AD is rapidly expanding worldwide due to its numerous benefits covering both sustainability and renewable energy generation. However there is a serious and expensive problem of disposing the current volume of waste liquid effluent produced called digestate.
It commonly used as a raw liquid fertiliser on land, but this has associated problems of run-off, leaching and eutrophication of water courses or it costs money to treat before being discharged into natural water bodies or disposed of via wastewater treatment plants. In addition, there are problems linked to storage and regulations regarding application of digestate onto fields.
It has been forecasted that this issue is likely to worsen with the increased capacity in AD forecast. These simple disposal techniques are unsustainable, placing further pressure on the industry and diminishing its green credentials.
We have created technology to convert the waste liquor into a low cost, organic granular fertiliser. The nutrients contained within the liquor are concentrated onto solids to higher levels which can be stored, transported easily and later used as a fertiliser.
We are developing a bolt-on device, which, when attached to final processing stage, can convert the liquid waste into a granular fertiliser. The remaining liquid will be of such low nutrient and organic quality that it can be easily disposed of via wastewater or natural water bodies. It has been designed to avoid any changes or modifications to new and existing AD plants.