Healthy, natural pastures is very valuable for biodiversity in the form of both plants and animals. An efficient use of pastures helps to preserve biodiversity, but grazing animals needs to be de-wormed to keep them healthy and to prevent harmful parasites spread on the pasture. The awareness about the environmental impact of the frequent use of deworming agents is low among the public. Some people are unaware that the absorption in horses of anthelmintics is incomplete, which make the circumstances about enviromental effect important to investigate further. The scientific evidence in this area is limited and more studies and trials are needed to deepen the knowledge about the effects of anthelmintics in the environment. Our report includes a compilation of studies conducted on anthelmintics and equine parasites, as well as an experiment which was conducted at the University of Halmstad biogaslaboratory April 2014. Anthelmintics have been shown to have negative impact on the manure ecosystem and especially against manure living fauna. Deworming routines has changed over the years as the equine industry has developed. Nevertheless, there’s still a lack of concrete approach to deworming.

Biogas is an expanding sector within the broad field of agriculture and animal production. Small-scale biogas offers local combined power and heating production and the substrate is transformed into high-quality biological fertilizer. This bachelor thesis focuses on a pig farm in south-western Sweden, where biogas is produced from pig manure, evaluates and suggests ways of optimizing the process and investigates whether investing in an upgrading plant would be a feasible and more cost-efficient option. The results show that the biogas plant is working well, although the production differs from the original plans. This shows in turn that planning and examining the basic conditions before making the investment is of great importance, as well as monitoring and keeping detailed statistics of the running process. Logistical factors make optimizing the process through additional substrates difficult. The thesis shows that investing in a Biosling upgrading plant would be a profitable option, supposing that the upgraded gas is sold via the natural gas infrastructure. Furthermore, many farmers are interested in producing their own fuel for tractors and other machines, which offers more future alternatives for the upgraded biogas. However, biogas producers in Sweden today are not offered any particular subsidies, which makes it especially hard for small-scale producers.

Eutrophication is one of the most serious environmental problems in the Baltic Sea due to factors such as nutrient discharges from different sources and long residence time. Eutrophication gives rise to increased primary production, often followed by oxygen depletion and disruption of important ecosystems. An action plan has been created by the Helsinki Commission (HELCOM) in order to achieve good ecological status of the Baltic Sea in the year of 2021. According to the action plan, 21 000 tonnes of nitrogen and 290 tonnes of phosphorus shall be decreased of the annual discharge from Sweden. The aim of methods within ecological engineering is to solve environmental problems, and the applications ranging from the harvesting of existing ecosystems to the construction of new ecosystems. This study evaluates if harvest of algae, reed, and mussels can help meeting the goals of the action plan considerably, in accordance with areas and biomass amounts that need to be harvested, and to assess the efficiency of the three biomasses with regards to nutrient reduction. The potential of harvested biomasses as substrates in biogas production and as fertilizers is investigated, and how much fossil CO2 that can be saved from being released to the atmosphere if net energy benefits, calculated from energy budgets in the biogas process, replaces fossil fuels. Life cycle inventories which extend from the harvest (i.e. from the Baltic coast of Sweden) to the production of biogas have been made in order to investigate the biogas potential of algal, reed, and mussel biomass. Suitability of the three biomasses as fertilizers has been assessed through comparison between nutrient sufficiency of crops and nutrient contents of the three biomasses (i.e. based on quotients of nitrogen). The quantity of biomass in the areas that can be harvested can help meeting the goals of the action plan drawn up by HELCOM, and mussels show to be most efficient with regards to nutrient reduction efficiency. Reed has the highest net energy benefit followed by algae, and both biomasses show potential of further investigation as substrates in the biogas production process. Mussels have low net energy benefit and thus are not a suitable substrate in biogas production. The three biomasses are suitable as fertilizers with respect to contents of nitrogen but the content of phosphorus occurs under the sufficiency levels for the crops (i.e. peas, grain, and sugar beets). For algae and reed, the potassium contents occur above the sufficiency level for peas and grain but under the level for sugar beets, mussels contain lower levels of potassium than the need of the investigated crops. / Eutrofiering är ett av de största miljöhoten i Östersjön och orsakas av faktorer som utsläpp av näringsämnen från olika källor samt lång uppehållstid. Eutrofiering ger upphov till ökad primärproduktion där syrebrist och störning av viktiga