Pyrolysis Of Scrap Tires Research Articles

Investigation of synergy and inhibition effects during co-gasification of tire char and biomass in CO2 environment

This study investigates the co-gasification of tire char (TC), as a low-quality side-product of scrap tire pyrolysis, and rambutan peel (RP). The objective of this study was to comprehend any synergistic/antagonistic effects during the co-gasification of TC/RP. For this, co-gasification of TC and RP (85:15, 70:30, 50:50, 30:70, and 15:85 wt% of TC:RP) was conducted in CO2 environment by non-isothermal thermogravimetric method. The samples were heated (15 K/min) under N2 to 923 K and then under CO2 to 1400 K. Comparison of the observed and theoretical results indicated the incidence of antagonism in blends with high proportion of TC (e.g., 85%TC–15%RP and 70%TC–30%RP), possibly attributing to the high content of acid oxides (SO3 (30.1%) and SiO2 (24.8%)) in the TC-ash which could inhibit the gasification by formation of inactive silicates in the presence of alkali/alkaline earth metal-rich biomass. In blends with higher content of biomass (e.g., 30%TC–70%RP and 15%TC–85%RP), the actual gasification rates were higher than the theoretically predicted ones showing the presence of a synergism associated with the natural catalysts (K2O (40.6%) and CaO (42.3%)) in RP-ash. Activation energy and thermodynamic studies confirmed the profound effect of biomass on enhancing the reactivity of TC in reaction with CO2. These promoting effects of biomass were associated with its considerably higher alkali index (133.4) than tire (5.6), its less graphitic structure with more structural defects, and imperfections compared with TC. According to the results, the inherently low reactivity of TC in gasification can be accelerated by co-feeding of biomass with TC.

Cost-effective sulfurized sorbents derived from one-step pyrolysis of wood and scrap tire for elemental mercury removal from flue gas

Sulfurized chars derived from one-step pyrolysis of wood and scrap tire are developed as cost-effective sorbents for elemental mercury (Hg0) capture from flue gas. This method can modify chars and enhance their Hg0 capture capability during samples preparation without additional modification. The sample characterization implies that a synergistic effect between wood and tire occurs during co-pyrolysis. For this reason, the BET surface area and pore volume of sulfurized chars have exceeded the weighted-average sum of biochar and tire-char. The existence forms of sulfur in sulfurized chars are sulfide, organic sulfur (sulfoxide, aliphatic sulfur, and thiophenic)/elemental sulfur and sulfate. At the optimum temperature (140 °C), the sulfurized chars present much higher Hg0 capture capability compared to biochar and tire-char. The best pyrolysis temperature for preparing sulfurized sorbents is 800 °C, and the optimum wood/tire blending ratio is 50%:50%. The presence of SO2, NO, O2, and HCl can promote mercury capture. The mechanisms responsible for Hg0 removal are investigated by XPS and Hg-TPD analysis. The results demonstrate that chemisorption dominates the Hg0 removal process, where organic sulfur/elemental sulfur can serve as active components for Hg0 oxidization into HgS.

Lessening coke formation and boosting gasoline yield by incorporating scrap tire pyrolysis oil in the cracking conditions of an FCC unit

We have studied the effect of adding scrap tire pyrolysis oil (STPO) as feed or co-feed in the cracking of vacuum gasoil (VGO) using a commercial equilibrated catalyst. The cracking experiments were performed in a laboratory scale fluid catalytic cracking (FCC) simulator using VGO, STPO, or a blend of the two (20 wt% of STPO), contact time = 6 s, catalyst/feed ratio = 5, and 530 °C. The composition of the different feeds has been correlated with the yield of products and the amount-location-nature of the deactivating species (coke). Our results indicate that adding STPO increases proportionally the gasoline yield, synergistically increase the yield of light cycle oil while uncooperatively decrease the yields of heavy cycle oil and coke. We further investigated the effect on coke formation, characterizing deeply the coked catalyst and coke. In fact, the coke deposited under the cracking of STPO is more aliphatic, lighter, and located in the micropores of the catalyst. The complete analysis of the coke fractions (soluble and insoluble) have lighted the peculiar chemistry of these species as a function of the type of feed used. The results point to a viable and economically attractive valorization route for discarded tires.

