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Makaringe, Nkateko Petra. "Plasma gasification of organic waste." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/61310.
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Four biomass materials, namely peach pips, pine wood, bamboo and Napier grass, and one example of chemical waste, lithium hexafluorophosphate (LiPF6), were studied. The biomass types were selected because they were easily accessible locally. The LiPF6 waste is solidified in poly(methyl methacrylate) (PMMA). Gasification of this solid is of interest to industry.
Prior to the gasification studies, TGA-FTRI analyses were conducted on the biomass samples. This was done to study their thermal behaviour under nitrogen as well as under oxygen. The results indicated that, in general, pyrolysis of biomass takes place in three stages, namely hydration, active pyrolysis, and passive pyrolysis. These stages occur at different temperatures depending on the type of biomass as well as the heating rate used. The conversion efficiency of these materials is increased under oxygen, due to the fact that combustion takes place in the presence of oxygen, either partially or fully, depending on the amount made available. TGA results obtained under nitrogen were used to compute the kinetic parameters of each biomass material.
Because their fluffy nature led to feed problems, bamboo and Napier grass were excluded from the plasma gasification experiments. Results obtained during the gasification of peach pips and pine wood indicated that conversion efficiency slightly increases with an increase in temperature. Feed rate seemed to have minimal effect on both conversion efficiency and gas concentration; the energy conversion efficiency did, however, improve.
The conversion efficiencies obtained by TGA and by the plasma system, were roughly similar. Due to the higher temperatures, ~ 1000 °C, of the plasma reactor, the gaseous products obtained were predominantly carbon monoxide and hydrogen. On the other hand, carbon dioxide predominated in the TGA-FTIR experiments. Only a slight trace of monoxide was observed. Plasma treatment of PMMA encapsulated waste LiPF6 also yielded carbon monoxide and hydrogen as main products.
The energy conversion efficiency observed for the plasma process was 30 40 %. This value is ratio of the combustion enthalpy of syngas yield and the electrical energy input into the plasma torch. The main heat loss was via the torch anode. This may be corrected by an improved thermo-mechanical design.Dissertation (MSc)--University of Pretoria, 2017.
Chemical Engineering
MSc
Unrestricted
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Boon, Hau Tan. "Process Simulation of Plasma Gasification for Landfill Waste." Thesis, KTH, Materialvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-229804.
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The growing amount of landfill waste within the EU could pose a problem in the future should there not be any effective treatment methods. This study aims to investigate the performance of landfill waste in a plasma gasification process by simulating the process in ASPEN Plus. The investigation is focused on the energy recovery potential of RDF based on composition and heating value of syngas, and cold gas efficiency (CGE). The plasma gasification system consists of a shaft gasifier and a separate tar cracking reactor where high temperature plasma is used for conversion of tar compounds considered in the model, which are toluene and naphthalene. In addition, the model is divided into five sections, namely drying, pyrolysis, char gasification, melting and tar cracking. Mass and energy balance of the system was performed to better understand the system. The results show that the plasma gasification system was able to produce a syngas with a LHV of 4.66 MJ/Nm3 while improving syngas yield by attaining a higher content of hydrogen. Thus, the plasma tar cracking of tar compounds can achieve a clean syngas and improve syngas yield. Parameter study on effect of ER show that syngas has higher heating value and CGE at lower ER. On the other hand, preheated air can help recover energy from the system while lowering the ER required for the char gasification process to meet the heat demand from partial combustion. The findings implied that landfill waste has energy potential by using a suitable treatment process such as plasma gasification.
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Lundegård, Erik. "Energy recovery – Gasification, combustion or plasma? : Competitor or complement?" Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-152102.
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Abstract Energy recovery – Gasification, combustion or plasma? - Competitor or complement? The Swedish waste-to-energy system has been developed during many years, and the facilities are well established within the waste management system. Even though the waste volume is significantly reduced by 70 – 80 %, the residues are quite challenging to manage due to high content of pollutants. The air emissions are quite low today, but since waste contains various kinds of contaminants, there is a high need for extensive flue gas cleaning, adding to the residue that must be handled. Today, the main part of residues from flue gas cleaning and fly ash from Swedish waste-to-energy facilities are transported to Langöya, Norway to be used for remedial purposes of an old limestone quarry. However, this option will probably be phased out sometime after the year 2023 – 2025 and other solutions must be considered such as e.g. gasification. The Plagazi Company has a patented process, including gasification and subsequent production of hydrogen gas, that may be used as a vehicle fuel. Although gasification is a well-known technique, there is still a great distrust in using the method for waste treatment purposes. There is a conception that gasification facilities are high energy consumers, with low operational performance and high investment costs. The present thesis is part of the B.Sc. Programme in Energy Engineering at the University of Umeå. The main thesis objectives are: Study and explain significant differences and similarities between waste incineration and gasification; Describe pros-and-cons regarding various methods to produce hydrogen gas; Describe different gasification techniques. In addition, the Plagazi-process is described; local plasma gasification with low environmental impact and a second step including production of hydrogen gas. The present study is based on a literature review and interviews with experts in the field. The report excludes biogas production in anaerobic digestion plants. The present report has proven that there are significant differences between various gasification devices. When making investment decisions regarding gasification as a waste treatment option; fuel quality and utilization of the syngas must be considered. The method developed by Plagazi may be suitable in the Swedish waste management system to treat household waste and/or flue gas residues from the combustion plants, for production of hydrogen gas as a vehicle fuel. A full-scale facility in operation is needed to evaluate the Plagazi process with respect to cost efficiency and performance. The Plagazi concept should not be viewed as a competitor to the profitable waste incineration plants, more preferably as a complement.
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Karunamoothei, V. "Restaurant food waste management using microwave plasma gasification technology." Thesis, Liverpool John Moores University, 2018. http://researchonline.ljmu.ac.uk/8723/.
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The novelty of this research is that it investigates an on-site solution for the treatment of restaurant waste using a microwave generated plasma for pyrolysis and gasification. The developed system has been used to treat waste from a city centre fast food restaurant. The system was designed with the aim of reducing the amount of waste being sent to landfill by approximately 94%. The waste is mostly food based but also includes paper waste such as napkins. It was separated into three categories: mixed food, paper and fries. Samples of the mixed food and paper waste were analysed for chemical composition and calorific value. A 2.45GHz magnetron was used to supply 1kW of microwave power to a plasma cavity that had an argon flow rate of 1.5 litre per minute. The design of the microwave plasma cavity was performed using the simulation software, COMSOL. The cavity consists of a tapered waveguide section that is shorted at one end to produce a stationary wave with a large electric field at the gas nozzle. The field is strong enough to produce a self-striking argon plasma when the power is applied. Nitrogen was used to keep the plasma cavity clear of smoke, vapours and other hot gas. The best nitrogen flow rates were found to be around 2 litres/minute, although 5 litres/minute was used in the test to avoid the CO sensor saturating. The combination of the argon and nitrogen was used to purge the gasifier of oxygen. The pressure inside the gasifier was held at 200mbar during the experiments. The resulting plasma jet was used to produce syngas from the waste samples inside a thermally insulated, steel-walled reactor. Temperature profiles were recorded to find the best gas flow rates. 10g samples of the three waste categories were tested in triplicate and the results are presented. Syngas production was recorded using a Quintox gas analyser that measured CO, CO2 and O2. The data was captured every 10s during testing using a PC running a custom-built LabVIEW program. This program was also used to set the microwave output power and record the reflected power and temperatures using National Instruments cDAQ modules with analogue to digital converters. The CO and H2 in syngas can be used as a fuel to offset the cost of running the plasma jet. The results reveal that it is possible to generate the syngas using waste food materials. This study has included an investigation of some of the parameters, including power and flow rates of argon and nitrogen, on the plasma created. Others effects were taken into consideration throughout the research such as the study of the sample moisture levels and the final reduction of mass after the experiment. The ashes produced by the tests were investigated using SEM/EDX analysis. These results are also presented and analysed.
