X-RAY DIFFRACTION USED TO MEASURE LEVELS OF SP2 AND SP3 CARBON IN FOSSIL FUELS: A MICROCOSM OF THE 1990'S, WORKING HARDER AND GETTING LESS

ABSTRACTThe sorption processes for hydrogen and carbon dioxide are of considerable, and growing interest, particularly due to their relevance to a society that seeks to replace fossil fuels with a more sustainable energy source. X-ray diffraction allows a unique perspective for studying structural modifications and reaction mechanisms that occur when gas and solid interact. The fundamental challenge associated with such a study is that experiments are conducted while the solid sample is held under a gas pressure. To date in-situ high gas pressure studies of this nature have typically been undertaken at large-scale facilities such as synchrotrons or on dedicated laboratory instruments. Here we report high-pressure XRD studies carried out on a multi-purpose diffractometer. To demonstrate the suitability of the equipment, two model studies were carried out, firstly the reversible hydrogen cycling over LaNi5, and secondly the structural change that occurs during the decomposition of ammonia borane that results in the generation of hydrogen gas in the reaction chamber. The results have been finally compared to the literature. The study has been made possible by the combination of rapid X-ray detectors with a reaction chamber capable of withstanding gas pressures up to 100 bar and temperatures up to 900 °C.

Download Full-text

Oxalic Acid as a Hydrogen Donor for the Hydrodesulfurization of Gas Oil and Deoxygenation of Rapeseed Oil Using Phonolite-Based Catalysts

Molecules ◽

10.3390/molecules25163732 ◽

2020 ◽

Vol 25 (16) ◽

pp. 3732

Author(s):

José Miguel Hidalgo Herrador ◽

Jakub Fratczak ◽

Zdeněk Tišler ◽

Hector de Paz Carmona ◽

Romana Velvarská

Keyword(s):

Oxalic Acid ◽

Rapeseed Oil ◽

Fossil Fuels ◽

Raw Materials ◽

Hydrogen Donor ◽

Gas Oil ◽

X Ray Diffraction ◽

X Ray ◽

Hydrogen Donors ◽

Temperature Programmed

The use of renewable local raw materials to produce fuels is an important step toward optimal environmentally friendly energy consumption. In addition, the use of these sources together with fossil fuels paves the way to an easier transition from fossil to renewable fuels. The use of simple organic acids as hydrogen donors is another alternative way to produce fuel. The present work reports the use of oxalic acid as a hydrogen donor for the catalytic hydrodesulfurization of atmospheric gas oil and the deoxygenation of rapeseed oil at 350 °C. For this process, one commercial NiW/SiO2–Al2O3 solid and two NiW/modified phonolite catalysts were used, namely Ni (5%) W (10%)/phonolite treated with HCl, and Ni (5%) W (10%)/phonolite treated with oxalic acid. The fresh phonolite catalysts were characterized by Hg porosimetry and N2 physisorption, ammonia temperature programmed desorption (NH3-TPD), X-ray diffraction (XRD), and X-ray fluorescence (XRF). The sulfided metal phonolite catalysts were characterized by XRD and XRF. Hydrodesulfurization led to a decrease in sulfur content from 1 to 0.5 wt% for the phonolite catalysts and to 0.8 wt% when the commercial catalyst was used. Deoxygenation led to the production of 15 and 65 wt% paraffin for phonolite and commercial solids, respectively. The results demonstrate the potential of using oxalic acid as a hydrogen donor in hydrotreating reactions.

Download Full-text

Cloning, purification, crystallization and preliminary X-ray studies of a carbohydrate-binding module (CBM_E1) derived from sugarcane soil metagenome

Acta Crystallographica Section F Structural Biology Communications ◽

10.1107/s2053230x14015520 ◽

2014 ◽

Vol 70 (9) ◽

pp. 1232-1235 ◽

Cited By ~ 2

Author(s):

Bruna Medeia Campos ◽

Thabata Maria Alvarez ◽

Marcelo Vizona Liberato ◽

Igor Polikarpov ◽

Harry J. Gilbert ◽

...

