Influence of low-density polyethylene addition on coking pressure

The increase of the coking pressure at low LDPE addition rates is associated with a less permeable coal plastic layer, which prevents the removal of the decomposition products and causes their retention in the semicoke matrix, evolving them in the post-plastic stage. Coking pressure decrease at high LDPE addition rates can be due to the charge shrinkage and the better permeability to the migration of oil components, which suggest a lower interaction between the coal and the LDPE. A delay in the degradation of LDPE is confirmed by the data provided by DRIFT and SEM.