The mineral sequestration of CO2 with the use of fly ash from the co-combustion of coal and biomass

Abstract

Summary As a result of energy production processes, the power industry is the largest source of CO2 emissions in Poland. Emissions from the energy sector accounted for 52.37% (162 689.57 kt) of the total emissions in 2015, which was estimated at 310.64 million tons of CO2. In recent years, the tightening of regulations on the use of renewable energy sources has resulted in an increased amount of biomass used in the professional energy industry. This is due to the fact that the CO2 emissions from biomass combustion are not included in the total emissions from the combustion of fuels, resulting in the zero- emission factor for biomass. At the same time, according to the hierarchy of waste management methods, recycling is the preferred option for the management of by-products generated during energy production. The fly ashes resulting from the biomass combustion in pulverized boilers (which, due to their chemical composition, can be classified as silicate ash) were subjected to analysis. These ashes can be classified as waste 10 01 17 - fly ash from co-firing other than mentioned in 10 01 16 according to the Regulation of the Minister of the Environment of December 9, 2014 on waste catalogues. The maximum theoretical carbon dioxide binding capacity for the analyzed fly ashes resulting from the co-combustion of biomass is 8.03%. The phase composition analysis of the fly ashes subjected to carbonation process has shown, in addition to the components identified in pure fly ash samples (SiO2, mullite), the presence of calcium carbonate − calcite − the primary product of the carbonation process, as indicated by the results of both X-ray and thermogravimetric analysis.The degree of carbonation has been determined based on the analysis of the results of the phase composition of fly ash resulting from the co-firing of biomass and bituminous coal. The calculated degree of carbonation amounted to 1.51%. The carbonation process is also confirmed by the lowered pH of the water extracts, decreasing from 11.96 for pure ashes to 8.7 for CO2 treated fly ashes. In addition, the carbonation process has reduced the leaching of pollutants, most notably chlorides, sulphates, and potassium.

Mineral Carbonation of Biomass Ashes in Relation to Their CO2 Capture and Storage Potential

“…The reference data for different BAs worldwide show that their CCS capacity is 1−17% (mean 5%), and such values are comparable or greater to those of many commercial adsorbents. 14,15,18,20,21,29 The above values are also similar to those determined for the short-term stored BAs, while the long-term stored and weathered BAs mostly reveal significantly higher CCS potential in comparison with the reference data. The present results and literature data demonstrate that BA is particularly prospective for CCS because the concentrations of key alkaline-earth and alkaline oxides can reach very high values.…”

Research on Utilizable Calcium from Calcium Carbide Slag with Different Extractors and Its Effect on CO2 Mineralization

“…Mineralized slag can also be used in building materials, for instance in the preparation of steel slag–gypsum carbide building materials [ 20 ]. CO 2 mineralization studies have also been conducted on other alkaline industrial solid wastes, such as high-calcium fly ash [ 21 , 22 , 23 , 24 ] and construction waste [ 25 , 26 ]. These alkaline industrial solid wastes exhibit excellent CO 2 mineralization capacity.…”

Investigation of Preparation and Shrinkage Characteristics of Multi-Source Solid Waste-Based Cementitious Materials

“…Bumanis et al [7] prepared bulk alkaliactivated materials using discarded metakaolin and recycled aluminum and evaluated their potential for inducing precipitation and adsorption to extract heavy metals from wastewater and directly applying them to fill roadbeds. Khalid et al [8] synthesized geopolymers using fly ash and slag as precursors using a one-step hydrothermal method. The adsorption test shows that the maximum adsorption capacity of the geopolymer for Pb 2+ is significantly better than the reported large volume adsorbents so far.…”