This is the “plasmix”, it seems only a waste but in reality it can be transformed into an alternative fuel called CSS which stands for secondary solid fuel.
We must first understand how plastic recovery takes place and understand why this process produces waste. First, the waste arrives at the plants and is sorted to separate the plastic packaging from the rest of the waste. The selected packaging is then transformed into flakes or granules used to create new products made of recycled plastic.
However, not all plastic can be recycled, the residual fraction not sent for recycling is called “plasmix”. These residues are shredded into fragments a few centimeters large, then the “deferrisation” is carried out, i.e. any fragments of ferrous metals are removed, the plasmix is taken to the hydraulic separator which separates the components with a high specific weight and to do so, jets of compressed air. Finally, an infrared optical separator detects if there are residual fragments of non-ferrous metals or chlorinated plastics such as PVC, when it finds them the system activates jets of compressed air which separates them from the rest of the waste, the interesting thing is that it is It is possible to set the sensitivity of the optical sensor, this therefore allows you to decide which degree of purity we want to give to our CSS.
SRF has on average a calorific value that oscillates between 18.0 and 25.0 MJ/kg, but in the best quality it can actually reach higher values by equaling the calorific value of petroleum coal which has a value between 25.0 and 30 0.0 MJ/kg.
The use of CSS compared to coal allows for significant environmental gains especially with regard to CO2 emissions, i.e. savings of approximately between 550 and 1,300 kg of CO2 per ton burned. Furthermore, coal is usually imported from the United States, Canada, Venezuela, Mexico and therefore using the CSS allows to reduce those emissions related to transport as well as logistical costs.