Sub-bituminous coal and admixtures with polyethylene terephthalate were co-processed. The main objective of the study was to produce coke and to determine how ratios of input raw materials affected its structure. All main product yields (coke, tar, gas) were characterized by petrological and chemical methods. The addition of PET to coal in coking blends had impacts on coke yield, its true density, volume contents of fissures and mean reflectance, volume and surface of pores, and the formation of aromatic structures in the coke. However, the properties of coke and gas did not change significantly until 20% of the coal had been replaced with PET bottles in the coal charge. (C) 2016 Elsevier B.V. All rights reserved.