Waste Tire Research Articles

Modelling, optimization and characterization of carbon black derived from waste tyre pyrolysis

This study explores how to maximise the yield of carbon black from waste tyre pyrolysis, paying particular attention to important process parameters including feedstock mass, residence time, and temperature. The study employed the use of the central composite design of the response surface methodology to investigate the relationship between the process parameters (feedstock mass, residence time, and temperature) and the carbon black yield. With an R2 and adjusted R2 of 0.99, and a highly significant F-value of 389.62, the model demonstrated excellent accuracy. Analysis of perturbation plots revealed that feedstock mass had the most significant influence on carbon black yield. The interplay of process parameters was illustrated by the 3D surface plots, which showed a positive correlation between the combined effects of feedstock mass and temperature and carbon black yield. The following parameters were found to be optimal for obtaining a maximum carbon black yield: 40 g of feedstock mass, 350 °C temperature, and 60 min of residence time. This produced a carbon black yield of 25.25 wt.%. This was remarkably comparable to the experimental yield of 25 wt.%, confirming the validity of the response surface methodology model. The characterisation of carbon black generated from waste tyre pyrolysis using FT-IR and SEM reveals a compact structure with little porosity and different functional groups. These characteristics increase the material's reliability, thermal stability, and resilience to environmental degradation, making it ideal for long-term applications like rubber reinforcement and composite manufacturing. The findings indicate the optimal production of carbon black at lower temperatures and shorter residence times. The present study establishes the foundation for further investigation into the optimisation of the pyrolysis process, suggesting that different process conditions be explored.

Tribological Impact of Carbon Black Nanoparticles Obtained from Recycled Waste Tires as Additive to Motor Oil

Abstract Used tires are commonly stockpiled at landfills, taking up a vast space of land and leading to serious environmental issues, which makes recycling and finding better waste management strategies necessary. This study explores the potential role of recycled material extracted from waste tires in the lubrication industry by examining different properties of motor oil with the addition of carbon black (CB) nanoparticles obtained from used tires via the pyrolysis process. The CB particles have been added to motor oil at various concentrations (0.5, 1, 2, and 4 wt.%), and several properties of the Oil-CB lubricant mixture, such as tribological, rheological, and lubrication, have been investigated. After testing different concentration samples, the 2 wt.% of CB in the motor oil showed the best tribological and rheological behavior compared to other samples. The improvement in motor oil performance with the addition of CB was evident in the mixed lubrication regime, with a more than 20% reduction in frictional and wear losses compared to the reference motor oil. This improvement in the oil's lubrication performance is attributed to the presence of CB nanoparticles between sliding surfaces operating as a third body that helps reduce the contact pressure and minimize solid-solid asperities contact. Therefore, this work demonstrates the viable role of carbon black recycled material in improving the lubrication properties of current motor oils.

Effect of tire pyrolysis oil and graphene oxide nanoparticles as an additive in the diesel engine.

The majority of industries throughout the world rely largely on fossil fuels as their primary energy source. However, these resources are finite and become scarcer by the day. Therefore, exploring alternative fuels and additives for diesel fuel is imperative to mitigate fuel consumption. A diesel engine powered with different blends of diesel fuel (DF), graphene oxide (GO) nanoparticles, and tire pyrolysis oil (TPO) was used in this investigation. The goal was to undertake in-depth evaluations of performance and emission characteristics. The findings of these investigations were compared to those obtained using neat diesel fuel as a baseline. In the study, diesel fuel blends containing various quantities of graphene nanoparticles (40, 80, and 120mg/L) and 10%, 20%, and 30% TPO were made. A single-cylinder, four-stroke, air-cooled spark-ignition engine was used for testing, with engine speed ranging from 1500 to 3500rpm with an increment of 500rpm. At 3000rpm, the engine running on DT10G80 blend fuel produced 10.46% greater torque than diesel fuel, and at 3500rpm, 11.7% more brake power. The BSFC of the DT10G80, which is 13.33% lower than that of diesel fuel, is the lowest at 2500rpm. When compared to diesel fuel, there are 33.3% and 19.8% fewer CO and NOx emissions, respectively, according to the emission analysis. Finally, combining nanoparticles, waste fuel tire pyrolysis oil, and diesel fuel improves engine power, decreases fuel consumption, and minimizes hazardous gas emissions and particulate matter.

