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This study investigates the effects of varying temperatures on the co-pyrolysis of wood sawdust (WS) and waste tires (WT) within a stainless steel fixed-bed reactor under a nitrogen atmosphere. The experiments were conducted at three different temperatures: 400 °C, 500 °C, and 600 °C, focusing on the thermal behavior and resultant product yields. At 600 °C, WS produced the highest oil yield (63.6 wt%), suggesting a tendency to generate more aqueous and volatile components. Conversely, WT alone showed an optimal oil yield of 46.4 wt% at 500 °C, while the WS-WT blend achieved 55.6 wt%. Gas chromatography-mass spectrometry (GC-MS) analyses of the pyrolytic oils indicated that WS-heavy mixtures were rich in aliphatic compounds, whereas WT-dominant samples had increased aromatic and phenolic contents, demonstrating the potential for creating valuable chemicals from waste. Additionally, gas analysis highlighted significant variations in syngas composition, with increased methane and decreased CO2 levels at higher temperatures, emphasizing the role of the water-gas shift reaction. These findings underscore the critical importance of temperature control in optimizing the efficiency and quality of products from co-pyrolysis, presenting a viable method for enhancing the value derived from waste materials.

The global scientific research circle and government agencies face a number of serious environmental challenges, one of which is the recycling of “End of Life Tires” (ELT). An estimation of one billion tires is expected to end their useful life annually, of which only roughly 50% are recycled at the moment, with the remainder ending up in landfills. Consequently, to solve this gap in the ELT's utilization rate, it is imperative to enhance the current application and furthermore create new applications for recycled tire materials. One of such areas that is currently being investigated is the introduction of waste tire into concrete as partial replacement of natural aggregates in concrete production. Despite its great prospects, it has drawbacks such as lack of proper bonding with the cement matrix and weak rubber intrinsic strength, which make it unsuitable for widespread usage as an aggregate. To get past this obstacle, numerous rubber treatment techniques that enhance the mechanical characteristics of rubber concrete remarkably as well as the bonding properties have been studied by researchers. The impact of rubber percentage replacement, rubber aggregate size and different treatment techniques on various mechanical characteristics of rubber concrete are examined in this review paper. But in order for the concrete industry to embrace it, the researchers need to devise a rubber treatment technique that can tackle the issues of high combustible and the harmful gases that are released from the rubber aggregates when they come in contact with fire.

This research aims to assess the rheological and mechanical characteristics of Self-compacting concrete (SCC) incorporating waste tire rubber aggregates (WRTA) as an interim substitute for coarse aggregates. However, the standard experimental modeling approach has significant obstacles when it comes to overcoming the nonlinearity and environmental susceptibility of concrete parts. Therefore, linear regression (LR) and extreme gradient boosting (XGBoost) were used as two standard single machine learning (ML) models to predict the aforementioned rubberized SCC features. In this study, conventional coarse aggregates were supplanted with WRTA at 0%, 5%, 10%, and 20% to uncover the optimal proportion of coarse aggregates substituting rubber. To find the optimum amount of WRTA to use as a substitute, the study follows the impacts of rubber on the self-compacting rubberized concrete's (SCRC) rheological and mechanical characteristics. The consequences on fresh properties were investigated by the slump flow, J-ring, and V-funnel tests, while compressive and splitting tensile strengths tests were conducted to assess mechanical properties. Increasing WRTA test outputs indicated a deterioration in workability and hardened qualities. While a 10% swapping ratio is deemed feasible for producing SCRC, optimal results were achieved by reducing environmental impacts and efficiently managing a significant volume of rubber tire waste with a 5% substitution of rubber within the coarse aggregates. The research findings indicated a noticeable decrease in fresh properties as the WRTA content increased. Notably, after 28 days, a 10% WRTA substitution led to a 34% reduction in compressive strength and a 28% decrease in splitting tensile strength, satisfying ACI standards. Furthermore, XGBoost demonstrated superior predictive performance with the highest R2 values, outperforming the LR model and affirming its efficacy in delivering more accurate predictions.

