L'objectif de ce travail est de valoriser des déchets de pneus usagés par pyrolyse afin d'obtenir un nouveau carburant comparable avec le gazole suivant la norme EN590. L'obtention de ce carburant était réalisée via l'optimisation des conditions de pyrolyse qui sont la température, la vitesse de chauffage (puissance de la résistance électrique) et du débit d'azote. Le rôle de l'azote est limité à purger le réacteur avant le début de la pyrolyse pour 30 minutes système. Le carburant produit est comparable au gazole avec un pouvoir calorifique de 45 MJ/kg, une densité de 0,85 et une teneur en goudron 7%. / The objective of this work is to get alternative fuel comparable with the available diesel in the market following the EN590. The fuel getting was via optimization of pyrolysis conditions which are temperature, heating rate (power of electrical resistance) and inert gas flow rate. The optimum values are 465°C, 650 Watts and without inert gas flow rate. Inert gas role is limited to purge the system for 30 minutes before start the pyrolysis to get rid of oxidative gases. The obtained product is comparable with the diesel as it has GCV 45 KJ/kg, low density of 0,85 and 7% tar content.

Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017. / Energy security, environmental and economic issues have spurred the interest in pyrolysis of scrap tyres for the production of fuels and energy in South Africa. However, the application of the process on a commercial scale is being hampered by the high cost required to upgrade the comparatively low quality pyrolytic products as well as the high energy input. Further insights into the mechanisms of thermal degradation of rubber will assist to improve on the process economics for production of liquid hydrocarbons fractions suitable for use as transportation fuels and chemicals. This study developed a correlation to predict the contents of waste tyres that will be converted into hydrocarbons during pyrolysis from the proximate analysis data. The mechanism/kinetics of thermal degradation behaviour of waste tyres is also studied, in order to locate the optimal temperature that will maximize the yield of liquid hydrocarbons and other recoverable materials. Data from thermogravimetric analysis is used to determine the kinetic constants for the pyrolysis reaction over a temperature range of 500 °C - 750 °C. A relationship between the optimal temperatures and the volatile mater content depending on the desired products was obtained. This is necessary to eliminate thermal cracking of the pyrolytic oil into the non-condensable gas that will result from excessive temperature and the associated energy cost. Relationship to determine the kinetic equation constants is presented as a function of the volatile matter content. An inductor furnace batch reactor system is used to carried out the pyrolysis reaction, using Argon as the inert gas to provide the oxygen free environment required. The products are sent through a 2-stage condensers, the first operated at room temperature to collect the pyrolytic oil, and the second maintained at -5 oC to collect the condensable pyrolytic gases.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 213-216). Also available in electronic version. Access restricted to campus users.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references. Also available in electronic version.

