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<p style="text-align: justify;">U disertaciji je prikazan matematički model<br />gasifikacije otpadnih automobilskih pneumatika.<br />Modelom je istražen uticaj količine ubačenog vazduha<br />i vodene pare u gasifikator i temperatura gasifikacije<br />na prinos gasovitih produkata. Numerička procedura<br />je rije&scaron;ena Newton-Raphson metodom a brojne<br />vrijednosti molskih udjela gasovitih komponenata u<br />ravnotežnoj mje&scaron;avini dobijene su kori&scaron;ćenjem<br />programskog jezika C.<br />U drugom dijelu disertacije prikazano je<br />eksperimentalno ispitivanje pirolize otpadnih<br />automobilskih pneumatika. Eksperimentalni rezultati<br />ukazuju da na prinos gasa, odnosno na prinos čvrstog<br />(koksnog) ostatka značajno utiču parametri: veličina<br />čestice otpadne gume, temperatura pirolize i brzina<br />zagrijavanja uzorka.</p> / <p>The dissertation presents a mathematical model of<br />gasification of waste automotive tires. The model<br />examined the impact of the amount of the loaded air and<br />water vapor in the gasifier and gasification temperature<br />to yield gaseous products. The numerical procedure is<br />resolved Newton-Raphson method and the numerical<br />values of mole portions of gaseous components in the<br />equilibrium mixture obtained using the programming<br />language C.<br />In the second part of the thesis is shown<br />experimentally testing pyrolysis of waste automotive<br />tires. Experimental results indicate that the yield of gas,<br />or to yield a solid (coke) significantly affect the rest of the<br />parameters: the size of the particles of waste rubber<br />pyrolysis temperature and heating rate of the sample.</p>

<p>U doktorskoj disertaciji vr&scaron;eno je ispitivanje procesa pirolize i gasifikacije<br />oklaska kukuruza. Istraživanje procesa pirolize obuhvatalo je definisanje<br />uticaja procesnih parametara (temperature pirolize, reakcionog vremena,<br />brzine zagrevanja i veliĉine ĉestica) na prinos ĉvrstog ostatka i pirolitiĉkog<br />gasa. Osim toga, vr&scaron;eno je ispitivanje sastava gasa u zavisnosti od<br />temperature. UtvrĊeno je da ispitivani procesni parametri imaju uticaj na<br />prinos ĉvrstog ostatka i bio-ulja, kao i na prinos i sastav pirolitiĉkog gasa.<br />Tokom ispitivanja procesa gasifikacije razvijen je funkcionalni matematiĉki<br />model gasifikacije oklaska kukuruza u struji vazduha koji bi trebalo da<br />omogući optimizaciju procesa gasifikacije goriva u cilju dobijanja gasovitog<br />proizvoda.</p> / <p>Doctoral dissertation investigates pyrolysis and gasification of corncob.<br />Investigation of pyrolysis process included defining the influence of process<br />parameters (pyrolysis temperature, reaction time, heating rate and particle<br />size) on pyrolysis gas and char yield. Also, temperature dependence of<br />pyrolysis gas composition was investigated. It was confirmed that process<br />parameters influence char and bio-oil yield and pyrolysis gas yield and<br />composition. A functional mathematical model of air-stream gasification of<br />corncob was developed in order to enable optimization of gasification<br />process with the objective of obtaining gaseous product.</p>

