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Tire pyrolysis oil (TPO) is one of the most interesting products derived from the pyrolysis of end-of-life tires. Among others, it contains valuable chemicals, such as benzene, toluene, ethylbenzene, and xylene (BTEX), as well as limonene. In order to recover these chemicals, a pilot-scale distillation plant has been designed, erected, and operated using TPO derived from an industrial-scale pyrolysis plant. The distillation facility consists of a packed column (20 kg/h) and is within the fifth technological readiness level. This work describes for the first time the fractioning of the TPO in a continuous operational mode under industrially relevant conditions. For this purpose, different reboiler temperatures (250–290 °C) and reflux ratios (up to 2.4) were preliminarily assessed on the yields and properties of the resulting products: light fraction (LF) and heavy fraction (HF). Thus, the distillation plant is capable of producing 27.0–36.7 and 63.3–73.0 wt % of LF and HF, respectively. The highest BTEX concentration in the LF (55.2 wt %) was found using a reboiler temperature of 250 °C and a reflux ratio of 2.4. Contrarily, the highest limonene concentration (4.9 wt %) in the LF was obtained at 290 °C in the reboiler without reflux. In this sense, the lower the reboiler temperature, the higher the BTEX, and the lower the limonene concentration in the LF. The main results herein obtained serve to gain key insights to operate packed distillation columns using complex and promising hydrocarbons as TPO in order to recover valuable products. In addition, this work provides significant information for optimizing the recovery efficiencies of both BTEX and limonene, as well as their potential applications including that for the resulting HF.

Waste tires are solid wastes with large annual output and with the potential for great harm to the environment. The pyrolysis of waste tires can recycle energy and produce reusable products. Although there are many reviews in the literature in regard to the pyrolysis characteristics of waste tires, no one paper focuses on reviewing and summarizing the tire char. This paper critically appraises the achievements of earlier reports and literature and assesses the current state-of-the-art for the production and application of tire char from waste tires. Initially, the thermal decomposition behavior of different tire rubbers is discussed and compared where it is shown that the different components of waste tire rubber have different thermal degradation characteristics. The influencing factors on the yield and quality of tire char are discussed and assessed in terms of different pyrolysis reactors and technologies, tire type and composition, and a range of pyrolysis process conditions. The composition of the waste tire and pyrolysis conditions are the main factors affecting the distribution of pyrolysis products. Pyrolysis technology and reactor equipment also have an effect on the distribution of pyrolysis products. The physical and chemical structural characteristics of tire char are critically reviewed in detail, including a comparison of the fundamental differences with commercial carbon black and modified tire char (physical activation and chemical activation). Finally, high-value application fields and developmental prospects of tire char are summarized. Through extensive literature review, a novel development was that tire char could be used as a source of gra-phene. The economic analysis of the various tire char applications should be one of the main research directions in the future. The keynote of this review is to promote intensification of waste tire recycling and treatment so that more tire char can be obtained from waste tire pyrolysis and thereby be reused

The aim of the article is to depict overall process of waste tire pyrolysis. By the team of researchers works of many scientists and pyrolysis plants in Germany, Hungary, Estonia, Norway, Brazil, Thailand, Malaysia and come up with the general scheme and described it. The importance of the work consist of several aspects. Firstly, it clears up nature from waste tires which require hundreds of years to decompose without outer factors. Secondly, the high demand to energy sources especially to green ones is increasing gradually. Lastly, but not less importantly, by products of the process can also be used in various fields.

This work studies the gasification of char derived from waste tire pyrolysis (pCB) by using a thermogravimetric analyzer under CO2/N2 atmospheres (20/80, 25/85 and 30/70 vol%) at different temperatures (825 °C, 850 °C, 875 °C, 900 °C and 925 °C). The main goal is the assessment of three different kinetic models for predicting not only the conversion (X) versus time (t) curve, but also the reaction rate (dX/dt) versus conversion (X) one, with high accuracy. At this respect, the Changing Grain Size Model (CGSM), the Random Pore Model (RPM) and a new model based on the RPM named the Hybrid Modified Random Pore Model (HMRPM) were used. The three models were fitted and the kinetic parameters such as the apparent kinetic constant (Ki(T,pj)), the reaction order (n), the activation energy (Ea) and the pre-exponential factor (A) were determined. The results suggest that the HMRPM is the model with better fitting because its ability to reproduce both conversion (X) and reaction rate (dX/dt); and hence, it is reliable to be integrated in both particle and reactor models, i.e. when the process is being designed and scaled-up. A drastically decrease in the reaction rate at the first stage of conversion (<20%) suggests a possible effect of volatile matter and inorganic compounds contained into the pCB. The n, Ea and A were found to be 0.543, 147.27 kJ/mol and 4.547 × 105 s−1, respectively.

