The paper is transdisciplinary. The complex overview on changes in policy and approach to waste tyres that leads to both solving environmental problem of post-consumer tyres and creating ...environmentally friendlier novel materials are presented. It is shown that in the world, the amount of polymer wastes increases every year. Most of them are in the form of post-consumer tyres. Recycling and recovery of such tyres is a serious environmental problem due to their very complex structure and composition. Moreover, storage of the whole post-consumer tyres takes a lot of space in landfills and pollute the environment. However, recently it has been reported a great progress in sustainable management of waste tyres. An important role in the progress of tyre recovery has played the establishment of the restrictive regulations, which prohibits stockpiling of tyres in landfills. This legislative steps have contributed to significant impact on the progress in the development of car tyres recovery. The most important is introducing of monitoring for improper stockpiling, producer responsibility for wastes tyres and the new tax system. With the help of mentioned changes and introducing environmentally friendlier technologies it appeared that the utilization of tyres can be cost effective. The applied technology can transform post-consumer tyres into a source of energy or valuable raw materials, from which can be obtained a wide range of sustainable polymeric composite materials characterized by quite good mechanical and functional properties. This new approach to post consumer tyres is undertaken in U.S., China, Japan and EU. From the overview it is clear that the grinded used tyres should not be treated any more as a pollutant but rather as a source of sustainable materials. Those materials belong to modern polymer-rubber composites obtained mainly from elastomers (natural and synthetic rubbers) or thermoplastics (PE, PP, PVC). The very important factor in making good composites is get the knowledge about the influence of amount, size and morphology of rubber granulate grains on interactions that occur in composites between the polymer matrix and tyre rubber grains and thus the properties. That last item was discussed in the final part of the overview.
•Waste tyres pose a serious environmental problem.•Key to the recovery of tyres with high performance is good law legislation.•Used tyres can be a source of sustainable new material.•Spent tyres can be used to produce ‘environmentally friendlier’ composites.•Sintering of rubber granulates is a way to obtain very cheap and useful materials.
► In EU’s member states were obliged to prohibit the stockpiling of used tyres in landfills. ► Nowadays, in many countries of EU, the level of recovery and recycling of used tyres is near 100%. ► ...Recycling and combustion of used tyres are the most popular methods in the management of these wastes. ► Used tyres are a source of valuable raw materials.
The dynamic increase in the manufacture of rubber products, particularly those used in the automobile industry, is responsible for a vast amount of wastes, mostly in the form of used tyres, of which more than 17 million tonnes are produced globally each year. The widely differing chemical compositions and the cross-linked structures of rubber in tyres are the prime reason why they are highly resistant to biodegradation, photochemical decomposition, chemical reagents and high temperatures. The increasing numbers of used tyres therefore constitute a serious threat to the natural environment.
The progress made in recent years in the management of polymer wastes has meant that used tyres are starting to be perceived as a potential source of valuable raw materials. The development of studies into their more efficient recovery and recycling, and the European Union’s restrictive legal regulations regarding the management of used tyres, have led to solutions enabling this substantial stream of rubber wastes to be converted into energy or new polymer materials.
In this article we present the relevant literature describing innovative organizational approaches in the management of used tyres in the European Union member countries and the possible uses of waste tyres as a source of raw materials or alternative fossil fuels.
The employment of used tyres as a new source of raw materials for different applications can be a partial solution to the great environmental problems generated by these products concerning their ...disposal at waste depots. In this study, high-resolution thermogravimetric analysis (Hi-Res TGA) is used to quantify the elastomer composition of SBR/NR in tyre formulations. This technique provides the ability to generate TGA derivative profiles (DTGA), which can be used to distinguish different formulations from appropriate calibration curves. Infrared spectroscopy (FTIR) is also employed for composition quantification of used tyres and the results are compared to those obtained by Hi-Res TGA. Both analysis methods give satisfactory results when applied to elastomer mixtures of known composition and to tyre rubbers of unknown composition. The study confirms the accuracy of high-resolution TGA–DTGA technique for rapid quantitative determination of elastomer blends in used tyres.
