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  • 1.
    Bohman, Mattias
    et al.
    Grontmij AB.
    Berglund Odhner, Peter
    Grontmij AB.
    Schabbauer, Anna
    Grontmij AB.
    Karlsson, Niklas
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Mattsson, Marie
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Rundstedt, Johan
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Biogas i Halland: Förbehandling av substrat och simulering av biogasflöden2011Report (Other academic)
    Abstract [sv]

    Bioenergicentrum i Halland (BEH) är ett projekt som ligger inom ramen för EU:s strukturfondsprogram. Projektet genomförs i Region Hallands regi som är regionens välfärds- och utvecklingsorganisation. Arbetet som bedrivs inom BEH syftar speciellt till att driva utvecklingen mot en ökad produktion och användning av bioenergi till biogas och i förlängningen fordonsgas. Genom att satsa på att skapa förutsättningar för innovation, kunskapsutveckling och samverkan främjas tillväxt och hållbar utveckling.

    Vid naturbruksgymnasiet i Plönninge utanför Halmstad finns idag en biogasanläggning som beskickas med bl.a. nötgödsel och matavfall. Dessutom finns en mindre pilotanläggning som är tänkt att fungera som en del av test- och verifieringsanläggning som BEH vill bygga upp i Plönninge. Som ett led i att utveckla dessa anläggningar och kunna erbjuda möjligheten till kunskapsinsamling genomfördes projektet som beskrivs i denna rapport. Uppdraget var att genomföra försöksrötningar på labb, använda resultaten för att skapa en modell som sedan kan nyttjas som ett verktyg i det inledande arbetet med att investera i en biogasanläggning som beskickas med lantbruksbaserade substrat. Högskolan i Halmstad (HH) genomförde försöksrötningarna och Grontmij (GM) använde sedan resultaten för att skapa en modell där bl.a. substrat, förbehandlingsteknik och driftkostnader finns med.

    Sammanfattningsvis kan sägas att majs som substrat fungerar bäst med de valda förbehandlingsmetoderna; kemisk behandling, termisk behandling och ultraljudsbehandling. Alla förbehandlingsmetoder med majs som substrat visade på ett positivt resultat, d.v.s. det ökade gasutbytet och dess värde (kr/kWh) översteg kostnaderna för de olika förbehandlingarna. Vad som måste beaktas är att produktionskostnaderna överlag är höga, med och utan förbehandling.

    Modellen har konstruerats på ett sådant sätt att den ska vara användarvänlig och med möjlighet att enkelt lägga till ytterligare substrat och förbehandlingsmetoder. Upprepningar av de försöksrötningar som genomförts kommer att öka tillförlitligheten hos modellen. Den fungerar som ett verktyg i att beräkna investeringsmarginalen för förbehandlingsutrustningen baserat på det valda substratet. På detta vis kan intressenter få en första indikation på om det är ekonomiskt rimligt att gå vidare med det tänkta substratet, den valda förbehandlingsmetoden, de planerade mängderna substrat etc.

    En investeringskalkyl har tagits fram för en gårdsanläggning som hanterar 5 000 ton substrat eller gödsel årligen. Det motsvarar 2-3 stycken medelstora mjölkgårdar. Kalkylen är översiktlig och syftar till att ge en första indikation på kostnader för de stora komponenterna såsom substratlager, rötkammare och rötrestlager. Kringarbeten såsom utredningar, markarbeten och geoundersökningar är inte med i kalkylen då dessa omkostnader till stor del avgörs av lokalisering och de förutsättningar som finns på platsen redan från start. Generellt kan dock sägas att den absolut billigaste och enklaste gårdsbaserade biogasanläggningen innebär en investering på 2,7-4 MSEK för flytgödsel från 100-300 mjölkkor.

    För BEH är det viktigt att skapa en plattform där intressenter kan komma för att genomföra försöksrötningar, byta erfarenheter och samla kunskap. För att uppnå detta är det nödvändigt att kunna erbjuda kunden kompletta och kompetenta lösningar på en och samma plats. Detta innebär ett erbjudande som innefattar försöksrötningar på labb-, pilot och fullskala. Ett förslag på konstruktion av pilotanläggning med övergripande principskiss ingår i denna rapport och fungerar som ett inledande arbete i projekteringen av en större pilotanläggning. Nödvändiga driftanalyser av rötrest ska kunna göras på plats i Plönninge på laboratoriet; analyser såsom enskilda organiska syror ska kunna skickas till lämpligt laboratorium. Personal ska kunna tillhandahållas för att driva och optimera rötningen enligt kundens syften och önskemål. På detta vis fungerar Region Halland som en länk mellan teori ochpraktik, mellan liten och stor skala och mellan aktörer från olika discipliner och geografiska områden.