[EN] This study pursues the valorization of waste tires by pyrolysis using a different approach for tire parts, specifically, the tire tread rubber and side wall rubber. Tire tread rubber was used to produce hot char with the purpose of using it as cracking catalyst. Side wall rubber was valorized by pyrolysis and online catalytic pyrolysis over tire tread rubber derived hot char in two fixed bed reactor. This work aims to improve the quality of pyrolysis products using tire tread rubber derived hot char as catalyst. The thermal decomposition behavior and products characteristics were tested by means of TG-FTIR, GC, GC-MS, nitrogen adsorption and SEM. Under catalytic pyrolysis temperature of 500−550 °C, a high yield of valuable single ring aromatics (concentration in the oil of 50 %) was obtained. The yield of gas can reach 10.5 wt.% after catalytic pyrolysis, which only 3.0 wt.% without catalytic pyrolysis. The yield of undesirable byproducts as PAHs and carbon deposits was also limited. This strategy represents a novel and feasible alternative to traditional waste tire catalytic pyrolysis processes using expensive catalysts as zeolite.

This work aims to study the pyrolysis of scrap tires as an end-to-end process, from its production to the combustion characteristics of the tire pyrolysis liquid (TPL) obtained. The TPL was produced in a continuous auger reactor (150 kWth) and its combustion characteristics were acquired through a drop tube facility, where the TPL burning behavior was compared to that of conventional heating oil (FO). The evaluated combustion characteristics included droplet and flame size evolution, burning rates, soot shell morphology, microexplosion occurrence and soot analysis. When compared to FO, TPL displayed considerably lower burning rates, although the consistent occurrence of microexplosions effectively shortened the TPL droplets lifetimes below those of FO. TPL also presented smaller flames and a higher propensity to soot. A TPL-FO blend of interest for heating applications (with only 5% of TPL due to its high sulfur content), was also tested, showing identical results to those of neat FO for all the studied combustion characteristics. The reported results are thought to provide valuable experimental data regarding the combustion behavior of a well characterized tire pyrolysis oil, which could also be used as the fuel-specific input data required for the simulation of realistic spray flames.

Pyrolysis offers the possibility to convert waste tires into liquid and gaseous fractions as well as a carbon-rich solid (CBp), which contains the original carbon black (CB) and the inorganic compounds used in tire manufacture. Whilst both liquid and gaseous fractions can be valorized without further processing, there is a general consensus that CBp needs to be improved before it can be considered a commercial product, seriously penalizing the pyrolysis process profitability. In this work, the CBp produced in a continuous pyrolysis process was demineralized (chemical leaching) with the aim of recovering the CB trapped into the CBp and thus, producing a standardized CB product for commercial purposes. The demineralization process was conducted by using cheap and common reagents (HCl and NaOH). In this sense, the acid treatment removed most of the mineral matter contained in the CBp and concentration was the main parameter controlling the demineralization process. An ash content of 4.9 wt% was obtained by using 60 min of soaking time, 60 °C of temperature, 10 mL/g of reagent/CBp ratio and HCl 4 M. The demineralized CBp (dCBp) showed a carbon content of 92.9 wt%, while the FRX analysis indicated that SiO2 is the major component into the ash. The BET surface area was 76.3 m2/g, and textural characterizations (SEM/EDX and TEM) revealed that dCBp is composed by primary particles lower than 100 nm. Although dCBp showed a low structure, the surface chemistry was rich in surface acidic groups. Finally, dCBp was used in Styrene Butadiene Rubber (SBR) compounding, probing its technical feasibility as substitute of commercial CB N550.

