Evaluation of the Environmental Impacts of a Tunisian Portland Cement Based on Life Cycle Assessment Methodology

Concrete is the most commonly used material in the world after water. Cement is the primary air pollutant in the concrete sector, and its production requires the release of carbon dioxide (CO2) which accounted for around 5–8% of the world CO2 emissions. As a result of the Tunisia growing urbanization, the country has increased dramatically its usage in cement. According to Tunisian data, the country produced around 6.12 million tons of cement in 2000 and 8.19 million tons in 2019, corresponding to 600 kg/Capita and 702 kg/Capita, respectively. The purpose of this study is to use the normalized life cycle assessment (LCA) methodology to assess the environmental impacts of producing 1 ton of Portland cement (20 bags of cement). The system boundaries for this study are cradle to gate, from the raw materials acquisition to the packaging unit. They include (raw materials, fuel production, transport, preparation of raw materials and fuel, clinkerization, cement mills, and packing). The LCIA method used to measure the environmental impact of the Portland cement is ReCiPe H 1.04 v2016. According to the results, the global warming potential of Portland cement has 839 kg CO2 eq. The clinkerization step is the most contributive to this impact with 88% of the overall system GHG emissions (due to high CO2 emission from the kiln). Clinkerization contributes to the other atmospheric categories such as ozone formation, fine particulate matter formation, ozone formation (terrestrial ecosystems), and terrestrial acidification with 90.5%, 69.0%, 90.3%, and 75.2%, respectively. However, fuel production steps have a significant contribution to the ozone depletion, ionizing radiation and Fossil resource scarcity with 54.7%, 73.7%, and 67.7%, accordingly. Improving cement manufacturing technology, reducing limestone and energy consumption while boosting energy recovery rates, and optimizing transport distance are all effective ways to mitigate the environmental problems of cement sectors in Tunisia.