Engineering for Environment Protection

文章题目 页数

作者: Helena Raclavská, Hana Škrobánková, Petr Pavlík, Veronika Sassmanová
摘要: Energy utilization (pyrolysis) of residue from fibre recycling of used beverage cartons is very important. Identification the optimal technology for separation of aluminium from pyrolytic carbon and assessment of its quality in relationship to the pyrolysis conditions is necessary for recycling of Al. The particles of pyrolytic carbon are not pure carbon, they contain only from 65 to 83 % of carbon, the rest in ash coming from sorting and collection of waste (glass, porcelain). Process of pyrolysis and/or utilization of charge reactor influenced the chemical composition of Al particles by carbon enrichment at the rim of particles up to 30 % leading to decrease of reactivity of Al surface.
作者: Dušan Stehlík, Petr Hyzl, Michal Varaus
摘要: Using waste building materials in pavements is one of the goals of transportation sustainable development in the Czech Republic. As part of research projects of the Technology Agency of the Czech Republic, a project was devised, which focused on maximal utilization of waste building materials when constructing pavements. After the initial verification of properties of the recycled aggregate (especially concrete waste building material), the research focus shifted towards the utilization of these waste building materials in cement bound granular mixtures.
作者: Martin Vantúch, Jozef Jandačka, Alexander Čaja
摘要: The article describes impacts of incinerating PET bottles and HDPE, LDPE bags in heat sources intended for combustion of solid fuels on emission load of environment. As primary fuel was intended brown coal and municipal waste was admixed in various amounts. The article describes the process of measuring and evaluating emissions during their incineration.
作者: Kateřina Žurková, Karla Kryštofová, Helena Raclavská, Hana Škrobánková
摘要: It is important to reduce the amount of municipal waste deposited in landfills, Czech Republic, therefore, puts more emphasis on the recovery of mixed municipal waste, which oblige and EU regulations. Production of solid alternative fuel that is suitable also due to less consumption of fossil fuels, is one of the uses of mixed municipal waste (Waste to Energy). A relatively high proportion of glass in mixed municipal waste is a major problem in the production of solid alternative fuel. The glass contained in the solid alternative fuel can be the cause of formation incrusts on heat transfer surfaces in combustion plants. For all examined types of glass, it was found that the melting temperature of the muffle furnace was 750 ° C. When using the method (ISO 540) for determining the temperature of softening , melting and flow showed no effect of the amount of glass in the ash, but the melting point was significantly higher (around 1,200 °C).
作者: Andrea Miškufová, Alexandra Medvecová, Anna Kochmanová, Dušan Olčák, Viktor Hronský
摘要: One of the negative aspects of MSW (municipal solid waste) incineration is production of hazardous fly ashes. MSW fly ash usually contains heavy metals like for example chromium, lead, cadmium and organic substances (dioxins, furans), soluble compounds (salts) and other harmful substances. According to environmental legislative and with respect to the environment fly ash as a hazardous waste should be stabilized before landfilling. This work deals with certain problems occurring at solidification process of MSW fly ash by cementation. This work also describes efficiency of stabilization by two different binders (slag cement and waste containing alumina and silica). Leachability tests by TCLP (toxicity characteristic leaching procedure) and compressive strength of original and solidified samples by use of uniaxial pressing were studied in order to find suitable parameters for effective stabilization.
作者: Tomáš Havlík, Dušan Oráč, Ján Jaščišák, Andrea Miškufová, Hedviga Horváthová
摘要: This work focuses on possibilities to recover tin and copper by hydrometallurgical processes from printed circuit boards (PCBs) of discarded personal computers after thermal treatment. For experimental work crushed and sorted printed circuit boards with various granularity /-8 +0 mm, -8 +3 mm, -3 +0 mm/ were used. They were exposed to thermal treatment at temperatures 300 °C, 500 °C, 700 °C and 900 °C before leaching for 15, 30 and 60 minutes. The two thermal treatments were studied: in air flow, i.e. burning, and pyrolysis (without air flow). For leaching experiments 1M solution of HCl at 80 °C was used. Under the mentioned conditions both samples, the thermally treated sample of PCB as well as the original untreated printed circuit board, were leached with the aim to compare the experimental results. Weight losses during burning accounted for 5 to 35 %, while pyrolysis caused weight losses from 10 to 30 %, depending on the thermal treatment temperature. The higher the burning temperature, the higher the extraction of copper into the solution with up to 98%.However, extraction of copper from non-burned samples does not exceeded 6 %. An opposite effect has been observed during leaching of tin, where the highest extraction was reached using thermally untreated samples, and extraction decreased with an increasing burning temperature. With increasing pyrolysis temperature a higher extraction level was observed during leaching of copper and tin into the solution. The maximal extraction was reached with the leaching of thermally untreated samples, namely 6 % for copper and about 68 % for tin whereas the extraction of copper and tin achieved with thermally treated samples was 63 % and 98 %, respectively.
