42 resultados para Hazardous materials.
em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland
Resumo:
Neste Oil has introduced plant oils and animal fats for the production of NExBTL renewable diesel, and these raw materials differ from the conventional mineral based oils. One subject of new raw materials study is thermal degradation, or in another name pyrolysis, of these organic oils and fats. The aim of this master’s thesis is to increase knowledge on thermal degradation of these new raw materials, and to identify possible gaseous harmful thermal degradation compounds. Another aim is to de-termine the health and environmental hazards of identified compounds. One objective is also to examine the formation possibilities of hazardous compounds in the produc-tion of NExBTL-diesel. Plant oils and animal fats consist mostly of triglycerides. Pyrolysis of triglycerides is a complex phenomenon, and many degradation products can be formed. Based on the literature studies, 13 hazardous degradation products were identified, one of which was acrolein. This compound is very toxic and dangerous to the environment. Own pyrolysis experiments were carried out with rapeseed and palm oils, and with a mix-ture of palm oil and animal fat. At least 12 hazardous compounds, including acrolein, were analysed from the gas phase. According to the experiments, the factors which influence on acrolein formation are the time of the experiment, the sphere (air/hydrogen) in which the experiment is carried out, and the characteristics of the used oil. The production of NExBTL-diesel is not based on pyrolysis. This is why thermal degradation is possible only when abnormal process conditions prevail.
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Wastes and side streams in the mining industry and different anthropogenic wastes often contain valuable metals in such concentrations their recovery may be economically viable. These raw materials are collectively called secondary raw materials. The recovery of metals from these materials is also environmentally favorable, since many of the metals, for example heavy metals, are hazardous to the environment. This has been noticed in legislative bodies, and strict regulations for handling both mining and anthropogenic wastes have been developed, mainly in the last decade. In the mining and metallurgy industry, important secondary raw materials include, for example, steelmaking dusts (recoverable metals e.g. Zn and Mo), zinc plant residues (Ag, Au, Ga, Ge, In) and waste slurry from Bayer process alumina production (Ga, REE, Ti, V). From anthropogenic wastes, waste electrical and electronic equipment (WEEE), among them LCD screens and fluorescent lamps, are clearly the most important from a metals recovery point of view. Metals that are commonly recovered from WEEE include, for example, Ag, Au, Cu, Pd and Pt. In LCD screens indium, and in fluorescent lamps, REEs, are possible target metals. Hydrometallurgical processing routes are highly suitable for the treatment of complex and/or low grade raw materials, as secondary raw materials often are. These solid or liquid raw materials often contain large amounts of base metals, for example. Thus, in order to recover valuable metals, with small concentrations, highly selective separation methods, such as hydrometallurgical routes, are needed. In addition, hydrometallurgical processes are also seen as more environmental friendly, and they have lower energy consumption, when compared to pyrometallurgical processes. In this thesis, solvent extraction and ion exchange are the most important hydrometallurgical separation methods studied. Solvent extraction is a mainstream unit operation in the metallurgical industry for all kinds of metals, but for ion exchange, practical applications are not as widespread. However, ion exchange is known to be particularly suitable for dilute feed solutions and complex separation tasks, which makes it a viable option, especially for processing secondary raw materials. Recovering valuable metals was studied with five different raw materials, which included liquid and solid side streams from metallurgical industries and WEEE. Recovery of high purity (99.7%) In, from LCD screens, was achieved by leaching with H2SO4, extracting In and Sn to D2EHPA, and selectively stripping In to HCl. In was also concentrated in the solvent extraction stage from 44 mg/L to 6.5 g/L. Ge was recovered as a side product from two different base metal process liquors with Nmethylglucamine functional chelating ion exchange resin (IRA-743). Based on equilibrium and dynamic modeling, a mechanism for this moderately complex adsorption process was suggested. Eu and Y were leached with high yields (91 and 83%) by 2 M H2SO4 from a fluorescent lamp precipitate of waste treatment plant. The waste also contained significant amounts of other REEs such as Gd and Tb, but these were not leached with common mineral acids in ambient conditions. Zn was selectively leached over Fe from steelmaking dusts with a controlled acidic leaching method, in which the pH did not go below, but was held close as possible to, 3. Mo was also present in the other studied dust, and was leached with pure water more effectively than with the acidic methods. Good yield and selectivity in the solvent extraction of Zn was achieved by D2EHPA. However, Fe needs to be eliminated in advance, either by the controlled leaching method or, for example, by precipitation. 