Keyword(s):

Fossil Fuels ◽

Plant Biomass ◽

Metagenomic Library ◽

Glycoside Hydrolases ◽

Diffusion Method ◽

Carbohydrate Binding ◽

X Ray Diffraction ◽

X Ray ◽

Cell Parameters ◽

Carbohydrate Binding Modules

In recent years, owing to the growing global demand for energy, dependence on fossil fuels, limited natural resources and environmental pollution, biofuels have attracted great interest as a source of renewable energy. However, the production of biofuels from plant biomass is still considered to be an expensive technology. In this context, the study of carbohydrate-binding modules (CBMs), which are involved in guiding the catalytic domains of glycoside hydrolases for polysaccharide degradation, is attracting growing attention. Aiming at the identification of new CBMs, a sugarcane soil metagenomic library was analyzed and an uncharacterized CBM (CBM_E1) was identified. In this study, CBM_E1 was expressed, purified and crystallized. X-ray diffraction data were collected to 1.95 Å resolution. The crystals, which were obtained by the sitting-drop vapour-diffusion method, belonged to space groupI23, with unit-cell parametersa=b=c= 88.07 Å.

Download Full-text

Preparation of Solid Fuel Hydrochar over Hydrothermal Carbonization of Red Jujube Branch

Energies ◽

10.3390/en13020480 ◽

2020 ◽

Vol 13 (2) ◽

pp. 480 ◽

Cited By ~ 2

Author(s):

Zhiyu Li ◽

Weiming Yi ◽

Zhihe Li ◽

Chunyan Tian ◽

Peng Fu ◽

...

Keyword(s):

Energy Recovery ◽

Fossil Fuels ◽

Fossil Fuel ◽

Hydrothermal Carbonization ◽

Amorphous Structure ◽

Biomass Energy ◽

X Ray Diffraction ◽

X Ray ◽

Solid Biofuels ◽

Forestry Residues

Biomass energy is becoming increasingly important, owing to the decreasing supply of fossil fuels and growing environmental problems. Hydrothermal carbonization (HTC) is a promising technology for producing solid biofuels from agricultural and forestry residues because of its lower fossil-fuel consumption. In this study, HTC was used to upgrade red jujube branch (RJB) to prepare hydrochar at six temperatures (220, 240, 260, 280, 300, and 320 °C) for 120 min, and at 300 °C for 30, 60, 90, and 120 min. The results showed that the energy recovery efficiency (ERE) reached maximum values of 80.42% and 79.86% at a residence time of 90 min and a reaction temperature of 220 °C, respectively. X-ray diffraction results and Fourier transform infrared spectroscopy measurements show that the microcrystal features of RJB were destroyed, whereas the hydrochar contained an amorphous structure and mainly lignin fractions at increased temperatures. Thermogravimetric analysis shows that the hydrochar had better fuel qualities than RJB, making hydrochar easier to burn.

Download Full-text

Characterization Techniques Coupled With Mathematical Tools for Deepening Asphaltenes Structure

10.20944/preprints202111.0308.v1 ◽

2021 ◽

Author(s):

Barbara Apicella ◽

Anna Ciajolo ◽

Andrea Carpentieri ◽

Ciprian Popa ◽

Carmela Russo

Keyword(s):

Fossil Fuels ◽

Data Interpretation ◽

Heavy Fraction ◽

X Ray Diffraction ◽

Mathematical Methods ◽

X Ray ◽

Molecular Weights ◽

Aromatic Molecules ◽

Wide Range ◽

Self Aggregation

Asphaltenes constitute a heavy fraction of fossil fuels and their characterization is still a very difficult and challenging issue due to their complex and variable composition. Asphaltene components are highly condensed aromatic molecules having some heteroatom and aliphatic functionalities. Their molecular weights distribution span a wide range, from hundreds to millions of units, in dependence on the diagnostic used, leading to speculation about possible occurrence of self-aggregation. In the present work, mass spectrometry, with properly developed mathematical methods, size ex-clusion chromatography and X-ray diffraction analysis have been applied to asphaltenes for giving some further insight on their MW distribution and characteristics. The results here reported give further quantitative support to the experimental data interpretation already reported in previous works.