ekosystem är vanliga påföljder. En aktionsplan har utformats av HELCOM som fastställer att Sverige ska reducera 21 000 ton kväve och 290 ton fosfor av de årliga utsläppen till Östersjön, med syftet att uppnå god ekologisk status år 2021. Metoder inom ecological engineering innefattar sund skörd av existerande ekosystem med syftet att lösa miljöproblem. I den här studien undersöks om skörd av alger, vass och musslor kan hjälpa till att möta miljömålen med påtaglig effekt, samt mängder och ytor som måste skördas av de tre biomassorna. Effektiviteten med avseende på näringsreducering hos de tre biomassorna jämförs. Potentialen för användning av de skördade biomassorna som substrat i biogasproduktion samt som gödningsmedel undersöks, samt hur mycket CO2 som kan besparas att släppas ut till atmosfären om nettoenergi från energibudgetar i biogasprocessen ersätter fossila bränslen. Energibudgetar som sträcker sig från skörd till biogasproduktion har utformats samt näringsinnehåll av de tre biomassorna jämfördes med näringsbehov hos vissa grödor för att ta reda på biomassornas eventuella potential som gödningsmedel. Beträffande biomassor och areor som finns att skörda visade det sig att metoderna kan möta miljömålen utformade av HELCOM. Musslor visade sig vara den mest effektiva biomassan att skörda med avseende på näringsämnesreducering. Vass erhöll högst nettoenergiutbyte (i.e. baserat på energibudgetarna) följt av alger, därmed finns potential för vidare undersökning av de båda biomassorna som substrat i biogasprocesser. Nettoenergiutbytet i biogasprocessen hos musslor var lågt vilket visar att musslorna inte är lämpligt som substrat. De tre biomassorna uppvisar lämplighet som gödningsmedel med avseende på kväveinnehåll men innehållet av fosfor ligger under näringsbehovet hos de grödor som undersöktes. Alger och vass uppfyller kaliumbehovet hos ärter och spannmål, men inte hos sockerbetor. Musslornas kaliuminnehåll är lägre än näringsbehovet hos samtliga grödor.

The growing need for climate mitigation solutions has contributed so thatbiochar has gained significant interest. Primary for its ability as a carbon sinkbut there is also a growing interest due to several other aspects within industriese.g. substitution effects, increased resource efficiency, an enabler forindustrial symbiosis, and its beneficial properties when put in soil that can increasegrowth. Previous studies of biochar have been dominant within the environmentalperspective of biochar, analyzing detailed characteristics of its propertiesand carbon sink potential. Some studies have a holistic perspective reflectingon countries specific energy mix and the different benefits of producingbiochar. However, previous studies are far too few to determine the value-chainof biochar. Hence previous studies have knowledge gaps within the holistic lifecycle approach from a provider or customer perspective of biochar, not reflectingon demand for quality requirements in different utilization areas and markets.The need for validation of the environmental and the economic performanceof biochar has to be established, and the economic perspective of biochar hasmajor knowledge gaps since previous studies are scarce. The study aims to establish the value-chain of biochar by evaluating theenvironmental, economic, and social perspectives through life cycle thinking.The core of the study is to distinguish value, which first has to reflect thebiochar quality requirements from providers and customers, captured throughinterviews and literature research. The quality requirements enable a goal forproducing biochar and determine what processes and biomass are needed fordifferent markets. This is evaluated through a case development which considersthe different quality requirements. Life cycle assessment (LCA) with acradle-to-grave perspective and life cycle costing (LCC) with a cradle-to-gatewere then used to distinguish biochar´s environmental and economic performance. The interviews and researched literature resulted in three cases being developed,biochar application in electric arc furnaces in steel production, agriculturalapplication, and commercial application through biochar-macadam. Thesteel industry has higher quality requirements due to the need to have a similarcomposition as fossil coal, resulting in biochar produced from wood being theonly option. The limitations for agricultural application are more related tothe allowed amount of phosphorus per ha and thus all the researched biocharapplies to different degrees. Biochar application in biochar-macadam is similarto agricultural application, however limited due to the EBC certification notallowing the production of biochar from sludge. The generated results from the LCA show that the climate performance isvastly different depending on what biomass was utilized and the different markets.Biochar produced from park and garden, and wood results in a higher climateperformance due to the higher carbon sequestration compared to biocharproduced from straw and sludge, however depending on how the biocharis utilized, the performance varies. During biochar application in electric arcfurnaces, the majority of the produced carbon sink is destroyed which resultsin worse climate performance, instead the majority of the reduced emissionscomes from the substituted fossil coal. Compared to biochar application inagricultural and biochar-macadam where the carbon sink stays intact, steel applicationstill has worse climate performance