Energy efficiency of substance and energy recovery of selected waste fractions

Abstract

In order to reduce the ecological impact of resource exploitation, the EU calls for sustainable options to increase the efficiency and productivity of the utilization of natural resources. This target can only be achieved by considering resource recovery from waste comprehensively. However, waste management measures have to be investigated critically and all aspects of substance-related recycling and energy recovery have to be carefully balanced. This article compares recovery methods for selected waste fractions with regard to their energy efficiency. Whether material recycling or energy recovery is the most energy efficient solution, is a question of particular relevance with regard to the following waste fractions: paper and cardboard, plastics and biowaste and also indirectly metals. For the described material categories material recycling has advantages compared to energy recovery. In accordance with the improved energy efficiency of substance opposed to energy recovery, substance-related recycling causes lower emissions of green house gases. For the fractions paper and cardboard, plastics, biowaste and metals it becomes apparent, that intensification of the separate collection systems in combination with a more intensive use of sorting technologies can increase the extent of material recycling. Collection and sorting systems must be coordinated. The objective of the overall system must be to achieve an optimum of the highest possible recovery rates in combination with a high quality of recyclables. The energy efficiency of substance related recycling of biowaste can be increased by intensifying the use of anaerobic technologies. In order to increase the energy efficiency of the overall system, the energy efficiencies of energy recovery plants must be increased so that the waste unsuitable for substance recycling is recycled or treated with the highest possible energy yield.