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.

Pyrolysis of sewage sludge by solid heat carrier.

The experimental study of fast pyrolysis of dried sewage sludge in the retorting system with solid heat carrier was performed. The yield of the main pyrolysis products such as gas, oil, pyrogenic water, and solid residue (pyrolytic char) was measured in the 490-580 °C range. The maximum oil yield in an amount of 38.5 wt% on dry ash free basis was registered at a temperature of 550 °C. The gas chromatographic-mass spectrometric (GC-MS) analysis of pyrolytic oil allows the identification of 58 hydrocarbons of different structures and different classes such as aliphatic, aromatic, oxygenated and nitrogen-containing compounds. The group composition of the obtained oil makes it possible to identify it as an analog of crude oil, which can be processed by standard technologies. The technological scheme of the facility for pyrolysis of sewage sludge based on the technology Galoter for the thermochemical processing of low-grade fuels was proposed with corresponding material and heat balance.