even when including substitution.Biochar-macadam production results in more emissions compared to agriculturalapplication due to the need to mix biochar with stones and compost,thus biochar in agriculture is the best option from a climate perspective. The economic aspects are generated through the conducted LCC which resulted inbiochar produced from park and garden, and sludge being more beneficial dueto the absence of acquisition costs. Production of biochar from wood provesto be difficult when considering a larger time frame, with the market for steelproduction not returning the investment. Biochar produced from straw hasa positive return on investment when considering the agriculture market, butnot for the production of biochar-macadam. The results show that the marketof biochar is very uncertain due to being considered immature and a futuremarket. The major uncertainty is connected with the immaturity of the market.The quality requirements are not reflected in the market pricing which isone of the major reasons for biochar utilization in the steel industry not beingeconomically beneficial. The value chain of biochar is a combination of many different economic,environmental, and social values. The conducted LCA shows that there areclimate benefits due to carbon sequestration, and a possibility to replace fossilreferences. Other than biochar there are also by-products such as heat and oilwhich can be utilized, improving the climate performance further. The multipleproducts also have economic benefits due to the potential of creating multipleproducts. The carbon sink can be sold as carbon credits, and the heat can beutilized in district heating. For providers, the creation of biochar is an enablerto reduce environmental impact, utilize products already within the system,and create value from waste. The structure of biochar generates a lot of valuefor customers. The porosity enables water storing capabilities which increasesthe efficiency of watering. This reduced the amount needed for soil applications,while also securing the harvest from drought and flooding. Even though thevalue chain of biochar shows that there is a lot of potential, it is still uncertainhow it will be integrated into society, and how the market will be shaped in theyears to come.

Carbon dioxide is released by natural and anthropogenic processes, such as the production and combustion of fossil fuels. Production of biogas also generates carbon dioxide, but of biogenic origin. The global, yearly emissions of greenhouse gases are regularly increasing, although agreements such as the Paris Agreement is signed by parties globally. Sweden has the goal to reach net-zero emissions by 2045, and thereafter to only obtain negative emission levels. To reach these goals the biogenic version of Carbon Capture and Storage (CCS) called Bioenergy with Carbon Capture and Storage (BECCS) is considered to be an essential strategy. Using carbon dioxide, through Carbon Capture and Utilization (CCU), in for example products, can complement BECCS since the strategy can increase the value of carbon dioxide. These strategies make it possible to reduce the climate impact of biogas production.  This master thesis aimed to chart different techniques in CCS and CCU to examine how they can be used to utilize or store carbon dioxide from biogas plants. What technical demands different solutions create was explored. The different techniques were assessed through a multi criteria analysis by a technological, environmental, marketable and economical standpoint to investigate which ones were the most suitable for a specific, studied case – Tekniska verken’s biogas plant. One suitable technique within CCU was analyzed through a screening of actors in the region. An environmental assessment of one technique in CCS and one in CCU were compared with the reference case Business as usual, to explore how a simulated biogas plant’s climate impact can change through the implementation of CCS and CCU.  The charting of literature gave findings of 42 different techniques, which were sifted down to 7; algae farming for wastewater treatment, BECCS in saltwater aquifers, carbon dioxide curing of concrete, bulk solutions, production of methanol, production of methane through Power To Gas and crop yield boosting in greenhouses. The multi criteria analysis pointed out carbon dioxide curing of concrete and BECCS in saltwater aquifers as suitable solutions for the studied case. The implementation of these techniques requires a liquefaction plant, infrastructure for transportation as well as business partners.  A life cycle assessment of the studied cases climate impact was given through modelling and simulation of a model plant of the studied case, with the functional unit 1 Nm3 biomethane. The reference case Business as usual had a climate impact of 0,38 kg CO2 eq, which corresponds to approximately one eighth of the climate impact of fossil fuels such as gasoline or diesel. By storing the carbon dioxide through BECCS in saltwater aquifers the climate impact decreased to - 0,42 kg CO2 eq. By utilizing the carbon dioxide through curing of concrete the biomethane’s climate impact decreased to -0,72 kg CO2 eq. The results thereby evince that Swedish biogas producers can improve their climate performance through CCS and CCU. / Koldioxid släpps ut av såväl naturliga som antropogena processer, exempelvis vid produktion och förbränning av fossila bränslen. Även vid biogasproduktion uppkommer koldioxid, men av biogent ursprung. Årliga globala utsläpp av växthusgaser ökar regelbundet, trots överenskommelser som Parisavtalet som syftar till att begränsa klimatförändringarna. Sverige ska nå nettonollutsläpp senast 2045 och därefter ha negativa utsläppsnivåer. För att uppnå detta mål anses en biogen version av Carbon Capture and Storage (CCS), det vill säga avskiljning och lagring av koldioxid, kallad Bioenergy with Carbon Capture and Storage (BECCS) vara en essentiell strategi. Tillvaratagande av koldioxid, genom Carbon Capture and Utilization (CCU), kan ge ett bra komplement till BECCS eftersom det nyttiggör koldioxid i produkter och kan öka värdet av koldioxid. Tekniker inom CCS och CCU möjliggör minskad klimatpåverkan inom biogasproduktion.  