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Serage, Noah Magonagone. "Plasma gasification for converting municipal solid waste to energy." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/20266.
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In South Africa most of the municipal solid waste is currently removed and taken to land fill sites for engraving. A very small percentage of this is recycled due to lack of exploration of alternative means of further processing. In 2011 approximately 108 million tonnes of waste, mostly being general waste was generated in South Africa. Ninety eight (98) million tonnes of this waste was disposed of at landfill sites (The Department of Environmental Affairs [DEA], 2012). Environmental engineers are finding municipal solid waste management to be a challenge, similarly do the city planners and local administration. The main reason being the difficulty brought about by the complexity in composition of the waste material, no availability of waste minimization technologies and the scarcity of land for landfill sites and their environmental impact (Lal & Singh, 2012). Anyaegbunam (2013) recommend that there is a disposal technique that can convert most of the landfill waste at reduced amount of money to what is being paid on other disposal techniques nowadays, regardless of its form or composition and produce an excess of clean energy, and that technique is called Plasma Gasification which carries a high capability of being economically efficient. According to Young (2010), plasma arc Gasification is a high-temperature pyrolysis process whereby the organics of waste solids (carbon-based materials) are converted into syngas. The syngas can also be sent to gas turbines or reciprocating engines to produce electricity. Few of these plants exist in the world, however there is none in South Africa due to municipal budgetary constraints and lack of evidence for return on investment. Gasification can be described as a thermo-chemical process wherein carbonaceous or carbon-rich feed stocks, for instance tree trimmings or biomass, coal, and petro-coke are transformed into a complex gas containing hydrogen and carbon monoxide (and smaller quantities of carbon dioxide and other trace gases) under high pressure, oxygen exhausted, strong heat and/or steam environments (SRS Energy Solutions, 2016) The problem of electricity shortages continues to increase and communities are unable to cope with the continuous rising electricity bills. It is forecast that electricity demand will grow by approximately 85% and thereby reaching 31 700TWH (terawatt hours) in the year 2035. This growth rate is anticipated at an annual rate of 2.4% of which the economic and population growth will be the driving force, while on the other hand the daily increase of waste at landfill sites poses many problems with regards to the lifespan of the landfill in case green technological disposal processes are not introduced.
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Maseko, Keabetswe. "Plasma biomass gasification in a 15 kW pilot facility." Diss., University of Pretoria, 2020. http://hdl.handle.net/2263/79279.
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Plasma gasification experiments were conducted on sucrose and crushed macadamia nutshells. The pilot-scale plasma gasification system used comprises a 15 kW DC plasma torch fitted to a 5 L gasification reactor. The DC plasma torch has an efficiency of ~30 % with most of the energy lost in the torch anode.
For the macadamia nutshells, the plasma input-power was set at 9, 11 and 14 kW. At each power input setting, four different feed rates were investigated, namely 0.5, 0.7, 1.04 and
1.14 kg/h. It was observed that as the power increases, conversion increases from 48 % at 9 kW to higher than 80 % at 14 kW. It was also observed that higher mass feed rates increase the conversion. The lower heating values of the syngas produced during gasification increased with higher power inputs and higher feed rates. At a feed rate of 1 kg/h, the maximum calorific power value was 3.45 kW, at a torch setting of 14 kW. The highest power values obtained was slightly more than 4 kW.
The effect of equivalence ratio (ER) was evaluated on the plasma gasification of sucrose. ER values of 1 and 2 were investigated. With an ER of 1, the CO/H2 ratio was 1.8 and the CO/CO2 ratio was 109. With an ER of 2, the CO/H2 ratio was 1.73, and the CO/CO2 ratio 18. As expected, an increase in ER enhances the formation of CO2. A low ER thus results in higher syngas quality.
At equivalent conditions the homogenous, crystalline sucrose yielded a CO/CO2 ratio of 109, significantly higher than the 29 for plasma gasification of the macadamia nut shells. A contributing factor to having better quality syngas, was the smaller the average particle diameter of the sucrose, 0.4 mm, compared to the 10 mm of the crushed macadamia nut shells was. Another contributing factor could be that the available carbon in the macadamia nut shells structure are more strongly bonded than in sucrose.
For additional insight, kinetic data for the pyrolysis of sucrose, fructose and glucose were obtained using a TGA-FTIR hyphenated system, at much lower heating rates than anticipated in plasma system, and TGA-DTG experiments on macadamia nut shells. Dynamic studies were performed on sucrose, fructose and glucose at heating rates of 5, 10, 15, 20 and 50 °C/min in an atmosphere of nitrogen flowing at 50 mL/min, and for the macadamia shell at heating rates of 5, 10 and 20 °C/min in an atmosphere of nitrogen flowing at 50 mL/min. The sugars yielded 80 % to 85 % conversion into gaseous products, while the conversion of the shells approached 90 %; the residue was biochar. The FTIR spectra showed the major products that form from the pyrolysis of sugars to be CO2, H2O, along with large quantities C-H-O-containing compounds, amongst them C5H4O2 and C6H6O3. The latter two compounds are probably condensible.Dissertation (MEng)--University of Pretoria, 2020.
Chemical Engineering
MEng
Unrestricted
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Kabalan, Belal. "Design, implementation and control of microwave plasma gasification system for syngas production." Thesis, Liverpool John Moores University, 2012. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.589784.
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This thesis provides a solution for sustainable energy production. It applies the newest technologies of microwave plasma on a traditional method known as gasification. The simulation of this system has been achieved through a high frequency structure simulator to decide the best design of the structure. Microwave radiation at the frequency of 2.45 GHz has been applied to ionise argon gas and convert it into plasma. It has been proven that plasma can be self-initiated with an appropriate electric field applied. This microwave-induced plasma is the heart and soul of the Liverpool John Moores University's gasification system. It is coupled to a gasification chamber to gasify the feedstock placed inside and extract its energy as synthesis gas (i.e. hydrogen and carbon monoxide). Feedstock used in this study is carbon based material including pieces of wood and palm date seeds. This work is novel as no other work upto the date of this thesis completion has studied the different variables affecting plasma creation, plus the automation and the fully control of the microwave plama gasification system. Results reveal that after improvement of the microwave-induced plasma by automated control, it was possible to increase the synthesis gas production to 25.7% hydrogen and more than 57.6% carbon monoxide. This study has included the effects of some parameters on the plasma created, thus on its efficiency. These parameters are; the power of the microwave radiation, the reflected power from the system, the flow rate of argon and the pressure inside the gasification chamber. Other effects were taken into consideration throughout the project such as the study of the sample's moisture levels on the gas production and the use of helium gas instead of argon for plasma creation. The system has proved the benefits of applying microwave-induced plasma technology on the gasification technology. These benefits can be summarised as the reduction of the input power needed for the procedure from the range of megawatts to 1 kilowatt, and the flexibility achieved through controlling the plasma jet for an improved process.
