The dissertation is dedicated to solving the current problem - the effective methods of development for using liquid pyrolysis products of waste automobile tires (LPPWAT).
Waste automobile tires (WAT) pose a significant threat to the environment. On the other hand, they are a potential raw material for energy production. Pyrolysis is one of the most promising WAT disposal methods in a circular economy.
The research aimed to study the possibility of using LPPWAT or their fractions as fuels for internal and/or external combustion engines without using scarce hydrogen and expensive catalysts.
It is shown that the method of condensation or rectification makes it possible to obtain a fraction > 200 °C from LPPWAT, which meets the requirements of DSTU 4058-2001, PN-C-96024:2011, ISO 8217:2017 for fuel oils, and gasoline fractions with unsatisfactory operational properties.
Further research was aimed at a detailed study of gasoline fractions (b.p.-140, 140-200, b.p.-200 °C) obtained during the pyrolysis of waste automobile tires, and the search for effective methods of their application/processing.
The obtained gasoline fractions (GF) were analyzed using standardized methods, IR spectroscopy and chromatography. It has been proven that GF cannot be used as commercial gasoline due to the high content of unsaturated and aromatic hydrocarbons.
Modifiers were synthesized from gasoline fractions to improve the adhesive properties of bitumen. It was found that the produced liquid products (the residue after obtaining bitumen modifiers) contain a lower amount of aromatic and unsaturated compounds compared to the initial GF, which, in turn, will reduce the content of these harmful components during their further use. Addition of the obtained modifiers to road bitumen of BND 70/100 brand in the amount of 1% wt. allows to obtain bitumen with improved adhesive properties.
In order to separate aromatic compounds, extraction separation of gasoline fractions was carried out at 140 °C, 140 - 200 °C. As a result, the obtained hydrocarbons were analyzed by IR spectroscopy and chromatography. It was found that the resulting refinate contains fewer arene structures and can potentially be used as a component of gasoline. The extract is a concentrate of aromatic and unsaturated hydrocarbons.
It is proved that it is inexpedient to divide the GF into separate parts, since the yield of modifiers is almost the same for both gasoline fractions, and the composition and physico-chemical indicators of raffinates and extracts of these gasoline fractions are similar.
To analyze the carbon content in individual structures (aromatic, alkane, and olefin) based on the model mixtures, the dependences of the response functions on the physico-chemical parameters of gasoline fractions and liquid products of their processing were developed using mathematical modeling. The resulting equations were acceptable for the initial model mixtures and allowed in most cases to predict the carbon content in the individual structures of the fr. 200 °C and its processing products.
The influence of the raw material mixture composition on the polycondensation process of formaldehyde from the fr. 200 °C for the resins' production, which were used as adhesive additives to bitumen, was studied. The study showed that the most optimal conditions for obtaining the modifier are 7.5% wt. formalin content and 3% wt. catalyst content.
It was found that the obtained resin significantly improves the adhesive properties of road bitumen. The product with 1% wt. modifier content meets the requirements for commercial bitumen brand BNDA 60/90.
Using N-methylpyrrolidone and diethylene glycol (DEG), the influence of the ratio of raw material: solvent on the extractive separation process of the fr. 200 °C to remove aromatic and partially unsaturated compounds. It is proved that the best physical and chemical properties in terms of their further use are characterized by refinates and extracts at a volume ratio of raw material to solvent of 1:2 in the presence of N-methylpyrrolidone, and 1:20 in the presence of DEG.
In general, the use of polycondensation with formaldehyde and extractive separation using polar solvents makes it possible to reduce the content of aromatic and unsaturated structures in the final product (raffinate), which can be used as a component of commercial gasoline.
A method for obtaining commercial gasoline was proposed, which includes polycondensation, extraction and compounding with gas condensate methods. Gasoline with the requirements "Euro 4" brand in terms of basic indicators by DSTU 7687:2015 was obtained.
Based on the research results, directions for the reconstruction and improvement of the WAT pyrolysis pilot unit were proposed, which will allow the production of boiler fuel, commercial gasoline, raw materials for the production of aromatic hydrocarbons and bitumen of the BNDA 60/90 brand.
