Co-Pyrolysis of Estonian Oil Shale with Polymer Wastes.

Recycling of polymeric wastes is important for both energy recovery and raw material processing. In light of the EU Green Deal, the oil shale industry is looking for new opportunities to use its production potential. As an intermediate stage, the co-pyrolysis of oil shale with waste plastic and tires will be considered acceptable. The article presents the kinetics of pyrolysis of Estonian oil shale, the main polymer components of municipal waste, and their mixtures with oil shale by the thermogravimetric analysis method. The influence of each component separately on the process of sample weight loss during co-pyrolysis was also studied. It is shown that when plastics are added to oil shale, the experimental and calculated data coincide according to the principle of the additive contribution of each component. Kinetic parameters were calculated according to the Coats-Redfern integral method and show that during the co-pyrolysis of mixtures of oil shale with polymer wastes, the value of the activation energy increases in comparison with the pyrolysis of oil shale. Based on the experimental data, it was determined that there is a manifestation of a synergistic effect in the form of an increase in the yield of liquid products during the co-pyrolysis of oil shale and polymer wastes.

Production of Isotropic Coke from Shale Tar at Various Parameters of the Delayed Coking Process.

This paper presents the results of studies on the production of coke at excess pressures of 0.15, 0.25, and 0.35 MPa with delayed coking of shale tar obtained by pyrolysis of oil shale in the Baltic Basin. To assess the quality of the resulting coke, properties such as the absolute density, yield of volatile substances, ash content, and total porosity were analyzed. The microstructure of the resulting coke was analyzed by X-ray diffraction, for which the evaluation criteria were the interplanar spaces d 002 and d 100 and the sizes of the Lc and La crystallites. The scanning electron microscopy (SEM) technique was used to confirm the results of the analysis of the formed structure of shale coke obtained earlier. The calcined samples were classified as cokes with an isotropic structure. In addition, the fractional composition of the obtained gasoline and gas oil fractions of delayed coking of shale resin was analyzed.