Artificial stones are building materials developed with stony waste aggregates and a polymeric resin as an agglomerate. Its mechanical properties, in general, overcome natural stone's properties, since the use of resin makes it possible to manufacture a less porous, that is, a denser material, more impermeable, and with greater mechanical resistance. However, its development is costly because it requires the use of high-quality aggregates. Waste can replace these aggregates, developing an economically and environmentally advantageous novel, sustainable artificial stone. This work's main goal is to develop a flexible sustainable artificial stone based on waste glass and waste tire agglomerated with a biopolymeric resin, polyurethane from castor oil, and evaluate its properties. Plates were manufactured with 22% of polyurethane resin and 78% of different proportions of the two wastes (glass and tire) mixed up. The molding was carried out under a 600 mmHg vacuum, a 6Hz vibration, and an 80° hot pressing for 20 min. The stones developed, named AS50GT and AS66GT, were lighter than other developed artificial stones, but less resistant to bending efforts since rubber tire is a polymeric material. However, they displayed a high Izod impact strength, evidencing that the development of artificial stones with glass and tire wastes and biopolymeric polyurethane resin is viable, not only from an economic and environmental point of view but also technically viable once both developed stones can be marked in the building construction industry.

Recovered carbon black (RCB) obtained from a tire pyrolysis plant was subjected to chemical and thermal treatments for application as a filler in rubber compounds. Carbon black was chemically treated with nitric acid by varying the temperature, time, and chemical-to-carbon black ratio. The iodine number was optimized using response surface methodology (RSM) and the Design Expert software. To increase the iodine number, the Box–Behnken design was utilized to optimize three parameters: temperature (30–50 °C), time (6–24 h), and ratio of carbon black to chemical (0.25–1.0 g/mL). Under optimal conditions, the surface area increased, and RCB was upgraded to commercial carbon black N330. RSM analysis indicted that the iodine number was maximized (117.34 mg/g) after treatment at 46.74 °C for 23.24 h using a carbon black/chemical ratio of 0.76 g/mL. The simulated data were experimentally validated by analyzing RCB_ EQ, which yielded an iodine number of 119.12 mg/g. The content of most heavy metals in RCB decreased by more than 90%, whereas the sulfur and chlorine content decreased by 43.27% and 53.96%, respectively. Based on thermogravimetric analysis, the RCB_13 carbon black additive was eliminated at temperatures of 620–800 °C.

This work investigated engine performance and emissions using waste tire oil-diesel-biodiesel blends. A sustainable fuel glycine max biodiesel was blended with the tire oil-diesel blends to improve performance, combustion, and exhaust emissions. The seven fuels including a 100% diesel 10–30% waste tire oil to 90-70% diesel, 10% tire oil +10% biodiesel +80% diesel, 30% tire oil+10% biodiesel+60% diesel and 10% biodiesel+90% diesel was used as fuels in a direct injection diesel engine. Up to 30% (vol) waste tire pyrolysis oil was blended with diesel. More than 30% of waste tire pyrolysis oil shows inferior solubility issues and inferior engine performance and emissions. Thus, this investigation was limited to 30% waste tire pyrolysis oil. All fuel blends showed similar properties to diesel. With similar engine performance, like torque, power, efficiency, energy, and exergy metrics, the blends showed insignificant variations in emissions (carbon dioxide, nitrogen oxide) compared to a reference diesel fuel. Interestingly, the experimental results were compared with the modelling results, and the maximum variations between them were 10%. The outcome of this research can promote waste tire pyrolysis oil as an alternative fuel for diesel engines and accords with alternative energy development initiatives all over the world.