100% Pure Mo/Cr product was achieved with quaternary ammonium salt (Aliquat 336) directly from the water leachate, without pH adjustment (pH 13.7). A Mo/Cr mixture was also obtained from H2SO4 leachates with hydroxyoxime LIX 84-I and trioctylamine (TOA), but the purities were 70% at most. However with Aliquat 336, again an over 99% pure mixture was obtained. High selectivity for Mo over Cr was not achieved with any of the studied reagents. Ag-NaCl solution was purified from divalent impurity metals by aminomethylphosphonium functional Lewatit TP-260 ion exchange resin. A novel preconditioning method, named controlled partial neutralization, with conjugate bases of weak organic acids, was used to control the pH in the column to avoid capacity losses or precipitations. Counter-current SMB was shown to be a better process configuration than either batch column operation or the cross-current operation conventionally used in the metallurgical industry. The raw materials used in this thesis were also evaluated from an economic point of view, and the precipitate from a waste fluorescent lamp treatment process was clearly shown to be the most promising.
Resumo:
Selostus: Haihtuvien orgaanisten yhdisteiden muodostuminen kuivikkeissa
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Selostus: Pohjois-Euroopan silikaattisten kalkitusaineiden reaktiivisuus astiakoemenetelmällä ja kahdella pH-staattisella menetelmällä arvioituna
Resumo:
The dynamical properties ofshaken granular materials are important in many industrial applications where the shaking is used to mix, segregate and transport them. In this work asystematic, large scale simulation study has been performed to investigate the rheology of dense granular media, in the presence of gas, in a three dimensional vertical cylinder filled with glass balls. The base wall of the cylinder is subjected to sinusoidal oscillation in the vertical direction. The viscoelastic behavior of glass balls during a collision, have been studied experimentally using a modified Newton's Cradle device. By analyzing the results of the measurements, using numerical model based on finite element method, the viscous damping coefficient was determinedfor the glass balls. To obtain detailed information about the interparticle interactions in a shaker, a simplified model for collision between particles of a granular material was proposed. In order to simulate the flow of surrounding gas, a formulation of the equations for fluid flow in a porous medium including particle forces was proposed. These equations are solved with Large Eddy Simulation (LES) technique using a subgrid-model originally proposed for compressible turbulent flows. For a pentagonal prism-shaped container under vertical vibrations, the results show that oscillon type structures were formed. Oscillons are highly localized particle-like excitations of the granular layer. This self-sustaining state was named by analogy with its closest large-scale analogy, the soliton, which was first documented by J.S. Russell in 1834. The results which has been reportedbyBordbar and Zamankhan(2005b)also show that slightly revised fluctuation-dissipation theorem might apply to shaken sand, which appears to be asystem far from equilibrium and could exhibit strong spatial and temporal variations in quantities such as density and local particle velocity. In this light, hydrodynamic type continuum equations were presented for describing the deformation and flow of dense gas-particle mixtures. The constitutive equation used for the stress tensor provides an effective viscosity with a liquid-like character at low shear rates and a gaseous-like behavior at high shear rates. The numerical solutions were obtained for the aforementioned hydrodynamic equations for predicting the flow dynamics ofdense mixture of gas and particles in vertical cylindrical containers. For a heptagonal prism shaped container under vertical vibrations, the model results were found to predict bubbling behavior analogous to those observed experimentally. This bubbling behavior may be explained by the unusual gas pressure distribution found in the bed. In addition, oscillon type structures were found to be formed using a vertically vibrated, pentagonal prism shaped container in agreement with computer simulation results. These observations suggest that the pressure distribution plays a key rolein deformation and flow of dense mixtures of gas and particles under vertical vibrations. The present models provide greater insight toward the explanation of poorly understood hydrodynamic phenomena in the field of granular flows and dense gas-particle mixtures. The models can be generalized to investigate the granular material-container wall interactions which would be an issue of high interests in the industrial applications. By following this approach ideal processing conditions and powder transport can be created in industrial systems.
