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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Ackumuleringspotential av PHA  från restströmmar inom pappersbruk : En studie om PHA från Gruvöns, Bäckhammars och Skoghalls bruk

Berglund, Alfred January 2018 (has links)
Plastic is one of the most universal materials used today. With a good future view, with new implementations and applications, it makes a lot of time to look at the production and management of the plastic materials. Plastic materials that have been used in our daily lives cause serious environmental problems. Millions of tons of these non-degradable plastics accumulate in the environment every year. The basic problem is that plastic is not naturally occurring in nature since containers are usually made of polyethylene terephthalate. This means that microorganisms do not have the ability to break it down to the current cycle. It takes hundreds of years for plastic containers to break down, not biologically but only degenerate into smaller and smaller pieces. Plastic breaks down into smaller pieces that become smaller and smaller until we cannot see them with the naked eye, mainly through heat and UV light. Although we cannot see them, they are still present and become part of our nature forever. Bioplastics is the plastic industry's tool to try to reduce these little pieces of our nature that will remain forever so that they do not grow more. With today's plastic packaging, which is said to be bioplastic, additives of, for example, cobalt and nickel, which are said to make it easier for the polymers to break down over time, have proven to be not as effective as they thought. Polyhydroxyalkanoates (PHA) are polymers which are biodegradable as based on their composition have different physical properties. PHA is a family of natural polyesters synthesized from various microorganisms discovered in 1926. Once discovered, interest has been high due to their biodegradability and its production from renewable resources. The polymers can be described generally as production from microorganisms under controlled conditions, where they occur naturally in organisms that classify them as biopolymers. Some of these polymers are already industrially produced on a large scale today. However, many still apply to several new areas but must be optimized for commercial production. Biopolymers can be classified into four groups. Amino-acid-based polysaccharides from bacteria, polyphenol-based and polyesters that this study is looking at. Depending on what the microorganisms possess for character traits and what they give to the substrate to break down, it gives polyesters with different physical properties. This case is a short-chain polyester to be formed, more specifically P3HB which is a three-carbon PHB polyester in its polymer which can be up to 5-7 units long. To avoid ongoing problems, a solution is needed. A solution that has received much attention to reduce plastic residues in nature is the use of biodegradable plastics and among them polyhydroxyalkanoates. Polyhydroxyalkanoates (PHAs) are common intracellular compounds found in bacteria, archaea and in few eukaryotes such as yeast and fungi. PHA acts as an energy storage polymer that is produced in some microorganisms when the carbon source is abundant and other nutrients such as nitrogen, phosphorus, oxygen or sulfur are limited. These polymers accumulate intracellularly up to 90% of the dry weight of the cell under nutritional conditions and act as energy saving materials. It has resembled mechanical properties like the traditional oil-based plastic such as polypropylene or polyethylene that can be formed with other synthetic polymers. PHA plastics possess many more applications, in agriculture, packaging and in the medical industry. It is biodegradable and also immunologically compatible. What the PHAs plaster can cause is an ultimate decomposition from a non-fossil source, which is exactly why it is very attractive. The purpose of this study was that from a hypothesis see within a limited time frame of ten hours of bio sludge from Gruvön, Skoghall and Bäckhammar's use could accumulate PHA with the aid of added readily degradable substrate. The process of the study will be a small part of a current research project together with Paper Province, Promiko, Pöyry and RISE. The aim of their study is to use residues from the forest industry to make hydrogen as well as bioplastics. This study will help to look at a subprocess of their cascading process. The aim of the study is to be able to measure the amount of PHA that could accumulate and rank the potential of the different uses. Using chemical analysis methods and extractions, it will provide opportunities to measure the accumulation of PHA in the various bacterial cultures of biomass from the use. The methods involve soxhlet extraction to successfully extract PHA from the bacteria. Dosage of substrate is sodium acetate piped from egg-diluted solution at 600 mg per dosage. In order for the dosage to be added at the right time, DO and the pH of the reactors were measured and logged throughout the course. FT-IR is used to view the course of events during the experimental period, linked to known features that may indicate that PHA is present in the bio sludge. Nutrients like phosphorus and nitrogen are measured, along with SÄ, SS, TOC, several before and after the experiment to compile discussion of the results. The conclusion was based on the analysis methods that the bio sludge that yielded the best yield was from Gruvöns use. This also relates best to the hypothesis of celebration and starvation, the relationship to which the bio sludge is exposed. The mine has a slurry in its five-step process which causes the bio sludge to return from step five where there is a shortage of food for bacteria to step three where there is a lot of food to consume. The rankings of the different uses relate to the hypothesis that the use of mining was best and the worst was the use of Bäckhammar. Based on the analysis methods included in the study, it can be concluded that the bio sludge that yielded the best yield was Gruvöns use with 13.6% of PHA / VS from the soxhlet extraction, the practice was best matched to the hypothesis. The ranking of the different bio sludge of the use is based on the hypothesis that Skoghall's use was second best followed by Bäckhammar's use which was the worst in accumulating PHA in the bacterial culture.
2