Pyrolytic transformation behavior of hydrocarbons and heteroatom compounds of scrap tire volatiles

Pyrolysis has been a major method to dispose the problem of scrap tires and it is gaining enormous attention all over the world. But less is known about its comprehensive transformation behavior of pyrolysis products. Experiments on pyrolysis of scrap tires were carried out using Py-GC/MS to investigate the distribution of volatile products at five typical temperatures of 200, 300, 400, 500, and 800 °C. Products generated at each temperature stage were categorized according to their functional group for exploring the possible chemical formation pathways. It was found that pyrolysis products were distributed at all temperature stages and predominantly produced at 300–400 °C. Hydrocarbon volatiles were mainly composed of alkenes, especially sesquiterpenes, D-limonene and isoprene. Heteroatom volatile products were all generated below 500 °C. Fatty acids, alkenyl alcohols, sulfides, diphenylamine, nitriles, and benzothiazole were predominant heteroatom products identified in this study. Based on Py-GC/MS results, pyrolytic transformation behavior of hydrocarbons and heteroatom compounds was proposed. In addition, a deeper investigation into the evolution of sulfur was conducted since it was the leading contaminant during the overall pyrolysis process. Results showed that about 60.98 wt% of total sulfur was distributed in the solid residues and was mostly in the form of sulfides and thiophenes. Sulfur content in liquid and gas products was 29.52 wt%, and 7.64 wt%, respectively. Overall, the results of this research presented an in-depth pyrolysis regularity of scrap tire volatiles and provided theoretical guidance for directional valorization of pyrolytic oil.

Scrap tires pyrolysis oil as a co-feeding stream on the catalytic cracking of vacuum gasoil under fluid catalytic cracking conditions

The co-feeding of scrap tires pyrolysis oil (STPO) on the catalytic cracking of vacuum gasoil (VGO) has been investigated with the aim of exploring the capacity of the refinery fluid catalytic cracking (FCC) unit to upgrade discarded tires at large-scale. The runs have been carried out in a CREC (Chemical Reactor Engineering Centre) riser simulator reactor that mimics the behavior of the industrial unit at the following conditions: 500–560 °C; catalyst/oil ratio, 3–7 gcat goil−1; contact time, 6 s. Obtained results with the blend of 20 wt% STPO in VGO have been compared with those obtained in the cracking of the pure streams, i.e., STPO and VGO, to get a proper idea of the synergetic effects that could be involved in the co-feeding. This way, when the STPO is co-fed with the VGO the production of naphtha (C5–C12) and light cycle oil (C13–C20) lumps are maximized, as the over-cracking reactions that convert them into gaseous products (C1–C4) are mitigated. Consequently, the co-feeding promotes the production of high-interest hydrocarbons for refineries. Additionally, the naphtha obtained in the cracking of the blend shows a lower content of paraffins and naphthenes than that obtained with the VGO, and higher of olefins and aromatics.

Catalytic pyrolytic platform for scrap tires using CO2 and steel slag

This study specifically examined CO2-cofeeding pyrolysis of scrap tire (ST) to enhance H2 generation. Thus, volatile pyrolysates (syngas and pyrolytic oil) from the thermolysis of ST in N2 and CO2 were compared to elucidate the mechanistic roles of CO2. To this end, laboratory scale of pyrolysis of ST from N2 and CO2 was conducted in this study. The gaseous effluents from a pyrolyzer showed that enhanced CO evolution only from CO2-cofeeding pyrolysis of ST. Moreover, a substantial decrease in the formation of benzene derivatives (BDs) including polycyclic aromatic hydrocarbons (PAHs) was discovered from CO2-cofeeding pyrolysis of ST. Those findings offered that CO2 could improve pyrolysis of ST by modifying the pyrogenic products, and those enhanced pyrolysis behaviors were ascribed to the homogeneous interaction between CO2 and pyrolysates from the pyrolysis of ST (more CO generation). To advance the identified roles of CO2, catalytic pyrolysis of ST in CO2 was carried out using steel slag (SS) as a catalyst. In the presence of SS, the effectiveness of CO2 on pyrolysis of ST was dramatically enhanced (~400% enhancement at 400 °C). Therefore, this study experimentally justified that the utilization of SS could alleviate the environmental burdens by adopting CO2 in pyrolysis of ST. Also, the CO enhancement by CO2 likely leads to the H2 enhancement when the water-gas-shift (WGS) reaction was also conducted. All experimental findings from this study suggested that the use of CO2 in pyrolysis of ST could be a breakthrough to enhance H2 formation.