Resumo:
Diplomityössä tutkittiin elinkaariarvioinnin ja sillä saatavien tulosten käyttöä ympäristömyötäisen tuotesuunnittelun tukena. Työn alussa kuvaillaan niitä asioita, jotka yhdistävät yrityksen ympäristöasioihin. Työn aikana suoritettiin kahden yritysten tuotteille elinkaariarvioinnit. Näistä tutkimuksista saatuja käytännön kokemuksia on käytetty diplomityössä. Pääpainopiste käytännön kokemuksissa oli itse elinkaariarvioinnin tekemisessä esille tulleissa seikoissa sekä tulosten tulkinnassa ympäristömyötäisen tuotesuunnittelun tavoitteiden asettamisen näkökulmasta. Ympäristömyötäisen tuotesuunnittelun tavoitteet ovat: materiaali- ja energiakulutuksen vähentäminen, kierrätettävyyden parantaminen, tuotteen käyttöiän pidentäminen ja ympäristölle haitallisten raaka-aineiden välttäminen. Jokaisella ympäristömyötäisen tuotesuunnittelun tavoitteella on oma erityispiirteensä, joka on huomioitava elinkaariarviointia käytettäessä. Työn aikana havaittiin, että erityinen huomio on kiinnitettävä lähtötietojen keruuvaiheeseen. Vielä nykyään on vaikea saada, etenkin alihankkijoilta, kaikkia tarvittavia inventaariotietoja. Tähän elinkaariarvioinnin suorittamisen kannalta ratkaisevaan vaiheeseen, on kaikkien osapuolten kiinnitettävä tulevaisuudessa huomiota. Myös tulosten tulkintaan kiinnitettiin huomioita. Merkittävien tekijöiden ja niihin vaikutusmahdollisuuksien havaitseminen on tärkeä osa tavoitteiden asettamista. Hyvin perusteltujen tavoitteiden asettamisen edellytys on kattavat ja luotettavat elinkaariarvioinnin tulokset. Nämä taas edellyttävät riittävän laajoja, laadukkaita ja yhdenmukaisia lähtötietoja, joita vielä nykyään on harvoin saatavilla.
