Rafal Gieleciak

Rafal Gieleciak
Natural Resources Canada | NRCan · CanmetENERGY-Devon

Doctor of Philosophy in Chemistry (University of Silesia, Katowice, Poland)

About

74
Publications
5,341
Reads
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930
Citations
Additional affiliations
April 2007 - present
Natural Resources Canada
Position
  • Research Officer
April 2007 - April 2019
Natural Resources Canada
Position
  • Researcher

Publications

Publications (74)
Article
Biocrudes are complex mixtures with significant amounts of oxygenates (<40 wt% oxygen) and their chemistry is different from that of petroleum. Therefore, co-processing of biocrudes with petroleum fractions in existing refineries is challenging and may require pre-treatment of biocrude. A thorough characterization can aid in understanding the chemi...
Article
Sustainable aviation fuels (SAFs) must demonstrate specific physical and chemical properties as well as material compatibility (i.e., seal swell) to be used as aviation turbine fuels. Several alternative jet fuels incorporated in ASTM D7566 are comprised mainly of n/iso-alkanes and can only be blended up to 50 vol% due to material compatibility and...
Article
A useful method for quantifying concentrations of various hydroxyl group containing molecular species in biocrudes involves chemically converting species into nonionizable, P-functionalized derivatives independently observed and quantified by phosphorus-31 nuclear magnetic resonance (³¹P NMR) spectroscopy. Full validation of this method requires im...
Article
In this work, the fouling behaviour of thermally processed bitumen products obtained by visbreaking was studied. The feedstock was prepared by blending raw oil sands bitumen with 15 vol% hydrotreated light oil (HLO). The visbreaking products obtained at different pitch (525 °C + fraction) conversions were characterized and tested for fouling tenden...
Article
Alternative fuels hold considerable promise as substitutes for petroleum diesel fuel. As such, biodiesel is a promising renewable fuel that has been developed and tested by a number of research groups. Quality control of this transportation fuel is of great significance to its commer-cialization. Conventional chromatographic and spectroscopic analy...
Article
Sulfur compounds in bitumen-derived gas oil undergo selective oxidation using a titanium-derived catalyst resulting in the formation of sulfones and sulfoxide species. Using caustic solution, the sulfones and sulfoxide species are then chemically converted to hydrocarbon compounds, by replacing C-S fragments with C-H fragments. In this study, we pr...
Article
In this study, we investigate the potential of co-processing hydrothermal liquefaction (HTL) biocrude with vacuum gas oil (VGO) in a hydrocracking process with hydrotreating as the first step. Experiments were conducted in a continuous hydroprocessing pilot plant in two stages: hydrotreating and hydrocracking. Two feeds were tested: pure VGO first...
Article
In this study, we investigate the feasibility of co-processing biocrude in petroleum vacuum gas oil (VGO) hydroprocessing units. The biogenic component of the feed was biocrude produced by hydrothermal liquefaction of woody biomass, while VGO from oil sands bitumen was selected as the hydrocarbon feed. To improve its processability, the biocrude sa...
Article
Sustainable aviation fuels remain the only near, mid, and likely long term solution for lowering the carbon emissions of commercial and military aviation. Determination of sustainable aviation fuel's chemical compositions and prediction of their properties is a critical first step for further research and development leading to the final certificat...
Article
Vacuum residue is the most diverse and structurally complex fraction of petroleum. In this work, we develop a representation of the molecular composition of this petroleum fraction. The underlying assumption is that vacuum residue is a continuum in molecular structure that can be described using probability distribution functions. The structural de...
Article
The stabilization of olefins in thermally processed bitumen is a focal area for development of bitumen partial upgrading technologies. While a number of approaches have been proposed, including alkylation, oligomerization, and adsorption, hydrotreating is still the most effective strategy for treating olefins in thermally cracked products such as c...
Article
The determination of olefin contents in liquid hydrocarbons by means of laser-based infrared spectroscopy was demonstrated for the first time in this work. This new technique utilizes a commercial mid-infrared External-Cavity Quantum Cascade Laser and a photoacoustic detector to monitor characteristic olefin C=C absorption bands in the ~1640–1680 c...
Article
