Used tyres as alternative fuel is widespread in cement industry all over the world: USA, Japan, Europe, Australia.
USA has approximately 6 million tons of used tyres a year, 53% of them are used for fuel.
Akmenės cementas AB started burning of used tyres on 23rd of May, 2006. The method patented in USA was chosen as the most suitable for long wet process rotary kilns.
Whole tyres are passed to kiln over transporter system through special feeding pipeline located in a mid of kiln. Temperature is up to 1200°C at the waste feeding point. For burning of non hazardous waste temperature up to 900 °C is enough. An advantage of cement production kilns is that no extra waste products remain while burning waste. All ash which forms during burning process compound into a product, clinker, composition, are stabilised and has no effect on product quality.
Currently about 10 % of fuel being used in the company is used tyres.
AB „Akmenės cementas” used waste tyres for thermal energy:
|7197,28 t||8089,36 t||9083,88 t||6856 t||7272 t|| 8574,44 t|
|2006 m||2007 m||2008 m||2009 m||2010 m|| 2011 m|
12 000 tonnes of non renewable fuel (coal) a year is being saved. More over, burning tyres emit less of CO2 to atmosphere than coal. Emission factor of coal is about 95 t CO2/ TJ, and emission factor of used tyres is 85 t CO2/ TJ.
Akmenės cementas AB issues certificates for companies regarding acceptance of unusable tyres and certificates approved by Ministry of Environment regarding recovery of taxable products or packaging waste. Based on these certificates economic subjects are exempted from packaging/product fee
According to the Good Working Practice, amount of waste (hazardous and non-hazardous) being burned in analogical clinker burning rotary kilns increasingly grows, because such equipment, the same as single-purpose waste burning equipment, meets the requirements for waste burning equipment most.
It is planned to burn separated municipal waste, differently named as solid recovered fuel, after dry production process will be implemented.