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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

Contribution to climate change of a proposed horse manurecomposting system

Nordlund, Sara January 2017 (has links)
Hästar producerar gödsel som är en   blandning av avföring, urin och det strömaterial som hästarna står på.   Hippologum är en ridanläggning i Umeå (Västerbotten, Sverige) som producerar   20-25 ton gödsel per vecka och när denna rapport skrevs hade anläggningen   ingenstans att lagra gödseln. Detta var våren 2016. Målet med denna studie var att   undersöka ett möjligt förvaltning- och komposteringssystem för hästgödsel   mellan Hippologum och deponi- och avfallscentret Dåva DAC (som också är   beläget i Västerbotten, Sverige) och var systemets största klimatpåverkan   finns. En liten marknads-undersökning baserad på personintervjuer och ett   kort kapitel om lagaspekter finns också med i rapporten. Enligt den screening livscykelanalys som genomfördes   inom ramen för denna C-uppsats är den största klimatförändrande effekten för   23 ton hästgödsel från Hippologum till Dåva DAC odlingen av fodret.   Marknadsundersökningen som utfördes kan inte direkt säga att det finns en   marknad i Umeå kommun för komposterad hästgödsel. Gällande den lagliga biten   så kan sägas att EU har mycket att säga till om gällande animaliska   biprodukter och att den lagliga aspekten tyckts vara väl utvecklad. / Horses   produce feces and urine and this mixed with a bedding material such as   sawdust or cutterdust gives you horse manure. Hippologum is an equestrian   facility in Umeå (county of Västerbotten, Sweden) which produces 20-25 tons   of manure per week and when this report was written the facility had some   trouble to get rid off the manure. This was in Spring 2016. The aim of this study is to look into the possible soil   improver production as a management strategy for the horse manure produced at   Hippologum and the report also looks   into which part of this proposed system which has the greatest climate   impact. The landfill- and waste   center Dåva DAC (also located in the county of Västerbotten, Sweden) is the   assumed receiver of the manure, and this is were the manure would be refined   (composted). Research based on personal interviews about the manure market in   Umeå municipality as well as a short chapter about legal aspects of manure   are also included in the report. According to the screening LCA conducted during this   thesis work the greatest impact for 23 tons of horse manure from Hippologum   to Dåva DAC is the cultivation of the   fodder. The report cannot conclude if there is a manure market in Umeå   municipality. Concerning the legal aspects it can be said that the European   Union has well developed legislation concerning animal by-products and   regulates many aspects of handling and treating of horse manure. / <p>2019-01-08</p>
2

Applikation av småskalig värme- och elproduktion : Simulering av anläggningsdrift samt nyttjande av hästgödsel för lokal biogasproduktion vid Sundbyholms travbana

Brandt, Pernilla, Löving, Therese January 2018 (has links)
The global community is facing great challenges as the energy system is transforming towards more reliable, effective, clean and renewable production. Small-scale and micro networks will play an important role in this changeover. Its advantages over today’s large conventional energy systems are their reliability and stability. In small-scale and micro networks, there is usually a variety of production units such as photovoltaic, wind power and micro-combined heat and power (micro-CHP). In this study, a small-scale network with an application of two different types of biogas fueled micro-CHPs is analyzed. The units are a micro gas engine (MGM) and a micro gas turbine (MGT). The application of micro-CHP is validated using a reference facility connected to a small-scale district heating network. The reference facility is a heat production plant at a horse race track outside Eskilstuna, Sweden consisting of an oil boiler, a pellet boiler and a heat storage tank. The potential in replacing the oil boiler with renewable micro-CHP is investigated. A simulation model is built in the software GAMS, using Mixed Integer Linear Programming (MILP) and the solver CPLEX, and the model is simulated using the heat demand from the horse race track. Results from the model validation shows that it is possible for both the MGM or the MGT together with the pellet boiler and the heat storage tank to fulfill the heat demand of the facility. The horse race track handles 4 000 m3 of horse manure annually, which is transported 124 km to a compost treatment facility. Therefore, a general analysis of biogas production from horse manure is conducted in order to investigate the possibilities for better horse manure treatment on site. A calculation for a biogas reactor with a capacity for the maximum biogas requirement of the micro-CHP is implemented. Horse manure is suggested to be co-digested with food waste, in order to provide a higher biogas exchange. The result of a Life Cycle Cost (LCC) analysis indicates difficulties in justifying an investment of a micro-CHP together with a biogas plant at current prices for heat and electricity. The results show that the payback period for the MGM is 7 years which is 2 years shorter than its lifetime and the MGT payback period is 12 year which also is it lifetime. The MGM shows the largest investment potential since it has an investment cost approximately 860 kSEK lower than for the MGT. The MGM also has a slightly higher electrical efficiency which results in higher revenues from produced electricity. The chosen MGM in this study is slightly smaller than the MGT, resulting in a lower biogas demand and a lower investment cost for a biogas plant. A sensitivity analysis shows great impact of the electricity price on the payback period for both types of micro-CHP. The results show that with an electricity price of 280 SEK/MWh, both the MGM and the MGT repays within their lifetime. But since MGM has a higher net present value at all electric prices, is the MGM considered to be a more economical feasible investment. What the authors think should be highlighted is also the environmental benefits of more efficient treatment of horse manure at the horse race track together with the possibility of local production of fuel resulting in reduced CO2 emissions by 47 tons/year.
3