The optimal approach to reducing surface torque when drilling uses oil-based or synthetic-based mud systems instead of aqueous mud systems. However, lower surface torque and drag can be achieved by lowering the water-based mud friction factors using lubricant additives. Torque can be reduced up to 25% with the suitable mud lubricant additives. Lubricant additives are viable methods for decreasing frictional resistance in drill strings during oil and gas drilling operations. In this study, bio-oil was produced from waste tire distilled pyrolytic oil and added to formulated standard aqueous drilling fluid to investigate its ability to reduce frictional torque during drilling. The lubricating properties of the proposed lubricant additive was compared with commercially used lubricant additive as reference samples (control). The simulation results were compared with measurements from the OFITE Lubricity Tester. The result shows that adding the distilled waste tire pyrolytic oil and produced bio-oil to the drilling mud decreased the coefficient of friction and torque to generate oily films on the contact-surface. The distilled pyrolytic oil and produced bio-oil torque values were in the range of 23.50–32.98 and 21.30–30.82 respectively. The commercial lubricant additive (control) gave 42.85% maximum torque reduction, while the produced bio-oil gave a similar maximum torque reduction of 41.88%. The result shows that, for a water-based drilling fluid, the friction coefficient between the drill string and rock formation, can be reduced with the application of the produced bio-oil. Thus, the produced bio-oil can be used to prevent differential sticking or free the stuck pipe during drilling.

About 25.7 million tons of waste tires (WT) are discarded each year worldwide causing important environmental, and health problems. This waste is difficult to manage and dispose due to its huge rate of generation and its extremely slow biodegradation. Therefore, many efforts are being made to valorise WTs into a series of marketable products under a circular economy framework. In the attempt to convert WT into higher-value products, thermochemical decomposition by pyrolysis has emerged as a promising process [1]. The pyrolysis is a thermochemical transformation (under an oxygen-depleted atmosphere) of the tire´s polymeric constituents: natural rubber (NR), styrene-butadiene rubber (SBR), and butadiene rubber (BR) into three major fractions. These fractions are a gas (10–35%, TPG) which is usually used as a heat source (50 MJ kg−1), a solid consisting mainly of recovered carbon black (12–45%, rCB), and a liquid fraction (35-65%, TPO) containing a complex mixture of organic compounds. Among the high-value compounds that can be found in the TPO are D,L-limonene, isoprene, benzene, toluene, mixed-xylene, ethylbenzene, styrene, p-cymene, and some polycyclic aromatic hydrocarbons. This mixture is commonly used as a diesel substitute and owing to its complex composition it rarely is seen as a source for more valuable products. To overcome such a complexity, and selectively produce specific chemical identities, different types of catalysts have been used [2,3].Herein, we provide a dataset from a systematic study about catalytic pyrolysis of WT for selectively producing benzene, toluene, and xylenes (BTX) and p-cymene on noble metals (Pd, Pt, Au) supported on titanate nanotubes (NT-Ti). The comprehensive analysis of this data was recently published, thus, the analytical techniques, experimental conditions and dataset are given in the present paper as a complement to that publication [1]. The reaction was evaluated in an analytical pyrolysis unit consisting in a micropyrolizer coupled to a mass spectrometer (Py-GC/MS) operating at temperatures between 400 and 450 °C in a fast pyrolysis regime (12 s). The effectivity of catalysts was measured in terms of selectivity to monoaromatics as BTX and p-cymene, under non-catalytic and for catalytic pyrolysis conditions. Moreover, the reaction was conducted on individual rubbers (Polyisoprene, Polybutadiene, and Styrene-Butadiene) and DL-limonene, to get deep insights into the transformation behaviour and reaction pathways. Therefore, the reader will find a data-in-brief paper containing some characterizations of the WTs used for the investigation, along with a complete dataset of Py-GC/MS results. Finally, the original files for the interpretation of the MS results are also provided, so that the reader can easily use this information to further expand the study to their own interest (industrial or scientific).