The thermal-wave resonant cavity (TWRC) technique has been used for thermal diffusivity measurements by many researchers. This study aims to reduce the uncertainty associated with TWRC signal processing (curve fitting) by means of numerical simulation and experimental verification. Simulations show that the plot of signal amplitude versus cavity le...
Conference Paper
The persistence of petroleum spilled into aquatic environments is highly dependent on the complex interplay of natural weathering processes, including evaporation, dispersion, biodegradation and photooxidation. While evaporation and biodegradation processes remove non-persistent fractions of crude oil from water relatively quickly, sunlight-induced...
Technical Report
This report summarizes the results of applying advanced statistical techniques to identify trends and correlations of the engine performance and emissions of the Fuels for Advanced Combustion Engines (FACE) diesel fuels with fuel properties and operating conditions (CRC Project AVFL-23: Data Mining of FACE Diesel Fuels). In 2009 the Coordinating Re...
Technical Report
Through the PERD 113 (p-001896.001) and ecoEII (p-001390.001) projects, CanmetENERGY collaborated with the US Department of Energy and the Coordinating Research Council (CRC) to develop methods to better characterize transportation fuels and in order to correlate detailed fuel chemistry with physical properties and ultimately with internal combusti...
Article
Information on the sulfur classes present in petroleum is a key factor in determining the value of refined products and processing behavior in the refinery. A large part of the sulfur present is included in polycyclic aromatic sulfur heterocycles (PASHs), which in turn are difficult to desulfurize. Furthermore, some PASHs are potentially more mutag...
Article
Full-text available
The primary objectives of this work were to formulate, blend, and characterize a set of four ultra-low-sulfur diesel surrogate fuels in quantities sufficient to enable their study in single-cylinder-engine and combustion-vessel experiments. The surrogate fuels feature increasing levels of compositional accuracy (i.e., increasing exactness in matchi...
Article
Advancing the capabilities of refinery process models requires fundamental knowledge of hydrocarbon composition and processing behavior at the molecular level. In common practice, however, the main obstacle to reaching such a level of understanding is the difficulty to characterize the molecular composition of petroleum and its derived products wit...
Article
Full-text available
Characterization of the chemical composition of petroleum vacuum distillate fractions is essential to advance the understanding of the fundamental chemistry of refining processes, such as fluid catalytic cracking and hydrocracking. This is a challenging task, primarily as a result of the limitations of current analytical techniques to deal with hea...
Article
To fully advance our understanding of hydrocarbon conversion chemistry requires powerful analytical methods to qualitatively and quantitatively characterize complex petroleum fractions at the molecular level. In the absence of such tools, an alternative solution is to model the molecular composition of hydrocarbon mixtures with limited analytical d...
Conference Paper
Renewable diesel and jet blending components may be produced by hydrotreating waste fats and vegetable oils. The resulting hydrocarbon components are paraffinic in nature and free of sulfur and aromatics. An isomerization process may follow to improve the cold weather properties. The main differences between renewable diesel and jet blending compon...
Article
Full-text available
Temperature coefficients of the refractive index (dn/dT ) in the 25 ◦C to 35 ◦C temperature interval for hydrocarbon mixtures containing as many as 14 compounds were investigated in this work. The measured −dn/dT of the mixtures were compared with calculations based on the values for each compound and their concentrations. Differences of about 1% b...
Article
Polar organic compounds found in industrial process waters, particularly those originating from biodegraded petroleum residues, include 'naphthenic acids' (NA). Some NA have been shown to have acute toxicity to fish and also to produce sub-lethal effects. Whilst some of these toxic effects are produced by identifiable carboxylic acids, acids such a...
Technical Report
In 2009, the Coordinating Research Council (CRC) Fuels for Advanced Combustion Engines (FACE) working group designed a matrix of nine diesel fuels to investigate the influence of cetane number (CN), aromatic content, and 90% distillation temperature (T90) on advanced combustion strategies. The application of comprehensive two-dimensional gas chroma...
Technical Report