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Liu, S. "Plasma gas cleaning processes for the conversion of model tar from biomass gasification." Thesis, University of Liverpool, 2018. http://livrepository.liverpool.ac.uk/3021510/.
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Occhinero, Marco. "Hydrogen production from automotive waste via integrated plasma gasification and water gas shift." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-262216.
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The growing amount of landfilled waste could pose a problem in many parts of the world due to the scarcity of landfilling space and environmental threats. In particular, automotive shredder residue (ASR) waste, a by-product of the dismantling of End of Life Vehicles (ELVs), has been proven to represent an issue in particular in the EU, where countries are struggling to compel to the directives that regulate this type of waste. At the same time, interest for hydrogen production methods is growing in the industries due to the advancement in fuel-cell technology for transportation and for power production. This study aims to investigate the performance of an integrated plasma gasification-hydrogen production system powered by ASR waste through the simulation of the process in ASPEN Plus. The investigation is focused on the potential for hydrogen production from ASR waste in terms of energy efficiency and quantity of hydrogen produced. The integrated system consists of an updraft plasma gasifier to generate clean syngas with high hydrogen content, a water gas shift reactor to furtherly enrich the gas of hydrogen content and a PSA unit to extract the hydrogen from the gas stream. The plasma gasification section of the model has been divided into four sub-systems that are drying, pyrolysis, char combustion and gasification, and melting. These four sub-systems are used to model the plasma gasification using the equilibrium method. On the other hand, the water gas shift reactor and the PSA unit have been modeled around experimental data. A Mass and Energy balance has been produced to understand the mass and energy flows within the system. The results show that the system is able to produce 238,5 kg/h of pure hydrogen from a feedstock of 2231 kg/h of ASR waste mixed with 89,2 kg/h of coke and 30 kg/h of limestone, achieving a 48% energy efficiency. Thus, the integrated system can achieve the production of pure hydrogen. The parameter study on the ER shows that hydrogen production and energy efficiency are higher at lower ER. On the other hand, increasing the SBR, while increasing the hydrogen content in the syngas, does not lead to higher hydrogen production at the system's output, causing a detrimental effect on energy efficiency. The findings of the study imply that ASR waste has the potential for hydrogen production when using a suitable treatment process.Den växande mängden avfall kan bli ett problem i många delar av världen på grund av brist på deponeringsutrymme och miljöproblem. I synnerhet har avfall från fordonsslipningsrester (ASR), en biprodukt från nedmontering av fordon (ELV), visat sig utgöra ett problem i EU, där länderna kämpar för att tvinga sig till de direktiv som reglerar denna typ av avfall. Samtidigt ökar intresset för väteproduktionsmetoder inom industrin på grund av framstegen inom bränslecellsteknologi för transport och för kraftproduktion. Syftet med denna studie är att utvärdera prestandan hos ett integrerat plasmaförgasningväteproduktionssystem drivet av ASR-avfall genom simulering av processen i ASPEN Plus. Undersökningen fokuserar på potentialen för väteproduktion från ASR-avfall när det gäller energieffektivitet och mängd väte som produceras. Det integrerade systemet består av en uppdaterad plasmaförgasare för att skapa ren syntesgas med högt väteinnehåll, en water gas shift reaktor för att ytterligare berika gasen med väteinnehåll och en PSA-enhet för att utvinna väte från gasströmmen. Plasmaförgasningsdelen i modellen har delats upp i fyra undersystem som är torkning, pyrolys, kolförbränning och förgasning, och smältning. Dessa fyra undersystem används för att modellera plasmaförgasningen med hjälp av equilibrium metoden. Å andra sidan har water gas shift reaktorn och PSA-enheten modellerats kring experimentella data. En mass- och energibalans har producerats för att förstå mass- och energi-flödena i systemet. Resultaten visar att systemet kan producera 238,5 kg / h rent väte från ett råmaterial på 2231 kg / h ASR-avfall blandat med 89,2 kg / h koks och 30 kg / h kalksten, vilket uppnår en 48% energieffektivitet. Således kan det integrerade systemet uppnå produktionen av rent väte. Parameterstudien på ER visar att väteproduktion och energieffektivitet är högre vid lägre ER. Å andra sidan leder ökning av SBR, samtidigt som man ökar väteinnehållet i syntesgas, inte till högre väteproduktion vid systemets output, vilket orsakar en skadlig effekt på energieffektiviteten. Resultaten av studien antyder att ASR-avfall har potential för väteproduktion när man använder en lämplig behandlingsprocess.
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Dai, Siyang. "OPTIMIZED WTE CONVERSION OF MUNICIPAL SOLID WASTE IN SHANGHAI APPLYING THERMOCHEMICAL TECHNOLOGIES." Thesis, KTH, Industriell ekologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187372.
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Thermochemical technologies have been proven effective in treating municipal solid waste (MSW) for many years. China, with a rapid increase of MSW, plans to implement more environmental friendly ways to treat MSW than landfill, which treats about 79 % of total MSW currently. The aim of this master thesis was to find out a suitable thermochemical technology to treat MSW in Shanghai, China. Several different thermochemical technologies are compared in this thesis and plasma gasification was selected for a case study in Shanghai. A model of the plasma gasification plant was created and analysed. Other processes in the plant including MSW pre-treating and gas cleaning are also proposed. By calculating the energy balance, it is demonstrated that plasma treatment of 1000 ton/day MSW with 70 % moisture reaches an efficiency of 33.5 % when producing electricity, which is higher than an incineration WtE plant (27 % maximum) and a gasification WtE plant (30 % maximum). Besides of the efficiency comparison, costs and environmental impacts of different technologies are also compared in this paper. The result indicated that given the characteristics and management situation of MSW in Shanghai, plasma gasification is a better choice to treat MSW in Shanghai.
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Ramakrishnan, Karthik. "Title Optimization and Process modelling of Municipal Solid Waste using Plasma Gasification for Power Generation in Trichy, India." Thesis, KTH, Materialvetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-157545.
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Zhang, Qinglin. "Mathematical modeling of municipal solid waste plasma gasification in a fixed-bed melting reactor." Doctoral thesis, KTH, Energi- och ugnsteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-47451.
