Molten chloride salts have been proposed to be used as the primary coolant in molten salt reactors, and as the heat transfer fluid in concentrated solar power plants in next generation energy system design. The corrosive properties of molten chloride salts make it challenging to find appropriate structural materials for plant/system realization. In this work, two corrosion mitigation strategies are investigated to determine the relative corrosion performance of high temperature alloys in molten chloride salt mixtures: (1) chemical purification of salt mixture using a Mg sacrificial anode and (2) developing a protective oxide layer on the surface of high temperature alloys after pre-oxidation. These corrosion inhibitors are studied in combination with each other to determine the relative corrosion performance of three high temperature alloys: Incoloy 800H (chromia former), Haynes 214 (alumina former), and Noram SX (silica former). The unprotected and pre-oxidized alloys were exposed to molten chloride salt (62.5 wt % KCl + 37.5 wt % MgCl2·6H2O) with and without 1.7 wt % Mg as a corrosion inhibitor for 100 h at 700 °C under inert Ar atmosphere. SEM-EDS characterization was used to compare cross-sections and surfaces of each alloy exposed to molten salt with and without Mg additions. SEM-EDS cross-sectional characterization revealed significant Cr depletion in each unprotected alloy, and reduced Cr depletion in alloys immersed in molten chloride salt mixtures with chemical purification included. The addition of Mg metal to the salt mixture resulted in the precipitation of MgO on the alloy surfaces. The oxide deposition of MgO on components may impact the thermal and mechanical performance of the system. Therefore, the addition of Mg should be optimized for use in an operational system. Cross-sectional analysis identified the dissolution of Cr2O3 and SiO2 oxide scales and a stable Al2O3 oxide scale post-exposure. / Thesis / Master of Applied Science (MASc)

Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós-Graduação em Engenharia e Ciência de Alimentos, Escola de Química e Alimentos, 2007. / Submitted by Caroline Silva (krol_bilhar@hotmail.com) on 2012-09-25T22:01:19Z No. of bitstreams: 1 avaliao de um processo de extrao e recuperao dos carotenides presentes no resduo da industrializao do camaro-rosa farfantepenaeus paulensis.pdf: 1948791 bytes, checksum: 9ef49c6fc9309bc36c75d41139143d07 (MD5) / Approved for entry into archive by Bruna Vieira(bruninha_vieira@ibest.com.br) on 2013-06-12T18:09:40Z (GMT) No. of bitstreams: 1 avaliao de um processo de extrao e recuperao dos carotenides presentes no resduo da industrializao do camaro-rosa farfantepenaeus paulensis.pdf: 1948791 bytes, checksum: 9ef49c6fc9309bc36c75d41139143d07 (MD5) / Made available in DSpace on 2013-06-12T18:09:40Z (GMT). No. of bitstreams: 1 avaliao de um processo de extrao e recuperao dos carotenides presentes no resduo da industrializao do camaro-rosa farfantepenaeus paulensis.pdf: 1948791 bytes, checksum: 9ef49c6fc9309bc36c75d41139143d07 (MD5) Previous issue date: 2007 / A astaxantina é um carotenóide da classe das xantofilas, amplamente distribuída em animais marinhos e aquáticos, sendo muito utilizada em formulações para aqüicultura e por suas propriedades antioxidantes, podendo também ser utilizada como corante alimentício por sua coloração avermelhada. Este carotenóide pode ser extraído de algas, bactérias e também de crustáceos como o camarão-rosa. Este crustáceo é amplamente capturado na região sul do Rio Grande do Sul, sendo que seu processamento gera mais de 60% de resíduos. O aproveitamento destes resíduos surge como uma alternativa a problemas de impacto ambiental, oriundos do seu despejo na lagoa dos Patos, bem como uma fonte alternativa de recursos para as indústrias e pescadores locais. Neste contexto, o objetivo deste trabalho foi a obtenção de carotenoproteína, utilizando resíduos provenientes da industrialização do camarãorosa(Farfantepenaeus paulensis) por meio de hidrólise enzimática com adição da enzima proteolítica Flavourzyme, e a partir dela, a purificação química da astaxantina, visando avaliar quais variáveis do processo possuíam efeito significativo, e depois de