ORWARE - A simulation tool for waste management

A simulation model, ORWARE (ORganic WAste REsearch) is described. The model is used for environmental systems analysis of waste management. It is a computer-based model for calculation of substance flows, environmental impacts, and costs of waste management. The model covers, despite the name, both organic and inorganic fractions in municipal waste. The model consists of a number of separate submodels, which describes a process in a real waste management system. The submodels may be combined to design a complete waste management system. Based on principles from Life Cycle Assessment (LCA) the model also comprises compensatory processes for conventional production of e.g. electricity, district heating and fertiliser. The compensatory system is included in order to fulfil the functional units, i.e. benefits from the waste management that are kept constant in the evaluation of different scenarios. ORWARE generates data on emissions, which are aggregated into different environmental impact categories, e.g. the greenhouse effect, acidification and eutrophication. Throughout the model all physical flows are described by the same variable vector, consisting of up to 50 substances. The extensive vector facilitates a thorough analysis of the results, but involves some difficulties in acquiring relevant data. Scientists have used ORWARE for seven years in different case studies for model testing and practical application in the society. The aims have e.g. been to evaluate waste management plans and to optimise energy recovery from waste.