•The pyrolytic oil from the experimental plant for pyrolysis of whole vehicle tyres was hydrotreating.•In the presence of CoMo–SiO2–Al2O3 catalyst the contents of sulphur were reduced from 1.1% to ...0.2% m/m.•In the presence of NiMo–Al2O3 catalyst sulphur content decreased to 0.1% m/m.•The bromine number in the case of the use of nickel–molybdenum catalyst decreased from 67.5 to 11.1g Br2/100g.•After separation of the light fraction, the residues can be used to compose fuel oils.
In the pilot plant for pyrolysis of whole tyres for passenger cars and vans we received a liquid product, hydrocarbon fraction known as pyrolytic oil, two solid products, i.e. pyrolytic carbon, scrap metal cord and gaseous mixture of hydrocarbons. The main goal of the research was to determine susceptibility of the obtained pyrolytic oils to hydrorefining. The analysis showed that hydrorefining process, carried out in the presence of commercial catalysts, allows for much improvement of its characteristics. However, it is necessary to apply relatively hard process conditions: temperature of at least 360°C and hydrogen pressure of about 5MPa. Then the product is desulphurised down to the sulphur content of less than 0.2% by weight and the unsaturated hydrocarbons are partially hydrogenated, which is characterised by the decrease of bromine number to less than 20g Br2/100g. As a result of high content of aromatic hydrocarbons, in respect of relatively high sulphur content, high density and low cetane index (lower than 35), even after hydrorefining process, pyrolytic oil can only be used as a component of fuel oils.
This paper discusses interactions between the generation, collection and recovery of used tyres while considering an indicator of their mass accumulation per area in Poland. Notably, this study aimed ...to assess selected issues related to used tyre management efficiency from 2008 to 2018 based on European Union and national regulations. Within 11 years, over 5 million Mg of used tyres was introduced into the domestic market—exceeding the amount required for 50 million registered vehicles. It was demonstrated that a significant tyre waste management process involved the recovery of 47% of all tyres, which was almost entirely correlated with the total volume of tyres. Only the growth trend for generated tyres was considered significant, and the rarely used indicator of the accumulation of used tyres per area exhibited an uneven accumulation of used tyres, with the highest amount being 48.06 Mg km
−2
in a region with a small area but a significant volume of waste tyres. Therefore, the management of used tyres requires action in the country to optimally increase this form of waste collection while consolidating the development, gathering and processing infrastructure in the context of further minimising environmental pressure and increasing the efficiency of their use by considering the 4R principle.
•Bitumen production using used engine oil, coal tar and waste tyres was initiated.•Three samples were produced and tested against a standard bitumen sample.•Bitumen samples went through the following ...tests: viscosity test, specific gravity test, softening point test, thin film oven test, flash and fire points tests as per ASTM standards.•Sample 2 with ratio of 1:2.5:1.5 for used engine oil, crumb rubber, and coal tar, respectively had properties very close to those of the standard bitumen sample.•The properties were: a viscosity of 93 cP, a specific gravity of 1.089, a softening point temperature of 65°C, thin film oven test of 0.35% mass loss, a flash point temperature of 218°C and a fire point temperature of 223°C•The bitumen was less susceptible to temperature change and for a given temperature, it has higher stiffness compared to tar.
Bitumen plays an important role especially in the community in terms of infrastructure where its properties are utilized. It is a semi-solid hydrocarbon product which is produced by removing the lighter fractions such as liquid petroleum gas from heavy crude oil during the refinery processes of crude oil. It consists of a mixture of organic liquids and it has a black colour, high viscosity and it is a sticky material. The most common method for its manufacture is fractional distillation of atmospheric residue from vacuum distillation where waxy distillates are used. To reduce the expenses for its production from crude petroleum, used engine oil, coal tar and used tyres from automobiles can be used in their correct ratio to produce bitumen. The process involves heating and mixing using a high-speed shear mixer. The oil is a medium to heat and melt the crumb rubber so that it will begin to degrade (depolymerize). Several key tests as per ASTM standards were performed to check if the bitumen was up to standard, and these included: (i) viscosity, (ii) specific gravity, (iii) softening point, (iv) thin film test, (v) flash point and (vi) fire point. The best formulated bitumen had a ratio of 20% engine oil, 50% crumb rubber and 30% coal tar with a viscosity of 93 cP, a specific density of 1.089, a softening point temperature of 65°C, thin film oven test of 0.35% mass loss, a flash point temperature of 218°C and a fire point temperature of 223°C. This bitumen showed better resistance to permanent deformation but less resistance to fatigue cracking, was less susceptible to temperature change meaning it could withstand hot climates, had less volatiles to give off and was a lower fire hazard.
