Cleaner Production Audit Based On LCA

Iron-making enterprises are among the top energy consumers and polluters and cause serious environmental pollution and energy exhaustion. Cleaner production (CP) is an effective way to solve the problems of iron-making enterprises. Through the implementation of cleaner production audit (CPA), iron-making enterprises can achieve the goal of saving energy, lowering consumption, reducing pollution and increasing efficiency. However, domestic CPA results have some limitations due to subjective factors in the process of determining the key auditing procedures and the lack of comprehensive evaluation on the environmental benefits of CP schemes. In order to improve the assessment method of CPA, life cycle assessment (LCA) is used for determining the key auditing procedures and evaluating the environmental benefits of CP schemes in the CPA of an iron-making enterprise. The main contents of this paper include:(1) The CML-Nov.2010 method was chosen for the characterization and normalization of the environmental impacts of the iron-making enterprise. Eight notable environmental impact categories were considered in this study, including Acidification Potential, Eutrophication Potential, Freshwater Aquatic Ecotoxicity Pot, Global Warming Potential, Human Toxicity Potential, Marine Aquatic Ecotoxicity Potential, Photochemical Ozone Creation Potential, and Terrestric Ecotoxicity Potential. Results showed that the greatest contribution factors in the iron making industry were CO2 emission from fuel gas consumption and pollutants from electricity production. Based on the results, reducing fuel gas use and decreasing electricity consumption in the iron-making process were determined as the the key auditing procedures.(2) 14 CP schemes are generated in this CPA. LCA was used to evaluate environmental impact of each CP scheme. Result showed that the scheme of "the use of recycled water" increased environmental impacts because of the transfer of environmental pollution in the whole life cycle, while the other 13 cleaner production schemes resulted in environmental benefits.(3) Cost analysis was used to evaluate whether extra economic burdens would be brought due to the CP schemes. Payback period (PP), net present value (NPV) and internal rate of return (IRR) of cost analysis methods were used to evaluate the economic impacts of each environmental feasible scheme. Results showed that these schemes are economically feasible.This paper was based on a combination of LCA and cost analysis methods to apply CPA in the iron-making enterprise, which improved the technical method of determining the key auditing procedures and evaluating CP schemes. This research can be used as technical guidance in CPA.