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The paper evaluates the possibility of efficiently processing waste generated in the process of biomass torrefaction into a non-toxic material, suitable for practical reuse. The water was evaporated from the liquid fraction resulting from the torrefaction of Virginia mallow, after which the resulting sludge was subjected to vitrification. The vitrification process was carried out at 1450 °C using tempered glass cullet, which constituted 85% by weight of the total processed material. The obtained product was subjected to the following analyses: microstructural characterization, X-ray diffraction, energy dispersive spectroscopy, spectroscopic tests, as well as measurements of hardness and ion leachability in an aqueous medium. It was found that vitrification of the sludge obtained from the waste liquid fraction leads to incorporation of the inorganic components of the waste into the glass structure, and in the case of organic components, causes their thermal decomposition. As a result of vitrification, a product was obtained that has no toxic properties and is characterized by favorable utility properties, i.e. low ion leachability and high hardness, higher than the hardness of the glass used in the vitrification process. The conducted research showed that vitrification is an effective method to recycle waste generated in the production process of treated biomass, and the product of the vitrification process can be used, for example, in the production of glassy building materials. • Wastes generated during biomass torrefaction can be effectively vitrified. • Vitrification process converts biomass torrefaction waste into a harmless product. • Vitrificat is amorphous and characterised by high hardness and low ion leachability. • Vitrification may be an alternative to other waste disposal techniques. [ABSTRACT FROM AUTHOR]

Abstract The main problem and also challenge was to find a satisfactory effective tool for real-time control the torrefaction/pyrolysis process of biomass and to evaluate (also in real-time conditions) biochar quality. This paper presents results from investigation on a new method for both evaluating biochar quality and control biomass thermal processing at temperatures of 300, 350 and 400 ◦ C. Thermal processing of biomass in this temperature range is torrefaction and pyrolysis. Investigation was focused on processing Virginia Mallow (Sida Hermaphrodita) energetic crops. Several strong correlations were observed as follows: carbon and hydrogen content in biochar (charcoal), oxygen content, ash and volatile matter from biochar, calorific value and temperature of the process and finally, acetic acid in condensate and carbon content in the biochar. The results show that the content of acetic acid, being one of the major compounds present in the condensate (black liquor, biooil), is in satisfactory linear correlation with the process temperature and furthermore, with carbon content in biochar. The mathematical description for this polynomial function was proposed as follows: Carbon (%) = 0.6e-3 x Acetic Acid (ppm)+49.5. The correlation between acetic acid in black liquor and carbon in biochar was used to introduce a new method which can be considered as a diagnostic tool for determining biochar quality in real-time conditions during biomass thermal processing. Hence, carbon content in biochar as well as its calorific value can be determined by measuring percentage of acetic acid in the condensate. This correlation was considered as the main novelty presented here. This method provides relatively fast evaluation of quality of biochar produced in industrial scale torrefaction systems, what makes it possible to optimize process parameters (temperature, retention time) in real time conditions and improve biochar production process in this way. Highlights • C H tradeoff for biochar is in strong linear negative correlation. • Acetic acid in biooil increased from 5 to 25% with process temperature increase. • Acetic acid in biooil is verifiable correlated with carbon content in biochar. • Acetic acid vs. carbon correlation can be used to control biochar quality. [ABSTRACT FROM AUTHOR]

There can be observed global interest in waste pyrolysis technology due to low costs and availability of raw materials. At the same time, there is a literature gap in forecasting environmental effects of thermal waste treatment installations. In the article was modelled the chemical composition of pyrolysis gas with main focus on the problem in terms of environmental hazards. Not only RDF fuel was analysed, but also selected waste fractions included in its composition. This approach provided comprehensive knowledge about the chemical composition of gaseous pyrolysis products, which is important from the point of view of the heterogeneity of RDF fuel. The main goal of this article was to focus on the utilitarian aspect of the obtained calculation results. Final results can be the basis for estimating ecological effects, both for existing and newly designed installations. Pyrolysis process was modelled using Ansys Chemkin-Pro software. The investigation of the process were carried out for five different temperatures (700, 750, 800, 850 and 900 °C). As an output the mole fraction of H 2 , H 2 O, CH 4 , C 2 H 2 ,C 2 H 4 , C 3 H 6 , C 3 H 8 , CO, CO 2 , HCl and H 2 S were presented. Additionally the reaction pathways for selected material were presented. Based on obtained results, it was established that the residence time did not influenced on the concentration of products, contrary to temperature. The chemical composition of pyrolytic gas is closely related to wastes origin. The application of Chemkin-Pro allowed the calculation of formation for each products at different temperatures and formulation of hypotheses on the reaction pathways involved during pyrolysis process. Further, based on the obtained results confirmed the possibilities of using pyrolysis gas from RDF as a substitute for natural gas in energy consumption sectors. Optimization of the process can be conducted with low financial outlays and reliable results by using calculation tools. Moreover it can be predicted negative impact of obtained products on the future installation. [ABSTRACT FROM AUTHOR]

The study assessed the possibility of using waste glass cullet from the screen part of CRTs (cathode ray tube) in the vitrification of asbestos-cement materials (ACM). The composition consisting of 50% by mass ACM and 50% by mass cullet was subjected to vitrification. The research material before and after vitrification was subjected to comparative analysis. As a result of vitrification, a transparent amorphous material was produced with a hardness about 7% higher than that of CRT glass and lower ion leachability in an aqueous environment compared to ACM. X-ray and spectroscopic examinations did not reveal the presence of chrysotile, i.e. a type of asbestos found in ACM. This fact proves that during vitrification the asbestos decomposed and formed a lattice of glass composed of the products of this decomposition. Moreover, the presence of heavy metals in the vitrified product was found, including Ba and Sr, the source of which was the CRT cullet. The obtained research results prove that ACM vitrification with CRT cullet leads to the effective utilization of both types of waste during one technological process. Therefore, the vitrification of ACM can be successfully carried out using waste CRT glass, and the harmless product obtained in the vitrification process can be used in practice. The use of CRT cullet in the vitrification of asbestos-cement materials will also have a positive impact on the environment as it will reduce the amount of electronic waste deposited in landfills. [Display omitted] • The vitrification of ACM can be successfully carried out using CRT glass cullet. • It is possible to simultaneously dispose of ACM and CRT cullet in one process. • The vitrification process transforms the hazardous wastes into a harmless product. • Vitrification is an effective method of neutralizing asbestos-cement materials. • The vitrification process leads to the complete decomposition of chrysotile. [ABSTRACT FROM AUTHOR]