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2. Evaluation of ash pozzolanic activity by means of the strength activity index test, frattini test and DTA/TG analysisSabina Dolenec, Vilma Ducman, 2018, izvirni znanstveni članek Povzetek: The pozzolanic activity of five different types of ash was studied using various direct and indirect methods. In addition to strength activity index (SAI) determination and the Frattini test, ash pozzolanicity was assessed via differential thermal and thermogravimetric analyses (DTA/TG) after curing for 7, 28 and 90 days. The results showed that, due to their respective mineralogical, chemical and physical characteristics, the ashes exhibited different levels of pozzolanic activity in terms of the amount of lime with which they could chemically bind, as well as reaction kinetics. Although SAI and Frattini test results were not in agreement in the case of some of the ashes, DTA/TG analysis revealed that a certain amount of portlandite was consumed, thus confirming the occurrence of a pozzolanic reaction. The results also showed that ashes with higher amounts of reactive SiO2 were more reactive, while those with higher BET surface areas displayed a faster pozzolanic reaction rate. Ključne besede: biomass ash, DTA/TG, fly ash, Frattini test, pozzolanic activity, SAI Objavljeno v DiRROS: 11.12.2023; Ogledov: 466; Prenosov: 234 Celotno besedilo (1,05 MB) Gradivo ima več datotek! Več... |
3. Methodology for evaluating the CO2 sequestration capacity of waste ashesSara Tominc, Vilma Ducman, 2023, izvirni znanstveni članek Povzetek: The concentration of CO2 in the atmosphere is constantly increasing, leading to an increase in the average global temperature and, thus, affecting climate change. Hence, various initiatives have been proposed to mitigate this process, among which CO2 sequestration is a technically simple and efficient approach. The spontaneous carbonation of ashes with atmospheric CO2 is very slow, and this is why accelerated carbonation is encouraged. However, not all ashes are equally suitable for this process, so a methodology to evaluate their potential should be developed. Such a methodology involves a combination of techniques, from theoretical calculations to XRF, XRD, DTA-TG, and the calcimetric determination of the CaCO3 content. The present study followed the approach of exposing ashes to accelerated carbonation conditions (4% v/v CO2, 50–55% and 80–85% RH, 20 ◦C) in a closed carbonation chamber for different periods of time until the maximum CO2 uptake is reached. The amount of sequestered CO2 was quantified by thermogravimetry. The results show that the highest CO2 sequestration capacity (33.8%) and carbonation efficiency (67.9%) were obtained for wood biomass bottom ash. This method was applied to eight combustion ashes and could serve to evaluate other ashes or comparable carbon storage materials. Ključne besede: CO2 sequestration, carbonation efficiency, coal ash, wood biomass ash, co-combustion ash, DTA-TG analysis Objavljeno v DiRROS: 08.08.2023; Ogledov: 630; Prenosov: 303 Celotno besedilo (3,73 MB) Gradivo ima več datotek! Več... Gradivo je zbirka in zajema 1 gradivo! |
4. Dataset for the article Methodology for evaluating the CO2 sequestration capacity of waste ashesVilma Ducman, Sara Tominc, 2023, zaključena znanstvena zbirka raziskovalnih podatkov Povzetek: The dataset supports the data in the tables and figures in the article Methodology for evaluating the CO2 sequestration capacity of waste ashes (doi: 10.3390/ma16155284). It contains the original masses of waste ash before and during carbonation treatment, the sequestered CO2 masses after carbonation treatment, mass uptake calculations, calcimetric measurements, calculations of theoretical maximum sequestered CO2 (based on XRF results) and carbonation efficiency (CE), original results of DTA/TG analysis of individual ashes, original results of XRF measurement and data from XRD analyses supported by X-ray diffractograms not published in the article. Ključne besede: CO2 sequestration, carbonation efficiency, coal ash, wood biomass ash, co-combustion ash, DTA-TG analysis Objavljeno v DiRROS: 14.07.2023; Ogledov: 997; Prenosov: 416 Raziskovalni podatki (245,99 KB) Gradivo ima več datotek! Več... |