Canadian firm Knowaste intends to build a £6 million, 30,000 tonne-per-year capacity plant in Tyseley, to start operating in January 2009. The company is seeking planning permission and an environmental permit.
The plant will process incontinence pads, bed liners and nappies collected from care homes, nurseries and hospitals by Birmingham-based Alpha Wastecare.
The UK disposes of some 800,000t of absorbent hygiene products each year, mainly to landfill.
The plant will shred material and wash it in a salt solution to "deactivate" its super-absorbent polymers. Density separation is then used to separate plastic and pulp fractions. It will produce 4,000t of plastic annually for recycling abroad. Pulp will be put through an on-site gasification plant to generate 1.5-megawatts of electricity, some of which will be exported to the grid.
According to Roy Brown, Knowaste’s president, the plant has become viable because of rising landfill tax and subsidy increases available under the Renewables Obligation for gasification plants burning biodegradable waste. From April 2009 two Renewable Obligation Certificates (ROCs) per megawatt hour of electricity will be available, up from 1 ROC/MWh now.
But questions hang over the process’s environmental benefits. Last year, a study on nappy disposal by Dutch consultancy CE Delft said Knowaste’s process had a greenhouse gas impact of 215 grams of carbon dioxide equivalent (CO2e) per kilogram of nappies, which compared unfavourably with both incineration and composting at 128g/CO2 and 86g/CO2 respectively.
Knowaste said most of the emissions were due to the energy used in the process and the gasification plant should reduce this.