A study on the performance of coke resistive cerium modified zeolite Y catalyst for the pyrolysis of scrap tyres in a two-stage fixed bed reactor

Catalytic pyrolysis is a useful technique for the conversion of scrap tyres into liquid fuels. Zeolite catalysts were employed in the pyrolysis of scrap tyres for the production of aromatic rich fuel. Deactivation of zeolite catalysts during pyrolysis reaction was investigated which played an important role in the product quality and composition. Herein, the performance of microporous zeolite catalysts and mesoporous MCM-41 catalyst was evaluated in a two-stage fixed bed reactor for the pyrolysis of scrap tyres. Comparative studies showed the increase in the production of aromatic compounds up to 23.7% over zeolite catalyst as compared to 18.7% over MCM-41 catalyst. However, Zeolite Y catalyst exhibited higher coke formation led to the rapid deactivation. The stability of zeolite catalysts is addressed by the incorporation of Cerium metal within the framework of two zeolite catalysts namely Zeolite Y and ZSM-5 through the ion-exchange technique. Parent and spent catalysts were characterised using synchrotron FT-IR spectroscopy, temperature-programmed desorption of ammonia (NH3-TPD), N2 Physisorption, scanning electron microscopy (SEM), inductively coupled plasma-optical emission spectrometry (ICP-OES), energy-dispersive X-ray spectroscopy (EDX), and hydrogen temperature-programmed reduction (H2-TPD). A higher percentage of aromatics were produced over the large pore Zeolite Y. Cerium ion-exchange decreased the formation of coke from 8.1% to 5.7% over submicron and large pore Zeolite Y catalyst. Moreover, naphthalene production decreased over both Ce-Zeolite Y and Ce-ZSM-5.

Thermogravimetric kinetic analysis and demineralization of chars from pyrolysis of scrap tire pretreated by waste coal tar

ABSTRACT With the remarkable increase in the number of vehicles worldwide, the disposal of scrap tire is a pressing issue. Pyrolysis is one treatment option to recover resources from the scrap tire, by which pyrolytic char with a high ash and sulfur content is generated, restricting its utilization value. The focus of this study was to improve the quality of the solid product obtained from scrap tire pyrolysis. In this paper, a feasible and effective approach is presented to remove ash from the char using a bench-scale unit. Unlike direct co-pyrolysis of the mixture of scrap tire and other materials, in the study, prior to pyrolysis, the scrap tire was soaked in waste coal tar for a few hours, and then, char was obtained from pyrolysis of the as-prepared scrap tire. According to the comparative analysis of thermogravimetric kinetics of the scrap tire and the as-prepared scrap tire, it revealed that the as-prepared scrap tire was more easily pyrolyzed under relatively low temperature with activation energy of 45.65 kJ/mol and at higher temperature with activation energy of 142.12 kJ/mol. With three kinds of acid (HCl, HNO3, and H2SO4) as the demineralization agent, comparative experiments on the removal of ash from the chars arising from pyrolysis of the as-prepared scrap tire (Char1) and the scrap tire (Char2) were carried out. The results showed that there were the highest efficiencies of ash removal from chars soaked in HCl solution, at 84.9% for Char1 and 59.6% for Char2. With HCl as the demineralization agent, a series of experiments on the removal of ash from Char1 and Char2 was conducted in which the effects of parameters, such as the mass ratio of the acid to the char (L/S), acid concentration, heating temperature, reaction time, stirring rate, particle size of the char, and the number of filtrate cycles, were systematically performed. Under the optimum conditions, the ash removal efficiencies for Char1 and Char2 reached 87.5% and 77.2%, respectively. The kinetics of the char demineralization process was also performed, conforming to a quasi-first-order rate equation. The results obtained indicated that the process of soaking scrap tire in waste coal tar is very useful for removing ash from the char.