obtido o extrato, foi estudada sua estabilidade frente à luz e temperatura, utilizando astaxantina dissolvida em óleo de soja, como oleoresina. Para analisar quais as variáveis que realmente influenciam no processo de obtenção da carotenoproteína, optou-se pela utilização do planejamento experimental saturado 23 com três pontos centrais, onde se têm três variáveis independentes em dois níveis: tempo (2 e 3 h), temperatura (40 e 50ºC) e concentração de enzima/substrato (0,1 e 0,3%); e como variáveis dependentes: rendimento, porcentagem de proteína e de lipídios. As condições ótimas para o processamento foram: tempo de hidrolise de 2 horas, temperatura de hidrólise de 50°C e concentração de Enzima/Substrato de 0,3%, obtendo um rendimento do processo 9,4% , um teor de proteínas de 70,9% e teor de lipídios de 1,6%. Já para o processo de purificação química da carotenoproteína também foi utilizado um planejamento experimental quadrático completo do tipo 23, com três variáveis independentes em dois níveis, sendo elas: tempo de extração (80 e 280 min), temperatura de extração (26,6 e 43,4°C) e proporção de hexano/ acetona (8 e 92%) e como variáveis dependentes a concentração de astaxantina com três pontos centrais e dois axiais, sendo que com um tempo de extração química de 120 mim, temperatura de extração de 30 °C e com uma proporção de Hexano e Acetona de 25% foi obtida a maior concentração de astaxantina que foi de 197,41 ppm.15. Finalmente foi estudada a estabilidade da oleoresina frente ao calor, apresentando-se estável durante as 8 primeiras horas de exposição à temperatura de 105°C. Já na estabilidade frente à luz, a oleoresina mostrou-se estável por um período de 7 dias. / The Astaxanthin is a carotenoide of the xanthophylls class, widely distributed in marine and aquatic animals, and is often used in formulations for aquaculture and for their antioxidant properties and may also be used as food coloring on its reddish color. Astaxanthin can be extracted of seaweed, bacteria and also of crustaceans as the pink-shrimp. The pink-shrimp is amply captured in the southern region of Rio Grande do Sul, where their processing generates more than 60% of waste. The use of such waste emerges as an alternative to problems of the environmental impact of their eviction from the Pato´s lagoon, as well as an alternative source of resources for industries and local fishermen. In this context, the aim of this study is the obtainment of carotenoprotein using wastes from pink-shrimp processing (Farfantepenaeus Paulensis) through the proteolitic enzyme Flavourzyme, and its chemical purification, aiming to evaluate which of the process variables have significant effects. Once obtained the extract, its stability was studied faced to light and temperature, using astaxanthin dissolved in soy resin oil. To analyze the variables that really influenced the process of carotenoprotein obtainment, it was used an experimental design saturated 23, with three independent variables in two levels: time (2 and 3h), temperature (40 and 50°C) and concentration enzyme/substrate (0.1 and 0.3%) and as dependent variables the yield, lipids and proteins percentage, with three central points. The best conditions for processing were hidrolysys time of 2 hours and 50ºC of temperature, concentration enzyme/substrate of 0.3%, and the yield obtained on the process was 9.4%, protein level of 70,9% and lipids of 1.6%. To the process of chemical purification of the carotenoprotein it was also used an experimental design saturated 23, with three independent variables in two levels: time of extraction (80 and 280 minutes), temperature of chemical extraction (26,6 and 43,4°C) and hexane and acetone proportion (8 and 92%) and as dependent variable the astaxanthin concentration, with three central points and two axial points considering 16 an chemical extraction time of 120 minutes, extraction temperature of 30ºC and hexane and acetone in a 25% proportion the highest astaxanthin concentration gained was 197,41 ppm. Finally the stability of the resin oil faced to heat was studied, presenting stable during the 8 early hours of exposure to temperature of 105ºC. Faced to light, the oil resin became stable during 7 days.