  • 2.
    Cansu Ertem, Funda
    et al.
    Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany.
    Wang, Liqian
    Shanghai Institute of Applied Physics, Shanghai, China.
    Mattsson, Marie
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Analyzing the impacts of inoculums to substrate ratio and pretreatment methods on the anaerobic biogas production from sugar beets2016In: ETIKUM 2016: Proceedings, Novi Sad: Faculty of technical sciences department of production engineering , 2016, p. 113-116Conference paper (Refereed)
    Abstract [en]

    This study evaluates the impacts of three different pretreatment methods on the biogas production from sugar beet, when it is anaerobically digested with a variety of inoculum mixing ratios. In this context, this research focuses on the influences of different pretreatment methods and inoculum on the digestibility on the digestibility. Sugar beet was anaerobically digested at 37°C. Actively digested cow manure slurry, vegetable and fruit residues mix was used as inoculum. The series of laboratory experiments using 32 digesters (each 1 L) were performed in batch operation mode. The results prove that inoculum and pretreatments could either enhance the biogas potential or totally inhibit the digestion. Key words: sugar beet, inoculum, pretreatment methods, biogas production.

  • 3.
    Kalén, Jonas
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Åkerlund, Nathan
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Gårdsbaserad biogas på Nya Skottorp: utvärdering och optimering av anläggningen och uppgradering av biogasen2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    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.

  • 4.
    Karlsson, Tommy
    Halmstad University, School of Business and Engineering (SET).
    Biogasrötning av socker- och foderbetor: Jämförelse av färska, stuklagrade samt ensilerade betor i laboratorieskala2012Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Fossil fuels are affecting our climate negatively and there is a limited amount of them in the world, which leads to the importance of finding alternative fuels. One alternative is biogas, which is produced though a digestion process of different organic materials in a biogasreactor. Organic substrate that comes from farms has the biggest potential to increase the production of biogas in Sweden. Primarily crops from farms, but also waste products like manure are of great importance.

    Today there is a calculated theoretical potential for biogasproduction of 14TWh per year, which is around ten times larger than Sweden’s production today. This potential depends on how much arable land that is used to produce crops for biogas though, and can be much larger. The biggest contributor to increase the biogasproduction is crops from farms and manure3. The reason for this is because sugar- and fodderbeets contain the highest amount of energy per hectare arable land for crops, and therefore it is interesting to study how to optimize the use of this energy.

    Usually the beets have to be stored after the harvest since the most of the beets cannot be used directly, and a consistent feed to the biogas reactors is favorable. The most common way to store the beets today is in covered storage or silage. The beets are usually in need of being co-digested together with another substrate since the amount of nitrogen that the beets contain are relatively low, and therefore the beets may be in need of co-digest with a substrate that contains a higher amount of nitrogen. For example are manure or slaughterwaste substrates containing high amounts of nitrogen, and therefore are co-digestion between beets and these kinds of substrates improving the ratio between carbon and nitrogen, which improves the digestion process. This is the reason why the beets were co-digested with manure from cattle during this study.

    The goal with this study were to compare newly harvested sugar- and fodderbeets potential for biogasproduction, with the production from beets that were placed in covered storage respectively silage. Another goal was to decide which type of beet, storage method and pre-treatment method that are the most optimal for co-digestion with manure from cattle.

    The tests showed that when newly harvested sugar- and fodderbeets were added the part size were a more important factor then when the beets had been stored or ensilaged. For newly harvested sugarbeets the biggest part size gave the highest production, while the newly harvested fodderbeets of the same size did not have time to digest properly, which resulted in that their production were the lowest. When the haulm from sugarbeets were added together with sugarbeets and co-digested with manure from cattle the results were more like the results from the fodderbeets.

    During the tests ensilaged beets had a higher production than the newly harvested and the beets that were stored covered. Even though the results from the ensilaged beets were modified since losses occurred from the ensilation process. Comparison between the groups showed no bigger differences in production for the sugarbeets, while for fodderbeets the second largest part size had a higher production than the others with fodderbeets. With ensilaged sugarbeets together with the haulm there was shown that the group with the second most amount of haulm gave a higher production than the rest of the groups that were co-digested with haulm.