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The increasing yield of municipal solid waste (MSW) is one of the main by-products of modern society. Among various MSW treatment methods, plasma gasification in a fixed-bed melting reactor (PGM) is a new technology, which may provide an efficient and environmental friendly solution for problems related to MSW disposals. General objectives of this work are to develop mathematical models for the PGM process, and using these models to analyze the characteristics of this new technology. In this thesis, both experimental measurement and numerical analysis are carried out to evaluate the performance of both air gasification and air&steam gasification in a PGM reactor. Furthermore, parameter studies were launched to investigate the effect of three main operation parameters: equivalence ratio (ER), steam feedstock mass ratio(S/F) and plasma energy ratio (PER). Based on the above analysis, the optimal suggestions aiming at providing highest syngas calorific value, as well as system energy efficiency, are given. Six experimental tests were conducted in a demonstration reactor. These tests are classified into two groups: air gasification (case 1 and 2) and air&steam gasification (case 3 to 6). In all these cases, the plasma gasification and melting of MSW produced a syngas with a lower heating value of 6.0-7.0 MJ/Nm3. By comparing the syngas yield and calorific value, the study found out that the steam and air mixture is a better gasification agent than pure air. It is also discovered that the operation parameters seriously influence the operation of the PGM process. A zero-dimensional kinetic free model was built up to investigate the influence of operation parameters. The model was developed using the popular process simulation software Aspen Plus. In this model, the whole plasma gasification and melting process was divided into four layers: drying, pyrolysis, char combustion&gasificaiton, and plasma melting. Mass and energy balances were considered in all layers. It was proved that the model is able to give good agreement of the syngas yield and composition. This model was used to study the influence of ER, S/F and PER on average gasification temperature, syngas composition and syngas yield. It is pointed out that a common problem for the PGM air gasification is the incomplete char conversion due to low ER value. Both increasing plasma power and feeding steam is helpful for solving this problem. The syngas quality can also be improved by reasonably feeding high temperature steam into the reactor. In order to provide detailed information inside the reactor, a two-dimensional steady model was developed for the PGM process. The model used the Euler-Euler multiphase approach. The mass, momentum and energy balances of both gas and solid phases are considered in this model. The model described the complex chemical and physical processes such as drying, pyrolysis, homogeneous reactions, heterogeneous char reactions and melting of the inorganic components of MSW. The rates of chemical reactions are controlled by kinetic rates and physical transport theories. The model is capable of simulating the pressure fields, temperature fields, and velocity fields of both phase, as well as variations of gas and solid composition insider the reactor. This model was used to simulate both air gasification and air&steam gasification of MSW in the PGM reactor. For PGM air gasification, simulated results showed that when ER varies from 0.043 to 0.077, both the syngas yield and cold gas efficiency demonstrated a trend of increasing. This is explained mainly by the increase of char conversion rate with ER. However, the increase of ER was restricted by peak temperature inside the fixed-bed reactor. Therefore, it is not suggested to use only air as gasification in the PGM process. The influence of plasma power is not obvious when PER varies from 0.098 to 0.138. The positive influences of steam addition on cold gas efficiency and syngas lower-heating-value are confirmed by the simulation results of PGM air&steam gasification. The main effect of steam addition is the rouse of water shift reaction, which largely accelerates the char conversion and final yields of hydrogen and carbon dioxide. The effect of steam injection is affected by steam feeding rate, air feeding rate and plasma power. Based on the above modeling work, Interactions between operation parameters were discussed. Possible operation extents of operation parameters are delimitated. The optimal points aiming at obtaining maximum syngas LHV and system CGE are suggested.
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Neves, Renato Cruz 1987. "Reforma de gás de gaseificação por meio de tocha de plasma : ensaios preliminares." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263019.
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Orientador: Caio Glauco SánchezDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: O desafio da tecnologia de reforma de gás de gaseificação é realizar a conversão de alcatrão e particulados em um gás, pois estes contaminantes podem trazer diversos problemas ao sistema de gaseificação como entupimento de filtros e corrosão. Dentre os equipamentos e métodos para a reforma do gás de gaseificação, encontra-se o plasma. Neste trabalho foi projetado, construído e ensaiado um sistema de reforma de gás de gaseificação proveniente de um reator de gaseificação utilizando a tocha de plasma. O sistema de reforma a plasma é constituído pela tocha de plasma inserida na garganta de um tubo convergente-divergente instalado na tubulação de saída do reator de gaseificação. A fonte de alimentação da tocha de plasma é o modelo Powermax1250 e a tocha é o modelo T80M, ambos da marca Hypertherm. A tocha de plasma utiliza nitrogênio como gás de trabalho, opera com pressão de 4; 0 bar no modo arco elétrico com corrente contínua, plasma térmico, não-transferido e alcança temperaturas superiores a 1673 K em distâncias menores que 30 mm. Na gaseificação foi utilizada a serragem de Peroba e Garapeira, fator de ar de 0; 22, velocidade de fluidização de 0,57 m.s-1 e utilizou-se 550 mm de altura do leito fixo de areia quartzosa. A coleta de alcatrão e particulado foi adaptada da norma CEN/BT/TF 143 ("Biomass gasification - Tar and particules in product gases - sampling and analysis"). Nas condições estudadas e analisadas deste trabalho, o valor obtido para a vazão mássica de alcatrão e material particulado foi de (5; 26+0; 58)10-3 g.s-1 para a gaseificação convencional enquanto que para a gaseificação utilizando a tecnologia da reforma de plasma foi de (3; 97+0; 14)10-3 g.s-1, que representou uma redução de 24; 52 %
Abstract: The technologic challenge on reformation of gasification gas is to convert tar and particulate matter into gas, because they can cause various problems on gasification system as corrosion and filters clogging. Among the equipment and methods for gasification gas reformation, it is used the plasma. In this work was designed, built and tested a system for gasification gas reformation from a gasification reactor using a plasma torch. The plasma system is formed by plasma torch inserted in the throat of a convergent-divergent tube installed in the outlet pipe of the gasification reactor. The power supply of the plasma torch is Powermax1250 and the model T80M plasma torch, both from Hypertherm brand. The plasma torch uses nitrogen as working gas, operates at a pressure of 4; 0 bar with arc current mode, thermal plasma, non-transferred and reaches temperatures above 1673 K in distances of less than 30 mm. In the gasification was used Peroba and Garapeira sawdust, air factor 0:22, fluidization velocity 0,57 m.s-1and 550 mm height fixed bed of quartz sand. The tar and particulate collection was adapted from CEN/BT/TF 143 (Biomass gasification - tar and particules in product gases - sampling and analysis). Under the conditions studied and analyzed in this work, the value obtained for the mass flow of tar and particulate material was (5; 26+0; 58)10-3 g.s-1 for conventional gasification while for using the reformation of gasification gas was de (3; 97+0; 14)10-3 g.s-1, which represented a reduction of 24:52 %
Mestrado
Termica e Fluidos
Mestre em Engenharia Mecânica
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Pang, Yin [Verfasser], Jürgen [Akademischer Betreuer] Karl, and Jürgen [Gutachter] Karl. "Plasma-assisted Gasification of Biomass and its Byproducts / Yin Pang ; Gutachter: Jürgen Karl ; Betreuer: Jürgen Karl." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2020. http://d-nb.info/1206734124/34.
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Materazzi, M. "Clean energy from waste : fundamental investigations on ashes and tar behavior in a two stage fluid bed-plasma process for waste gasification." Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1473348/.
