Knowaste (Knowaste, 2016) is a UK company that has been researching and developing technologies for recycling absorbent hygiene products since the 1990s. In 2011, Knowaste opened a treatment facility in West Bromwich, Midlands (UK), that was operative from 2011 to 2013. It had a capacity of 36 000 t/year and accepted waste from commercial collectors and local authorities. This plant was closed in May 2013 for financial reasons, but the company is now planning to develop a new nappy recycling facility in Hayes, West London, which should be launched in late 2017, as well as further facilities.
The Knowaste technology is a process in which shredded nappies are stirred and washed, separating the nappy fibres and gel from the shell plastics. Within an air-controlled working environment, AHP waste is delivered in a dedicated receiving bay. The waste is shredded, separated and, using advanced thermal treatment technology (autoclave), sterilised. At this stage, the super absorbent polymers are collapsed via a chemical treatment, rendered inert and the moisture is released.
There follows further sorting and separation of plastics and fibres and removal of contaminants. The plastics continue through granulation and multiple washing stages before being pelletised to be used in new products such as plastic components or as an ingredient in composite materials replacing concrete and steel. The fibres are washed, dried and processed for use in pet litter, concrete and tarmac additive, brick manufacture and insulation materials. Of the original components of the AHPs, 100 % can be recovered and sent for recycling, with the remaining solids and liquids sent for treatment.
Knowaste produced a video to present their technology. It is available at: https://www.youtube.com/watch?v=etz5DFY-HfQ