High-temperature pyrolysis of waste tires is a promising method to produce high-quality carbon black. In this study, carbon black formation characteristics were investigated during tire pyrolysis at 1000-1300 °C with residence times of < 1 s, 1-2 s, and 2-4 s. It is shown that with temperature increasing from 1000 °C to 1300 °C carbon black yield was increased from 10% to 27% with residence times of 2-4 s. Carbon black exhibited a core-shell nanostructure over 1100 °C and the graphitization degree was promoted with the temperature and residence time. While the mean particle diameter decreased with the temperature to 69 nm at 1300 °C and further increased by residence time. The molecular-level evolution from tire to initial carbon black was further revealed by reactive force field molecular dynamics simulations. Light oil, gas, and radicals were transformed to initial cyclic molecules and long carbon chains via carbon-addition-hydrogen-migration, H-abstraction-C 2 H 2 -addition, and radical-chain reactions, subsequently forming PAHs. The coupling of PAHs aliphatic side chains formed large graphene layers that gradually bent to fullerene-like cores and generated incipient carbon black. The process mechanism from volatiles evolution to carbon black was proposed, which may be helpful for obtaining high-quality carbon black from high-temperature pyrolysis of waste tires., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Fast co-pyrolysis has been suggested as a promising technique to solve the environmental issues and simultaneously recover value-added products from polymer wastes. However, to date, no studies have focused on fast co-pyrolysis of printed circuit boards (PCB) and waste tire (WT). Therefore, we comprehensively investigated the fast co-pyrolysis of PCB and WT using pyrolysis-gas chromatography/mass spectrometry. The results show that an increase in temperature during fast pyrolysis improved the interactions between the PCB and WT pyrolyzates, increasing the formation of aliphatic and aromatic compounds. The formation of p-cymene was greatly induced by the isomerization and dehydrogenation reactions of D-limonene. Co-pyrolysis reduced the formation of brominated phenols and benzothiazole from PCB and WT pyrolysis, respectively, whereas promoted the interactions between Br- and S/N-containing radicals, concentrating them into heavy compounds. Increasing the temperature enhanced the release of heteroatom compounds. The findings suggest that debromination of PCB achieved via dehydrogenation of WT pyrolysis provoked secondary reactions of olefins and interactions of heteroatom radicals. The major products were accurately predicted by different fitting models using response surface methodology, indicating the synergistic interactions during co-pyrolysis. The results were beneficial for optimizing the experimental parameters to obtain the maximum yield of desired products., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Environmental problems caused by waste tires have become so glaring that it has attracted wide attention. This case study seeks to examine the properties of carbon black from waste tires continuous commercial scale pyrolysis. This work aims to contribute to this growing area of research by exploring the difference between the properties of products under the condition of mass production and those under the condition of laboratory scale or pilot scale production. A pyrolysis prototype, with a waste tire mass flow rate of 50-60 t d -1 was constructed and introduced. Steel-included tire granulates were pyrolyzed in micro-negative pressure furnace at about 420 ± 20 °C. This kind of nonstripping, micro-negative pressure and low-temperature continuous thermal pyrolysis technology can reduce the stripping process between rubber and steel wire, reduce the requirement of equipment sealing, and improve the utilization rate of resources. All three products including pyrolytic carbon black (CBp), tire pyrolysis oil (TPO) and pyrolysis gas showed good characteristics. Pyrolysis gas had been successfully re-used for pyrolysis furnaces and dryers. The higher heating value of TPO estimated to 37-40 MJ/ kg, which was comparable to diesel fuel through further treatment. Results of proximate analysis, element analysis, XPS, FTIR, XRD and surface structure confirmed that CBp with commercial scale production showed no apparent data difference with those in other small scale research cases. The morphological changes of carbon black particles were suggested, revealing a possible internal structure of CBp aggregates in commercial scale pyrolysis. This study is an attempt to push the existing research in this field to commercial production. This