Margretelunds reningsverk i Åkersberga står såsom andra svenska avloppsreningsverk inför nya utmaningar i samband med anpassningen till ett mer hållbart och cirkulärt samhälle. För att bidra till en bra lokal miljö med få transporter och minimerad lukt, uppnå en hög grad av fosforåtervinning, samt reducera organiska och icke-organiska föreningar i slammet ska Roslagsvattenb i samarbete med IVL Svenska Miljöinstitutet utvärdera C-Greens OxyPower HTC-teknik. HTC-tekniken är hydrotermisk karbonisering (HTC) kombinerat med våtoxidation av HTC- vatten. Det våta slammet tas om hand på reningsverket och omvandlas till en fast kolanrikad produkt så kallad HTC-biokol eller hydrokol. HTC-processen innebär uppvärmning av det våta slammet (180–260°C) under högt tryck och syrefria förhållande med vatten närvarande. Hydrokolet som bildas kan uppgraderas till bränsle, jordförbättringsmedel eller aktiverat kol.  I detta arbete studerades potentialen att använda hydrokol som jordförbättringsmedel genom att undersöka biokolets fysikaliska- och kemiska egenskaper. Hydrokol jämfördes med biokol från pyrolys som också är en förkolningsprocess av biomassa vid höga temperaturer (300–650 °C) under syrefria förhållande dock utan närvaro av vatten.  Baserat på resultatet från publicerade studier, har hydrokol potentialen att ersätta eller komplettera mineralgödsel. Hydrokol förbättrar markens bördighet och produktivitet genom att t.ex. öka den totala växttillväxten, förbättrar mineraliseringen av näringsämnen och tillgängligheten av fosfor, samt ger en långsam frisättning av näringsämnen. / Margretelund's treatment plant in Åkersberga, like other Swedish sewage treatment plants, faces new challenges in connection with the adaptation to a more sustainable and circular society. In order to contribute to a good local environment with few transports and minimized odors, achieve a high degree of phosphorus recovery, and reduce organic and inorganic pollutants in the sludge, Roslagsvatten, in collaboration with the IVL Swedish Environmental Institute, will evaluate C-Green's OxyPower HTC-technology.  The HTC-technology is hydrothermal carbonization (HTC) combined with wet oxidation of HTC-water. The wet sludge is taken care of at the treatment plant and converted into a fast carbon-enriched product called HTC-biochar or hydrochar. The HTC-process involves heating the wet sludge (180–260°C) under high pressure and oxygen-free conditions with water present. The hydrochar that is formed can be upgraded to fuel, soil improver or activated carbon.  In this work, the potential of using hydrochar as a soil improver is studied by examining the biochar's physical and chemical properties. Hydrochar was compared with biochar from pyrolysis, which is also a charring process of biomass at high temperatures (300–650 °C) under oxygen-free conditions but without the presence of water.  Based on the results of published studies, hydrochar has the potential to replace or supplement mineral fertilizers. Hydrochar improves soil fertility and productivity by e.g. increase overall plant growth, improve nutrient mineralization and phosphorus availability, and provide a slow release of nutrients.

No description available.

The purpose of this investigation was to study the factors affecting the low-temperature carbonization of seam number one, Penn-Lee coal from southwestern Virginia, by determining the effect of pretreatment of the charge, temperature of the retorting gas, and time of retorting on the yields and properties of the products of carbonization. After an examination of the literature pertinent to the investigation, a pilot-scale carbonization unit was constructed. The construction of the unit consisted partly of the modification of an existing fluidization unit. Various auxiliary apparatus were also added to the modified unit for more satisfactory operation. A series of bench-scale tests were performed to study the effect of pretreatment conditions on the free-swelling index, the weight loss, and the volatile matter in Penn-Lee coal. Time and temperature had a significant effect upon the free-swelling index. Temperature of pretreatment had a significant effect on the weight loss during pretreatment. Time and the time by temperature effect were found to be significant with regard to the volatile matter remaining in the coal after pretreatment. Also, the decomposition point of Penn-Lee coal was found to lie between 427 and 454 °C (800 and 850 °F). Twelve pilot-scale tests were performed to study the effect of carbonizing conditions on the products of carbonization. The pretreatment time had a significant effect upon the dry tar yield, the tar viscosity, the tar specific gravity, and the twenty per cent tar distillation temperature. The time of carbonization had a significant effect upon the gas yield. None of the variables studied showed a significant effect within the range studied, upon the volatile matter in the char product, the bulk density of the char, or the calorific value of the char. / Ph. D.