Review on production of liquid fuel from co-pyrolysis of biomass with scrap/waste tire

The oil produced by the pyrolysis of biomass has potential for use as a substitute for fossil fuels. However, the oil needs to be upgraded since it contains high levels of oxygen, which causes low calorific value, corrosion problems, and instability. Generally, upgrading the pyrolysis oil involves the addition of a catalyst, solvent and large amount hydrogen, which can cost more than the oil itself. In this regard, the co-pyrolysis technique offers simplicity and effectiveness in order to produce a high-grade pyrolysis oil. Co-pyrolysis is a process which involves two or more materials as feedstock. The feedstocks were biomass and tire waste. The pyrolysis of scrap tires at a temperature of 500 o C produced an oil yield of 44.1 wt%. The increase in oil yield from co-pyrolysis processes of Pine wood and tire wastes was found to be 64.8 wt%. The HHV of tire waste pyrolysis liquid alone was 43.8MJ/kg while for the co-pyrolysis of tire waste and pinewoods was 46.8MJ/Kg. The results of many studies showed that the use of co-pyrolysis technique can improve the characteristics of pyrolysis oil, e.g., increase the oil yield, reduce the oxygen content, reduce the water content, and increase the calorific value of the oil. Keywords: Co-pyrolysis, Biomass, Tire-waste and Calorific-value

Insights into pyrolysis and co-pyrolysis of tobacco stalk and scrap tire: Thermochemical behaviors, kinetics, and evolved gas analysis

In this study, the co-pyrolysis kinetics of tobacco stalk and scrap tire were investigated via thermogravimetric analyzer, while Fourier transform infrared spectrometer was used for the analysis of gas-phase products transition. The pyrolysis of tobacco stalk could be divided into three stages: moisture removal, volatile removal, and slow decomposition of residues. And there was an additional stage of the decomposition of additives for scrap tire. The positive interaction between tobacco stalk and scrap tire occurred when their ratio is 2:8, at which both differential thermal gravity peak temperatures reached a minimum of 320.5 and 390.7 °C in their corresponding regions. The size of the tire particles (from 250 μm to 3 mm) appeared to have little effect on the differential thermal gravity peak temperature of the mixtures. From the results of the kinetic analysis, the synergistic effect at multiple mixing ratios made the energy required for the co-pyrolysis process significantly lower than that of the single pyrolysis. Under the mixed conditions, the formation of organic gases and CO2 was suppressed, the possible mechanism involved was discussed. The results obtained in this study can be used to understand the co-pyrolysis of tobacco stalk/scrap tire and provide a basis for further industrial applications.

Production of Liquid and Solid Fuel by the Technique of Microwave Pyrolysis of Scrap Tires and its Analysis

Production of Liquid and Solid Fuel by the Technique of Microwave Pyrolysis of Scrap Tires and its Analysis

Economic, Environmental and Social Benefits of Adoption of Pyrolysis Process of Tires: A Feasible and Ecofriendly Mode to Reduce the Impacts of Scrap Tires in Brazil