Anaerobic digestion of horse manure : renewable energy and plant nutrients in a systems perspective

Hadin, Åsa January 2016 (has links)
In horse keeping horse manure is produced, which can be utilized as a fertilizer or considered a waste. Horse manure constitutes a resource in terms of both plant nutrients and energy. In addition energy policies and objectives aim at replacing fossil fuels with renewable energy sources. The interest to improve resource recovery of horse manure increases due various incentives for renewable vehicle fuels, legal requirements on management of manure, and environmental impact from current horse manure management. This thesis aims at describing horse manure management in a life cycle perspective. This is made by (1) identifying factors in horse keeping affect­ing the possibility to use horse manure as a biogas feedstock and to recycle plant nutrients, (2) analysing factors in anaerobic digestion with influence on methane potential and biofertilizer nutrient content and (3) comparing the environmental impact from different horse manure treatment methods. Literature reviews, systematic combining, and simulations have been used as research methods. The results show that horse keeping activities such as feeding, indoor keeping, outdoor keeping and manure storage affect the amount and charac­teristics of horse manure and thereby also the possibilities for anaerobic digestion horse manure. Transport affects the collected amount and spread­ing affects loss of nutrients and nutrient recycling. Simulation results in­dicate the highest methane yield and energy balance from paper bedding, while straw and peat gave a higher nutrient content of the biofertilizer. The highest methane yield was achieved with a low rate of bedding, which in the cases of woodchips and paper is also preferable for plant nutrient recycling. Still, results indicate the best energy balance from anaerobic digestion with a high ratio of bedding. The environmental impact assessment indicates a reduction in global warming potential for anaerobic digestion compared to incineration or composting. / Vid hästhållning alstras hästgödsel som kan användas som växtnäring eller anses vara ett avfall. Hästgödsel utgör både en växtnäringsresurs och en energi resurs. Dessutom styr uppsatta energimål mot att förnybar energi ska ersätta fossila bränslen. Intresset för att öka resursutnyttjandet av hästgödsel ökar på grund av olika incitament för förnybara drivmedel, lagstiftning om gödselhantering och miljöpåverkan från dagens hantering av hästgödsel. I den här avhandlingen beskrivs hästgödselhantering i ett livscykel­perspektiv genom att (1) identifiera olika faktorer vid hästhållningen som påverkar möjligheten att utvinna biogas ur hästgödsel och återföra näringen till jordbruksmark, (2) analysera faktorer i biogasprocessen som påverkar den specifika metanmängden och innehållet av växtnäring i gödseln och (3) jämföra olika gödselhanteringsmetoders miljöpåverkan. Metoderna i avhan­dlingen har varit litteraturstudier, systematisk kombination av teori och em­piri samt simulering. Resultaten visar att utfodringen, om och hur hästarna hålls inomhus och utomhus och hur hästgödsel lagras påverkar mängden hästgödsel och dess egenskaper, och därmed också hur den fungerar som ett biogassubstrat. Trans­porterna har betydelse för hur mycket gödsel som kan samlas in och spridas, medan gödselspridningen påverkar näringsförluster och närings återföring. Resultaten från simuleringarna indikerar högst metanutbyte och bäst energi­balans från papper som strömaterial, medan halm och torv gav högre växt­näringsinnehåll i biogödseln. De högsta resultaten på specifik metanmängd nåddes med låg andel strö, vilket också var positivt för växtnäringsinnehållet vid scenarierna med spån och papper. Samtidigt indikerar resultaten att en hög andel strömaterial ger den bästa energibalansen. Miljöpåverkansbedöm­ningen indikerar att potentialen för klimatpåverkan minskar om hästgödsel behandlas i en biogasprocess jämfört med förbränning eller kompostering.

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