Determination of the concentration of hydrocarbons in samples analyzed by comprehensive two-dimensional gas chromatography (GCxGC) is mostly based on Flame Ionization Detection (FID) signal measurements. Since its invention in 1958, the FID has become one of the most popular and widely used detectors in gas chromatography. Current studies are focus...
Article
'Naphthenic acids' (NAs) in petroleum produced water and oil sands process water (OSPW), have been implicated in toxicological effects. However, many are not well characterized. A method for fractionation of NAs of an OSPW was used herein and a multi-method characterization of the fractions conducted. The unfractionated OSPW acidic extract was char...
Technical Report
This report documents and compares the results of detailed analyses of the physical and chemical properties of ten advanced alternative and renewable diesel fuels and four commercial ultra low sulfur diesels (ULSDs). A key objective of this study conducted by the AVFL-19 Working Group of the Coordinating Research Council (CRC) Advanced Vehicle/Fuel...
Conference Paper
Reducing the carbon footprint of industrial processes used to convert Canadian oil sands crudes into clean transportation fuels is a major challenge for upgraders, refiners, and the R&D community. Co-processing biomass with petroleum/bitumen derived feedstocks may provide an alternative solution since the GHG emission from the production and proces...
Technical Report
This report documents the results of detailed analyses of the physical and chemical properties of three FACE Diesel Fuels that were reformulated: FD2B, FD4B, and FD7B. The original matrix of FACE Diesel Fuels was designed by the Fuels for Advanced Combustion Engines (FACE) Working Group of the Advanced Vehicle/Fuel/ Lubricants (AVFL) Committee of t...
Conference Paper
Noble metal catalysts (e.g. Pt, Pd) are commonly used in hydrogenation processes. They have higher hydrogenation capability than base catalysts (e.g. Co, Mo, Ni), but can be easily poisoned by sulphur compounds and lose their activity. This paper presents a specially prepared noble metal catalyst which uses a Pt encapsulated zeolite material to pre...
Article
Noble metal catalysts are commonly used in hydrogenation processes. They are more effective than base metal catalysts such as Mo, Ni, or Co catalysts. However, noble metal catalysts are generally used in environments with sulfur concentrations below 10 ppm since they are susceptible to sulfur poisoning. This paper presents a noble metal catalyst sp...
Technical Report
This report provides detailed chemical and structural hydrocarbon type information for the aromatic hydrocarbon streams. The results presented in this report consist of data obtained using the following analytical techniques: GC-FIMS (gas chromatography-field ionization mass spectrometry) and GCxGC (comprehensive two-dimensional gas chromatography)...
Technical Report
This report provides standard as well as detailed chemical and structural hydrocarbon type information for the aromatic hydrocarbon streams. The results presented in this report consist of data obtained using the following analytical techniques: PIONA (n-paraffin, iso-paraffin, olefin, naphthene and aromatic, ASTM D5443M), DHA (detailed hydrocarbon...
Technical Report
This report provides detailed results from a variety of standard ASTM International-type analyses and advanced characterization techniques conducted to measure the chemical and physical properties of a matrix of diesel test fuels known as the Fuels for Advanced Combustion Engines (FACE) diesel fuels.The work was coordinated by a fuels characterizat...
Article
A variety of issues decide the efficiency of 3D QSAR methods, and their practical importance for drug design is still controversial. This refers both to the predictive ability and the possibility for the indication of these areas within 3D molecular representations that are responsible for biological or chemical effects. Technically, the latter com...
Article
We used comparative molecular surface analysis to design molecules for the synthesis as part of the search for new HIV-1 integrase inhibitors. We analyzed the virtual combinatorial library (VCL) constituted from various moieties of styrylquinoline and styrylquinazoline inhibitors. Since imines can be applied in a strategy of dynamic combinatorial c...
Article
Quantitative Structure Activity Relationship (QSAR) is a term describing a variety of approaches that are of substantial interest for chemistry. This method can be defined as indirect molecular design by the iterative sampling of the chemical compounds space to optimize a certain property and thus indirectly design the molecular structure having th...
Article
