Sverige har som mål att bli helt fossilfri till år 2045. Energymyndigheten har därför tagit fram ett förslag till Vätgasstrategi för att ställa om vätgasproduktionen till att vara helt fossilfri till 2045. Idag används ca 180 000 ton vätgas, vilket motsvarar ett energiinnehåll på ca 6 TWh. Termo-kemisk omvandling av fossila bränslen står för 67% av Sveriges vätgasproduktion, medan 30% är biprodukter från industriella processer och 3% produceras med elektrolysörer. Att ersätta all fossil vätgas med elektrolysör-baserad vätgas innebär en elförbrukning motsvarande 60-126 TWh/år, vilket är en ökning på 40-80% jämfört med de 159 TWh el producerade i Sverige 2020. Energimyndigheten bedömer att vätgas har en viktig roll i att lyckas göra Sverige fossilfritt, delvis genom att den ska kunna fungera som energibärare eller energilagring för att jämna ut variationer i produktion hos förnybara energikällor. Av den anledningen kommer antagligen behovet av vätgas öka, och därmed även energibehovet för att producera vätgas öka ännu mer än 60-126 TWh/år om den fossila vätgasen ska bli ersatt med endast elektrolysör-baserad vätgas. Med tanke på begränsningar i expansion av förnybar elproduktion, kommer behovet av vätgas antagligen inte kunna täckas av endast elektrolysör-baserad vätgas. Därför bör möjligheterna för att även satsa på bio-vätgas, där vätgas produceras av antingen bakterier eller genom refinery av biobaserade råvaror, undersökas. Detta examensarbete ska undersöka möjligheter för vätgasproduktion i Sverige och jämföra olika produktionteknikers förutsättningar. En hypotes är att en hållbar strategi är att kombinera elektrolysör-baserad vätgas med bio-vätgas för att få en diversifierad produktion. Att ha olika produktionsmetoder som komplementerar varandra ger en mer stabil och säker produktion, eftersom de kommer påverkas olika av förändringar i produktionsförutsättningar i samhället. Detta arbete söker svara på följande frågor: Vilka tekniker finns tillgängliga för industriell/kommersiell produktion, var borde R&D riktas för de tekniker som inte är redo för kommersiell produktion, vilket Carbon Footprint (CF) har de olika teknikerna, en uppskattad produktionskostnad för de olika teknikerna, och vilken tillgänglighet för de olika råvarorna finns i Sverige? / Sweden has a goal to be completely fossil-free by 2045. Accordingly, the government has published a suggested Hydrogen Strategy to have made all hydrogen production in Sweden fossil-free by 2045. The Swedish hydrogen use is 180,000 ton, equaling an energy content of 6 TWh/year. Thermo-chemical conversion of fossil fuels accounts for 67% of Swedens hydrogen production, while 30% is byproducts from industry and 3% is electrolysis production. To replace all fossil hydrogen with electrolysis production, would give an increase of electrical demand with 60-126 TWh/year, or 40-80% increase compared to the 159 TWh electricity produced during 2020 in Sweden. Furtherly, the Ministry of Energy deem hydrogen to be key in the general transformation of Sweden to become fossil-free, with one reason being that hydrogen can be used as energy carrier to even out the variations in electricity production that renewable energy has. The need of hydrogen will therefore most likely increase until 2045, thus the electric energy demand for hydrogen production will increase as well, if it would be replaced solely with production using electrolysis. Given the constraints to the capacity of electricity production from renewable sources alone in Sweden, the electricity demand for hydrogen cannot be met by the electricity production. Thus, the possible role of biohydrogen, where hydrogen is produced using biorefinery or microbial production, should be investigated. This master thesis project will investigate the feasibility of hydrogen production in Sweden and compare different options for hydrogen production. A hypothesis of the project is that the most sustainable strategy for hydrogen production in Sweden will be with a diversified portfolio of production designs. Both biohydrogen and electrolysis hydrogen from renewable energy will complement each other in the future. By doing so, the energy sector will be more sustainable and stable since the techniques do not react alike to change in production conditions. The report aims to answer: What techniques are available for industrial production, where should R&D be directed for techniques not ready for industry, what is the estimated carbon footprint (CF) of the industrially available techniques, what is the estimated production cost for each technique, what availability is there in Sweden for the feedstock needed for each technique?

<p>The development of reliable, robust and low-cost sensor devices is growing in importance and an ongoing challenge. From environmental monitoring and household safety to food and biopharmaceutical industries, the necessity for specific analyte detection is crucial. Over the years researchers have come up with myriad materials that can be used for efficient sensing devices. The materials employed are governed by application and performance criteria as well as the sensing mechanism, which might be based on physical or chemical principles. In this thesis, two different types of electrochemical sensor technologies were examined with special attention paid to the application of the devices, the materials used, and their feasibility for scalable manufacturing.</p> <p>In the first study, binary mixtures of conducting and semiconducting nanomaterials were explored as promising candidates for the manufacturing of low-cost ethylene sensor on flexible substrates. Ethylene (C2H4) is a small plant hormone which has been shown to affect the growth and senescence of flowers, leaves and fruits. Currently available devices have demonstrated high ethylene sensitivities with great potential for technology size reduction; however, some are not practical for use outside of the laboratory, lack portability, or require more research to demonstrate their reproducibility and stability in different environments, as well as selectivity to C2H4 in large-scale applications. Conductometric gas sensors based on a combination of carbon nanotubes (CNTs) and exfoliated molybdenum disulfide (MoS2) coated with molecular receptors is demonstrated for the selective detection of ethylene, including details on materials preparation, manufacturing, and characterization. Mixtures of CNTs and exfoliated MoS2 were deposited onto screen-printed interdigitated electrodes on plastic substrates, with optimization for scalable and continuous manufacturing by roll-to-roll methods. C2H4 detection levels of 0.1 ppm were readily achieved with responses on the second timescale.</p> <p>The second sensor technology shows how thin-film potentiometric electrodes based on ion-selective membranes can be designed to tolerate sterilizing radiation while providing excellent performance and signal stability. This sensor's development was motivated by the expanding need for single-use bioreactor systems in the biopharmaceutical industry, which require strict control over cell culture conditions for several weeks or more. Until recently, critical analysis has been conducted mostly by offline or “at-line” sampling of aliquots withdrawn from the sterile bioreactor. The latter is inefficient and can increase the risk of contamination. Inspired by the challenges related to cost, integration and performance following irradiation a potentiometric pH electrode was developed, intended for single-use applications. It was shown to be radiation-tolerant while providing reliable data comparable to a commercial pH meter over a period of three months. The electrodes exhibited quasi-linear signal drifts of +0.28 mV/day or 0.005 pH units/day. Thin-film γ-irradiated electrodes could provide accurate pH readings in sterilized culture media using a single-point calibration, within 0.07 pH units of a commercial meter with glass electrode and daily calibration. Furthermore, to advance the development of market-ready sensors past the conceptual stage, a few automated processes for scalable membrane deposition were investigated.</p>

No description available.