From domestic and industrial waste water will have to be cleaned before it can be released into lakes and streams again. This purification takes place through various stages of treatment plants. Wastewater contains many substances that are harmful to the environment as well as human and animal health, so it is important that the purification that is done is done in an efficient and thoughtful manner. The steps that are common in Swedish cleaning plants are mechanical, biological and chemical purification. These purification steps ensure that larger particles do not come out to the open water, convert nitrogen into nitrogen through the activation process, and that by chemical treatment, the emission of phosphorus is reduced. All of these purification steps can be designed differently and vary from purification plants to purification plants. Therefore, the degree of purification and emissions can distinguish between different treatment plants. Because there are many factors involved in the processes at Swedish waste treatment plants, it is important to carry out annual audits to detect problems that can lead to environmental damage.If cleaning does not work, exercise can increase in lakes and seas, which causes people and animals to suffer. Bottom dead and acid deficiency are already a major problem for the Baltic Sea. In order to reduce the negative environmental effects, emissions of nutrients are drastically reduced. This concerns the release of nutrients from all countries around the Baltic Sea.This study focuses on nitrogen and phosphorus purification from 5 wastewater treatment plants, Henriksdal's purification plant (Stockholm), Ryaverket (Gothenburg), Sjölunda purification plant (Malmö), Kungssängsverket (Uppsala) and Duvbacken purification plant (Gävle). Information about its activities has been obtained through interviews and works own reports.The purification plants use different technical solutions, and all treatment plants meet today's requirements for purification. The biggest difference is the degree of nitrogen purification. All wastewater treatment plants have a history of changes in technical solutions to improve treatment. Cleaning wastewater from households and industries costs a lot of money for the treatment plants, so it's always a challenge for the wastewater treatment plants to clean the water in the best possible way without costing too much.It is expected that the cleaning requirements will be tightened and all treatment plants should continue to develop to increase efficiency. Current purification requirements are designed to suit the recipient's sensitivity. If the EU's idea of ​​the same degree of purification across the country is transformed into requirements, Duvbacken will need to significantly improve the nitrogen treatment at the waste water treatment plant. / Från hushåll och industri kommer det avloppsvatten som måste renas innan det kan släppas ut i sjöar och vattendrag igen. Denna rening sker genom olika steg i reningsverk. Avloppsvattnet innehåller många ämnen som är skadliga för miljön samt människors och djurs hälsa, därför är det viktigt att reningen som sker görs på ett effektivt och genomtänkt sätt. De steg som är vanliga i de svenska reningsverken är mekanisk, biologisk och kemisk rening. Dessa reningssteg ser till att större partiklar inte följer med ut till det öppna vattnet, omvandlar kväve till kvävgas genom aktivtslamprocessen, samt att genom kemisk rening minskar man utsläppen av fosfor. Alla dessa reningssteg kan utformas på olika sätt och variera från reningsverk till reningsverk. Därför kan reningsgraden och utsläppsmängderna skilja mellan olika reningsverk. Eftersom det är många faktorer som spelar in när det gäller processerna på svenska reningsverk är det viktigt med årliga granskningar för att upptäcka problem som kan leda till miljöskador.   Fungerar inte reningen kan bland annat övergödningen öka i sjöar och hav vilket leder till att människor och djur drabbas. Bottendöd och syrebrist är redan ett stort problem för Östersjön. För att minska de negativa miljöeffekterna gäller det att utsläppen av näringsämnen minskar drastiskt. Detta gäller utsläpp av näringsämnen från alla länder runt om Östersjön.   Denna studie fokuserar på kväve och fosforrening från 5 st avloppsreningsverk, Henriksdals reningsverk (Stockholm), Ryaverket (Göteborg), Sjölunda reningsverk (Malmö), Kungssängsverket (Uppsala) och Duvbackens reningsverk (Gävle). Information om dessas verksamheter har erhållits genom interjuver och verkens egna rapporter.   Reningsverken använder olika tekniska lösningar, och samtliga reningsverk uppfyller dagens krav på rening. Största skillnad är reningsgraden för kväve. Samtliga reningsverk har en historia av förändringar av tekniska lösningar för att förbättra reningen. Att rena avloppsvattnet från hushåll och industrier kostar mycket pengar för reningsverken, därför är det hela tiden en utmaning för reningsverken att rena vattnet på bästa möjliga sätt utan att det kostar för mycket.   Man kan förvänta sig att reningskraven skärps och alla reningsverk bör fortsätta att utvecklas för att öka effektiviteten. Nuvarande krav på reningsgrad är så utformad att de är anpassad till recipientens känslighet. Om EU:s ide om samma reningsgrad över hela landet omvandlas till krav, kommer Duvbacken behöva förbättra kvävereningen vid reningsverket avsevärt