Rehabilitation and Strengthening of Damaged Reinforced Concrete Beams Using Carbon Fiber-Reinforced Polymer Laminates and High-Strength Concrete Integrating Recycled Tire Steel Fiber

Currently, millions of tires are consumed annually, which necessitates the efficient disposal of these quantities of spent tires and the development of means to convert them into useful materials. This research deals with the effect of adding the steel fibers extracted from used car tires (RSFs) to incorporate them as concrete components to obtain high-strength concrete (HSC). The HSC was used in this paper to strengthen the pre-damaged beams by jacking. In the first phase, twelve beams were subjected to an overload equal to 80% of their total expected bearing capacity to obtain damaged RC beams, while one beam was loaded to failure (reference beam, RB0). In the second phase, the damaged beams were strengthened with HSC jacketing integrating RSFs with three contents (0, 0.25, and 0.5%) or by HSC jacking and bonded CFRP laminates to the bottom surface of the jacket. Moreover, the Abaqus finite element (FE) program was implemented to simulate the upgraded damaged beams. The result ensured enhanced HSC compressive and tensile strengths by 11.6–14.4% and 11.6–20.9% as the RSF % increased from 0 to 0.25 and 0.5%, respectively. Using the HSC jacket with 0, 0.25, and 0.5% RSF to strengthen the RC-damaged beams increased the load capacity by 8.8, 14.5, and 20.1%, respectively compared to RB0. Furthermore, strengthening the damaged RC beams with both HSC jacket and CFRP laminates enhanced their load capacity by 41.9, 45.5, and 50.3% as the HSC integrated 0, 0.25, and 0.5% RSF, respectively, compared to RB0. Finally, the FE model could reveal several aspects related to the behavior of the damaged beams strengthened with jackets and CFRP laminates and the interaction between the different beam components.

Development of an Alternative Bitumen Rejuvenator Consisting of Waste Oils and Reacted and Activated Rubber (RAR)

After a long-term in service on pavement, bituminous material exposure to environmental conditions and traffic loads leads to inevitable aging, causing an increase in binder viscosity and making it stiffer. On the other hand, the absence of proper elimination and illegal dumping of waste oil and tire rubber can lead to serious environmental risks. This research aims to investigate the possibility of using waste engine oil (WEO) and waste cooking oil (WCO) separately combined with reactive and activated rubber (RAR) as new alternative rejuvenating agents. In this study, 5% of waste oil (WCO, WEO) and 15% of RAR were added to the aged bitumen with a penetration grade of 20/30. The virgin, aged, and rejuvenated bitumen were investigated for their physical and chemical properties using penetration, softening point, and Fourier transform infrared spectroscopy (FTIR) tests, as well as the effect of thermal cycles (heating and cooling) on the cracking resistance of bituminous mixtures containing regeneration bitumen using the Fénix test. The study outcome indicated that these rejuvenators could effectively soften and restore the basic properties of the aged bitumen to a normal level of 40/50. Meanwhile, the bituminous mixture with the aged bitumen rejuvenated with both oils and tire rubber (AB-WRCO and AB-WREO) showed the best cracking behavior. Therefore, these alternative solutions involve not only reusing the aged bitumen but also reusing the waste oil and tire rubber in order to attain environmental protection and economic benefits.

Upcycling Automobile End-of-Life Tires for Development and Characterization of Circular Plasterboards

The number of end-of-life tires (ELTs) has increased enormously in the world during the last decades, accumulating progressively in landfills and ecosystems. For this reason, the application of secondary raw materials derived from their recycling has become one of the great challenges for today’s society. In this work, different types of prefabricated plaster products were developed incorporating recycled rubber aggregates from ELTs in different granulometries, aiming to study their feasibility to develop construction systems. It was possible to replace up to 40% of the original raw material, obtaining plasterboards that exceed the 0.18 kN flexural breaking load established by regulations. Likewise, the addition of these rubber aggregates reduced the thermal conductivity of the gypsum composites, and the thermal resistance of the lightened partitions was improved by up to 21.8% when used in conjunction with thermal break layer. On the other hand, its greater durability against the action of water was also tested, and fire resistance class B-s1, d0, was obtained. With all these positive results, this study presents a possible application of recycled rubber aggregates for the development of prefabricated plates and panels, addressing one of the main gaps in the literature, the applicability of these building materials produced under circular economy criteria in sustainable construction.

Modification and Aging Mechanism of Crumb Rubber Modified Asphalt Based on Molecular Dynamics Simulation.