El Ministerio de Medio Ambiente, Vivienda y Desarrollo Territorial emitió la Resolución 1457 de 2010 con el fin de establecer el sistema de gestión de residuos de llantas usadas en Colombia. Sin embargo, el problema continúa: acumulación sin control, contaminación visual y atmosférica, proliferación de vectores y propagación de enfermedades. En este marco, se realizó la revisión bibliográfica de las alternativas que se están empleando en el país para el manejo de residuos de llantas usadas. Este estudio es la base para desarrollar otras opciones para el uso de estos residuos.

Tire pyrolysis liquid (TPL)/diesel fuel blend (50/50 vol.%) was fed in a residential boiler unit of 29.1 kW of nominal power, assessing its potential use as alternative heating fuel oil (HFO) for domestic heating. Process performance was compared to that observed for conventional diesel fuel. Both, 50/50 blend and reference diesel fuel were tested at three different positions of the screw which regulates the fuel–air ratio (optimized for diesel fuel). Different operating parameters, such as water and exhaust temperature profiles and boiler efficiency, were evaluated. In addition, concentrations of pollutant gases (CO, NOx and THC) and particulate matter (PM) through total number of particles were measured. The study was carried out under the most critical transient process for any thermal machine: the start-up. Regarding to the fuel effect, the 50/50 blend gives thermal efficiencies slightly higher compared to those found for diesel fuel at all positions tested. In addition, both CO and THC concentrations were slightly lower for the alternative fuel compared to those found for the conventional fuel, being more representative at the lower relative fuel ratio (position 5). However, PM concentrations for 50/50 blend were higher to those found for diesel fuel at all positions of the regulator screw. This work demonstrates the great potential for using a high proportion of TPL fuel blended with diesel fuel without the need of modifying original regulation parameters of boiler, although some properties of TPL should be improved in order to decrease the PM concentrations.

This paper shows the maximum limit on syngas composition obtained from volatiles released in waste tire pyrolysis when they are submitted to an air–steam partial oxidation process. Thus, from mass and energy balances and a stoichiometric equilibrium model, syngas composition and reaction temperature as well as some process parameters were predicted by varying both the equivalence ratio (ER) and the steam to fuel ratio (SF). In addition, pyrolysis experiments were performed using a continuous auger reactor, and the influence of pyrolysis temperature on composition of both volatiles and char was studied. Consequently, the resulting syngas characteristics were correlated with the pyrolysis temperature. The stoichiometric equilibrium model showed that an ER down to 0.4 is a practical limit to perform the air–steam partial oxidation process. When the process is carried out only with air, volatiles obtained at high pyrolysis temperature lead to lower reaction temperature and higher LHV of syngas in comparison with those found at low pyrolysis temperature. The H2 production is favored between 0.20 and 0.40 of ER and seems to be more influenced by the H/C ratio than by the water gas-shift reaction. On the other hand, the steam addition shows a more notable effect on the H2 production for volatiles obtained at the highest pyrolysis temperature (600 °C) in agreement with the lower reaction temperature under these experimental conditions. This thermodynamic analysis provides essential data on the optimization of syngas production from volatiles released in waste tire pyrolysis prior to run any test.

Pyrolysis is becoming a promising alternative to tackle the waste disposal problem related to used tires as well as for the production of alternative liquid fuels. However, the practical applicability of the products obtained from waste tire pyrolysis has been rather limited. This work aims to increase the knowledge about some key properties of the tire pyrolysis liquid (TPL) obtained in a continuous auger reactor on pilot scale, and its blends with diesel fuel (D). Kinematic viscosity, density, heating value, oxidation stability, lubricity, water content, cold filter plugging point (CFPP), and smoke point have been measured for different TPL/D blends. Values for both pure fuels and blends have been compared to the requirements established for diesel fuel (standard EN 590) and to other TPL properties data reported in literature. Additionally, the flash point, the distillation curve, the calculated cetane index (CCI), and the total acid number (TAN) have also been determined for the pure fuels. These properties show the useful window for the utilization of TPL because they indicate its quality as a fuel in diesel engines or other power systems. Mixing rules for calculating some key properties of TPL/D blends as a function of TPL content have also been used in order to model the blend behavior.

in this study, waste tire was used as raw material for the production of activated carbons through pyrolysis. Tire char was first produced by carbonization at 550 degrees C under nitrogen. A two factorial design was used to optimize the production of activated carbon from tire char. The effects of several factors controlling the activation process, such as temperature (850-950 degrees C), time (2-6 h) and percentage of carbon dioxide (70%-100%) were investigated. The production was described mathematically as a function of these three factors. First order modeling equations were developed for surface area, yield and mesopore volume. It was concluded that the yield, BET surface area and mesopore volume of activated carbon were most sensitive to activation temperature and time while percentage of carbon dioxide in the activation gas was a less significant factor.