This study addressed the development of a pilot plant for pyrolysis of scrap tires to obtain carbon black and other byproducts. The work was motivated by the goal of contributing to the development and dissemination of knowledge about existing technologies that allow modern economies to transform waste into valuable products, by documenting and discussing an empirical application in Brazil. Thispaper describes the development of a market for steel scrap, pyrolytic oil and carbon black products obtained from a vacuum pyrolysis process. The research work was conducted in Brazil, and was guided by the twofold purpose of reducing the environmental impacts, while gaining economical sustainability. Modern economies increasingly need to devise strategies to address energy generation while preserving natural ecosystems. These strategies include leveraging the use of renewable energy sources. Acknowledging that scrap tires hold an enormous potential as a sustainable energy option, this study aimed to contribute to the development and maturity of eco-friendly processing approaches to realize its full potential. The work involved a preliminary phase concerned with the operation of vacuum pyrolysis of scrap tires at a laboratorial scale, followed by the design of the pilot plant that operated for 10 years, at the time of the study, with a 100 kg/h batch flow. Results show that the yield of the pyrolysis process was 41% pyrolytic oil, 38% carbon black, 12% gas, and 8.9% steel scrap, with a calorific value of 36 MJ/kg per tire. The carbon black was composed of 90% carbon, and the pyrolytic oil was composed of 66% gasoline and 33% other oils, which have higher quality and can be commercialized with a potential profit over 3 million dollars/year.

Cracking of Scrap Tires Pyrolysis Oil in a Fluidized Bed Reactor under Catalytic Cracking Unit Conditions. Effects of Operating Conditions

Tire valorization by catalytic cracking of scrap tires pyrolysis oil has been investigated in a riser simulator reactor under fluid catalytic cracking (FCC) unit conditions using an equilibrated FC...

Characterization of Bitumen Modified with Pyrolytic Carbon Black from Scrap Tires

Pyrolytic carbon black (CBp) from scrap tire pyrolysis is a potential modifier for the bitumen industry. Binders containing different contents of CBp were prepared and experimentally investigated to examine the effects of CBp on the electrical and thermal conductivity, conventional physical properties, rheological properties, high-temperature antirutting performance, aging resistance, and storage stability. Laboratory test results indicated that the incorporation of CBp effectively improves the electrothermal properties, rheological properties, high-temperature rutting resistance, and aging resistance. It also increases the viscosity and decreases the storage stability of bitumen. The study confirms that CBp-modified bitumen with proper selection of content can be a multifunctional paving material.

Production of Non-Conventional Fuels by Catalytic Cracking of Scrap Tires Pyrolysis Oil

Different commercial equilibrium fluidized catalytic cracking (FCC) catalysts have been tested in the upgrading of scrap tires pyrolysis oil (STPO) with the aim of obtaining automotive-like fuels. ...

Performance Evaluation of Single Cylinder Diesel Engine Using Tyre Pyrolysis Oil (TPO) Blends

Increasing industrialization and motorization led to a significant rise in demand of petroleum products. As these are the non-renewable resources, it will be troublesome to predict the availability of these resources in the future, resulting in uncertainty in its supply and price and is impacting growing economies like India importing 80% of the total demand of the petroleum products. Many attempts have been made by different researchers to find out alternate fuels for Internal Combustion engines. Many alternate fuels like Biodiesel, LPG (Liquefied Petroleum Gas), CNG (Compressed Natural Gas) and Alcohol are being used nowadays by different vehicles. In this context pyrolysis of scrap tyres can be used effectively to produce oil, thereby solving the problem of waste tyre disposal. In the present study, Experimental investigations were carried out to evaluate the performance and emission characteristics of a single cylinder diesel engine fueled by TPO10, TPO15, and TPO20 at a crank angle 280 before TDC (Top Dead Centre) and injection pressure of 180 bar keeping the blend quality by controlling the density and viscosity of tyre pyrolysis oil within permissible limit of euro IV diesel requirement. The performance and emission results were analyzed and compared with that of diesel fuel operation. The results of investigations indicate that the brake thermal efficiency of the TPO - DF blend decreases by 4 to 8%. CO emissions are slightly higher but within permissible limit of euro IV emission standards. HC emissions are higher by about 40 to 60% at partial load whereas smoke opacity is lower by about 14% to 22% as compared to diesel fuel.

Experimental analysis of waste tyres as a sustainable source of energy

Nowadays, the stability of energy supply that additionally should be sustainable is one of the most important global issues. Thus, many new potential energy sources are being investigated. Since automobile industry is growing, a huge amount of waste tyres (WT) occur each year. Pyrolysis of scrap tyres can be considered as a sustainable way to recover significant amounts of energy as well as the valuable materials. Potential of waste tyres in the energy sector is studied in this work. Proximate, ultimate and thermogravimetric (TG) analysis of mechanically grounded WT sample was done. Waste tyres feature high heating value combined with carbon content as high as 87.90 % (on dry ash-free basis). Additionally, TG analysis allows to choose optimal operating temperature for pyrolysis process which is between 350 and 500°C. However, the sulphur content is also relatively high – around 2 wt.% - and it is the most important challenge for utilizing this waste in a thermochemical way.

