WASTE OR RESOURCE: SOLID ENERGY’S BENEFICIAL USE OF WASTE STREAMS Paul Weber1, Joe Wildy1, Fiona Crombie1, William Olds1, Phil Rossiter1, Mark Pizey1, Nathan Thompson2, Paul Comeskey2, Dave Stone2, Andrew Simcock3, Andy Matheson1, Karen Adair4, Mark Christison5, Hayden Mason6, Mark Milke7 1-Solid Energy New Zealand Ltd; 2-Stockton Alliance New Zealand Ltd; 3-Biodiesel New Zealand Ltd; 4-Bio-Protection Research Centre, Lincoln University; 5-Christchurch City Council; 6-Holcim New Zealand Ltd; 7-Natural and Civil Engineering School, University of Canterbury Correspondence to:
[email protected] Abstract In the last decade Solid Energy New Zealand Ltd - in collaboration with its research, applied technology and business partners - has made considerable progress in identifying waste resource streams which can be beneficially reused to support the state owned enterprise’s business objectives. Within the company’s coal business, Christchurch City’s high-quality biosolids are being used as a topsoil supplement in mine site rehabilitation. Coal ash from boilers is being used to create a capping material which reduces the formation of acid mine drainage. Cement kiln dust, a by-product of cement-manufacturing, is being used for waste rock capping to reduce acid mine drainage, and as a binding agent to fill and make safe underground voids prior to mining. Waste mussel shell is being used to create sulphate- reducing bioreactors to lower acidity and metals loads in mine water. Within Solid Energy’s renewable energy companies (Nature’s Flame and Biodiesel New Zealand) - approximately 150,000 tonnes of wood pellet fuel has been manufactured from untreated plantation-grown pinewood offcuts, shavings, and sawdust; 6,000 tonnes of used cooking oil has been collected for conversion into biodiesel.