466 research outputs found

    Combustion of large solid fuels in cement rotary kilns

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    Potential for ORC application in the Portuguese manufacturing industry

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    Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente, perfil Gestão e Sistemas AmbientaisThe European Directive on Energy Efficiency (Directive 2012/27/EU) entered into force in 2012 to translate the EU ―20-20-20‖ Efficiency Target into binding legislation. Each Member State was obligated to set an indicative national energy efficiency target and to achieve a certain amount of final energy savings by 2016. The second Portuguese National Action Plan for Energy Efficiency (PNAEE 2016) defines a target of 8.2% for savings on final energy consumption by 2016. Savings in Industry account for 24% of the target, but less than half of it was executed through the former Plan (PNAEE 2008-2015), by the end of 2010. Worthwhile energy saving opportunities remains such as the recovery of the great amounts of wasted heat in industrial processes. Some technologies have been proposed to generate electricity from low temperature heat sources, among which the Organic Rankine Cycle (ORC). The present work assesses the wasted heat in some sectors of the Portuguese manufacture industry and the potential to implement ORC systems. The methodology developed was based on the analysis of 116 industrial plants through energy audits and other documents. The 50 plants that revealed potential for ORC implementation were the base for estimations and represent 16% of the manufacture industry total energy consumption in 2010. The national support schemes for power generation from renewable resources and cogeneration do not contemplate specifically the electricity production through waste heat recovery. Therefore, the country lacks on an appropriate framework. This study provides a preliminary assessment of the benefits reachable through waste heat-to-power generation and intends to help focus future efforts by the government on the inclusion of ORC in national strategies as an energy efficiency measure in Industry. A total of 8 sectors were analysed but only 4 are included in the final universe: Ceramic, Cement, Basic metals and Wood & Cork. For these, ORC units of 48 kWe to 3.3 MWe installed power are feasible, showing payback times typically between 2 and 6 years. For an estimated total investment of 104 M€ in ORC systems in the Ceramic, Cement, Basic metals and Wood & Cork industries, about 37 MWe installable power could mean executing 5.2 to 6.6% of the Portuguese 2016 Target of savings on Final Energy consumption in Industry, with associated avoided emissions of 132 kt CO2e/year

    Production of ceramic tiles by using marine sludge additives

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    Thesis (Master)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2006Includes bibliographical references (leaves: 89-94)Text in English; Abstract: Turkish and Englishxii, 94 leavesThe harbour sediment accumulated in time in the zmir Bay was investigated by a number of researchers from various aspects. These sediments called marine sludge in this thesis contain organics and heavy metals which pose an important environmental problem. Marine sludge removed from the harbor is required to be safely kept in some form. In this thesis, production of ceramic tiles by using marine sludge additives was investigated. The sludge is regarded as a suitable raw material for ceramic tile production because of its physical properties and chemical composition. After the sludge is removed from the harbor floor, it was subjected to a series of treatments such as washing, sieving, dewatering, drying and grinding. This treated marine sludge was pressed in the form of pellets and sintered in the 1000-1100 °C range. The treated, untreated and sintered marine sludge along with the separated shells present in marine sludge were characterized by a variety of techniques such as XRD, FTIR, and SEM-EDX. Marine sludge powders at different proportions (0-50 %) were blended via incorporation into a structural ceramic tile raw material. The mixtures were compressed, and then pellets were fired at temperatures in the 1000-1200 °C range with one-hour hold with a firing rate of 10 °C/min. The products were characterized for mechanical and microstructural properties. Marine sludge added tiles were observed to have higher compressive strength after firing at 1100 °C. The sludge addition caused a lower firing temperature for densification/vitrification of the pellets with higher pore content. Their densities and water absorption values were determined. The densities and water absorption of the tiles fired at 1100 °C was observed to decrease with increasing sludge addition. Leaching tests were performed by varying the leach solution pH and ground tile particle size for chemical durability of the products in the final part of the work. The leaching data have shown that heavy metals were immobilized in the vitrified ceramic structure. The results of this work indicated that blending marine sludge in to the ceramic powder mixtures in the 20-50% range was beneficial for tile production

    Charcoal as an alternative reductant in ferroalloy production: A review

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    peer-reviewedThis paper provides a fundamental and critical review of biomass application as renewable reductant in integrated ferroalloy reduction process. The basis for the review is based on the current process and product quality requirement that bio-based reductants must fulfill. The characteristics of different feedstocks and suitable pre-treatment and post-treatment technologies for their upgrading are evaluated. The existing literature concerning biomass application in ferroalloy industries is reviewed to fill out the research gaps related to charcoal properties provided by current production technologies and the integration of renewable reductants in the existing industrial infrastructure. This review also provides insights and recommendations to the unresolved challenges related to the charcoal process economics. Several possibilities to integrate the production of bio-based reductants with bio-refineries to lower the cost and increase the total efficiency are given. A comparison of challenges related to energy efficient charcoal production and formation of emissions in classical kiln technologies are discussed to underline the potential of bio-based reductant usage in ferroalloy reduction process

    Alternative Fuel for Portland Cement Processing

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    Optimization of production parameters in sms plant, welspun

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    Welspun Steel Limited produces steel billets of various dimensions 30% of which are sent to produce Re-bars. WSL’s TMT is presently the second best TMT available for business and industry based constructions in the market after JINDAL’s. As per the Welspun Fellowship Program, the student has undergone a training period alongside doing the project in optimizing the production of the WSL plant in Anjar, Gujarat. The thesis details the findings and discusses the current issues that a typical secondary steel industry, namely WSL, is facing along with some theoretical suggestions. DRI + Scrap is the raw material in the secondary steel production in WSL. A conclusive study is conducted to check the tap times, just by melting DRI without the steel scrap. The results indicate a success and so a new method, posing a new set of problems though, to be experimented and researched on. Finally, sets of loopholes, neglected zones and bottlenecks have been identified all through the process of steel making and casting. Suggestions have been insisted and some of them were effectively implemented

