Carbon footprint of recycling systems

Abstract: Recyclable materials from household waste are in Sweden at present collected primarily in a bring system with recycling sites where people can leave sorted packaging materials. In other European countries such as the United Kingdom, recyclables are instead increasingly collected kerbside in a co-mingled fraction and sorted in a materials recovery facility (MRF).This study compares the two collection systems with respect to total energy and global warming potential (GWP). Halmstad municipality is the chosen geographical boundary and the functional unit is the weight of the recyclable material produced by one person living in Halmstad during one year (kg/ (capita'year)).Both collection systems are modelled and analysed with the GaBi 4 LCA software. An increase in collection levels is modelled for the co-mingled system due to its higher level of service. Recycled materials are assumed to replace virgin materials. Non-recycled materials are sent to a combined heat and power incineration plant.The results show similar performance for GWP for both collection systems and about 15 % better performance for the bring system for total primary energy use. Analysis shows that the results are highly dependent on the reject level in the MRF and the choice of electricity production for the total system.