Resumo:
Tämän diplomityön tavoitteena oli tutkia saneeraus- ja remontoimistuotteiden osalta maahantuontia Suomeen ja transitoliikennettä Suomen kautta Venäjälle. Lähtökohtana oli Suomen logistinen asema ja mahdolliset kilpailukykyyn vaikuttavat tekijät, joista on luotu potentiaalisia tulevaisuuden kuvia. Kaikki tulokset johdettiin LOADER/CLIENT –tutkimusprojektin yhteyksistä. Tutkimuksen tavoitteisiin päästiin empiiristä tutkimusta varten kootun teorian kautta, joka koostuu toimitusketjun hallinnasta ja tämänhetkisestä parhaimmasta käytännöstä eli ns. kolmen A:n menetelmästä. Lisäksi teoriaosuudessa tarkasteltiin toimitusketjun yritysten välisiä suhteita, kansainväliseen toimitusketjuun liittyviä tekijöitä sekä tulevaisuuden haasteita. Työn empiiristä tutkimustietoa kerättiin pääasiassa haastattelujen, mutta myös muiden tutkimuksen tuloksien kautta. Tutkimusmenetelmä oli laadullinen puolistrukturoitu teemahaastattelu, jota varten ryhmä remontoimiseen ja saneeraukseen liittyviä yrityksiä ja heidän käyttämiä logistisia operaattoreita sekä projektin johtoryhmää haastateltiin. Tutkimuksen tulosten mukaan suurin osa haastatelluista yrityksistä näkee Suomen logistisen aseman hyvänä tällä hetkellä ja lähivuosina. Etenkin arvotavaroiden transito- kuljetuksissa Suomen asema nähdään vahvana vuosien kokemuksen ansiosta. Tällä hetkellä arvotavaroiden toimitusaika ja kokonaiskustannukset varastoimisineen ja käsittelyineen ovat vastaavia tai jopa edullisempia verrattuna esimerkiksi reitteihin Baltian maiden kautta. Baltian maiden kehitys voi heikentää Suomen kilpailukykyä hetkellisesti, mutta todennäköisesti ei pidemmällä aikavälillä. Haastateltujen henkilöiden mielestä Suomen logistiseen kilpailukykyyn tulevaisuudessa vaikuttaa eniten kaksi kriittistä tekijää. Suomen tulisi ensinnäkin keskittyä ja kehittää arvotavaran transitokuljetuksia. Toiseksi, säilyttääkseen kilpailukykynsä, Suomen satamien palveluiden kuten tullin ja ahtaajien tulisi olla joustavasti käytettävissä 24 tuntia vuorokaudessa vuoden jokaisena päivänä.
Resumo:
Drying is a major step in the manufacturing process in pharmaceutical industries, and the selection of dryer and operating conditions are sometimes a bottleneck. In spite of difficulties, the bottlenecks are taken care of with utmost care due to good manufacturing practices (GMP) and industries' image in the global market. The purpose of this work is to research the use of existing knowledge for the selection of dryer and its operating conditions for drying of pharmaceutical materials with the help of methods like case-based reasoning and decision trees to reduce time and expenditure for research. The work consisted of two major parts as follows: Literature survey on the theories of spray dying, case-based reasoning and decision trees; working part includes data acquisition and testing of the models based on existing and upgraded data. Testing resulted in a combination of two models, case-based reasoning and decision trees, leading to more specific results when compared to conventional methods.
Resumo:
Studies regarding the field of this work aim to substitute industrial mechanical conveyors with pneumatic conveyors to overcome the disadvantages in solids flow regulation and risks posed to production and health. The experimental part of this work examines how the granular material properties, fluidizing airflow rate, equipment geometry, and pressures along the pipes affect the mass flow rate through the system. The results are compared with those obtained from previous experiments conducted with alumina. Experiments were carried out with a pilot scale downer-riser system at Outotec Research Center Frankfurt. Granular materi-als used in this work are named as sand, ilmenite, iron ore 1 and iron ore 2.
Resumo:
The objective of the thesis was to define the quality potential of DIP and hardwood CTMP based raw material furnish for a printing paper production and to define the end product's pulp-based boundary conditions especially when thinking of Chinese markets. Although the Chinese paper industry expands rapidly, the production of some paper grades is still exiguous. Especially the softwood resources are limited in Asia, thus the purpose of the thesis was to find out the possibilities to produce printing paper in China from local raw materials. Bleached CTMP can be produced, for example, from fast-growing hardwood species like eucalyptus and poplar. Therefore in this thesis it was examined if good quality printing paper is possible to produce by using deinked pulp and hardwood CTMP based furnish. In the first section of experimental part, various deinked pulps and chemithermomechanical pulps were compared. The deinked pulps were from China, Central Europe and Finland. Central European was made for magazine papers, and the Chinese as well as the Finnish pulps were made for newsprints. Two of the BCTMPs were from China and those both were made from poplar, whereas one BCTMP was made from eucalyptus in a pilot plant. There were significant differences especially between BCTMPs and their paper properties. In the second section of experimental part, the deinked pulp and eucalyptus BCTMP were blended to produce handsheets. The results show that producing the highest quality printing paper would be difficult from these raw materials. Deinked pulp affected especially the strength and optical properties as well as calender blackening. The BCTMP was found to have effects mostly on the smoothness, strength and optical properties as well as calender blackening.