Detta examensarbete syftade till att kartlägga olika alternativ inom teknikerna CCS och CCU för att undersöka hur dessa kan användas för att nyttiggöra eller lagra koldioxid från biogasanläggningar, samt att undersöka vilka tekniska krav som ges av lösningarna. Utifrån en multikriterieanalys bedömdes vilka lösningar som var tekniskt, miljömässigt, marknadsmässigt och ekonomiskt motiverade för tillvaratagande av koldioxid. Bedömningen genomfördes genom att studera specifikt fall som var Tekniska verken i Linköpings biogasanläggning. Den lösning som valdes ut som lämplig inom CCU analyserades ur ett marknadsmässigt perspektiv genom en översiktlig kartläggning av aktörer i regionen. Därefter studerades klimatpåverkan från en förenklad modell av Tekniska verkens biogasanläggning för att undersöka hur denna förändras vid implementering av en lämplig lösning inom CCS respektive CCU.  Genom en screening av lösningsförslag identifierades 42 lösningsförslag inom CCS och CCU som sållades ner till sju stycken; algodling vid vattenrening, BECCS i saltvattenakviferer, betong härdad av koldioxid, bulklösning, metanoltillverkning, tillverkning av metan genom Power To Gas samt växthusodling. Multikriterieanalysen visade att koldioxidhärdad betong inom CCU och BECCS i saltvattenakviferer inom CCS var lämpliga lösningar för det studerade fallet. För implementering av förslagen krävdes bland annat en förvätskningsanläggning, infrastruktur för transport och samarbetspartners.  De studerade scenariernas klimatmässiga livscykel erhölls genom modellering och simulering av en modellanläggning av det studerade fallets biogasanläggning i programvaran SimaPro med användning av den funktionella enheten 1 Nm3 fordonsgas. Resultatet visade att fordonsgasen i referensfallet har en klimatpåverkan på 0,38 kg koldioxidekvivalenter. Fordonsgasens klimatpåverkan var cirka en åttondel av fossila bränslen såsom bensin och diesels klimatpåverkan. Vid lagring av koldioxid genom BECCS i saltvattenakviferer förändrades klimatpåverkan till - 0,42 kg koldioxidekvivalenter. När koldioxid användes till härdning av betong förändrades fordonsgasens klimatpåverkan till -0,72 kg koldioxidekvivalenter. Detta innebär att svenska producenter av biogas kan förbättra sin klimatpåverkan genom såväl lösningar inom CCS som CCU.

Energy from solar photovoltaic (PV) are generated as direct current (DC) and almost all of today’s electrical loads in residential buildings, household appliances and HVAC system (Heating Ventilation and Air-conditioning) are operated on DC. For a conventional alternating current (AC) distribution system this requires the need for multiple conversion steps before the final user-stage. By switching the distribution system to DC, conversion steps between AC to DC can be avoided and, in that way, losses are reduced. Including a battery storage–the system’s losses can be reduced further and the generated PV energy is even better utilised. This thesis investigates and quantifies the energy savings when using a direct current distribution topology in a residential building together with distributed energy generation from solar photovoltaic and a battery storage. Measured load and PV generation data for a single-family house situated in Borås, Sweden is used as a case study for the analysis. Detailed and dynamic models–based on laboratory measurements of the power electronic converters and the battery–are also used to more accurately reflect the system’s dynamic performance. In this study a dynamic representation of the battery’s losses is presented which is based on laboratory measurements of the resistance and current dependency for a single lithium-ion cell based on Lithium iron phosphate (LFP). A comparative study is made with two others, commonly used, loss representations and evaluated with regards to the complete system’s performance, using the PV and load data from the single-family house. Results show that a detailed battery representation is important for a correct loss prediction when modelling the interaction between loads, PV and the battery. Four DC system topologies are also modelled and compared to an equivalent AC topology using the experimental findings from the power electronic converters and the battery measurements. Results from the quasi-dynamic modelling show that the annual energy savings potential from the suggested DC topologies ranges between 1.9–5.6%. The DC topologies also increase the PV utilisation by up to 10 percentage points, by reducing the associated losses from the inverter and the battery conversion. Results also show that the grid-tied converter is the main loss contributor and when a constant grid-tied efficiency is used, the energy savings are overestimated.