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Over the past thirty years, the major factor that has prevented the widespread uptake of advanced gasification technologies for treating municipal solid waste (MSW) and biomass fuels has been the presence of tars and char contaminants in the syngas product, which makes the gas unsuitable for power production using energy efficient gas engines or turbines. Furthermore, the large quantities of ashes and volatile material in waste materials produce a large amount of residues downstream, as well as significant corrosive inorganic vapours and ash deposition issues. Advanced Plasma Power (APP) have developed a 2-stage thermal process where the raw syngas generated in a conventional bubbling fluid bed gasifier (FBG) is further treated in a plasma converter (PC) unit to crack and reform these tar and char species to provide a refined syngas suitable for use in a power island. At the same time, inorganic particulate and ash-type components are converted into a stable vitrified product that can be recycled as ceramic glass or road paving material. The fate of the potential deposit-forming elements arising from waste materials in a two-stage process will clearly influence the conversion efficiency, as well as the nature and extent of any harmful deposits along the thermal plant. Therefore, how the main constituents differentiate into gas phase and solid products can be monitored and controlled in the FBG first, and in the PC after, becomes a very important question. The purpose of this PhD project was to gain a fundamental understanding as to how the key process operating variables may impact the final quality of the syngas exiting the thermal plant, especially with regard to the fate of the ash forming components (i.e. agglomeration, slugging, fouling and vitrification) and the behaviour of the volatile matter (i.e. mixing, segregation and gas phase reaction mechanism) in the two stages. A systematic study was conducted to evaluate the effect of the key operating variables on the quality and quantity of the syngas exiting each unit, with specific attention to the behavior of tar components, and other key contaminants (chlorine, sulphur, heavy metals, etc.). On this side, the FBG reactor seems to play a crucial role on the two stage process efficiency evaluation. Within this context, a large part of the study herein was aimed at developing a fundamental understanding on the fluid dynamic behaviour (fluid-particle and particle-particle interaction) of a bubbling fluidized bed operated at high temperature, up to 800˚C. This included process analysis based on operation of a pilot plant using a municipal waste feedstock (40-100 kg/hr). In addition to fluidization tests, laboratory analyses, such as X-ray diffraction (XRD), X-ray fluorescence (XRF), and Inductively Coupled Plasma Mass Spectrometry (ICP-MS), were carried out to investigate the characterization and speciation of bottom and fly-ashes. The results obtained from these physical tests could be used to explain the phenomena observed for some of the materials tested in demonstration runs at APP, which showed changes in the fluidization behaviour for different ash compositions. In parallel, the potential of thermal plasma for the reforming of fluid bed tars and ash vitrification was investigated. Evaluation of plasma chemistry was performed by comparing experimental data from the pilot plant with thermodynamic and thermal kinetic predictions. Oxygen atoms initially formed from CO2 were identified as the major active species involved in the oxidative decomposition of hydrocarbon intermediates and soot precursors. The same mechanism was used to describe the reforming of organosulphur compounds, produced from gasification of sulphur-rich wastes (e.g. automotive shredded residues, demolition wood, etc.). This provides a clearer understanding of the mechanism as to how potentially hazardous elements evolve and provides guidance in the implementation of two-stage processes utilising solid wastes as alternative fuels.
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Zheng, Yaoyao. "Investigation of the conversion of fuels in the presence of solid oxygen carriers and the development of a plasma-assisted chemical looping system for H2 production." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/286023.
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The thesis, entitled 'Investigation of the conversion of fuels in the presence of solid oxygen carriers and the development of a plasma-assisted chemical looping system for H2 production', presents the work of Yaoyao Zheng in the Department of Engineering, University of Cambridge, for the degree of Doctor of Philosophy. The thesis focused on chemical looping conversion of fuels, which employ oxygen carriers to supply oxygen, followed by the regeneration of the reduced oxygen carriers in air. Combustion of a Polish coal-derived char was first carried out in a fluidised bed reactor in the presence of Fe2O3 or ZrO2-supported Fe2O3. CO2 was introduced to the fluidised bed, to allow the char to be gasified in situ, prior to the reaction with the oxygen carriers. The presence of Fe2O3 did not alter the gasification step, given that the gasification of the char was free of external mass transfer limitation. A numerical model was developed to describe the gasification behaviour, as well as predicting the effect of CO on gasification. The inhibition effect of CO on char gasification was found more significant than expected. Combustion of biomass (wood pellets), by Fe2O3 or mayenite-supported CuO was studied in a fluidised bed. This was to understand how efficient the wood pellets were combusted by the oxygen carriers, as well as the distribution of the products. A tar measurement system, based on a plasma reactor, was first developed. With the developed measuring system, it was found that both Fe2O3 and mayenite-supported CuO were efficient for combusting wood pellets. Particularly, the CLOU nature of CuO makes mayenite-supported CuO a promising candidate for direct combustion, without introducing any reactive gaseous oxidant. The final part of the dissertation was focused on developing a plasma-assisted chemical looping system for H2-rich gas production (PCLH) from CH4 at mild temperatures (~ 673 K). SrFeO3-, Fe2O3, and Ni-doped SrFeO3- and Fe2O3 were investigated as the packing material. Total combustion of CH4 was observed in SrFeO3-. The addition of Ni onto SrFeO3- significantly improved the selectivity towards H2; whilst it was only active in the fresh cycle. Fe2O3 was found to be inert for converting CH4; however, the addition of Ni to form NiO/Fe2O3 dramatically improved H2 production and the reactivity maintained high for three redox cycles. The energy cost of such PCLH was comparable to that of water electrolysis.
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Meillot, Erick. "Contribution a l'etude d'un plasma d'arc de vapeur d'eau : application a la gazeification de charbon pulverise en plasma d'arc." Toulouse 3, 1988. http://www.theses.fr/1988TOU30030.
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On presente le developpement d'un prototype preindustriel d'une torche a plasma d'arc de vapeur d'eau. Calcul des proprietes thermodynamiques (composition chimique, enthalpie massique, chaleur specifique) du systeme ar/h::(2)o, a pression constante, entre 700 et 15000 k. On presente les evolutions des coefficients de transport du systeme ar/h::(2)o en fonction de la temperature. La thermolyse de l'eau est abordee a l'aide d'un modele numerique. Dimensionnement d'un reacteur plasma pour la synthese de gaz produit sont calcules pour differents types de charbon. Modele numerique de simulation de la gazeification de charbon pulverise dans un reacteur a lit entraine avec prise en compte de la granulometrie
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Laaksonen, Minna. "Simulation and Optimization of an Air Pollution Control System Dealing with Flue Gases from Combustion of Syngas Produced through a Municipal Solid Waste Plasma Gasification and Melting Process." Thesis, KTH, Energi- och ugnsteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-103352.