Resumo:
This work proposes a method of visualizing the trend of research in the field of ceramic membranes from 1999 to 2006. The presented approach involves identifying problems encountered during research in the field of ceramic membranes. Patents from US patent database and articles from Science Direct(& by ELSEVIER was analyzed for this work. The identification of problems was achieved with software Knowledgist which focuses on the semantic nature of a sentence to generate series of subject action object structures. The identified problems are classified into major research issues. This classification was used for the visualization of the intensity of research. The image produced gives the relation between the number of patents, with time and the major research issues. The identification of the most cited papers which strongly influence the research of the previously identified major issues in the given field was also carried out. The relations between these papers are presented using the metaphor of social network. The final result of this work are two figures, a diagram showing the change in the studied problems a specified period of time and a figure showing the relations between the major papers and groups of the problems
Resumo:
PIXE (Particle Induce X-ray Emission spectrometry) was used for analysing stem bark and stem wood of Scots pine, Norway spruce and Silver birch. Thick samples were irradiated, in laboratory atmosphere, with 3 MeV protons and the beam current was measured indirectly using a photo multiplicator (PM) tube. Both point scans and bulk analyses were performed with the 1 mm diameter proton beam. In bulk analyses, whole bark and sectors of discs of the stem wood were dry ashed at 550 ˚C. The ashes were homogenised by shaking and prepared to target pellets for PIXE analyses. This procedure generated representative samples to be analysed, but the enrichment also enabled quantification of some additional trace elements. The ash contents obtained as a product of the sample preparation procedure also showed to be of great importance in the evaluation of results in environmental studies. Spot scans from the pith of pine wood outwards, showed clearly highest concentrations of manganese, calcium and zinc in the first spot irradiated, or 2-3 times higher than in the surrounding wood. For stem wood from the crown part of a pine this higher concentration level was found in the first four spots/mms, including the pith and the two following growth rings. Zinc showed increasing concentrations outwards in sapwood of the pine stem, with the over-all lowest concentrations in the inner half of the sapwood. This could indicate emigration of this element from sapwood being under transformation to heartwood. Point scans across sapwood of pine and spruce showed more distinct variations in concentrations relative to hearth wood. Higher concentrations of e.g. zinc, calcium and manganese were found in earlywood than in denser latewood. Very high concentrations of iron and copper were also seen for some earlywood increments. The ash content of stem bark is up to and order higher than for the stem wood. However, when the elemental concentration in ashes of bark and wood of the same disc were compared, these are very similar – this when trees are growing at spots with no anthropogenic contamination from the atmosphere. The largest difference was obtained for calcium which appeared at two times high concentrations in ashes of bark than in ashes of the wood (ratio of 2). Pine bark is often used in monitoring of atmospheric pollution, where concentrations in bark samples are compared. Here an alternative approach is suggested: Bark and the underlying stem wood of a pine trees are dry ashed and analysed. The elemental concentration in the bark ash is then compared to the concentration of the same element in the wood ash. Comparing bark to wood includes a normalisation for the varying availability of an element from the soil at different sites. When this comparison is done for the ashes of the materials, a normalisation is also obtained for the general and locally different enrichment of inorganic elements from wood to bark. Already a ratio >2 between the concentration in the bark ash and the concentration in the wood ash could indicate atmospheric pollution. For monitoring where bark is used, this way of “inwards” comparison is suggested - instead of comparing to results from analyses of bark from other trees (read reference areas), growing at sites with different soil and, locally, different climate conditions. This approach also enables evaluation of atmospheric pollution from sampling of only relative few individual trees –preferable during forest felling.