LCA allocation procedure used as an incitative method for waste recycling: An application to mineral additions in concrete

Abstract

LCA allocation procedure used as an incitative method for waste recycling : An application to mineral additions in concrete.This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited.In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: a b s t r a c t Waste recycling avoids waste landfilling and all associated releases. It also allows for saving nonrenewable resources. However, the new commercial interest for waste can be seen as a shift in their status from waste to co-product. This has important consequences for environmental load allocation between the different industrial products (and co-products) in industrial plants. In this paper, the specific case of cement has been studied. Actually, to reduce the environmental impact of cement and concrete, industries have been engaged over the last 10 years to increase the replacement of Portland cement by alternative cementitious materials that are principally industrial waste or by-products. In this study, the environmental impacts of two different Supplementary Cementitious Materials (SCM), blast furnace slag and fly ash, are considered using Life Cycle Assessment methodology through a study of the influence of different allocation procedures on environmental impacts of SCM in concrete. Three allocation procedures are tested. In the first one, which is the current practice, no allocations are done. As for the two others, the environmental burdens of the system are respectively associated with the relative mass and some current economic values of the co-products and products. The results are discussed according to the specificity of the cement substitution products (SCM) and the driving forces that are identified for the use of these co-products. Then, a description investigation of another allocation procedure is proposed based on the fact that it is not the relative economic value that permits to evaluate the environmental burdens but the contrary. This last allocation procedure could be generalised for other waste recycling and be used as a regulation tool between the different industrial branches.

Improving the CO2 performance of cement, part I: utilizing life-cycle assessment and key performance indicators to assess development within the cement industry

“…In the reviewed LCA studies of cement, allocation is handled in different ways. Some studies have choices similar to those of this study (Boesch and Hellweg, 2010;Chen et al, 2010), while others use system expansion (Lee and Park, 2005) or do not clarify this issue (Flower and Sanjayan, 2007;Huntzinger and Eatmon, 2009;Navia et al, 2006;Nisbet and Van Geem, 1997).…”

“…In this process calcium carbonate decomposes and CaO and CO2 is produced (Worrell et al, 2001). This is called calcination and it is highly important from a greenhouse gas emission perspective, since in the process carbon bound in minerals is transformed into CO2 (Chen et al, 2010). The calcination typically causes more than 50% of total CO2 emissions from cement production, and a large share of the remaining emissions originates from combustion of the fuels in the kiln (Huntzinger and Eatmon, 2009).…”

“…Life Cycle Assessments (LCA) are commonly used to study the environmental impacts from the cement industry (Chen et al, 2010;Lu, 2010;Ortiz et al, 2009) and such studies are important to learn more about this industry and about strategies for reducing the impact. For example, these studies tell us that the production of ordinary Portland cement commonly results in CO2 emissions exceeding 0.9 tonnes CO2/tonne cement and that each tonne of cement might require input of 1.5-1.6 tonnes of raw materials, 3000-4300+ MJ of fuel energy and 120-160 kWh of electrical energy (EIPPCB, 2013;Nicolas and Jochen, 2008;Price et al, 2010).…”

“…There is also limited information available on the lifespan of concrete structures and the subsequent processes. A broadened scope focusing on concrete would have been much more complex and it appears to be a common choice to apply a cradle-to-gate perspectives in LCA studies of cement (Boesch and Hellweg, 2010;Chen et al, 2010;Huntzinger and Eatmon, 2009;Josa et al, 2004). However, Kapur et al (2008) have modeled the end of life phase of concrete.…”

“…To calculate the elementary flows regarding the upstream processes almost all identified LCA studies have utilized LCA databases, especially regarding the emissions related to upstream processes (Boesch and Hellweg, 2010;Boesch et al, 2009;Chen et al, 2010;Nisbet and Van Geem, 1997;Pade and Guimaraes, 2007). Consequently, the impression is that this project is based on more case-specific data than many other similar studies.…”