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The aim of this report is to study a proposed air pollution control (APC) system designed to treat flue gases produced during the combustion of waste derived syngas. In order to achieve this objective, a literature study was done to gain insight into the pollution formation during gasification and combustion of syngas, and a model of the APC system was built using the Aspen Plus software. This model was used in four different case studies aimed at optimizing the water and chemical requirements throughout the system. Several different types of wastes were considered; municipal solid waste (MSW) representing that which is normally generated in developed countries, MSW representing that which is normally generated in developing countries, a waste composition representing that of the plastic fraction of MSW, and a waste composition representing that of the biomass fraction of MSW. Based on the results of the literature study, a few conclusions could be drawn. Sulfur compounds could be expected to be found in the form of H2S in the syngas and SO2 in the flue gases. Chlorine compounds could be expected to be found in the form of HCl and the nitrogen compounds in the form of NH3, HCN and N2 after gasification and NO after combustion. The amount of research done in the area of MSW gasification, and combustion of MSW based syngas, is, however, small, and more research is needed. Based on the results of the case studies, the amount of NaOH varied greatly depending on flue gas composition and negligibly depending on recirculation setup. The total amount of water required varied notably between the different cases studied and no case stood out clearly as the optimal case for all four waste compositions. The case studies seemed to indicate a trend towards an increased total water requirement with an increase in the amount recirculation. The four best cases where cases 2,3,4 and 10, out of which case three has been recommended as a good initial estimate from which to depart when finding the optimal setup for a specific system under study. In case 3, 40 wt% of the fresh water from the first splitter was sent to the direct contact scrubber, 50 wt% of the remaining fresh water was sent to the absorption tower, 40 wt% of the liquid leaving the absorption tower was recycled back to the direct contact scrubber, and 40 wt% of the remaining water leaving the absorption tower was recycled back to the absorption tower.
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Demarthon, Romain. "Modélisation et simulation d’un étage haute température pour la purification d’un gaz chargé en goudrons et en particules carbonées par assistance plasma." Thesis, Pau, 2013. http://www.theses.fr/2013PAUU3001/document.
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Afin de répondre aux besoins croissants en énergie primaire, le groupe Europlasma a développé le procédé CHO-Power permettant de valoriser énergétiquement un mélange de refus de tri d’ordures ménagères et de résidus de biomasse. L’une des particularités de ce procédé est l’utilisation d’un réacteur de dégradation thermique des goudrons et des particules solides fines par assistance plasma. L’objectif de cette étude de mieux appréhender les mécanismes réactionnels mis en jeu lors de l’épuration thermique du gaz. Dans cette optique, un réacteur pilote a été dimensionné puis construit sur la plate-forme de Recherche et Développement d’Europlasma. Il a été ensuite nécessaire de modifier le schéma réactionnel permettant la modélisation numérique de la dégradation des goudrons. Ce schéma réactionnel, couplé à l’utilisation d’un logiciel de mécanique des fluides numérique, permet de représenter les processus couplés (chimie, aéraulique, transferts thermiques) se déroulant au sein du réacteur. Deux modifications importantes ont été alors apportées au modèle cinétique simplifié jusque-là utilisé : la modélisation d’une phase discrète réactive permettant de prendre en compte la gazéification des particules de résidus carbonés et l’ajout de nouvelles voies réactionnelles afin de mieux modéliser la formation des particules de suie et de ses précurseurs. À terme, la comparaison des valeurs expérimentales à celle issues de la modélisation numérique permettra de valider ou non le schéma réactionnel dans sa globalitéIn order to contest to the high world demand for primary energy, the Europlasma group developed a new process, called CHO-Power, to enhance the thermochemical potential of a mixture of urban waste and biomass residues. One of the characteristics of this process is the use of a high temperature reactor assisted by a plasma torch for tar and soots thermal cracking. The aim of this study to improve the knowledge of the global reaction mechanism involved during the thermal treatment of gas. In this context, a pilot plant reactor was designed and built on the Europlasma Research and Development Center. During this work, the reaction pathway used to represent tars cracking at high temperature has been enhanced. Coupled to a computational fluid Dynamics Software, allow simulating the complex processes occurring within the reactor (aeraulics, reaction, and heat transfer). Two major changes were made to the simplified kinetic model previously used: the modeling of a discrete and reactive phase to take into account the possible particle gasification of carbonaceous residues and the addition of new reaction pathways to enhance the modeling of the formation of soot and its precursors. The comparison between the experimental and numerical values will validate or not the global reaction scheme and will give important information about the next evolution of the tar degradation scheme
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Santos, Ramiro Batinga dos. "Montagem e avaliação experimental de uma planta piloto de gaseificação operando com carvão vegetal e briquete de cana-de-açúcar." Universidade Federal de Alagoas, 2011. http://repositorio.ufal.br/handle/riufal/413.
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The search for technologies for sustainable development which meets the economic and environmental viability, has provided meetings, and conferences among all nations. Clean energy production and environmental preservation are growing issues and promoted these events worldwide. On the world stage of evolution predicts energy supply that is gradually increasing and the share of biofuels (both ethanol and biodiesel) in the energy world, notably: (i) growth in the production of coal to liquid (CTL, English coal to liquid), (ii) increased demand for unconventional transportation technologies (hybrid and flex fuel cars), and (iii) increased capacity and nuclear power generation and accelerated improvements in energy efficiency. Currently, the use of the potential energy contained in organic materials such as agricultural waste, industrial and urban are still below the potential energy that exists in these inputs. Gasification is a thermochemical process for converting biomass into a gas fuel with basic features. This technology allows and the use of combined cycle with integrated gasification (IGCC), ie, the use of gases produced in gasification Otto cycle engines or gas turbine to produce electricity, and the application of the technique of capture and storage carbon (Carbon Capture and Storage, CCS), which gives low emission of sulfur, offers ease of processing multiple inputs and results in different energy products and post-processable. The choice of gasifier must be in accordance with the abundant supplies in the region. The biggest challenges for the advancement of gasification technology are the high cost of technology compared to the current price of a barrel of oil and lack of skilled labor to operate the system. This thesis aimed to assembly and assessment experiences of a pilot plant for gasification, processing inputs pertaining to the region (coal and briquette sugar cane bagasse), as the results achieved and the production of synthesis gas analysis and the production of electricity.Fundação de Amparo a Pesquisa do Estado de Alagoas
A procura por tecnologias para um desenvolvimento sustentável o qual satisfaça a viabilidade econômica e ambiental, tem proporcionado reuniões, encontros e conferências entre todas as nações. Produção de energia limpa e preservação ambiental são temas crescentes e fomentados nesses eventos em todo mundo. No cenário mundial de evolução da oferta de energia prognostica-se que seja crescente e gradual a participação de biocombustíveis (tanto etanol quanto biodiesel) na matriz energética mundial, destacando: (i) crescimento na produção de carvão para líquido (CTL, do inglês coal to liquid); (ii) aumento na demanda de tecnologias de transporte pouco convencionais (carros flex fuel e híbridos); e, (iii) aumento na capacidade e geração de energia nuclear e melhorias aceleradas em eficiência energética. Atualmente, o aproveitamento do potencial energético contido nos materiais orgânicos, tais como: resíduos agrícolas, industriais e urbanos ainda são aquém do potencial energético existente nesses insumos. A gaseificação é um processo termoquímico de conversão da biomassa em um gás com características basicamente combustíveis. Esta tecnologia permite a utilização do Ciclo Combinado com a Gaseificação Integrada (IGCC), isto é, a utilização dos gases produzidos na gaseificação em motores de Ciclo Otto ou turbina à gás para produção de energia elétrica, além da aplicação da técnica de captura e armazenamento de carbono, (Carbon Capture and Storage-CCS), que proporciona baixa emissão de enxofre, oferece facilidade em processar vários insumos e resulta em diversos produtos energéticos e pós processáveis. A escolha do tipo de gaseificador deve ser de acordo com os insumos abundante da região. Os maiores desafios para o avanço da tecnologia da gaseificação são os altos custos da tecnologia frente ao preço atual do barril de petróleo e a falta de mão de obra especializada para operação do sistema. Esta dissertação teve por objetivo a montagem e a avaliação experimental de uma planta piloto de gaseificação, processando insumos próprios da região (carvão e briquete de bagaço de cana), como resultados alcançaram a produção e análise dos gases de síntese e a produção de energia elétrica.
