Eco-efficiency assessment; Production of bleaching chemicals for the Elemental Chlorine Free, ECF, pulp industry - A Case study at Eka Chemicals (AkzoNobel Pulp and Paper Chemicals)

Le résumé fourni par la source

Sustainable development embraces three dimensions and main areas; economic growth, social\nprogress and ecological aspects. Eco-efficiency assessment is a business tool which can be used in\norder to compare two or several products, processes, activities or plants from an environmental and\ncost perspective. The tool is one way for companies to include sustainable development when it\ncomes to future strategic decision making. Eka Chemicals is a business unit within AkzoNobel mainly\nproducing and supplying chemicals and know how to the pulp and paper industry. The company is\napplying eco-efficiency assessments in order to learn more about their products and introducing lifecycle\nthinking in their organization.\nThe main objective with this thesis is to investigate the feasibility of developing a flexible model of\nalternative production systems and transfer it into Eco-efficiency assessments. A case study at Eka\nChemicals acts as the basis for the thesis and it focuses on production processes for bleaching\nchemicals used by the ECF pulp and paper industry. A second objective is to increase the\nunderstanding of the bleaching chemicals production systems in terms of environmental and economic\nperformance. Based on assumptions about; (1) the geographic location of the production and (2)\nsystem properties decision making at Eka can affect, four different production systems are compared\nin terms of eco-efficiency; (1) SVP-LITE, (2) SVP-SCW, (3) chemical island and (4) integrated plant.\nIt was found feasible to develop a flexible model for Eco-efficiency assessment. In the approach\nchosen, the systems are divided into background systems and foreground systems. Scenario analysis\nis applied and the scenarios are designed to distinguish background system properties from\nforeground system properties. This methodological choice makes it possible to identify important\nparameters and assumptions that affect the overall performance of the systems investigated. It further\nstructures and speeds up the procedures since the assessment can focus on a certain part of the\nsystem at a time.\nThe alternative production systems studied show significant differences regarding the environmental\nimpact dimension. When it comes to the economic dimension, it is not possible to differentiate and\nrank the alternative production systems by use of an eco-efficiency diagram.\nThe most important conclusion of the case study is that the assumption regarding how the electricity\nused for producing the bleaching chemicals, on the pulp mill site or elsewhere, is crucial for the\nranking of the production systems compared. The chemical island is more eco-efficient if the electricity\nused is produced from biomass. When Russian electricity grid mix is used, the SVP-SCW scores best\nwith regard to eco-efficiency.\nIt is further concluded that the geographical location of the production of ECF- pulp bleaching\nchemicals is a key parameter when trying to find the most eco-efficient alternative. The choice of\nproducing sodium chlorate on-site or not is also an important parameter affecting the eco-efficiency of\nthe production systems. Since transportations have a small influence on the eco-efficiency, the sodium\nchlorate is produced preferably off-site and transported to the pulp mill if the electricity system for onsite\nproduction is characterized by fossil fuels. If the on-site electricity system includes a large share\nof renewables, on-site production of sodium chlorate is preferred.

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