Pyrolysis has been extensively studied in past decades as its potential to convert organic wastes into bio-fuels. Pyrolysis is an overall endothermic process but preformed exothermically at its early stage. The overall energy consumption as well as the product quality and yield are affected by the heating rate and the operation temperature. In order to reach its full potential to produce bio-fuels, the energy consumption of the process has to be minimised. An idea to reduce the pyrolysis energy consumption is observed, which suggests trapping the exothermic heat released in the beginning of the pyrolysis process and using it to fulfil the energy requirement of the endothermic reactions at the end of the process. To achieve this, the pyrolysis has to be performed in multiple stages. The operation strategy of the multi-stage pyrolysis, including the number of stages, the operating conditions (e.g. process temperature, heating rate) and residence times of each stages, have to be carefully designed to obtain the most energy saving and the best product yield. The operating strategy of a pyrolysis process therefore greatly depends on the pyrolysis kinetics and the control of heat transfers. Waste tire pyrolysis is chosen as the study example in this paper. The corresponding reaction kinetics at different heating rates are investigated via experiments. Based on the experimental results, a mathematical model integrating kinetics and heat transfers is then developed. The objective of the model is to design a suitable operation strategy for the multi-stage pyrolysis process. A four-stage strategy is finally proposed for the tire pyrolysis, which has the sequence of heating, adiabatic, heating and adiabatic. The strategy is verified by the model, and it is capable to save about 22.5% energy consumption compared to the conventional strategy. (C) 2011 Elsevier B.V. All rights reserved.

Siddika, A., Al Mamun, M. A., Alyousef, R., Amran, Y. M., Aslani, F., & Alabduljabbar, H. (2019). Properties and utilizations of waste tire rubber in concrete: A review. Construction and Building Materials, 224, 711-731. Available here

Tato disertační práce se zabývá možností využití pryžového granulátu získaného zpracováním odpadních pneumatik pro modifikaci silničního asfaltu. Vzniklý asfalt modifikovaný pryžovým granulátem se používá jako alternativa polymerem modifikovaného asfaltu v hutněných asfaltových směsích. V teoretické části jsou popsány reologické vlastnosti asfaltových pojiv a historie a současný stav řešené problematiky ve světě a v ČR. Praktická část práce obsahuje popis vlastností vybraných pryžových granulátů a vyrobených asfaltů modifikovaných pryžovými granuláty s důrazem na jejich reologické vlastnosti a změnu těchto vlastností způsobenou stárnutím při vysoké teplotě. Dále jsou popsány empirické i funkční vlastnosti asfaltových směsí s asfaltem modifikovaným pryžovým granulátem. Laboratorní vlastnosti asfaltových směsí byly ověřeny v reálných podmínkách provozu na 32 pokusných úsecích. Na základě výsledků disertační práce bylo umožněno vytvoření předběžných technických podmínek Ministerstva dopravy (TP 148) a později jejich revidování. V závěru jsou provedené práce shrnuty a zdůrazněny výsledky disertační práce., Presented dissertation thesis is focused on the possibility of using the crumb rubber from waste tires for modification of paving grade bitumen. The resulting asphalt rubber can be used as an alternative to polymer modified bitumen in compacted bituminous mixtures. The theoretical part describes the rheological properties of asphalt binders and the history and today state of the art in the world and in the Czech Republic. The practical part of the work contains a description of the properties of chosen crumb rubbers and produced asphalt rubbers focused on their rheological properties and on change of these properties caused by the aging at high temperature. Subsequently, the chosen empirical and functional properties of bituminous mixtures with asphalt rubber are described. Laboratory properties of these mixtures were verified under real service conditions on 32 test sections. Based on the dissertation thesis results the preliminary technical specification of the Ministry of Transport (TP 148) and their following revision were approved. The conclusion of the work summarizes and highlights the results of the dissertation.