Thesis (MBA)--Stellenbosch University, 2012. / Tyre waste from end-of-life tyres (ELTs), sometimes erroneously defined as a type of waste, in fact represents a renewable energy resource that is highly competitive as replacement fuel to coal in the form of tyre-derived fuel (TDF) or useable as rubber crumb in other products. In this research study, the main utilisation options considered were based on rubber crumbing through ambient and cryogenic processing. Pyrolysis, the so-called ‘holy grail’ of tyre technologies, rubberised asphalt products, TDF options and various other product options from tyre crumb as basis were considered. Although pyrolysis technology is highly commendable and environmentally friendly, it is still a process with too many variants and presents an unstable economic model that is not attractive to entrepreneurs. Rubberised asphalt depends on policy decisions from local and national authorities supporting initial higher spending and allowances on budgets to acquire future savings from the longevity in the product. The policy requirements and the instability that politically-inspired decisions carry with them are contributing to the unattractiveness of this solution to the entrepreneurial fraternity. Through government requiring a certain percentage of asphalt pavements to contain rubber (like in the United States of America (USA)), rubberised asphalt could be a very useful and viable option to produce. In the USA, the Environmental Protection Agency (EPA) recently avoided the return to coal in industrial kilns currently using TDF based on its beneficial carbon dioxide (CO2) emission and cost structures by defining TDF as Reasonably Available Control Technology (RACT) to existing coal-burning industrial kilns. In South Africa, the usage of TDF should be of interest to Eskom and the cement industry. TDF (produced from end-of-life tyres), defined as a renewable energy resource due to its proven biomass component and with its high calorific value, presents higher energy output values in comparison to coal and furthermore presents the industry with lower input costs per ton and reduces the CO2 emission factor. Entrepreneurial intervention involving Eskom and/or the cement industry in South Africa with the utilisation of end-of-life tyres as renewable energy resource is an overdue business opportunity. With more than ten million tyres per year available in South Africa and a stockpile of more than fifty million waste tyres, sustainability of TDF supplies is a reality. TDF is much cheaper per ton than coal and emits approximately 20 percent less CO2 and/or CO2e than low-grade coal to produce the same electricity output. From all the information gathered, it is clear that in countries where coal energy is extensively used, TDF utilisation not only reduces the tyre waste issues, but it also serves as an environmentally-friendly renewable energy resource in electricity production and cement kilns; the industry with some of the highest CO2 emission risks. The final chapter of this report presents a schedule representing the choice of tyre processing and disposal methods ranked by environmental preference and defining the priorities linked to process and product choice.

published_or_final_version / Civil Engineering / Master / Master of Philosophy

The objective of this study was to remove mercury vapor from municipal waste incinerator (MWI) by the adsorption of powder activated carbon (PAC) prepared from the pyrolysis of waste tire. The study focused on the measurement of mercury concentration in flue gas emitted from municipal waste incinerator, the preparation of PAC from the pyrolysis of the waste tire and impregnated with sulfur, and the adsorption capacity of mercury by the self-made PAC. The measurement of heavy metals in flue gas emitted from four typical MWIs was conducted in this study. Experimental results obtained from the measurement of mercury from flue gas indicated that the removal efficiency of mercury ranged from 83.71%~96.22%for the tested MWIs. This study revealed that the injection of PAC in flue gas would enhance the removal efficiency of mercury. Besides, oxided mercury (Hg2+) can be removed much more easily than elemental mercury (Hg0). Experimental results obtained from the pyrolysis of waste tires indicated that the pyrolysis temperature of waste tire was approximately 400~500¢J, and the percentage of carbon residue is 35~37%. With higher temperature and water feed rate and longer activation time, the specific surface area and total pore volume of PAC increased while the average pore radius decreased. The highest specific surface area of PAC obtained in this study was 996 m2/g. In addition, experimental results obtained from sulfur impregnation process indicated that the specific surface area of PAC decreased dramatically as sulfur was added to PAC. Experiment results obtained from the adsorption capacity of HgCl2 on PAC by column test indicated that PAC with higher specific surface area could adsorb more HgCl2 at room temperature (25¢J). The adsorption capacity of sulfur impregnated PAC decreased at 25¢J was due to the decrease of specific surface area of PAC. However, results from the comparison of two PAC with similar specific surface area indicated that the PAC with higher sulfur content had higher adsorption capacity. It suggested that the addition of sulfur to PAC could enhance the adsorption of HgCl2 at 25¢J. Experimental results obtained from column tests at 150¢J showed that the adsorption capacity of PAC increased as sulfur content of PAC increased. These results suggested that the adsorption mechanism of HgCl2 by PAC was mainly physical adsorption at lower temperature and it was chemisorption at higher temperature. Besides, the self-made PAC demonstrated the similar adsorption capacity of HgCl2 with commercial PAC used in MWIs.

Thesis (M. Phil.)--University of Hong Kong, 2010. / Includes bibliographical references (p. 129-142). Also available in print.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 241-249). Also available in electronic version. Access restricted to campus users.