Thesis (MBA)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: It was found that the hot metal cost of ISCOR Newcastle's single blast furnace can significantly be reduced by the correct use of an integrated model to predict reductant cost based mainly on coal blend. The model uses coal ash chemistry, fluiidity, vitrinite rank and volatile matter to predict coke strength after reaction (CSR), coke ash and coking yield. CSR is used to predict maximum allowable coke nut- and pea consumption in the furnace as well as hot blast temperature. Pitch injection levels are predicted using CSR and blast furnace production rates. Coke ash, pitch injection and hot blast temperature is used to predict the coke rate. The above is used with imported Chinese coke cost to accurately predict reductant cost. It was found that the current optimum blends should include Australian en Nieu Zeeland coals because of price and quality conciderations. Because of its low cost of production and low quality the optimum percentage of Grootegeluk in the blend is determined largely by its transfer price. / AFRIKAANSE OPSOMMING: Die vloeiyster koste van ISCOR Newcastle se enigste hoogoond kan drasties verlaag word deur die korrekte gebruik van 'n geïntegreerde model wat reduktant koste voorspel op grond van steenkoolmengsel. Die model gebruik die chemiese samestelling van steenkool-as, fluiiditeit, vitriniet rang en vlugstof om kooks warmsterkte (SNR), kooks-as en verkooksingsopbrengs te voorspel. SNR is gebruik om die maksimum kooksneute- en -erteverbruik in die hoogoond sowel as blaastemperatuur te voorspel. Pikinspuiting is bereken met SNR en hoogoond produksietempo's. Pikinspuiting en blaastemperatuur word saam met kooks-as gebruik om kookskoers te voorspel. Bogenoemde is saam met die koste van ingevoerde Chinese kooks gebruik om reduktant koste akkuraat te voorspel. Daar was bevind dat die huidige optimum mengsels Australiese en Nieu Zeelandse steenkool moet bevat as gevolg van huidige prys- en kwaliteitsoorwegings. As gevolg van sy lae produksiekoste en lae kwaliteit word die optimum hoeveelheid Grootegeluk bepaal deur sy oordragprys.

Made available in DSpace on 2017-07-25T19:29:42Z (GMT). No. of bitstreams: 1 HEVANDRODELALIBERA.pdf: 1991168 bytes, checksum: 70b0a9b14552766c3ef2f056353f43ad (MD5) Previous issue date: 2009-03-31 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The many oil crises that have occurred in the past decades and the dependence of the Brazilian energy matrix on fossil fuels, as well as the environmental problems caused by their use, have pressed for advances in the search for new alternative fuels and, in a way, also made them possible. Fuels made from vegetable oils are particularly interesting, as they may substitute the diesel, the most consumed liquid fuel. The global energy matrix tends to follow in this direction until new solutions arise, despite existing problems in the functioning of the engines, particularly when using vegetable oils. For this study, two 50-hour tests were done on a direct injection, mono-cylinder micro-tractor fueled with 100 crude sunflower oil. The vegetable oil was at room temperature in the first test (E-1), and heated to an approximate temperature of 90 C in the second test (E-2). The cylinder head gasket burned after running for 50 hours in the first test. An increase of the compression ratio was observed in both tests. The carbonization of the injection system in the E-2 test was 81.5 lower than E-1. The carbonization of the intake system in the E-2 test was 51.7 lower than E-1, and the carbonization of the exhaust system in E-2 was 33.4 lower than in E-1. The carbonization in E-1 was about the same as in E-2 in the combustion chamber. Compared to diesel, the fuel consumption was 2.3 higher in E-1 and 0.7 higher E-2. The lubricant oil was contaminated with vegetable oil in both tests. Generally, E-2 was better than E-1. / As diversas crises do petróleo ocorridas nas últimas décadas, a dependência da matriz energética brasileira dos combustíveis fósseis e os problemas ambientais causados pela utilização destes têm forçado e, de certo modo, viabilizado o avanço das pesquisas na busca de combustíveis alternativos, principalmente com relação a aqueles que podem substituir o petrodiesel, como os derivados dos óleos vegetais, pois este é o combustível liquido mais consumido. Mesmo com a existência de problemas no funcionamento dos motores quando utilizados combustíveis derivados dos óleos vegetais, até o surgimento de novas soluções o cenário da matriz energética mundial tende a seguir este rumo. Neste trabalho realizaram-se dois ensaios de 50 h de duração, em um micro-trator monocilíndrico de injeção direta, utilizando 100 de óleo de girassol como combustível. No primeiro ensaio (E-1) utilizou-se óleo vegetal entrando a temperatura ambiente no sistema de injeção do motor e no segundo ensaio (E-2) aqueceu-se o óleo a uma temperatura de aproximadamente 90 C. No primeiro ensaio após 50 h foi constatada a queima da junta de cabeçote. Para os dois ensaios foi encontrado um aumento da pressão de compressão. Para a carbonização do bico injetor, a do E-2 foi 81,5 menor que a do E-1. A carbonização do sistema de admissão do E-2 foi 51,7 menor que do E-1 e a carbonização do sistema de exaustão do E-2 foi 33,4 menor que a do E-1. Para a câmara de combustão a carbonização do E-1 foi praticamente igual ao do E-2. Com relação ao consumo de combustível do E-1 e do E-2 foram respectivamente de 2,3 e 0,7 maiores que o petrodiesel. No caso do óleo lubrificante, houve contaminação por óleo vegetal combustível nos dois ensaios. No geral o E-2 mostrou-se melhor que o E-1.

Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1979. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Vita. / Bibliography: leaves 594-611. / Sc.D.

Pioneering work performed by Rosalind Franklin over half a century ago provided the first structural models of two distinct carbon types: those that become graphitic during carbonization at high temperatures, and those that do not. Moreover it is known that certain properties of carbonaceous materials including combustion, surface area, electrical resistivity, and catalytic properties are influenced by mineral impurities. The nature of this division in biocarbon structure and the known effects of minerals on carbon properties have led to this work; three principal topics were addressed; (1) the investigation of the solid state structure of biocarbons derived from various biomass feedstocks, (2) the removal of inorganic minerals from biomass, and (3) the investigation of biocarbon electronic structure subsequent to doping with select inorganic minerals. Charcoals and carbonized charcoals (i.e. biocarbons) were prepared from a wide variety of biomass substrates, including pure sugars containing 5- and 6-membered rings with furanose and pyranose configurations, lignin, agricultural residues (corncob and nut shells) and a hard wood. These biocarbons were subject to proximate and elemental analysis, gas sorption analysis, and analysis by ICP-MS, SEM, XRD, ESR, 13C CPMAS NMR, and MALDI-TOF MS. All the carbonized charcoals contained oxygen heteroatoms, had high surface areas, and were excellent conductors of electricity. Doping the biocarbon with boron or phosphorus resulted in a slight improvement in its electrical conductivity. The XRD analysis indicated that the carbonized charcoals possess an aromaticity of about 71% that results from graphite crystallites with an average size of about 20 . The NMR analysis confirmed the highly aromatic content of the carbonized charcoals. The ESR signals indicated two major types of carbon-centered organic radicals. A number of techniques employed highlighted differences between carbonized charcoals and synthetic graphite but none more so than MALDI-TOF spectrometry. The biocarbons contained readily desorbed discrete ions with m/z values of 701, 685, 465, 453, 429, and 317. All of the above findings were used to develop a model for the structure of carbonized charcoal that is consistent with the biocarbon's oxygen content, microporosity and surface area, electrical conductivity, radical content, and its MALDI-TOF spectra. The removal of inorganic mineral constituents from various biomass feedstocks was achieved via simple washing/soaking techniques using two different aqueous media; deionized water and citric acid. The most effective and consistent demineralization treatment for removing minerals from biomass involved a hot 0.1 molL-1 citric acid percolation treatment, ca. 67% of inorganic mineral matter was removed. Mineral matter at the levels present in typical biomass derived charcoals and carbons had no significant influence upon the surface area or the electrical resistivity in carbonaceous materials after high heat treatment (950 C).