Tato disertační práce se zabývá možností využití pryžového granulátu získaného zpracováním odpadních pneumatik pro modifikaci silničního asfaltu. Vzniklý asfalt modifikovaný pryžovým granulátem se používá jako alternativa polymerem modifikovaného asfaltu v hutněných asfaltových směsích. V teoretické části jsou popsány reologické vlastnosti asfaltových pojiv a historie a současný stav řešené problematiky ve světě a v ČR. Praktická část práce obsahuje popis vlastností vybraných pryžových granulátů a vyrobených asfaltů modifikovaných pryžovými granuláty s důrazem na jejich reologické vlastnosti a změnu těchto vlastností způsobenou stárnutím při vysoké teplotě. Dále jsou popsány empirické i funkční vlastnosti asfaltových směsí s asfaltem modifikovaným pryžovým granulátem. Laboratorní vlastnosti asfaltových směsí byly ověřeny v reálných podmínkách provozu na 32 pokusných úsecích. Na základě výsledků disertační práce bylo umožněno vytvoření předběžných technických podmínek Ministerstva dopravy (TP 148) a později jejich revidování. V závěru jsou provedené práce shrnuty a zdůrazněny výsledky disertační práce., Presented dissertation thesis is focused on the possibility of using the crumb rubber from waste tires for modification of paving grade bitumen. The resulting asphalt rubber can be used as an alternative to polymer modified bitumen in compacted bituminous mixtures. The theoretical part describes the rheological properties of asphalt binders and the history and today state of the art in the world and in the Czech Republic. The practical part of the work contains a description of the properties of chosen crumb rubbers and produced asphalt rubbers focused on their rheological properties and on change of these properties caused by the aging at high temperature. Subsequently, the chosen empirical and functional properties of bituminous mixtures with asphalt rubber are described. Laboratory properties of these mixtures were verified under real service conditions on 32 test sections. Based on the dissertation thesis results the preliminary technical specification of the Ministry of Transport (TP 148) and their following revision were approved. The conclusion of the work summarizes and highlights the results of the dissertation.

Tato disertační práce se zabývá možností využití pryžového granulátu získaného zpracováním odpadních pneumatik pro modifikaci silničního asfaltu. Vzniklý asfalt modifikovaný pryžovým granulátem se používá jako alternativa polymerem modifikovaného asfaltu v hutněných asfaltových směsích. V teoretické části jsou popsány reologické vlastnosti asfaltových pojiv a historie a současný stav řešené problematiky ve světě a v ČR. Praktická část práce obsahuje popis vlastností vybraných pryžových granulátů a vyrobených asfaltů modifikovaných pryžovými granuláty s důrazem na jejich reologické vlastnosti a změnu těchto vlastností způsobenou stárnutím při vysoké teplotě. Dále jsou popsány empirické i funkční vlastnosti asfaltových směsí s asfaltem modifikovaným pryžovým granulátem. Laboratorní vlastnosti asfaltových směsí byly ověřeny v reálných podmínkách provozu na 32 pokusných úsecích. Na základě výsledků disertační práce bylo umožněno vytvoření předběžných technických podmínek Ministerstva dopravy (TP 148) a později jejich revidování. V závěru jsou provedené práce shrnuty a zdůrazněny výsledky disertační práce., Presented dissertation thesis is focused on the possibility of using the crumb rubber from waste tires for modification of paving grade bitumen. The resulting asphalt rubber can be used as an alternative to polymer modified bitumen in compacted bituminous mixtures. The theoretical part describes the rheological properties of asphalt binders and the history and today state of the art in the world and in the Czech Republic. The practical part of the work contains a description of the properties of chosen crumb rubbers and produced asphalt rubbers focused on their rheological properties and on change of these properties caused by the aging at high temperature. Subsequently, the chosen empirical and functional properties of bituminous mixtures with asphalt rubber are described. Laboratory properties of these mixtures were verified under real service conditions on 32 test sections. Based on the dissertation thesis results the preliminary technical specification of the Ministry of Transport (TP 148) and their following revision were approved. The conclusion of the work summarizes and highlights the results of the dissertation.