The batch removal of hexavalent chromium (Cr(VI)) from wastewater under different experimental conditions using economic adsorbents was investigated in this study. These adsorbents were produced from ...the pyrolysis and activation of the waste tyres (TAC) and from the pyrolysis of sawdust (SPC). The performance of these adsorbents against commercial activated carbon F400 (CAC) has also been carried out. The removal was favoured at low pH, with maximum removal at pH=2 for all types of carbon. The effects of concentration, temperature and particle size have been reported. All sorbents were found to efficiently remove Cr(VI) from solution.
The batch sorption kinetics have been tested for a first-order reversible reaction, a first-order and second-order reaction. The rate constants of adsorption for all these kinetic models have been calculated. The applicability of the Langmuir isotherm for the present system has been tested at different temperatures. The thermodynamic parameters (Δ
G
0,
K
c) obtained indicate the endothermic nature of Cr(VI) adsorption on TAC, SPC and CAC.
This study aimed to determine the effect of the supplied pyrolysis oils (oils obtained from the pyrolysis of used tyres and the depolymerisation of plastics) on the activity of the ...hydrodesulphurisation catalyst. Each pyrolysis oil was added at 20% weight to a standard feedstock and processed on pilot plant reactors under the set conditions of a commercial unit, including an activated catalyst. Following the catalyst stabilisation, the standard material was changed to the mixture with the pyrolysis oils. The reaction conditions, particularly the reaction temperature, were controlled. The results of the product analyses were compared with the EN 590 standard for evaluating diesel fuel; the hydrogenated mixed fuel meets most requirements. Only the density, flash point, distillation curve and lubricity have minor deviations, which could be adjusted by treating the sample before or after hydrogenation. The properties of the products, in terms of the low-temperature properties, were also investigated. The tyre-derived pyrolysis oils showed improved low-temperature properties, possibly due to the higher levels of the aromatic hydrocarbons. The pyrolysis oil obtained from the depolymerisation of the plastics was found to be more suitable for use in refineries without substantially impacting the existing technologies. For the tyre-derived pyrolysis oils, higher reaction temperatures were required for processing, which could affect the catalyst operation.
This paper aims to study the surface topography of composite reinforced by fabric from used tyres. By the research was used an atomic force microscopy (AFM). AFM can drive the force between the sense ...probe and the surface and the in Z axis can move piezo and sensor. The composites were reinforced with fibres from used tyres. After homogenization the thermoplastics matrix and fibres from used tyres we pressed test specimens and after this technology was material tested by atomic force microscopy. Generally we can say, therefore, it provides important information about the surface of the display material and its properties that are necessary to know for the further examination, in particular for of utilization the material and displayed by using atomic force we can get a clearer idea of the investigated materials and other behavior in a various mechanical tests.
Mosquito vectors are extending their range via international travel and trade. Climate change makes New Zealand an increasingly suitable environment for less tropically adapted exotic mosquito ...vectors to become established. This shift will add a multiplier e ect to existing risks of both the establishment of new species and of resident exotic species extending into new areas. We describe trends in the border interceptions of exotic mosquitoes and evaluate the role of imported goods as a pathway for these introductions. Ae. aegypti and Ae. albopictus, the two most commonly intercepted species, were only intercepted in Auckland. Used tyres and machinery were the main mode of entry for both species. The majority of Ae. albopictus were transported as larvae by sea, while most Ae. aegypti were transported as adults by air. Continuing introductions of these mosquitoes, mainly arriving via Japan or Australia, increase the risk of the local transmission of mosquito-borne diseases in New Zealand in general and in the Auckland region in particular. These findings reinforce the need for a high performing and adequately resourced national biosecurity system, particularly port surveillance and inspection. Recommended biosecurity improvements are described.
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