A Data-Driven Reaction Network for the Fluid Catalytic Cracking of Waste Feeds

Establishing a reaction network is of uttermost importance in complex catalytic processes such as fluid catalytic cracking (FCC). This step is the seed for a faithful reactor modeling and the subsequent catalyst re-design, process optimization or prediction. In this work, a dataset of 104 uncorrelated experiments, with 64 variables, was obtained in an FCC simulator using six types of feedstock (vacuum gasoil, polyethylene pyrolysis waxes, scrap tire pyrolysis oil, dissolved polyethylene and blends of the previous), 36 possible sets of conditions (varying contact time, temperature and catalyst/oil ratio) and three industrial catalysts. Principal component analysis (PCA) was applied over the dataset, showing that the main components are associated with feed composition (27.41% variance), operational conditions (19.09%) and catalyst properties (12.72%). The variables of each component were correlated with the indexes and yields of the products: conversion, octane number, aromatics, olefins (propylene) or coke, among others. Then, a data-driven reaction network was proposed for the cracking of waste feeds based on the previously obtained correlations.

Scrap Tires Pyrolysis: Product Yields, Properties and Chemical Compositions of Pyrolytic Oil

This investigation involves an experimental study on the pyrolysis of scrap tires under different operating conditions such as feedstock size and pyrolysis temperature by highlighting the properties of the whole liquid products generated during each thermal degradation process. The complete conversion temperature for the pyrolysis of used tires was close to 500‒550°C. The characteristics of liquid fraction were determined by elemental analysis, chromatographic and spectroscopic techniques and distillation data. All the obtained atomic ratios are around 1,4 which is significant that such pyrolytic liquids are a mixture of aliphatic and aromatic compounds derived from polymeric materials. Analysis of the pyrolytic oil (pyro-oil) by chromatographic analysis showed that it was a complex mixture of organic compounds C5‒C26, aromatics and a large proportion of light hydrocarbons that can be used as liquid fuels. Furthermore, the comparison distillation data indicates that more than 40% of such pyrolytic oil fraction with the boiling point range between 180‒360°C is specified for diesel. It is noted that the viscosity decreases obviously from 4.87 to 1.79 with the increase in temperature.

Pyrolysis of scrap tyres pretreated by waste coal tar

For disposal of scrap tyres, there have been a lot of studies done by previous researchers, but it yet remains a longstanding challenge in practice. To find a solution for this problem, the feasibility of a proposed approach in a laboratory scale was tested. The pyrolysis of scrap tyres pretreated by waste coal tar (noted as “as-pretreated” tyres) was performed in a batch reactor at atmospheric pressure. Waste coal tar was used to modify the scrap tyres to improve the pyrolysis efficiency of scrap tyres input and the quality of the product tar. The swelling behavior of scrap tyres soaked in waste coal tar at 10 °C, effect of pyrolysis temperature on the product yields, and the synergies during pyrolysis of the as-pretreated tyres and co-pyrolysis of scrap tyres/waste coal tar mixture were all investigated in detail. The results observed found that by comparison of the calculated yields and the observed experimental yields for pyrolysis products, the synergy from co-pyrolysis of scrap tyres/waste coal tar mixture boosted the gas yield without increasing the tar yield. In contrast, the synergy during pyrolysis of the as-pretreated tyres could enhance the tar yield, but reduced the gas and char yields. According to the distillation range analyses of the tar, more light fractions were found in the tar from pyrolysis of the as-pretreated tyres, in which the gasoline fraction, diesel fraction and kerosene fraction were 38.4 wt%, 46.8 wt% and 50.2 wt%, respectively. This work is expected to be helpful in further use of scrap tyres.