Waste must be recycled in as environmentally friendly a way as possible in accordance with the Recycling Management Act (KrWG) of February 24, 2012. Waste reuse has priority wherever possible. This requires a resource-preserving stepped economy, such as used materials resulting from construction work, after reconditioning if necessary, must be brought back to use for the original purpose. This fully applies to the use of wooden sleepers.
There are two possible ways to dispose of old wooden sleepers that have been removed:
Both versions benefit in ecological and economic aspects from the use of new WEI Type C impregnation oil.
There are legal restrictions on the reuse of used, tar oil-impregnated railway sleepers. These are anchored in the German Chemicals Prohibition Ordinance. For example, indoor use, use on children’s playgrounds or for other purposes that could lead to regular contact with human skin and distribution to private end users has been prohibited since 1991 (according to the Tar Oil Ordinance – TeeroelV). In the new version of the Chemicals Prohibition Ordinance of June 13, 2003, the sale of old used sleepers is restricted to reuse as a railway sleeper or for commercial or industrial purposes of different kinds in accordance with the original production purpose. Sale to farmers, etc. was prohibited.
The wood sleeper was classified in waste category A IV in the Waste Wood Ordinance (AltholzV) of August 15, 2002. In the circular economy law (KrWG-new waste law from June 1, 2012, which succeeded the circular economy waste law KrW/AbfG), old sleepers are classified as hazardous waste. The waste code for this is 17.02.04* (wood, glass and plastic containing hazardous substances or contaminated by hazardous substances). Since this is hazardous waste, old sleepers must be disposed with a disposal certificate and accompanying note.
From April 1, 2010, everyone who handles hazardous waste must keep evidence electronically (proof of disposal and accompanying note) and register. This is the eANV electronic waste verification procedure.
As a rule, old sleepers are disposed of in the form of energy recovery in systems requiring approval in accordance with 17. BImSchV. The high caloric value of tar oil-impregnated wooden sleepers (at least 11,000 kJ/kg) results in energy recovery (in accordance with Section 8, paragraph 3 of the KrWG).
While the caloric value of absolutely dry, untreated firewood is approximately 15 Mj/kg, burning 1 kg of old sleepers (beach or oak) releases between approximately 24 and 27 MJ of thermal energy. This means that nearly 1 kg of heating oil (caloric value 43 MJ) can be replaced with 2 kg of old sleepers. This translates to enormous savings in fossil fuels – an important contribution to climate protection.
Based on new findings from ecological evaluation studies, the effects of energy use of old sleepers on global warming, acidification, and human toxicity (such as heavy metals, dioxins, and furans) are significantly lower when than when burning most fossil fuels (such as hard coal and lignite).
Disposal plants produce wood chips from railway sleepers. These are then added to thermal recycling in biomass-fuelled power plants.