Decomposition of Used Tyre Rubber by Pyrolysis: Enhancement of the Physical Properties of the Liquid Fraction Using a Hydrogen Stream

Abstract

Abstract:The disposal of discarded tyres represents an environmental challenge for solid waste management entities. The need to reduce solid waste in urban areas along with the depletion of natural resources have made it necessary to reincorporate used materials into productive processes, giving value to what is considered waste, and minimizing the requirement of natural resources. In this study, pyrolysis was selected to thermally decompose used ground waste vulcanized rubber from automobile tyres. This rubber was exposed to the pyrolytic process in an indirectly heated batch reactor at three different temperatures. Three fractions (i.e., gas, liquid and solid) were obtained during the process. The effect of a hydrogen stream on the properties of the liquid fraction was analysed and characterized following the American Society for Testing and Materials procedures (ASTM) for the pyrolysis of liquid fuels. A multifactorial statistical analysis was used to evaluate the experimental data and thermographs of the process were recorded. Differences in thermographs suggest a different degradation pathway for the rubber exposed to 600 • C compared to the rubber exposed to lower temperatures. Temperatures in the range of 450 to 500 • C favored the production of carbon black regardless of the use of a hydrogen stream. In contrast, high temperatures favored the production of liquid and gas fractions. The highest production of liquid fraction was obtained at 550 • C, where 37% of the rubber was turned into liquid. Results also showed that a constant flow of hydrogen improves the appearance of the pyrolysis liquid. Furthermore, the hydrogen atmosphere reduces the sulphur content, water and sediments; and increases the values for the heat of combustion and the liquid fraction.

End of Life Tires as a Possible Source of Toxic Substances Emission in the Process of Combustion

“…In contrast to direct combustion, however, it is possible to control the pyrolysis process within some limits. The authors of [8] determined that the temperature of the process affects rubber decomposition and, respectively, pyrolysis products. Raising the temperature above 500 • C contributed to the production of liquid and gas fractions.…”

“…Thus, a large proportion of ELTs consists of organic compounds and can be considered as an energy resource. Differences in heat treatment and in gas atmosphere during pyrolysis lead to a different degradation pathway for the rubber [8]. One can obtain a larger or smaller quota of gases, liquid product, and pyrocarbon.…”

Combustion and emission characteristics analysis of waste tyre pyrolysis oil

“…Banihani et al [27] adopted the thermal pyrolysis method of waste tyre in presence of catalyst to prepare oil in which the effect of catalysts and their ratio on the pyrolysis product oil is investigated and found that the maximum liquid yield obtained from pyrolysis of waste tyre with catalyst like activated alumina and zeolite as 49.32% and 51.54% compared to 42.48% without catalyst. Ramirez-Canon et al [28] analyzed the effect of liquid fraction of TPO on environment and found that the presence of hydrogen stream improves the appearance of fuel and also reduces the sulphur content, water and sediments and increases the heating capacity of fuel.…”

Extraction sample preparation of pyrolysis oil of waste automobile tires with its component and quantitative GC-MS analysis

“…Одним из наиболее эффективных способов переработки вторичного сырья с целью получения жидкого топлива является пиролиз. Продукты пиролиза могут быть использованы в качестве ценных углеводородов или углеводородного топлива [1][2][3]. Анализ Химического состава жидкого пиролизата важен как для оценки степени его токсичности, так и для поиска эффективного способа его очистки и дальнейшего использования в качестве топлива.…”