作者: Marek Baláš, Martin Lisý, Jiří Pospíšil
摘要: Gasification is one of the technologies for utilization of biomass. Gasification is a transformation process that converts solid fuels into gaseous fuels. The gaseous fuel may be subsequently applied in other technologies with all the benefits that gaseous fuels provide. The principle of biomass gasification is a common knowledge. It is thermochemical decomposition oof the fuel in presence of gasification agent. Heat from the endothermic reaction is obtained by a partial combustion of the fuel (autothermal gasification) or the heat is supplied into a gasifier from the outside (allothermal gasification). Oxygen for the partial combustion is supplied in the gasification medium. Quality, composition and amount of the producer gas depend on many factors which include type of the gasifier, operating temperature and pressure, fuel properties (moisture content) and type and amount of gasification medium. Commonly, air, steam and oxygen and their combinations are used as a gasification medium. Every kind of gasification agents has its significant advantages and disadvantages.Research and analysis of the gasification process must pay special attention to all operating parameters which affect quality and amount of the producer gas that is the efficiency of the conversion itself. Composition of the producer gas, calorific value, and content and composition of impurities are especially observed as these are the basic characteristics directly affecting subsequent application of the gas. Steam addition has a significant impact on gas composition. Steam decomposition into hydrogen and oxygen, and their subsequent reactions increases amount of combustibles, hydrogen, methane and other hydrocarbons. Steam addition in the gasification also affects amount and composition of tar and has a negative impact on heat balance.Energy Institute at the Brno University of Technology has a long tradition in research of biomass gasification in atmospheric fluidized bed reactors. Air was used as a gasification medium. This paper describes our experience with gasification using a mixture of air and steam. We analysed the whole process and in this paper we wish to describe the impact of temperature on outputs of the process, especially temperature of leaving steam and temperature of gasification reactions.
作者: Ján Gaduš, Tomáš Giertl, Viera Kažimírová
摘要: In the paper experiments and theory of biogas production using industrial waste from paper production as a co-substrate are described. The main aim of the experiments was to evaluate the sensitivity and applicability of the biochemical conversion using the anaerobic digestion of the mixed biomass in the pilot fermentor (5 m3), where the mesophillic temperature was maintained. It was in parallel operation with a large scale fermentor (100 m3). The research was carried out at the biogas plant in Kolíňany, which is a demonstration facility of the Slovak University of Agriculture in Nitra. The experiments proved that the waste arising from the paper production can be used in case of its appropriate dosing as an input substrate for biogas production, and thus it can improve the economic balance of the biogas plant.
作者: Michal Holubčík, Alexander Čaja, Jozef Jandačka, Marián Jobb
摘要: Waste production is greater every year with society evolution. The same problem is also in Slovak republic, but Slovakia is significantly behind other developed countries in municipal waste management especially in area of energy utilization and recovery of the municipal waste. This problem will be totally reflected after the ban of the waste dumping in landfills. This work solves the problem of waste management in the Žilina region of Slovakia. Žilina region produces approximately 185000 tons of municipal waste. At present there is the majority of the waste dumped in the landfills. Large part of this waste could be energy utilized. Except municipal waste can be also used other types of the waste for the energy utilization. The paper evaluates energy potential of municipal waste in Žilina region. During the work it was determined the ratio composition of the waste in the Žilina region. There were measured gross calorific value, low calorific value and humidity on the waste samples. Based on these results it was determined energy potential of the municipal waste in the Žilina region. This energy potential could provide part of the heat and electricity for the Žilina region after using appropriate methods of thermal disposal.