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Lavaee, Mohammad Saleh. "Waste to Energy (WTE): Conventional and Plasma-assisted Gasification - Experimental and Modeling Studies." Thesis, 2013. http://hdl.handle.net/10012/7461.
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Ever-increasing amounts of industrial and residential wastes and their environmental footprint dictates the need for effective Waste Management practices. Thermal waste processing technologies play an important role in energy recovery from the waste. Conventional and more importantly Plasma-assisted Gasification, an advanced thermal processing technology, have been introduced as promising and environmentally benign ways for energy utilization from biomass and municipal solid waste (MSW).
This work aims to study the thermal technologies, which result in production of synthesis gas that is useful for heat and power generation; therefore, conventional and plasma-assisted gasification of biomass/MSW are reviewed. In addition, various economic, environmental and policy-related issues are examined in this study.
From the experimental and modeling perspective, this study also reports on the work conducted to characterize the gasification process using a gasification reactor called Gasifier Experimenters Kit (GEK) level IV. Both the syngas quality and quantity have been investigated based on a variety of feedstock, such as wood charcoal, poplar and tamarack wood chips. Moreover, the composition of the gas has been analyzed using a Gas Chromatography (GC) unit and the exact concentrations of carbon monoxide, hydrogen, methane and nitrogen were measured. In this study, a thermochemical model based on the experimental setup (GEK IV) has also been developed in the AspenPlus?? environment, an established simulation tool in chemical engineering and the energy industry. This model is capable of predicting the syngas composition, the energy required for the gasification reactions. A comparative analysis involving the experimental and simulation results is presented in this study.
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Zeng, Wen-Jie, and 曾文傑. "A study of biomass gasification by dielectric non-thermal plasma technology." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/68840194443701020136.
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碩士龍華科技大學
工程技術研究所
100
Plasma pyrolysis provides high temperature and high energy for reaction as the reaction sample is rapidly heated up to a high temperature. Plasma pyrolysis is more advantageous than conventional pyrolysis processes, as it produces a gas with low tar content and high heating value. We study a plasma coupling reaction at fluidized-bed plasma reactor to increase decomposition rate of biomass material of cellulose, lignin, and want to product light hydrocarbon compounds. Under the experimental conditions, the plasma fluidized bed gasification reaction wood powder gasification ratio available up to 85%, when the plasma voltage greater than 28kV to 31kV reaction, the gasification ratio as the voltage of the plasma response increases rapidly, and different flow rates of hydrogen and nitrogen plasma reaction wood gasification ratio at the level of the original penetration ratio have reversed the order of the case, presented by the cross-state line. Plasma response to the voltage higher than 31kV and below 28kV, the wood gasification reaction mechanism has changed. In the low-voltage plasma reactions of nitrogen in the hydrogen flow increases, along with wood gasification rate will increase; the contrary in the high voltage plasma reactive nitrogen in the hydrogen flow increases, along with wood gasification rate will decrease. In this study, hydrogen ratio is 33% and plasma voltage is 37kV, four hours of operating time, we can get the optimum operating conditions. About gas product of biomass gasification, CO2 concentration is 878ppm, CO concentration is 46ppm, CH4 concentration is 13ppmv.
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Liau, Yi-Ru, and 廖依如. "Co-treatment of Industry Waste and Greenhouse Gas Using Plasma Gasification and Melting Process." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/54qux2.
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碩士國立宜蘭大學
環境工程學系碩士班
102
Plasma Gasification Melting (PGM) process is a system that treats biomass or waste in a plasma reactor to optimum recovery of energy and resource as well as aching the purpose of gasification and melting at the same time. The plasma thermal treatment of wet paper sludge (WPS) and forestry wood waste (FWW) blends (WFB), sewage sludge (SW) and green liquor drug (GLD) are studied. The sources of WFB and GLD were rejected wastes from a paper plant located at east Taiwan, and SW was collected from Yi-Lan sewage wastewater treatment. This process was performed in pilot-scale 10 kW torch plasma and designed to investigate the effects of batch and semi-batch feeding of sample and their results on product yields, gas composition and thermal treatment performance were addressed. From the heating value (HV) and primate analyses, the HVs of SW and WFB are all higher than the limited value of the design of an incinerator. The combustible components of WFB and SW were about 91.82 and 54.04 wt%, respectively. For the PGM process, WFB is preferred to produce syngas from the gasification while SW is suitable for the melting coupled with gasification due to its high ash components. In the same time, the volume reduction was effective and extra energy of syngas was attended. Controlled at 873 K of torch plasma reactor, the higher heating value (HHV) of residue increased to 1.26 time of sample and its maximum value reached to 5288 kcal/kg for WFB. The production of syngas (CO and H2) is the major component, and almost 90% of the gaseous products appear in 2 min of reaction time, with relatively high reaction rates. About WFB, The maximum instantaneous concentrations and the corresponding time of CO and H2 occur at 187,208 and 232,193 ppmv, respectively, and 0.75 min for 873 K, with 0.5 min sampling interval. For batch operation, the total syngas ratio is about 81.47 wt. % (CO of 75.94 and H2 of 5.53 wt.%) of raw sample, and the mass ratio of residue is 0.53 wt.%. In addition to the PGM process, the effects of oxidation agents were also evaluated and divided into two parts: gaseous CO2 and solid type of CO2 (GLD as the source). The tested parameters were: types of sludge, temperatures, reaction time, mixed ratios, batch and semi-batch etc. From the gaseous CO2 injection in PGM process of WFB, the increases of the highest concentrations of H2 and CO were 48.74 and 23.55 %, respectively. From the results of accumulated mass percentages, the mass increases of H2 and CO were 55.51 and 14.72 %, respectively. It is proved that gaseous CO2 injection helps the gasification of WFB in PGM process. In the batch and semi-batch tests of gaseous CO2 injection in SW, the production of CO was obvious; however, they were not important in H2 and CH4. Furthermore, considering the degradation of CO2, they were 38.99 % in semi-batch test and 25.37% in batch test; semi-batch test was higher than that of batch test. In summary, higher H2 production and CO2 degradation were appeared in WFB test and higher CO and CH4 productions were shown in SW tests. Therefore, the residues of SW in PGM process can enhance the CO2 degradation with the continuous production of CO. In the tests of the input of solid type of CO2 in PGM process, GLD would release CO2 in the plasma aura as oxidation agent. Three mixed ratios of SW/GLD were tested; the highest H2 production was appeared at SW/GLD = 1/1 while the highest production of CH4 at SW/GLD = 1/1.5, CO and CO2 increased with the increase of GLD input. Therefore, it is evidenced that GLD can be effective as solid type of CO2 at an optimum input ratio. Also with the increase of temperature, the degradations of CO2 and CH4 rose as well as the CO production; however, it slightly restrained the H2 output, moreover, total production of syngas increased obviously. From the residue analyses, the input of solid type CO2 made the reaction more completely with the comparison to the gaseous CO2 injection. From the scanning electron micrograph (SEM) spectra, the raw WFB was displaced as long fiber and the construction eas complete, however, SW and GLD had broken image. Furtheremore, WFB became to broken piece after the PGM process with ash and small piece of fiber co-existed, SW and GLD displaced the spherical nanotype materials and didn’t have different SEM images. The residues from the PGM process were almost the inorganic components that were converted into 100% non-leachable vitrified lavas, and were non-hazardous from the TCLP tests. Finally, this study addressed a novelty PGM modified direction and technology in addition to the solid type CO2 co-treatment as oxidation agent.