Three-dimensional quantitative structure-activity relationship (3D QSAR) modeled for alpha-asarone derivatives using the comparative molecular surface analysis (CoMSA) allowed us to reveal a correlation between the activity of these compounds and the electrostatic potential at the molecular surface. The grid formalism (s-CoMSA) allowed us to indica...
Article
Shape analysis is a powerful tool in chemistry and drug design. In the current work, we compare the results of CoMFA and Comparative Molecular Surface Analysis (CoMSA), the 3D-QSAR method, for a series of hypolipidemic and antiplatelet asarones and antifungal N-myristoyltransferase inhibitors. In this publication we show that a sector CoMSA formali...
Article
Full-text available
In our work, leading to new styrylquinoline and styrylquinazoline inhibitors of HIV integrase, we analyzed virtual combinatorial library that includes these compounds. Using this method we were able to find interesting synthetic targets. We optimized synthetic procedure yielding such compounds and obtained a couple of new analogues. Their activity...
Article
In the current work we investigated 3D-QSAR data by the use of the coupled leave-several-out (LSO) and leave-one-out (LOO) cross-validation (CV) procedures. We verified the above mentioned scheme using both simulated data and real 3D QSAR data describing a series of CoMFA steroids, heterocyclic azo dyes and styrylquinoline HIV integrase inhibitors....
Article
Shape analysis is a powerful tool in chemistry and drug design, and molecular surface defines shape in the molecular scale. In the current publication we presented a novel formalism for the comparative molecular surface analysis (s-CoMSA). The method enables both quantitative modeling of 3D-QSAR and finding possible pharmacophoric sites. The method...
Article
Despite recent investigations aimed at developing for dye molecules Quantitative Structure Activity Relationships on the basis of the data that describe 3D molecular structure of these molecules (so-called 3D QSARs), it is still uncertain whether a pharamacophore hypothesis can be used for modeling dye–cellulose affinities. We have used the Compara...
Article
Despite recent investigations aimed at modeling 3D QSAR for dye molecules a controversy still exists: can a pharamacophore hypothesis be used for such purposes. In the present publication we reported on the application of the CoMSA method for modeling 3D QSAR of azo and anthraquinone dyes. We obtained very predictive models, which significantly out...
Article
Full-text available
We have used SOM and grid 3D and 4D QSAR schemes for modeling the activity of a series of dihydrofolate reductase inhibitors. Careful analysis of the performance and external predictivities proves that this method can provide an efficient inhibition model.
Article
The application of the CoMSA method to analyze 3D QSAR of 50 steroid aromatase inhibitors is described. The 3D QSAR model obtained, reaching a value of cross-validated q(2) = 0.96 (s = 0.31), significantly outperforms those reported in the literature for the CoMFA or CoSA (CoSASA). It is shown that the Uniformative Variable Elimination UVE-PLS or m...
Article
Full-text available
The application of the SOM network in drug design and molecular diversity is discussed. In particular, examples of the applications of the Comparative Molecular Surface Analysis (CoMSA) are reviewed. Molecular surface is a fuzzy category, inspired by the macroscopic world, which has no unique equivalent in the molecular scale. However, it is somewh...
Article
Full-text available
Several applications of the COMSA were discussed including a series of the potential anti-HIV drugs and a series of dyes.
Article
Using the Kohonen neural network, the electrostatic potentials on the molecular surfaces of 14 styrylquinoline derivatives were drawn as comparative two-dimensional maps and compared with their known human immunodeficiency virus (HIV)-1 replication blocking potency in cells. A feature of the potential map was discovered to be related with the HIV-1...
Article
A self-organizing neural network was used to design a novel method capable of the quantitative prediction of molecular properties. The method is based on the comparison of molecular surfaces performed by the coupled neural network and PLS system. Unlike CoMFA and related methods it does not compare the properties describing a discrete set of points...
Article
Different architectures of self-organizing neural networks (SOM) have been used for modeling 3D QSAR. The atomic coordinates and partial atomic charges were used as input signals. In particular, the steroids complexing corticosteroid binding globulin (CBG) that are used as a benchmark measuring the performance of drug design methods have been appli...

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Projects (6)
Project
Develop strategies to co-process biogenic feedstocks in existing petroleum refinery units