Cement serves quite literally as the foundation of the building boom. It is an important driver of economic progress in most countries. The amount and type of fuel consumed in producing cement not only affects costs, but has social and environmental consequences.
The Cement Association of Canada sought to understand:
- What are the environmental, social and economic impacts of using alternative fuels compared with conventional fuels in cement manufacturing?
- How does the use of alternatives in cement manufacturing compare with other possible end-of-life options like recycling or disposal in landfills?
To answer these questions, NBS commissioned this systematic review for the Cement Association of Canada. NBS selected researchers Vito Albino, Rosa Maria Dangelico, Angelo Natalicchio, and Devrim Murat Yazan of the Department of Mechanical and Management Engineering, Politecnico di Bari, Italy. The researchers systematically reviewed 110 prior studies to answer the research questions, drawing on academic, institutional and practitioner sources. Their findings were subjected to double-blind peer review by experts from academia and industry.
This report provides a comprehensive overview of the current literature on cement manufacturing with respect to emissions control and the use of alternative fuels. Its powerful synthesis is useful for both academic researchers and practitioners engaged with the cement industry or waste-to-energy efforts.
Alternative Fuels Studied
The report examines the most common alternative fuels used:
- Municipal solid waste (MSW)
- Industrial, commercial & institutional (IC&I) residues
- Sewage sludge / biosolids
- Animal / bone meal, specified risk material
- Waste wood
- Used tires
- Other biomass
In Chapter 3, the researchers identify impacts for each type of fuel in key categories: environmental and human health, economic, and social.
The figure details these impact categories
Figure 1.1: Impact Categories for Alternative Fuels in Cement Manufacturing
In Chapter 4, the researchers provide tables synthesizing these findings, enabling easy comparison across different types of fuel.
Table 4.4 Synthesis of Findings Related to Environmental and Social Impacts
Chapter 4 also compares of end-of-life management options for alternative fuels. Appendices provide additional details on specific research findings for each fuel and end-of-life option.
Great Potential for Alternative Fuels
The research findings show positive opportunities for alternative fuels, but also identify knowledge gaps. Key findings include:
- Resource consumption and conservation improves with the use of alternative fuels
- With some exceptions, using alternative fuels instead of fossil fuels reduces net greenhouse gas emissions,.
- Metal and hazardous air pollutant emissions presented different trends among the alternative fuels.
- Burning alternative fuels in cement kilns decreases the demand for landfills.
- From the few findings available on social and human health impacts, impacts depend on the particular alternative fuel used.
- Except for hazardous waste, using alternative fuels in the cement industry raises technical issues.
- The economic impact is generally positive, with the exception of IC&I residues, waste wood, and plastics.
- The availability of alternative fuels depended on the specific alternative fuel.
Opportunities for Application – and More Research Needed
The environmental, social, health and economic impacts of cement plants is a major concern for Canadian stakeholders. A switch to alternative fuels could reduce the impact of plants on the environment, communities, and human health and bring about economic benefits. Yet, gaps in our knowledge remain (see report Appendices), with health and social impacts particularly unclear. In 2008, Canada’s cement industry contributed more than $3.2 billion to Canada‟s GDP, employed 27,000 workers, and produced close to 13.7 million metric tonnes of cement. Continuing to understand its impacts and options is important for Canada’s economic, environmental, and social well-being.