Sustainable Supply of Scandium for the EU Industries from Liquid Iron Chloride Based TiO2 Plants

Scandium (Sc) applications in solid oxygen fuel cells, aeronautics and heat exchange systems are forecasted to increase significantly without a sufficient continuous Sc supply for Europe. ScaVanger is an EU project for upscaling Sc extraction and purification technologies from various TiO2 pigment production residues. High purity Sc2O3 and ScF3 will be produced at competitive prices for the EU market. The ScaVanger process is expected to result in a 10% higher production rate and higher product purity as processing starts with a unique cleaning process of actinides. The first plant at a major European TiO2 pigment production site will be supplying about 30 t/a of Sc2O3.

Evaluating the reactivity of CuO-TiO2 oxygen carrier for energy production technology with CO2 capture

Chemical looping combustion (CLC) processes have been shown to be promising and effective in reducing CO2 production from the combustion of various fuels associated with the growing global demand for energy, as it promotes indirect fuel combustion through solid oxygen carriers (SOC). Thus, this study aims to synthesize, characterize and evaluate mixed copper and titanium oxide as a solid oxygen carrier for use in combustion processes with chemical looping. The SOC was synthesized based on stoichiometric calculations by the polymeric precursor method and characterized by: X-ray fluorescence (XRF), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM-FEG) with EDS, and Programmed Temperature Reduction (PTR). The oxygen carrying capacity (ROC) and the speed index of the reduction and oxidation cycles were evaluated by Thermogravimetric Reactivity (TGA). The main reactive phase identified was: The CuO phase for the mixed copper and titanium oxide were identified and confirmed by X-ray diffraction using the Rietveld refinement method. The reactivity of the CuO-TiO2 system was high, obtaining a CH4 conversion rate above 90% and a speed index of 40%/min. Due to the structural characteristics and the reactivity tests of this material, it is concluded that mixed copper and titanium oxide have the necessary requirements to be used in chemical looping combustion (CLC) processes.

Effects of solid oxygen fertilizers and biochars on nitrous oxide production from agricultural soils in Florida

Elevated levels of nitrous oxide (N2O) emissions are a matter of concern in agricultural soils especially when flooding (hypoxic conditions) results from over irrigation or frequent rains. This study is the first to report the use of two solid oxygen fertilizers (SOFs, calcium peroxide and magnesium peroxide) to reduce N2O production in mineral and organic soils amended with N fertilizer in a short-term laboratory incubation besides two biochars. In general, organic soil had greater N2O production than mineral soil. Soils amended with nitrogen fertilizer exhibited increased N2O production, by 74 times in mineral soil and 2 times in organic soil. Both solid oxygen fertilizers in mineral soil (98–99%) and calcium peroxide in organic soil (25%) successfully reduced N2O production than corresponding N fertilized treatments. Additionally, a greater level of available nitrate–N (52–57 and 225 mg kg−1 in mineral and organic soil, respectively) was recorded with the solid oxygen fertilizers. Corn residue biochar with N fertilizer increased N2O production in mineral soil but decreased in organic soil, while pine bark biochar with N did not affect the N2O production in either soil. Depending on soil, appropriate SOFs applied were able to reduce N2O production and maintain greater nitrate–N levels in flooded soil. Thus, solid oxygen fertilizers can potentially be used as an effective way to reduce N2O emission from hypoxic soil in agricultural production systems.

Chemical Looping Combustion Related Processes Using Solid Oxygen Carriers Oxidized in CO2 Atmosphere

Chemical-looping combustion (CLC) is an attractive process in CO2 capture, especially when solid oxygen carriers are used in it. The main requirements for oxygen-transporting materials include appropriate oxidation (in air) and reduction (in the presence of fuel) ability. In the paper a conceptual proposition for CLC-related processes with the application of solid oxygen carriers oxidized in both air and CO2 atmosphere has been presented. The possibility of the “looping” process on the same carriers using both CO2 and air atmosphere as an oxidizing agent allows us to enrich the concept of CLC and related processes by proposing a cyclic recirculation of the produced CO2 back to the installation. The oxidizing of solid oxygen carrier in a CO2 atmosphere is accompanied by CO emission from the plant. This toxic gas could be transformed into a useful product in any chemical process. It is possible to combine the looping processes with manufacturing of any appropriate morphological form of carbon in the cyclic CO disproportionation process. The combined process could lead to a lower CO2 emissions to the environment. SrTiO3 doped by Cr (STO:Cr) and a mixture of TiO2- and Ni-based compounds (TiO2-Ni) were investigated as oxygen transporting materials. The experiment methodology based on thermogravimetric, diffraction and spectroscopic studies was shown. Thermogravimetric (TGA) and Powder Diffraction (XRD) measurements were provided in-situ during a few cycles in a reducing (Ar+3 % H2) and oxidizing environment. Moreover, the STO:Cr powders were characterized ex-situ by the X-ray Photoelectron Spectroscopy (XPS) method. It was found that in tested conditions the cyclic process of the investigated powders’ oxidation and reduction is possible. Satisfactory results considering the oxygen transport capacity was obtained for the TiO2-Ni sample.

Solid Oxygen-Purifying (SOP) Filters: A Self-Disinfecting Filters to Inactivate Aerosolized Viruses

Normal heating, ventilation, and air conditioning (HVAC) systems typically use high-efficiency particulate air (HEPA) filters, which can filter dust, various pollutants, and even bacteria and viruses from indoor air. However, since HEPA filters cannot not clean themselves and due to the nature of these microbes which can survive for long periods of time, changing these filters improperly could transmit pathogenic bacteria or viruses, and could even lead to new infections. This study indicated that these manufactured Solid Oxygen-purifying (SOP) filters have the potential to self-disinfect, filter, and inactivate aerosolized viruses. MS2 bacteriophage was used as a model virus in two different experiments. The first experiment involved aerosolization of the virus, while the second were a higher viral load using a soaking method. The SOP filters inactivated up to 99.8% of the virus particles in both experiments, provided that the density of the SOP filter was high. Thus, SOP filters could self-clean, which led to protection against airborne and aerosolized viruses by inactivating them on contact. Furthermore, SOP filters could be potentially use or addition in HVAC systems and face masks to prevent the transmission of airborne and aerosolized viruses.

Stability and metallization of solid oxygen at high pressure

Using first principles theory, a metallic molecular phase of solid oxygen is determined to be thermodynamically stable at elevated temperatures in the pressure range between 50 and 100 GPa.

Operando diffuse reflectance UV-vis spectroelectrochemistry for investigating oxygen evolution electrocatalysts

A diffuse reflectance UV-vis spectroelectrochemical study on Zn0.35Co0.65O and CoAl2O4 tracking the changes of solid oxygen evolution catalysts under working conditions to derive structure-activity correlations and insights in the active structures.