the SINTEF prototype for online gas and liquid measurements has been established as part of the CCUS-ALIGN project. The new design has low complexity and improved robustness, making it applicable as integrated part of industrial monitoring systems. The established prototype was successfully tested for monitoring of trace gas emission from a CO2 capture pilot plant, demonstrating measurements of nitrosamines at levels far below the lower detection limits of commercial industrial online analyzers. Results from testing of a condensate collector prototype indicate high capture efficiency for analytes of interest, including analytes present in aerosols during operation conditions where the absorber emit mist to the atmosphere. The measurement concept has potential for significantly reducing the costs related to manual gas measurements for critical trace gas components in plant operation. Application of the concept can enable continuous measurements of nitrosamines and other critical trace gas analytes in the emissions to air not currently available in absorption-based CO2 capture processes.publishedVersio

Biodegradation of oil spill dispersant surfactants in cold seawater

While biodegradation of chemically dispersed oil has been well documented, only a few studies have focused on the degradation of the dispersant compounds themselves. The objective of this study was to determine the biodegradation of dispersant surfactants in cold seawater, relevant for deep sea or Arctic conditions. Biotransformation of the surfactants dioctyl-sodium sulfosuccinate (DOSS), Tween 80, Tween 85, and α/β-ethylhexylsulfosuccinate (EHSS, expected DOSS hydrolysis product) in the commercial dispersants Corexit 9500, Dasic Slickgone NS and Finasol OSR52 were determined. The biotransformation studies of the surfactants were performed in natural seawater at 5 °C over a period of 54 days without oil present. The surfactants were tested at concentrations of 1, 5, and 50 mg/L, the lower concentration being as close as possible to expected field concentrations. Experiments with dispersants concentrations of 1 mg/L resulted in rapid biotransformation of Tween 80 and Tween 85, with depletion after 8 days, while DOSS showed rapid biotransformation after a lag period of 16 days. The degradation half-life of DOSS increased from 4.1 days to >500 days as Corexit 9500 concentrations went from 1 mg/L to 50 mg/L, emphasizing the importance of performing experiments at dispersant concentrations as close as possible to environmentally relevant concentrations. EHSS showed limited degradation compared to other surfactants. This study shows that the surfactants DOSS, Tween 80 and Tween 85 in the three chemical dispersants studied are biodegradable in cold seawater, particularly in environmentally relevant concentrationsacceptedVersio

Microencapsulation of Peppermint Oil by Complex Coacervation and Subsequent Spray Drying Using Bovine Serum Albumin/Gum Acacia and an Oxidized Starch Crosslinker

Most liquid food flavours such as essential oils are volatile and prone to degradation in the presence of oxygen, light, moisture and high temperatures. Microencapsulation of volatile ingredients prior to use in food or beverages is a commonly used process to limit loss and degradation of flavours and aromas during processing and storage. Here, peppermint essential oil was microencapsulated via complex coacervation using a combination of bovine serum albumin and gum Acacia as wall materials. The resulting core-shell microcapsules were chemically crosslinked with a modified food-grade starch, and subsequently spray dried, resulting in dry microcapsules which could be easily redispersed in aqueous solutions. Microcapsule formation and stability, as well as microencapsulation yield of peppermint oil, were investigated as a function of polymer concentration, core material load/wall thickness and crosslinker concentration. The crosslinked peppermint oil microcapsules were spherical and mononuclear both before and after spray drying and redispersion, whereas control coacervate samples without crosslinker did not withstand the spray drying process. Microencapsulation yield as analysed by GC-MS showed no loss of peppermint oil during or after complex coacervation, and 54% loss after spray drying for the best combination of Polymer:Oil ratio and crosslinker concentration used here, indicating good overall protection of the core material.publishedVersio

Combined analytical strategies for chemical and physical characterization of tar from torrefaction of olive stone

The advance in analytical methodology is critical for progress in 1) biorefinery and 2) torrefaction product commercialization. The chemical characterisation of torrefaction liquid and concentrated tar produced by Arigna Fuels’ pyrolysis plant allowed identification of polar, volatile, non-volatile compounds, species containing organically bound sulphur and nitrogen heteroatoms. The results suggest that only combined use of ion chromatography with Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, and 1H-13C HS-QC can provide comprehensive information on sugar-like material and lignin-derived compounds. Due to the technical robustness and short analysis time, Fourier Transform Ion Cyclotron Resonance Mass Spectrometer was found to be a promising tool for tar analysis containing heavy molecular compounds. Importantly from a technological standpoint, the presence of aromatic and saturated compounds in both liquid and concentrated tar samples indicated the predominance of lignin-derived compounds over products originating from cellulose and hemicellulose polymers.publishedVersio

Combined analytical strategies for chemical and physical characterization of tar from torrefaction of olive stone

The advance in analytical methodology is critical for progress in 1) biorefinery and 2) torrefaction product commercialization. The chemical characterisation of torrefaction liquid and concentrated tar produced by Arigna Fuels’ pyrolysis plant allowed identification of polar, volatile, non-volatile compounds, species containing organically bound sulphur and nitrogen heteroatoms. The results suggest that only combined use of ion chromatography with Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, and 1H-13C HS-QC can provide comprehensive information on sugar-like material and lignin-derived compounds. Due to the technical robustness and short analysis time, Fourier Transform Ion Cyclotron Resonance Mass Spectrometer was found to be a promising tool for tar analysis containing heavy molecular compounds. Importantly from a technological standpoint, the presence of aromatic and saturated compounds in both liquid and concentrated tar samples indicated the predominance of lignin-derived compounds over products originating from cellulose and hemicellulose polymers.publishedVersio

Exploration of degradation chemistry by Advanced analytical methodology

publishedVersio

Exploration of degradation chemistry by Advanced analytical methodology

publishedVersio

Demonstration of a novel instrument for online monitoring of absorber emissions to air

A novel concept for online monitoring of nitrosamines, solvent amines and their degradation products in amine absorber emissions to air was demonstrated at the Tiller CO2-lab pilot facility. The monitoring concept is based on SINTEF patent No. PCT/EP2011/073557. The measurement method applies gas sampling by capture of analytes in a condensate stream from a single stage condensate collector unit. An improved design for the SINTEF prototype for online gas and liquid measurements has been established as part of the CCUS-ALIGN project. The new design has low complexity and improved robustness, making it applicable as integrated part of industrial monitoring systems. The established prototype was successfully tested for monitoring of trace gas emission from a CO2 capture pilot plant, demonstrating measurements of nitrosamines at levels far below the lower detection limits of commercial industrial online analyzers. Results from testing of a condensate collector prototype indicate high capture efficiency for analytes of interest, including analytes present in aerosols during operation conditions where the absorber emit mist to the atmosphere. The measurement concept has potential for significantly reducing the costs related to manual gas measurements for critical trace gas components in plant operation. Application of the concept can enable continuous measurements of nitrosamines and other critical trace gas analytes in the emissions to air not currently available in absorption-based CO2 capture processes

Exploration of degradation chemistry by Advanced analytical methodology

publishedVersio