Title : Sorting and recycling of construction and demolition wood waste
Abstract:
The construction industry in Sweden generates significant quantities of wood waste, of which a substantial portion is currently utilised for energy extraction. However, there is a growing interest in exploring alternative uses for this material. This study investigates the feasibility of recycling wood waste from construction and demolition activities before resorting to energy recovery.
The research analysed wood waste from three distinct construction phases: framework, interior, and demolition. Employing a sorting method developed through literature review and industry consultations, four potential sorting options emerged: finger jointing/reuse, cross-laminated timber, laminated timber, and particleboard.
The distribution of wood waste varied across the construction phases. During interior work, the waste included pallets, wooden panels, and studs. Similarly, the framework phase yielded a mix of materials, albeit with a lower proportion of panel components.
Optimal sorting recommendations were as follows:
- Framework waste: 19% of the wood waste was suitable for finger jointing/reuse, 2% for cross-laminated timber, 35% for laminated timber, and 100% for particleboard.
- Interior waste: 12% was suitable for finger jointing/reuse, 3% for cross-laminated timber, 10% for laminated timber, and 100% for particleboard, assuming acceptable sorting for weathered and soiled wood.
- Demolition waste: Only Treetex and rough-sawn boards were present, suitable exclusively for particleboard production.
In conclusion, wood waste can be repurposed effectively rather than solely relying on energy extraction. Prioritising laminated timber and particleboard sorting is recommended until challenges with cross-laminated timber and finger jointing/reuse are addressed.
Although recommending prioritisation of laminated timber and particleboard, this industry and its business model need to be developed to suit the reuse of wood waste. The most contaminated boards may not be feasible for reuse in the building material industry, at least not in the near future. Instead, tests were conducted to investigate whether this material could be pelletised for energy purposes. The research yielded pellets with good quality and good combustion properties. With local sorting and processing of wood waste to pellets, the resulting high bulk density pellets is a more refined fuel compared to wood waste.
Audience Take Away Notes:
- The result can help chosing a more sustainable use of wood waste than incineration.
- Sorting and recycling of wood waste can increase the capturing of carbondioxide as a part of circular bioeconomy.
- When raw materials for pellets for energy purposes are scarse, a new source can be wood waste from the construction and demolition industry.