Carbon fibers contain more than 90 wt. % carbon. They have low density, high specific strength and modulus, and good temperature and chemical resistance. Therefore, they are important candidate as reinforcement materials. Carbon fiber is made by pyrolysing precursor polymers. Polyacrylonitrile (PAN) which has been used as precursor to produce high strength carbon fiber is used as precursor in this study. The theoretical tensile strength of carbon fibers can reach over 100 GPa. Currently, the best commercial carbon fibers reach only 7.5 GPa. To make good quality carbon fiber and to narrow the gap between theoretical values and currently achieved experimental properties, the entire manufacturing process including fiber spinning, stabilization and carbonization, needs to be improved optimized. In this dissertation, the stabilization processes of gel-spun PAN/carbon nanotubes (CNTs) composite fibers are studied. PAN/CNT (1 wt. % CNT) composite fibers are spun by dry-jet gel-spinning. Three types of CNTs with different number of walls and varying catalyst content are used as additives. The effect of different types of CNTs on the properties of the stabilized fibers was compared. It is found that the CNTs with the highest surface area shows the best reinforcement efficiency on the tensile modulus, and reduces the formation of β-amino nitrile. The residual catalyst in the range of 1 to 4 wt. % shows little effect on the mechanical properties of the stabilized fibers. Stabilization involves complex chemical reactions, including cyclization, oxidation, dehydration, and cross-linking. These complex reactions are separated by using different gas environments during stabilization. The cross-linking reaction has the highest activation energy among all stabilization reactions, and requires a temperature higher than 300 DegC to be completed. The effect of applied tension on the stabilized fiber properties are investigated, and it is found that higher tension leads to better properties for the stabilized fiber, including higher Young's modulus, higher orientation, less formation of β-amino nitrile, and less shrinkage. The relationship between stabilization conditions and the mechanical properties of the carbonized fiber is investigated, and the methods to identify optimum stabilization conditions are proposed. It is observed that the highest tension should be applied during both stabilization and carbonization, and the mechanical properties of the resulting carbon fibers are increased if fibers are further stabilized at a temperature of ~ 320 DegC to improve the cross-linking degree as compared with the fibers only stabilized at 255 DegC. The optimum stabilization time depends on both the stabilization temperature and on the applied tension. A new characterization method by monitoring the dynamic mechanical properties, while stabilization is in progress is used to narrow down the range of the optimum stabilization time. Also, the effect of carbonization temperature on the ultimate carbon fiber properties is studied in the batch process carbonization. Preliminary studies are carried out to find the relationship between the structure and properties of precursor fibers and the tensile strength of carbon fibers, including mechanical properties and co-monomers of precursor fibers.

The world’s appetite for energy is producing growing quantities of CO2, a pollutant that contributes to the warming of the planet and which currently cannot be removed or stored in any significant way. Other natural reserves are also being devoured at alarming rates and current assessments suggest that we will need to identify alternative sources in the near future. With the aid of materials chemistry it should be possible to create a world in which energy use needs not be limited and where usable energy can be produced and stored wherever it is needed, where we can minimize and remediate emissions as new consumer products are created, whilst healing the planet and preventing further disruptive and harmful depletion of valuable mineral assets. In achieving these aims, the creation of new and very importantly greener industries and new sustainable pathways are crucial. In all of the aforementioned applications, new materials based on carbon, ideally produced via inexpensive, low energy consumption methods, using renewable resources as precursors, with flexible morphologies, pore structures and functionalities, are increasingly viewed as ideal candidates to fulfill these goals. The resulting materials should be a feasible solution for the efficient storage of energy and gases. At the end of life, such materials ideally must act to improve soil quality and to act as potential CO2 storage sinks. This is exactly the subject of this habilitation thesis: an alternative technology to produce carbon materials from biomass in water using low carbonisation temperatures and self-generated pressures. This technology is called hydrothermal carbonisation. It has been developed during the past five years by a group of young and talented researchers working under the supervision of Dr. Titirici at the Max-Planck Institute of Colloids and Interfaces and it is now a well-recognised methodology to produce carbon materials with important application in our daily lives. These applications include electrodes for portable electronic devices, filters for water purification, catalysts for the production of important chemicals as well as drug delivery systems and sensors. / Der stets wachsende globale Energiebedarf führt zu immer weiter zunehmenden Emissionen von Kohlenstoffdioxid, einem umweltschädlichen Gas, das als eines der Hauptprobleme im weltweiten Klimawandel darstellt. Bislang ist es jedoch nicht möglich, dieses Kohlenstoffdioxid in sinnvoller Weise zu verwerten oder einzulagern. Zudem existieren weitere Probleme in der globalen Energieversorgung, da viele natürlich vorkommende Rohstoffe sehr schnell ausgebeutet werden, so dass in naher Zukunft dringend alternative Energiequellen gefunden werden müssen, um den aktuellen Problemen zu begegnen. Der Wissenschaftszweig der Materialchemie zielt in diesem Zusammenhang darauf ab, dazu beizutragen, die bestehende Energieinfrastruktur nachhaltig zu verändern. Dabei stehen verschiedene Aspekte im Vordergrund: Energie sollte in allen gewünschten Mengen jederzeit verfügbar und auch speicherbar sein. Zudem sollte ihre Erzeugung ohne umweltschädliche Abfallprodukte ablaufen. Tiefgreifende Eingriffe in die Umwelt, v.a. durch den übermäßigen Abbau von Rohstoffen, sollte nicht mehr erforderlich sein. Auf diese Weise können die Folgen des bisherigen Klimawandels eingedämmt werden und neue Schäden an der Umwelt vermieden werden. Neue, grüne Industrie- und Energieprozesse schützen hier also nachhaltig den Planeten. Bei der Forschung an nachhaltigen Formen der Energieversorgung beschäftigen sich Materialchemiker in mannigfaltiger Weise mit Kohlenstoffmaterialien. Diese sollten idealerweise kostengünstig und ohne hohen Energiebedarf produziert werden können. Am vielversprechendsten sind Materialien, die eine flexibel gestaltbare Morphologie besitzen, d.h. die besondere strukturelle Eigenschaften besitzen, wie z.B. Porosität oder chemisch veränderte und damit funktionale Oberflächen. Idealerweise sollten solche neu entwickelten Materialien nicht nur als Speicher von Energie oder Energieträgern dienen, sondern auch nach ihrer Lebensdauer als funktionales Material zur Verbesserung der Bodenqualität eingesetzt werden können und dort noch weiter als potentielle Senke für Kohlenstoffdioxid dienen können. Die zuvor beschriebenen Themen und Probleme stellen den Gegenstand der vorliegenden Habilitationsschrift dar: die Entwicklung einer alternativen Methode zur Herstellung von Kohlenstoffmaterialien aus Biomasse in Wasser bei geringen Temperaturen. Dabei handelt es sich um die sogenannte hydrothermale Karbonisierung, die in den letzten fünf Jahren von einer Gruppe junger, talentierter Wissenschaftler unter der Anleitung von Frau Dr. Titirici am Max-Planck-Institut für Kolloid- und Grenzflächenforschung erarbeitet und weiterentwickelt wurde zu einer heutzutage anerkannten und verbreiteten Methode. Zudem wurden die über diesen Weg gewonnenen Materialien erfolgreich in zahlreichen, für den Alltag wichtigen Anwendungen eingesetzt, so z.B. als Elektroden in tragbaren elektronischen Geräten, als Filtermaterialien für die Aufreinigung kontaminierten Wassers, als Katalysatoren für wichtige chemische Reaktionen, als Trägermaterial für Arzneimittel und als Sensoren.

