By-products of combustion are the result of electricity and heat production in power generation units fired with fossil fuels. The management of combustion by-products at PGE Group turns waste into high-value substances that are used in other branches of economy (cement industry, construction, road-building, mining) and thus reduces the volume of ultimate waste generated. In 2020 alone, a total of 4.33 million tonnes of valuable commercial materials, including ash, slag and gypsum from flue gas desulphurisation systems, were generated in power plants and combined heat and power plants belonging to PGE Group during the production of electricity and heat.
The re-use of combustion by-products in various branches of industry has tangible benefits for the environment. The nuisance of landfills for people and the natural environment is reduced as there is no need to allocate new land for building them and the accompanying infrastructure.
By-products of combustion successfully replace natural raw materials (e.g. natural gypsum, aggregate), thus reducing their extraction as well as emissions that accompany their extraction. The responsible use of secondary raw materials, such as gypsum from flue gas desulphurisation plants, is a good example of implementing the principle of priority for secondary raw materials in economic processes. Such measures help to protect fossil resources for future generations.
Another important aspect is the reduction of greenhouse gas emissions in production cycles that use combustion by-products. A case in point is the reduced carbon footprint of cement production processes using fly ash or gypsum board production processes using synthetic gypsum. The use of ash with a high calcium content from commercial power generation reduces CO2 emissions that accompany the industries producing traditional binders such as cement or lime. In this way, the conventional power generation sector contributes to the avoidance of CO2 emissions due to the use of combustion by-products supplied from power plants to cement production factories. According to a report prepared by the National Centre for Emissions Balancing and Management, thanks to the production of binders from combustion by-products, which successfully replace cement and natural lime in selected geotechnical applications – mainly in road construction, CO2 emissions can be reduced by almost 568,000 tonnes over a period of five years.