work generates fresh insight into the viability of continuous commercial pyrolysis and demonstrates the feasibility of the operation, providing reference for many researchers and units who study the pyrolysis technology of waste tires with the feasibility of industrial production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Recently, the recycling of waste tires has caused widespread concern for its environmental issues. The experience of the producer responsibility and tax system is of great beneficial to developing countries. The article also elaborates on the efforts of Chinese government to focus on establishing and perfecting waste tire treatment system by strengthen legislation. The main reasons such as immature market, non-uniform policy and repeated taxation for the survival difficulties of waste tire recycling enterprises in China are summarized. Among numerous resource methods, pyrolysis has been considered as a promising thermochemical process to deal with the waste tires. Unlike other similar reviews that mainly focus on its liquid phase, special attention has been given to solid char, pyrolysis carbon black, due to its wide application and high-value utilization in the future. We summarize the available research on application of pyrolysis carbon black as an alternative to commercial carbon black in rubber manufacture, as activated carbon in pollution control and as biochar for soil improvement. Analysis of the available data revealed that 1) the influence of temperature and time has been basically established; 2) catalyst type, dosage and reactor selection should be adjusted according to product demand; 3) pickling has become the primary means of improving pyrolysis carbon black; 4) the type of modifier and modification method must be adjusted according to the specific characteristics of the raw materials and needs to be combined with the experimental results to realize resource utilization and give full play to its economic value., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Preparation of sulfur self-doped char derived from waste tire (WT) was realized via two successively processes of pyrolysis and activation treatment. WT was firstly pyrolyzed at 400 °C, 600 °C, 800 °C, and 1000 °C to collect waste tire chars (WTCs) and they were subsequently activated at 800 °C with potassium ferrate (K 2 FeO 4 ). The specific capacitance of activated waste tire chars at different pyrolysis temperatures (AWTCs-x-800) decreased from 92.60 F/g to 54.05 F/g at 1 A/g with pyrolysis temperature rising from 400 °C to 1000 °C. As for AWTCs-x-800, higher pyrolysis temperature promoted pore-forming process before 800 °C, and higher pyrolysis temperature enlarged pores after 800 °C. Increase of pyrolysis temperature promoted decomposition of alkyl-aryl CC bonds, transformation of relative small to large aromatic ring system, ordered arrangement of carbon atoms. Besides, it was found that sulfur doping content dominated in specific capacitance performance before 800 °C while surface area dominated after 800 °C. The large surface area and high S 2p 3/2 (-C-S-C-, sulphide bridge) content were beneficial for the larger specific capacitance while more S 2p 5/2 (-C-SOx-C- (x = 2-4, sulphone bridge) had the negative effect. Pyrolysis mainly affected sulfur doping properties, lower pyrolysis temperature promoted sulfur enrichment and S 2p 3/2 generation. Activation promoted surface area improvement and sulfur conversion, higher pyrolysis temperature promoted surface area improvement and sulfur release before 800 °C while the promotion effects weakened after 800 °C, and sulfur transformation of S 2p 3/2 converting to S 2p 5/2 strengthened at higher pyrolysis temperature., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this study, carbonized waste tires were directly used as a high-performance anode material in microbial fuel cells (MFCs). The effect of the pyrolysis temperature used for waste tire carbonization on the current output performance was investigated to determine the optimal pyrolysis temperature. Thermal gravimetric analysis/differential scanning calorimetry showed that tire carbonization started at 200°C and ended at about 500°C; the weight loss was about 64%. When used in an MFC, the electrode obtained from waste tires carbonized at 800°C gave a current density of 23.1±1.4Am -2 , which is much higher than that achieved with traditional graphite felt anodes (5.5±0.1Am -2 ). The results of this study will be useful in optimizing the design of carbonized waste tire anodes for enhancing MFC performances and will alleviate the environmental problems caused by waste tires., (Copyright © 2017 Elsevier B.V. All rights reserved.)