Assessment of greenhouse CO₂ emissions associated with the cement manufacturing process

The goal of the present work was to identify the impact of carbon dioxide (CO₂) emissions on a cement plant's workplace environment and its surrounding area. The concentration levels of CO₂ over the study domain were investigated by means of the Weather Research and Forecasting/California Puff Model (WRF/CALPUFF) integrated modeling system (TRC Environmental Corporation, Windsor, CT, USA). Two sources were modeled for the current study: CO₂ resulting from the calcination of raw materials and fuel consumption in three kilns and power plant emissions, which were treated as point sources, and vehicular-based CO₂ emissions, emitted during the transportation of raw materials from the quarry to the crusher, which was modeled as a line source and calculated using the activity data collected from the cement plant and the emission factors as described by various environmental agencies. A comparison between the predicted results and the allowable limits of CO₂ were made to investigate the environmental quality in the study area. The results of the study revealed that the CO₂ contributions due to line source emissions were higher within and outside the plant than those from the point sources during the selected winter days. On the other hand, the individual contributions made by the point sources in the selected summer days exceeded the line source contributions, even though the combined contribution of CO₂ (from both types of sources in the workplace and nearby areas) was at its height during the chosen winter days. Furthermore, maximum average concentrations, as predicted by CALPUFF for a standard period of 1 hr, were at higher than permissible levels during the selected days in both winter and summer. Within an average 24-hr period, the maximum modeled concentrations of CO₂ were at the higher end of allowable limits during the designated winter days and at the lower end throughout the summer days.