    Investigation of alternative supplementary cementitious materials and a new method to produce them

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    Zementklinker ist der Hauptbestandteil von Zement und verbraucht zu dessen Herstellung signifikante Mengen von natürlichen Ressourcen und trägt gleichzeitig zu seiner sehr ungünstigen Treibhausgasbilanz bei. In dieser Arbeit wird gezeigt, dass Zementersatzstoffe mit spezifischen Eigenschaften aus Abfallstoffen wie Kieswaschschlämmen, Strassenwaschschlämmen und Gipskartonplatten ohne Leistungseinbußen auf Produktseite, bei geringeren Temperaturen und geringerer CO2 Emission hergestellt werden können. Entsprechend den angestrebten Eigenschaften solcher zum Teil anthropogener Zementbestandteile wurden lokal verfügbare geeignete Abfallstoffe ausgewählt und thermisch aktiviert. Eine industriell anwendbare Methode zur Aktivierung solcher Stoffe bei Temperaturen von 700 °C – 850 °C wurde entwickelt und patentiert. Es basiert auf einem neu entwickelten Trocknungsverfahren und der Kombination von zwei Produktionslinien, um durch die Verknüpfung der Gasströme beider Systeme eine energieeffiziente thermische Behandlung von Abfallstoffen zu ermöglichen sowie auf umweltfreundliche Weise einen Zementersatzstoff herzustellen.:Table of Contents List of Tables List of Figures List of Abbreviations Glossary Chapter 1: Introduction 1.1 Motivation 1.2 Research hypotheses and objectives 1.3 Research methodology 1.4 Thesis outline Chapter 2: State of the art in SCM production 2.1 Supplementary cementitious materials 2.2 Classification of SCMs 2.2.1 Classification according to origin 2.2.2 Classification according to reaction behaviour 2.3 Chemical composition of SCMs 2.4 Formation of hydraulic or pozzolanic minerals in thermal processes 2.4.1 Cement clinker 2.4.2 Burnt oil shale 2.4.3 Fly ash 2.4.4 Calcined clay 2.5 Performance of composite cements 2.6 Calcining technologies 2.6.1 Flash calciner 2.6.2 Rotary calciner 2.7 Comparison of process technologies 2.8 Summary of Chapter 2 Chapter 3: Alternative SCMs and a new method for activation 3.1 Introduction 3.2 Target of alternative SCM 3.3 Waste materials 3.3.1 Aggregate washing sludge 3.3.2 Road cleaning sludge 3.3.3 Deconstruction gypsum 3.4 Producing alternative SCMs 3.5 Thermal activation of alternative SCMs 3.6 Limitations in current calcining technology 3.6.1 Difficult emission control 3.6.1.1 Particulate emission 3.6.1.2 Gaseous emission 3.6.2 Challenging material preparation 3.6.3 Demand for noble fuels 3.6.4 Difficult colour control 3.6.5 Strict temperature control 3.6.6 CO2 footprint of calciners 3.7 Proposed new method of calcination 3.7.1 Feed material handling 3.7.2 Thermal heat-exchange system 3.7.3 Clay calciner design 3.7.4 Grinding 3.8 Summary Chapter 3 Chapter 4: Theoretical Considerations 4.1 Material considerations 4.1.1 Composition of alternative SCM 4.1.2 Anticipated products and characteristics 4.2 Process considerations 4.2.1 System capacity 4.2.2 Material characteristics 4.2.3 Material receiving, crushing and handling 4.2.4 Thermodynamic modelling 4.2.4.1 Mass balance 4.2.4.2 Drying and cooling heat balance 4.2.4.3 Calcination heat balance 4.2.4.4 Gas balance 4.2.4.5 Impact on clinker kiln line 4.2.4.6 Impact of calcite on the gas balance 4.2.5 Calciner design 4.2.6 Colour control 4.2.7 Emission prediction 4.2.7.1 Emission during drying 4.2.7.2 Emission during calcination 4.2.8 CO2 footprint of produced material 4.2.9 Grinding requirements 4.3 Summary of Chapter 4 Chapter 5: Experimental tests and proof of concept 5.1 Introduction 5.2 Sampling and characterization 5.2.1 Kaolinitic AWS from France 5.2.2 Non-kaolinitic AWS from Switzerland 5.2.3 Road cleaning sludges from Switzerland 5.2.4 Deconstruction gypsum from Switzerland 5.2.5 Sample preparation and shipping 5.3 Drying screw conveyor testing 5.4 Calcination testing 5.4.1 Mineralogy of activated products 5.4.1.1 Non-kaolinitic SCM 5.4.1.2 Kaolinitic AWS from France 5.4.2 Colour 5.5 Crushing tests 5.6 Grinding tests 5.7 Mortar compressive strength testing 5.8 Water demand testing 5.9 Summary of Chapter 5 Chapter 6: Experimental results 6.1 Characteristics of activated materials 6.2 Concrete performance and colour 6.2.1 Thermally activated kaolinitic AWS from France 6.2.2 Thermally activated non-kaolinitic alternative SCM from Switzerland 6.3 Equipment dimensioning 6.3.1 Process mass flow 6.3.2 Heat-exchanging screws and thermal oil system 6.3.3 Rotary calciner dimensioning 6.3.4 Ball mill dimensioning 6.4 CO2 reduction 6.5 Summary of Chapter 6 Chapter 7: Conclusion and outlook 7.1 Conclusions 7.2 Outlook. Literatur
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