A Case Study on Sustainable Practices

M. Afifi1, Shehab. M.El-Aryan1, A. Hamdy Abu Zaid1, A. Zaghloul1, M. Hekal1, M. ElSaid2

1 ASEC Technical Center

2 Al-Nahda Cement Plant

Abstract:  

Cement production is a significant contributor to global carbon emissions, accounting for approximately 7% of total CO2 emissions worldwide (Mallagray, et al. 2020). In Egypt, the cement sector is responsible for 14% of CO2 emissions, emitting over 800 kilograms of CO2 per ton of cement, surpassing the global average of 600 (Elghamrawi 2023). This paper presents a case study of Al-Nahda Cement Plant, analyzing its carbon footprint across various operational processes. The study aims to identify key sources of emissions and evaluate potential mitigation strategies to enhance sustainability.

1. Introduction:  

The cement industry is one of the most energy-intensive manufacturing sectors. Cement is made by fusing limestone and clay in temperatures up to 1450°C. The process produces gray, rock-like balls called clinker (which is then ground into cement), in chemical reactions that emit large amounts of carbon dioxide. The production of clinker accounts for about 90 percent of the CO2 emissions of cement production (please see graphic below) (Mallagray, et al. 2020). This case study evaluates the carbon footprint of Al-Nahda Cement Plant, focusing on its production methods and energy sources during 2023 and compared to 2022 (Base year).

2. Methodology: 

The assessment employed a combination of quantitative data analysis and qualitative assessments.

The type of data that needs to be collected depends on the specific greenhouse gases (GHG) model, which depends on requirements such as the final admissible uncertainty, data availability, costs, pre-existence of other data or other reasons. The type of data that is used as input to different quantification methods includes: 

1. activity data, such as mass, volume, energy; 

2. net calorific values;

3. emission factor, expressed as ton CO2e/quantity of activity data; 

4. composition data, expressed as carbon content;

5. oxidation factors; 

6. conversion factors; 

7. emissions, on a mass basis per a reference period. (ISO 14064 Technical Committee 2018)

Data were collected on site as primary data. Emissions were then calculated according to the GHG protocol (Ranganathan, et al. 2004).

3. Findings:

Direct emissions (Scope 1 according to GHG protocol) responsible for 93.49% of total emissions; while indirect emissions (Scope 2 according to GHG protocol) responsible for 6.51% of total emissions.

Direct emissions: The cement production process at Al-Nahda Cement Plant emits approximately 857 kg of CO2e per ton of cement produced. The majority of emissions come from calcination (approximately 61.31%) and from stationary combustion (approximately 31.94%); while emissions come from mobile source only 0.24%.

Indirect emissions mainly calculated from electricity purchased.

4. Discussion

The findings highlight the decrease in GHG emissions compared to the base year 2022, as shown in chart (1):

Despite the increase in the value of absolute emissions related to process by 1.73% due to the increase in clinker production during 2023 compared to 2022; the total emissions values ​​decreased by 3.99% due to the energy saving whether through optimizing specific heat consumption or optimizing specific power consumption.

This is clearly demonstrated by comparing the amount of carbon dioxide relative to the amount of clinker produced, as shown in chart (2): 

Relative carbon dioxide emissions for process are the same 525 kg CO2e/ton Clinker during 2022 and 2023; while Relative carbon dioxide emissions for stationary combustion decreased from 322 kg CO2e/ton Clinker during 2022 to 274 kg CO2e/ton Clinker during 2023. In addition to Relative carbon dioxide emissions for purchased electricity decreased from 57.0 kg CO2e/ton Clinker during 2022 to 55.8 kg CO2e/ton Clinker during 2023.

5. Recommendations

 There are several opportunities available to reduce carbon dioxide emissions according to detailed studies by the ASEC Technical Center, as follows:

Alternative raw material (AR): ASEC's technical support team, in cooperation with National Research Center, is studying the by-product of one of the factories adjacent to the Al-Nahda plant with the aim of reducing carbon dioxide emissions by producing low energy cement.

Alternative fuels (AF): In light of the joint cooperation between ASEC and Al-Nahda Company, the use of alternative fuel is currently being studied in order to reduce carbon dioxide emissions resulting from stationary combustion.

Energy Saving: ASEC continues its plans to reduce energy consumption, whether by optimizing specific heat consumption or optimizing specific power consumption.

Blended Cement: The ASEC Technical Office, in cooperation with Al-Nahda Cement Company and with the support of National Research Center, is studying two types of cement with the aim of reducing GHG emissions up to 37%.

6. Conclusion  

This case study on Al-Nahda Cement plant underscores the urgent need for the cement industry to adopt sustainable practices to mitigate its carbon footprint. The proposed strategies not only contribute to emission reductions but also create opportunities for innovation and improved resource management in the industry. Future research should focus on long-term effects of these practices on overall emissions and operational efficiency.

References

Elghamrawi, Saleh. 2023. Greening the Cement Industry in Egypt: Exploring Decarbonisation Policies for the Cement Industry. Cairo: American University in Cairo.

ISO 14064 Technical Committee, ISO. 2018. Greenhouse gases. Part 1: Specification with guidance at the organization level for quantification and reporting of greenhouse gas emissions and removals. Switzerland.: International Organization for Standardization.

Mallagray, Juan Villar , John Anagnostou, Marek Stec, Li Tu, and Sabine Schlorke. 2020. Strengthening Sustainability in the Cement Industry. Washington: International Finance Corporation.

Ranganathan, Janet , Laurent Corbier, Pankaj Bhatia, Simon Schmitz, Peter Gage, and Kjell Oren. 2004. The Greenhouse Gas Protocol-A Corporate Accounting and Reporting Standard. USA: World Resources Institute and World Business Council for Sustainable Development.