Asphalt modified with treated waste tires has good environmental protection and application value. However, the nano-modification mechanism of crumb rubber (CR) with asphalt is still unclear. This research investigates the mechanism, aging, and interfacial interaction with the aggregate of CR modification asphalt (CRMA). The base asphalt and CRMA (original and aged) and two typical aggregate models were constructed. The accuracy of the model was verified through multiple indicators. The effects of CR and aging on the physical properties (density, compatibility, and diffusion coefficient), mechanical properties, component interaction behavior, and interfacial interactions with aggregates of CRMA were systematically analyzed. The results showed that the CR reduced the diffusion coefficient of asphalt by about 31%. The CR inhibited the movement of the components of asphalt (especially saturate and aromatic), which significantly improved the mechanical properties of asphalt. The compatibility between asphalt and CR significantly deteriorated after aging. The difference in the solubility parameter was about four times that before aging. It is instructive for the regeneration of CRMA. Aging led to a decrease in the shear modulus and Young's modulus of both base asphalt and CRMA, which verified and quantified the adverse effects of aging on the mechanical properties. Comparing the two aggregates, CaCO3 had a greater adhesion with asphalt than SiO2. The difference ranged from 22.5% to 39.9%, which quantified the difference in the adhesion properties of acid base aggregates with asphalt. This study can provide theoretical guidance for the modification and application of CRMA.

The effect of waste tire granules on the properties of polyethylene terephthalate thermoplastic

The utilization of waste tire granules (WTG) as a reinforcing agent in polyethylene terephthalate (PET) offers a sustainable approach to enhancing thermoplastic composites. PET is known for its recyclability, while WTG provides a solution for waste tire management. This study examines the effect of WTG content and particle size on PET/WTG composites. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) were used to analyze the composites' morphology and chemical composition. Mechanical tests evaluated elongation and impact performance with WTG incorporation. SEM showed a compatible morphology between the PET matrix and WTG. FTIR spectra displayed characteristic vibrations of polyisoprene from WTG and PETspecific functional groups. The inclusion of WTG significantly improved mechanical properties that leads to enhanced elongation at break (EB) and increased ductility. Impact strength also improved notably at 10% WTG. These findings demonstrate the potential of WTG as a filler to enhance PET mechanical properties and contribute to sustainable waste management as well as the development of value-added products from recycled materials.

Cu-doped waste-tire carbon as catalyst for UV/H2O2 oxidation of ofloxacin.

Ofloxacin (OFX), commonly employed in the treatment of infectious diseases, is frequently detected in aquatic environments and poses potential ecological risks. UV/H2O2 oxidation has been recognized as an efficient approach for removing antibiotics. In this study, Cu-doped waste-tire carbon was prepared and used as a UV/H2O2 catalyst for the degradation of OFX. The results showed that the OFX removal was 89.3% within 90min under the optimal reaction conditions. It was found that ZnO, used in the tire manufacturing to promote rubber vulcanization for enhanced stability and durability, played an important role in UV/H₂O₂ oxidation for OFX degradation. Toxicity experiments conducted with a microbial degradation respirometer demonstrated that the treated water exhibited low toxicity. This study introduces a sustainable catalyst derived from waste tires, and facilitating the development of metal-carbon catalysts for the effective removal of antibiotics from wastewater.

Mitigation of zinc leaching from waste ground tire rubbers through polymer encapsulation

The increasing disposal of waste tires is a growing environmental challenge requiring innovative recycling and reuse approaches. Crumb rubber, derived from end-of-life tires, has potential for various applications where resilience and elasticity are required. However, as highlighted by the upcoming ban on using crumb rubber granulate as infill for artificial turf in the EU, one of the most prominent issues, zinc leaching, urgently requires an effective solution. We studied a range of commercial polymer coatings as a zinc leaching barrier through batch and column leaching tests. This study demonstrates that coatings can reduce the leaching down to 1 % of that of uncoated rubber, reducing environmental risks while improving the prospects for continued use of crumb rubber in various applications. The physico-chemical relation between the coating structure and zinc leaching is elucidated for the most promising coatings by comparing the leaching results with FTIR, GPC and 1H NMR analyses. The use of certain additives shows a cumulative effect to further reduce zinc leaching, while improving UV- and moisture stability. Thermal stability is controlled by the stability of the polymer base. These findings allow us to tailor the mechanical properties to various applications requiring specific elasticity and durability, while retaining the versatility and adaptability of crumb rubber in a range of scenarios. Additionally, the use of additives, typically cheaper than the polymer matrix, enhances the economic viability. By effectively controlling zinc leaching and tailoring mechanical properties through coatings, this study offers a way to extend the life and utility of waste rubbers.

Chemical conversion of recovered carbon black (rCB) from end-of-life tires (ELTs) pyrolysis to reduced graphene oxide (rGO): From waste to advanced materials

This study introduces a circular and economic strategy to produce reduced graphene oxide (rGO) from recovered carbon black (rCB). Using a modified Hummers method followed by chemical reduction of graphene...

