The potential of FBC fly ashes to reduce CO2 emissions

Alicja Uliasz-Bocheńczyk,Eugeniusz Mokrzycki

doi:10.1038/s41598-020-66297-y

Abstract

The production of electricity and heat in Poland is the reason why the commercial power industry is the largest emitter of CO2. At the same time, significant amounts of solid by-products of combustion, which can be used to bind CO2 by mineral carbonation, are generated during the production processes. The article presents the results of research on mineral sequestration of CO2 (suspension-CO2) using fluidized bed combustion (FBC) fly ashes from hard coal combustion. The analyzed fluidized bed combustion (FBC) fly ashes were characterized by a significant free CaO content (1.7–6.8%) and a high CO2 binding potential ranging from 9.7 to 15.7%. In the case of fluidized bed combustion (FBC) fly ashes suspensions, the basic product of the carbonation process is calcium carbonate, which is clearly indicated by the results of the phase composition determination of solidified suspensions of fluidized bed combustion (FBC) fly ashes. The degree of carbonation, i.e. the degree of CO2 binding, calculated on the basis of the calcium carbonate content, in the analyzed suspensions was up to 1.1%. Mineral carbonation also reduces the leachability of pollutants such as: Zn, Cu, Pb, Ni, As, Hg, Cd, Cr, Cl, and SO42-. The pH is also reduced from about 12 to about 9. Aqueous suspensions of fluidized bed combustion (FBC) fly ashes with introduced CO2 can potentially be used in underground mining. These activities are in line with the concepts of Carbon Capture and Utilization and the idea of circular economy.

Highlights

The production of electricity and heat in Poland is the reason why the commercial power industry is the largest emitter of CO2
One of the possibilities to reduce CO2 emissions is mineral sequestration using waste generated in the same energy production process
Mineral sequestration is a method of reducing CO2 emissions, in which fly ashes from coal combustion play a special role

Summary

Introduction

The production of electricity and heat in Poland is the reason why the commercial power industry is the largest emitter of CO2. Aqueous suspensions of fluidized bed combustion (FBC) fly ashes with introduced CO2 can potentially be used in underground mining These activities are in line with the concepts of Carbon Capture and Utilization and the idea of circular economy. This is due to the fact that coal is the primary fuel used in the power industry, which is conditioned by the abundant resources of this energy source in Poland Due to these conditions, it will be difficult to reduce CO2 emissions from energy production. Mineral sequestration is a method of reducing CO2 emissions, in which fly ashes from coal combustion play a special role. They are produced in the same energy production process; mineral sequestration may allow their economic use

Findings

Discussion

Conclusion