Browsing by Author "Kiviranta, Maarit"

Life cycle assessment is a method to estimate potential environmental impacts of a product from cradle to grave. The life cycle of waste starts when product, e.g. cardboard box is discarded. The main goal of this study was to estimate by LCA, how discarded cardboard should be utilized and the collection organised to minimize the harmful environmental impacts. Environmental impacts studied were climate change, eutrophication of soil and particles. The impacts were evaluated by using four different scenarios. In scenarios, discarded cardboard was not sorted at all (Scenario 0) or sorted and collected from regional collection points (kerbside collection) and/or from residential buildings (Scenarios 1-3). The sorted cardboard was utilised to produce cardboard cores for industry. The cardboard that was not sorted was transported by mixed household waste collection to the waste incineration plant where the generated heat and electricity were utililized. Environmental benefits were gained if emissions to environment could be avoided by replacing normal processes by recycling and incineration. For cardboard recycling, the process replaced was CTM-pulp production from virgin forest and for incineration, the fuel used to the average heat and electricity production in Finland. In all studied environmental impact classes, all scenarios produced environmental benefits. In climate change and particles, scenario 0, where all cardboard was utilized in incineration plant, achieved most benefits and the scenario 3, where the maximal amount of cardboard was sorted and collected from residential buildings, achieved the least. However, the differences between the scenarios - especially in climate change class - were small. In eutrofication class, the results were inverse to climate change and particles classes. The most beneficial scenario was the one, where the maximal amount of cardboard was sorted and collected from residential buildings. Due to the dissimilar results of different environmental impact classes it is not simple to say how to utilize discarded cardboard. When applying the results, it should be noticed that the results depend on which energy and material products are produced, and foremost, on what kind of products they replace. The final conclusions concerning which alternatives are the best depend on which environmental impacts are emphasized.