The pulp and paper industry (PPI) is a business that produce large amounts of residues annually. Besides bark, large quantities of sludge are produced from the various parts of the industrial process. The sludge that comes from the biological wastewater purification process is denoted biosludge and is known as a particularly problematic waste product. It is of interest to reduce the amount of sludge from the PPI or to find new ways of handling the produced sludge. The common way to treat the PPI sludge is by incineration in the site’s bark boiler. The material is however difficult to dewater and often does more harm than good in the boilers. Different technologies to try and dewater the sludge further have been investigated previously, one that has recently been noted is hydrothermal treatment. The technology described in this thesis work is called hydrothermal carbonization (HTC) which uses water as a reaction media to turn the sludge into a coal-like material called hydrochar. The hydrochar has a higher heating value than the initial sludge and is more hydrophobic which makes it easier to dewater. This Master’s thesis describes the process technologies of the HTC process and presents some of the recent work done within the area. The properties of different residues from the PPI are presented before the integration of an HTC process on the biorefinery site in Domsjö, Sweden is discussed using previously published articles. A survey concerning sludge from industries within a 500 km range of the Domsjö biorefinery site is made to investigate whether residual streams similar to the ones at the Domsjö site are available in the vicinity. The results show that an HTC process demands energy in the form of steam and/or electricity. A previously made pinch and total site analysis show that the most accessible steam at the Domsjö biorefinery site, that most appliances and process steps uses, is at 7 bars. There are also steam levels of 20 and 32 bar in the area, which is within the range an HTC plant requires. The HTC process water demands further treatment which puts an extra stress on the already existing water purification process. The Domsjö biorefinery site produces 6000 tonnes of biosludge per year. Several HTC companies produce units that normally treat 20000-50000 tonnes of sludge per year, which indicates that additional sludge could be added to reach full capacity. The survey shows that there are similar materials available in the surroundings. It is concluded that further investigations concerning the sludge materials must be made before real implementation consequences can be calculated.