Effect of addition of the scrap tires and waste plastics pyrolysis oil residue on the quality of the feed for hydrocracking and FCC

Effect of addition of the scrap tires and waste plastics pyrolysis oil residue on the quality of the feed for hydrocracking and FCC

Parametric investigation of the effects on waste tire pyrolysis oil in a downdraft tube reactor

Parametric investigation of the effects on waste tire pyrolysis oil in a downdraft tube reactor

Environmental Life Cycle Assessment of Encapsulated Rejuvenators from Mining Truck Waste Tires via Pyrolysis for Asphalt Self-Healing

Environmental Life Cycle Assessment of Encapsulated Rejuvenators from Mining Truck Waste Tires via Pyrolysis for Asphalt Self-Healing

Dry-process reusing the waste tire rubber and plastic in asphalt: Modification mechanism and mechanical properties

Dry-process reusing the waste tire rubber and plastic in asphalt: Modification mechanism and mechanical properties

A systematic review of the environmental and health effects of waste tires recycling

A systematic review of the environmental and health effects of waste tires recycling

Coupling of molten salt heating tire pyrolysis process with carbon black modification process: Technical economic evaluation and life cycle assessment

Coupling of molten salt heating tire pyrolysis process with carbon black modification process: Technical economic evaluation and life cycle assessment

Waste-based value-added feedstocks from tire pyrolysis oil distillation: defossilization of the petrochemical industry

Waste-based value-added feedstock.

Physical Properties and Marshall Stability of High-Density Polyethylene and Rubber Crumb Modified Bitumen for Road Application

Standard bitumen used in road construction may not meet engineering requirements due to it becoming brittle in cold weather and softening in hot weather. This study investigates the mechanical and physical properties of bitumen modified with high-density polyethylene (HDPE) and rubber crumb for road applications. Bitumen sourced from Ilaje, Ondo State, Nigeria, underwent characterisation tests including penetration, softening point, ductility, and fire point. Waste HDPE and rubber crumb, collected from dumpsites in Zaria, Kaduna State, Nigeria, were sorted, washed, dried, and milled to a size of 600 microns. The waste plastic was then blended with the bitumen using an optimised mix design obtained from the design of experiment. Characterisation tests (Marshall stability, penetration, softening point, ductility, and fire point) were performed on the resulting waste plastic-modified bitumen. The test results showed that the stability of the road asphalt increases as the proportion of HDPE and rubber crumb used in the bitumen modification increases. The control group (100% bitumen) exhibited the lowest Marshall stability (19.81 kN, 13.12 kN, and 17.82 kN for samples A, B, and C, respectively). The stability of sample A increased by 62.2%, the stability of sample B increased by 75.6%, and that of sample C increased by 56.6%. Based on the research findings, modifying bitumen with waste materials offers several advantages for road construction, which are reducing material costs as waste plastics and tires are readily available, waste utilisation reduces environmental impact, and modified bitumen enhances road durability.

Assessing the usage of end-of-life tire pyrolysis oil as an alternative fuel in a diesel engine in the point of energy, exergy, exergoeconomic, exergoenviroeconomic, and sustainability parameters

ABSTRACT The present study examines the utilization of fuel blends comprising waste tire pyrolysis oil (WTPO) at varying ratios (10%, 20%, 30%, and 40%) in a compression-ignition (CI) engine at different loads (25%, 50%, 75%, and 100%). This is with a view to elucidating the performance and emission characteristics of the blends in detail. The performance and emission data were subjected to detailed analysis. Energy, exergy, exergoeconomic, exorgoenviroeconomic, and sustainability analyses were conducted with the objective of comparing the fuel blends. Based on these analyses, the energy dissipation of the engine, exergy losses, cost of power from the engine shaft, and sustainability index (SI) were calculated for each fuel at all operating conditions. As the fraction of WTPO in the fuel blends increased, fuel consumption increased and energetic efficiency declined owing to the lower energy content of the alternative fuel additive. As the percentage of WTPO in the fuel blends increased gradually, the exergy losses increased, resulting in a decline in exergy efficiency. At the highest load, the exergetic efficiency of TP20 was found to be 5.65% higher than that of TP40. Given that the cost of traditional diesel fuel (D100) was 73.3% higher than WTPO, the cost of power from the engine shaft decreased as the WTPO ratio ascended in the blends. Consequently, the aforementioned parameter for TP10 was calculated to be 144.55 $/GW at a load of 75% while 120.90 $/GW was found for TP40. The greatest quantity of CO2 released into the environment was 11,512.4 kg CO2/month in TP40 at the highest load. Under the same conditions, it was calculated as 5,958.2 kg CO2/month for D100. In the context of an SI based on load, a reduction of 5.89% was observed in the case of conventional D100 in comparison with TP40 in the CI engine operating at full load. The findings of the present examination indicate that WTPO may be a viable alternative fuel for CI engines running on D100.