Download Full-text

Growth and Characterization of Polycrystalline Silicon Thin Films for Photocatalytic Splitting of Water in Oxide-Si Tandem Cells

10.20944/preprints202007.0274.v1 ◽

2020 ◽

Author(s):

Ali Zahid ◽

Umer Zahid ◽

Aamir Hasan ◽

Muhammad Khuldoon

Keyword(s):

Band Gap ◽

Fossil Fuels ◽

Crystalline Silicon ◽

X Ray Diffraction ◽

Active Electrode ◽

Band Gap Engineering ◽

X Ray ◽

Silicon Thin Films ◽

Deposition Parameters

With the decline in fossil fuels, hydrogen-based alternatives provide a reliable and clean source for sustainable energy generation. In these endeavors, photochemical splitting for hydrogen production through tandem cells has been the source of much theoretical and experimental research in science. Much focus has been placed on interfacial band gap engineering as one of the most promising routes in the generation of hydrogen.This present work explores sputtering of n-silicon to form the active electrode in a n-Si | n-TiO2 tandem cell and investigates the effect of variations in sputtering and post sputtering treatment parameters (rapid thermal annealing and long cycle annealing) for successful deposition of crystalline Silicon. The samples were successfully characterized via Raman Spectroscopy, X-ray Diffraction and Optical Transmission Spectroscopy to ascertain prevalent crystalline order and optical band gap, under different sputtering and post-sputtering conditions. Relevant conclusions were drawn to ascertain the best possible deposition parameters of n-Si for photocatalytic water splitting.

Download Full-text

Fourier Transform Infrared (FTIR) Spectroscopy and X-Ray Diffraction (XRD) Analysis of Synthetic Waste during Combustion Process

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.851.220 ◽

2020 ◽

Vol 851 ◽

pp. 220-227

Author(s):

Sukarni Sukarni ◽

Lukman Arifianto Andi Saputra

Keyword(s):

Fourier Transform ◽

Ftir Spectroscopy ◽

Fossil Fuels ◽

Combustion Process ◽

Value Added ◽

Fourier Transform Infrared ◽

Xrd Analysis ◽

Volatile Matter ◽

X Ray Diffraction ◽

X Ray

The availability of synthetic waste (SW) continuously increases, but on the contrary fossil fuels resources always decrease. The potential of SW for alternative fuel is critical to investigate for overcoming the problem generated from its overabundance and to provide its value-added. In this study, the changes of the macromolecular and the mineralogical during the SW combustion processes were investigated by Fourier Transform Infrared (FTIR) spectroscopy and x-ray diffraction (XRD), respectively. The combustion has been performed by using thermogravimetric analyzer (TGA) at a heating rate of 10 °C/min, from 25 to 1000 °C, with 100 ml/min constant flowrate of air atmosphere. According to the TGA results, the decomposition stage of the sample can be identified as a function of temperature and time. From ambient temperatures to 293 °C the sample experienced the first decomposition process that was correlated with the moisture losses and light volatile release. Macromolecular changes occurred at the temperature 293 °C where functional group of C–H in methylene was decomposed due to the removal of volatile matter. From the temperature of 293 to 485 °C the sample underwent the second stage of decomposition. The XRD result showed that mineral changes occurred at the temperature of 485 °C where the KCl compound was formed. In line with the escalating temperature, SiO2 was decomposed at a temperature of 590 °C. The final stage occurred at the temperature 625 to 1000 °C indicated by constant of TG line. At 625 °C, XRD result indicated the significant increasing of the CaCO3 compound.

Download Full-text

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071107 ◽

1973 ◽

Vol 31 ◽

pp. 132-133 ◽

Cited By ~ 1

Author(s):

R. E. Herfert

Keyword(s):

Surface Characterization ◽

Analytical Techniques ◽

X Ray Diffraction ◽

Depth Of Penetration ◽

X Ray ◽

The Past ◽

Transmission Electron ◽

Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Download Full-text

Ribosome Structural Organization

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051670 ◽

1974 ◽

Vol 32 ◽

pp. 332-333

Author(s):

James A. Lake

Keyword(s):

Ribosomal Proteins ◽

Structural Organization ◽

Three Dimensional ◽

Small Subunit ◽

Structural Studies ◽

X Ray Diffraction ◽

Specific Antibodies ◽

X Ray ◽

E Coli ◽

Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

Download Full-text

Electron Microscopy of Human Gallstones

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065523 ◽

1971 ◽

Vol 29 ◽

pp. 296-297

Author(s):

C. Wolpers ◽

R. Blaschke

Keyword(s):

Electron Microscopy ◽

Room Temperature ◽

Bile Pigment ◽

X Ray Diffraction ◽

Triclinic Crystal System ◽

X Ray ◽

Follow Up Study ◽

Infra Red ◽

Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

Download Full-text