Att gräva guld i textilindustrin : förutsättningar för att öka värdet på industriellt textilt restmaterial / Digging gold in the textile industry : conditions for increasing the value of industrial textile waste

Brevik, Anna, Bäärnhielm, Elin January 2021 (has links)
Idag förbränns tonvis med textil i Sverige som aldrig har blivit använd. Detta som en effekt av att dagens textilindustri är uppbyggd som en linjär modell där nya råvaror ständigt går in i systemet och avfall lämnar det. Krav ställs nu på nationell nivå i Sverige att textilindustrin måste ställa om och bli cirkulär som en del i att klara klimatmålen. Detta ställer stora krav på svenska företag att hantera det textila restmaterial som uppstår i deras processer på helt nya sätt. För att textilt restmaterial ska kunna bli råvara till en annan produkt behövs nya system och ibland branschöverskridande samarbeten där den enas avfall blir den andres råvara. Denna studie bidrar med insikter om de utmaningar som svenska företag står inför när textila restmaterial ska bli råvara samt hur möjligheter kan tas tillvara genom nätverkande och kunskapsutbyte. Med observationer, en enkät och intervjuer undersöktes textila produktutvecklings- och produktionsföretags behov och hinder för användning av textila restmaterial som råvara. I studien har också de behov av resurser och nätverk företagen har för att kunna öka användandet av textila restströmmar utforskats. Studien visar på att attityden till att samla in textila restströmmar bland producerande företag är positiv och att det finns goda möjligheter för ökad insamling av industriella textila restmaterial med en hög grad av spårbarhet. Den visar också att det för företag som vill använda restmaterial efterlyses möjligheter för effektiv insamling samt bearbetning eller förädling av materialen. Alla delar i värdekedjan behöver ses över och för att möta utmaningen och det finns ett behov av att tänka annorlunda och våga prova nya vägar och samarbeten. Resultatet av denna studie visar på att en plattform för enbart handel av textila restmaterial inte är tillräckligt, företagen behöver också kunna knyta nya kontakter, få se på goda exempel och samverka kring logistiken kring insamling för att uppnå effektivitet. / In today’s textile industry, tons of textiles are incinerated every year without being used once. This because the textile industry today is built like a linear system, in which raw materials enter the system and then leave it in the form of waste. Requirements are now set on a national level in Sweden that requires the textile industry to change its direction and become circular as a part of achieving the Sustainable Development Goals. This poses massive requirements on Swedish textile companies to handle their textile waste material in their processes in new ways. For textile waste material to become the raw material in a new product, new systems are necessary and sometimes cross-industry collaborations are needed. This study aims to contribute with knowledge about the challenges that Swedish textile companies face when textile waste materials are becoming the raw material in new products, and the opportunities to take advantage of through networking and knowledge sharing. With observations, a survey, and semi structured interviews the challenges and opportunities of Swedish textile product developing companies and textile production companies for collecting and using textile waste material was studied. The study also investigates the need for resources and expanded networks that the companies have, to increase the use of textile waste as a raw material. The study shows that the attitude among the production companies to sort and collect their textile waste is positive and that there are great opportunities for an increased collection of textile industrial waste material with a high level of traceability. The study also shows that for the companies that want to use textile waste material as a raw material in their products, new systems for effective collection and processes for refining the materials are asked for. To meet these requirements all parts of the value chain need to be reconsidered and new ways of thinking needs to be applied to try new collaborations and find new paths. The result of the study shows that a platform for just trading materials is not good enough, the companies are also in need of new contacts, inspiration, and solutions for efficient logistics in sorting, collecting, and distributing materials.

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