Aerogel insulation materials for industrial installation : properties and structure of new factory-made products

In this article the comparisons of two new factory-made Chinese aerogel products with the Pyrogel® product, all available on the market, are presented. The aerogel products are in a flexible blanket form and all products are dedicated for high temperature applications. The properties of the samples such as their dimension stability, water vapour transmission and water absorption are also described. Additionally the microstructure and chemical composition of the products are analysed using SEM/ EDS (scanning electron microscopy coupled with X-ray energy-dispersive spectroscopy). The differences in the maximum service temperature are presented. The internal self-heating of the aerogel samples is described and is compared to a similar effect observed in mineral wool samples. The results in the change of the thermal properties in a wide range of temperatures (+ 10–600°C) are shown. The obtained results are correlated with the mineral wool data. The correlation shows an advantage in a highefficiency thermal performance of aerogel products compared to other insulation materials at high temperatures

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

Obtaining an Artificial Aggregate from Cement-Asbestos Waste by the Melting Technique in an Arc-Resistance Furnace

Nowadays, asbestos waste still remains a serious problem. Due to the carcinogenic properties of asbestos, which are related to its fibrous structure, the exposure to asbestos mineral and asbestos-containing materials (ACM) causes dangerous health effects. This problem can be solved by recycling techniques, which allow the re-use of neutralized asbestos waste, instead of disposing it in special landfills. The article presents the results of research aimed at investigating the possibility of obtaining aggregates from asbestos waste by the fusion process in the electric arc-resistance process. A mixture of ACM with selected fluxes was were melted and then cast to form a grain of aggregates. The chemical composition of the material was determined before and after the melting process. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were applied to evaluate the effects of the fusion process. The main properties of the obtained aggregate were also measured. The results confirmed that the fibrous structure of asbestos was destroyed in the obtained material, which can be successfully used for the production of artificial aggregates

Manufacture of Fine-Pored Ceramics by the Gelcasting Method

The fine-pored materials represent a wide range of applications and searches are being continued to develop methods of their manufacturing. In the article, based on measurements on fine-grained powders of Al2O3, TiO2, and SiO2, it has been demonstrated that gelcasting can be relatively simple method of obtaining of nanoporous materials with high values of both specific surface area and open porosity. The powders were dispersed in silica sol, and the gelling initiator was NH4Cl. The usefulness of experiment design theory for developing of fine-pored materials with high porosity and specific surface area was also shown

Functionalization of the Implant Surface Made of NiTi Shape Memory Alloy

To functionalize and improve the biocompatibility of the surface of a medical implant made of NiTi shape memory alloy and used in practice, a clamp, multifunctional layers composed of amorphous TiO2 interlayer, and a hydroxyapatite coating were produced. Electrophoresis, as an efficient method of surface modification, resulted in the formation of a uniform coating under a voltage of 60 V and deposition time of 30 s over the entire volume of the implant. The applied heat treatment (800 °C/2 h) let toa dense, crack-free, well-adhered HAp coating with a thickness of ca. 1.5 μm. and a high crack resistance to deformation associated with the induction of the shape memory effect in the in the deformation range similar to the real implant work after implantation. Moreover, the obtained coating featured a hydrophilic (CA = 59.4 ± 0.3°) and high biocompatibility