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Lee, Hsuan-Yi, and 李宣億. "The Development of Hot Gas Cleanup System for Thermal Plasma Torch for Biomass Gasification." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/07810555519086581154.
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碩士國立中央大學
機械工程研究所
96
In recent years, developed countries have invested a lot in the development of Integrated Gasification Combined Cycle system. The researched and developments of the Moving Granular Bed Filter also get more and more attention. The dust particulates would be stopped adhered to filter media in the granular bed when the flue gas passes the filer. However, there are still many problems in the GBF, such as the formation of stagnant zones and filter sands been broken in the process, which influence the filtration efficiency. We have already successfully developed various kinds of flow corrective elements in the louver-system overcome the problem of stagnant zone. This study continues our earlier achievements to develop the rotational drum sieve system to improve the efficiency. We also performed a series of cold test, focusing on the filter efficiency and the variation of the pressure drop in the filter. The mass flow rate, gas velocity and the quantity of the broken filter media are discussed. The optimum filter efficiency could be found out by the results of cold tests in this thesis and it could be used for designing the prototype of the moving bed filter.
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Yost, Matthew R. "Analytic Hierarchy and Economic Analysis of a Plasma Gasification System for Naval Air Station Oceana-Dam Neck." Thesis, 2014. http://hdl.handle.net/10945/43383.
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Old Dominion University, Engineering Management and Systems Engineering Department, ENMA 605 Program Capstone, Final ProjectCIVINS
Background: Naval Air Station (NAS) Oceana-Dam Neck is a Master Jet Base located in Virginia Beach that currently has a population of over 28,000, this includes active duty military, family members and civilian employees. Currently the Public Works Department of Oceana maintains a contract with a municipal solid waste (MSW) Disposal Company for the collection of MSW generated on the base and disposal at a local landfill. Additionally the base receives its energy requirements from Dominion Virginia Power. In utilizing these services a substantial amount of financial resources must be committed to ensure an uninterrupted supply of these services and to maintain the infrastructure on base to supply them. Investment in a plasma gasification system allows for the opportunity to reduce the financial requirements of both of these demands as it provides for the disposal of MSW and in the process generates power for base usage. The plasma gasification system utilizes a plasma torch to ionize gas and organic matter, typically MSW, into synthetic gas and sag. The synthetic gas consists of carbon monoxide and H2, which can be utilized as a liquid or gas fuel for electrical or thermal energy generation. Thus in utilizing a plasma system two problems are potentially solved by this one solution.
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Narmandakh, Bazarsad. "Coal fuel gas cleaning by non-thermal pulsed corona discharge plasma and “reach” regulation compatibility assessemnt for trace elements extraction from gasification ash." Master's thesis, 2016. http://hdl.handle.net/10400.1/9823.
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Dissertação de mestrado, Inovação Quimica e Regulamentação, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016Atmospheric small-scaled fixed-bed gasifiers fed with cheap low rank sub-bituminous coal produces syngas (CO and H2) with high tar content, which is one of the impurities produced along the main syngas from coal gasifications. This organic impurity with high molecular weight hydrocarbons is of interest as they polymerize or condense to more complex structucres throughout the involved process pipers or heat exchangers, leading to fouling and attrition problems, which eventually leads to lose of overall plant efficiency and increased operation costs. To avoid such event, either expensive non-tar forming coal (semi-Anthracite or Anthracite) must be used or an effective tar removal unit integration in the overall process should be made. Plasma is the fourth state of matter and it contains free radical, ions and excited molecules and they create a highly reactive atmosphere as these reactive species carry enough energy to initiate tar decomposition reactions. Non-thermal plasmas are already successfully utilized in air pollution control for the VOC removal. Within the non-thermal pulsed corona discharge plasma scope, Technical university of Eindhoven (TU/e) studied biomass tar reforming (naphthalene as the tar model) and various syngas compositions were tested to study their impact on tar removal process. Furthermore, non-thermal pulsed corona discharge plasma is found to be effective in tar reforming and is created by supplying electricity and nitrogen gas to the plasma reactor. Created plasma dissociates the CO2 components in the syngas into CO and O radicals, which the unstable reactive O radicals oxidize tars into light hydrocarbons (CH4). 50% nitrogen content in the syngas due to plasma requirement limits its usage only as fuel gas for heating or electricity generation. After determining utilizing of plasma together with atmospheric fixed-bed gasifier is technologically possible, the demand for it in fuel gas application to generate heat is researched. The research involved carefully looking at energy policy of that chosen particular country and their main source of energies. According to the International Energy Agency’s 2015 statistics, China and India are placed largest coal consumers in the non-OECD countries ranking. It was estimated that China currently needs over 8000 fixed-bed gasifier (8000 plasmas) to meet the industrial heat demand. Assuming a similar development in India, in total 2000 fixed-bed-gasifiers will be needed in the next years. In the researched countries, current alternative method to generate heat instead of Natural gas or LPG is fuel gas via coal gasification. Non-tar forming quality coal are gasified, but they are either expensive due to the high demand and are not widely available. Syngas from this case is cleaned through electrostatic precipitator light tar collectors (if present) before utilizing it. These fuel gas-cleaning methods are to remove very small amount of light tars (if present) and dusts. It is a common practice in developing countries to produce fuel gas via coal gasification for the puspose of heat and electricity generation. It was found that this method is cost effective than using natural gas or LPG. Furthermore, it was found that fuel gas generation via plasma-involved case were even more cost effective than the current state of art case by at least 10%. The fuel gas production cost via plasma involved proposing configuration is competitive over the fuel gas production cost from the current state of art. In addition to cost benefits, plasma cleaned fuel gas production approach allows utilizing of low rank coal and does not utilize water, hence fresh water consumption and pollution is prevented. Abundantly available coal ashes are potential untapped resource for trace elements (TE). In 2014, the European union member states (EU-28) had consumed 285 million tones of hard coal and based on the world trace elements average in world coal, the available TE for extraction exceeds 1 tonne per year. Therefore, TE extraction from available coal ashes in EU-28 is subject to REACH regulation. However, there is no entry on ECHA database for such process. The entries at ECHA database regarding coal ash are only for the utilization for construction materials purpose. Lack of commercially available extraction technology optimized for coal ash, limited understanding of trace elements modes of occurrence, origin, and toxicological data relating to all possible chemical contaminants rising from extraction process are not well understood and are not presently available. More research and development effort must be done in order to obtain these missing information and to perform full chemical characterization of the coal ash to optimize trace elements extraction process for that particular coal and to identify all possible waste streams. Such that, needed toxicological data according to REACH regulation is obtained.