Carbon footprint analysis of calcined gypsum production in the Czech Republic

Sustainable development efforts aimed at substantial reduction of carbon dioxide emissions focused research activities in this field, among others, on a partial or full replacement of Portland cement by environmental more friendly alternatives. Calcined gypsum can be considered as one of possible options in that respect. However, although the environmental impact is an important issue, gypsum was analyzed only rarely and sufficiently accurate data are still missing. In this paper, a carbon footprint analysis of two types of gypsum ranging from cradle to gate according to ISO 14067 is presented. The inventory data based on primary data obtained from the producers of natural gypsum and flue gas desulfurization gypsum in the Czech Republic are completed by the emission factors obtained from the literature survey. The results of the carbon footprint analysis show that the carbon dioxide emissions related to the manufacturing of calcined gypsum from flue gas desulfurization gypsum are 105.3 kg of carbon dioxide/t, i.e., 25.2% lower than for the application of natural gypsum. Calcination is identified as the most harmful process from the point of view of carbon dioxide generation for both raw materials; it is responsible for 55% and 72% of total carbon dioxide emissions for natural gypsum and flue gas desulfurization gypsum, respectively. The obtained information is essential for further design and development of new types of composites meeting the requirements of sustainable development better than today's mainstream solutions.