Master of Engineering / Global warming and diminishing energy supplies are two major current concerns. Disposal of plastic wastes is also a major concern. The aim of this research is to address these three concerns by developing a solar powered process, using waste plastics as fuel to generate energy. Research into: i) solar concentrators for high temperature thermochemical processes, and ii) pyrolysis/gasification of waste plastics has been separately reported in the literature. In this study the aim was to bring these fields of research together to design a solar receiver-reactor suitable for the production of a synthesis gas, consisting of hydrogen, from waste plastics. To achieve this aim, studies of plastic decomposition behaviour using the thermal analysis method known as thermogravimetric analysis were conducted. Solar concentrators and their potential to be used for thermochemical processes were also studied. Firstly, the thermal decomposition behaviour of common plastics, namely low density polyethylene (LDPE), high density polyethylene (HDPE), polyethylene terephthalate (PET) and polyvinyl chloride (PET), were studied using thermogravimetry at heating rates of 5, 10, 20, 50 and 100 ºC/min. The kinetic parameters for the decomposition were determined from these experiments. Secondly, a simple solar receiver-reactor in which the plastic decomposition could be achieved was designed. The solar receiver-reactor designed was a quartz tube reactor which can be placed in the focus of a dish type parabolic concentrator capable of generating up to 3 kW in the focus of diameter 50 mm. The thermogravimetric analysis of plastic samples showed that LDPE, HDPE and PET have a single-step decomposition, whereas PVC has a two-step decomposition. The first step was related to the release of hydrogen chloride from the PVC and the second step was related to the release of hydrocarbon from the polymer backbone. If PVC is pretreated to release HCl it can be mixed with other plastics for a single step decomposition. It is likely that a single step plastic decomposition can be achieved in a directly irradiated solar receiver-reactor to generate useful gases consisting of hydrogen.

Master of Engineering / Global warming and diminishing energy supplies are two major current concerns. Disposal of plastic wastes is also a major concern. The aim of this research is to address these three concerns by developing a solar powered process, using waste plastics as fuel to generate energy. Research into: i) solar concentrators for high temperature thermochemical processes, and ii) pyrolysis/gasification of waste plastics has been separately reported in the literature. In this study the aim was to bring these fields of research together to design a solar receiver-reactor suitable for the production of a synthesis gas, consisting of hydrogen, from waste plastics. To achieve this aim, studies of plastic decomposition behaviour using the thermal analysis method known as thermogravimetric analysis were conducted. Solar concentrators and their potential to be used for thermochemical processes were also studied. Firstly, the thermal decomposition behaviour of common plastics, namely low density polyethylene (LDPE), high density polyethylene (HDPE), polyethylene terephthalate (PET) and polyvinyl chloride (PET), were studied using thermogravimetry at heating rates of 5, 10, 20, 50 and 100 ºC/min. The kinetic parameters for the decomposition were determined from these experiments. Secondly, a simple solar receiver-reactor in which the plastic decomposition could be achieved was designed. The solar receiver-reactor designed was a quartz tube reactor which can be placed in the focus of a dish type parabolic concentrator capable of generating up to 3 kW in the focus of diameter 50 mm. The thermogravimetric analysis of plastic samples showed that LDPE, HDPE and PET have a single-step decomposition, whereas PVC has a two-step decomposition. The first step was related to the release of hydrogen chloride from the PVC and the second step was related to the release of hydrocarbon from the polymer backbone. If PVC is pretreated to release HCl it can be mixed with other plastics for a single step decomposition. It is likely that a single step plastic decomposition can be achieved in a directly irradiated solar receiver-reactor to generate useful gases consisting of hydrogen.

Waste can be considered as an urban burden or as a valuable resource depending on how it ismanaged. Different waste treatment technologies are available at present to manage municipal solidwaste (MSW). Various actors are involved to develop waste treatment technology for certain area.The aim of this study is to analyze the driving forces in technical development in waste sector inSweden. The study is also done to identify emerging waste management technology in Sweden.Moreover, a comparative study of existing and emerging technologies is done by Life CycleAssessment (LCA) model. An extensive literature review and pilot questionnaire survey among thewaste management professionals’ is done for the study. LCA model is developed by SimaProsoftware CML2 baseline method is used for identifying environmental burden from the wastetechnologies.Dry composting, Pyrolysis-Gasification (P-G), Plasma-Arc are identified as potential emergingtechnologies for waste management system in Sweden. Technical developments of thesetechnologies are influenced by indigenous people’s behavior, waste characteristics, regulations, healthor environmental impact and global climate change. Comparative LCA model of P-G andIncineration shows that, P-G is a favorable waste treatment technology than Incineration for MSW,especially in acidification, global warming and aquatic eco-toxicity impact categories.