    The tests can be concluded by that newly harvested and the sugarbeets that were stored covered are more suitable to be co-digested together with manure from cattle than fodderbeets when looking at these percentage admixtures and preconditions. When the beets have been ensilaged is it more favorably to use fodderbeets then sugarbeets together with manure from cattle. The part size was shown to have no bigger significance. To sum up ensilaged beets over all seem to be more favorably to co-digest with cattle manure than newly harvested or beets that were in covered storage. The production per gram VS were significantly higher although correction calculations.

  • 5.
    Landgren, Emilia
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Wallman, Sabina
    Halmstad University, School of Business and Engineering (SET).
    Hästavmaskningsmedels påverkan på miljö och välfärd2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    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.

  • 6.
    Lerin, Tommy
    Halmstad University, School of Business and Engineering (SET).
    Förutsättningar och Avsättningar för Biogas för Gröna Vessigebro: Version 1.02014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The community Vessigebro, in Falkenberg and its surrounding areas housing one percent of all dairy cattle and two percent of all pigs in Sweden. This means that there is a large amount of manure as a basis for producing biogas in the area. A number of farmers have therefore formed a cooperative named Vessigebro biogas and started the project Green Vessigebro, with the goal of creating the conditions for a more profitable and more sustainable agriculture production.

    The study deals with the conditions and sale opportunities of the feasibility study Green Vessigebro. The study has looked at the work that was previously carried out for the biogas that could be produced on the farms in Vessigebro, The main pipeline for natural gas on the Swedish west coast and its operators, the Swedish Competition Act , Electricity Act , Natural Gas Act, the District Heating Act , Sustainability Act , previously proposed measures, municipality interest in biogas from Vessigebro , possible collaborations, possible sale opportunities and perform calculations with data from the municipality Ljungby for a suggested transportation of biogas between Vessigebro and Ljungby.

    The study shows that there are several interesting sale opportunities for biogas from Vessigebro. The production and use of biogas in Sweden is increasing and the trend seems set to continue. Six gas retailers can buy gas, which EON is the most established around Vessigebro with a distribution network. EON: s distribution network runs only a few kilometers from the planned upgrading plant , in Vessigebro. An already built upgrading facility is one mil from Vessigebro. Swedegas is the only main pipeline network owner with storing and balancing responsibility on the main line that is closer than EON distribution network. A number of suppliers and industries have shown interest in purchasing the biogas and the interest from potential buyers are likely to increase when the biogas production starts. A collaboration with, for example, "Arena Bioenergy Halland" increases business intelligence and can provide an increased influence with policy proposals. The use of gas and the interest is too low for the moment for tractors, boats, trains, buses and taxis to be a possible outlet specifically for Vessigebro biogas.

    The conditions make it interesting for Vessigebro biogas to look at five different options for sale opportunities of the biogas. Three options are based on a pipeline to either the pipeline, owned by Swedegas or EON distribution line alternatively a pipeline to EON upgrading facility. One possibility is to replace vehicles that run on fossil fuels with gas-powered vehicles providing a local use and purpose and the aims of the project Green Vessigebro. The calculations made by the study with different conditions shows that a very interesting and possible sale opportunity is a transportation of biogas between Vessigebro and Ljungby.

    The conclusion from the study shows that conditions and sale opportunities are good for the planned biogas production of Green Vessigebro to become reality.

  • 7.
    Mishra, Navin
    Halmstad University.
    Analysis of fault ride through disturbances in wind energy2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
  • 8.
    Yang, Fan
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Mesophilic anaerobic digestion conducted in single unit reactor at increasing ammonia concentrations2011Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The use of mesophilic anaerobic digestion for treatment of organic wastes is a growing biotechnology for sustainable energy supply. Ammonia inhibition is a major problem in anaerobic digestion mainly when digestion of nitrogen-rich substrates such as livestock wastes and manure occurs. This paper provides a summary of research conducted on ammonia inhibition of the anaerobic process. An experiment with mesophilic digestions of swine manure was conducted in single unit reactors, which were controlled under different ammonia concentrations by addition of NH4Cl in different amounts. From the experimental results, it was shown that NH4Cl could be an effective chemical agent for removing foam and scum in the digester. Methane production was decreased with the increasing NH4Cl addition until a collapse was observed between 11.2 g NH4+-N/l and 13.2 g NH4+-N/l. Contrary to the findings in thermophilic digestion, a dysfunction of acidogenesis was also observed since both gas and methane production was delayed with increasing NH4Cl addition. These findings suggest different ammonia inhibition principles in mesophilic and thermophilic digestion. It was further indicated that methanogenesis could produce a high percentage of methane although gas production was inhibited.

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