Esse trabalho avaliou a aplicação do reator anaeróbio operado em batelada e batelada alimentada sequenciais com agitação mecânica e biomassa imobilizada (AnSBBR) à produção de biometano pelo tratamento de vinhaça. As variáveis de interesse foram a carga orgânica volumétrica aplicada, a estratégia de alimentação e a temperatura. O volume de meio líquido do reator foi de 3 L e o volume tratado de 1 L por ciclo, com residual de 2 L. O tempo de ciclo foi de 8 h, com tempos de enchimento de 10 min para batelada e 240 min para batelada alimentada. Após a Condição Preliminar, realizaram-se as Condições 01 a 08 em batelada (30°C), a Condição 09 em batelada alimentada (30°C) e a Condição 10 em batelada (45°C). Para o aumento da carga orgânica de 1,0 até 10,0 gDQO.L-1.d-1 houve aumento na produtividade de metano, sendo o máximo valor molar atingido de 123,4 molCH4.m-3.d-1 e volumétrico de 2767 mL-CNTPCH4.L-1.d-1. Quanto ao rendimento entre metano produzido e matéria orgânica consumida, o valor máximo foi de 13,8 mmolCH4.gDQO-1 (88% do teórico), com carga orgânica de 7,50 gDQO.L-1.d-1. Para batelada alimentada, o rendimento e a produtividade foram menores (PrM = 102,5 molCH4.m-3.d-1, PrV = 2296,9 mL-CNTPCH4.L-1.d-1 e YM-CH4/DQO = 11,8 mmolCH4.gDQO-1, 76% do rendimento teórico), como também a 45°C (PrM = 35 molCH4.m-3.d-1 e YM-CH4/DQO = 7,1 mmolCH4.gDQO-1). Os parâmetros do modelo cinético de primeira ordem, de modo geral, apresentaram tendência de aumento com a carga e, para batelada alimentada, os valores foram próximos à batelada. A distribuição de ácidos voláteis nas condições em batelada e batelada alimentada foi principalmente entre ácidos acético, propiônico e butírico e a 45°C predominou o ácido propiônico. A vinhaça mostrou potencial de aproveitamento energético até a carga de 10,0 gDQO.L-1.d-1 e concentração de 10000 mgDQO.L-1, valor próximo de um terço da concentração in natura. / This study assessed the feasibility of an anaerobic sequencing batch and fed-batch biofilm reactor (AnSBBR) with agitation treating vinasse for biomethane production. Applied volumetric organic load, feed strategy and temperature were the variables of interest. The liquid medium in the reactor was 3 L, and the treated volume was 1 L per cicle, with a residual of 2 L. Time cycle length was 8 h, with feeding time of 10 min for batch and 240 min for fed-batch. After the Preliminary Condition, Conditions 01 to 08 in batch (30°C), Condition 09 in fed-batch (30°C) and Condition 10 in batch (45°C) were carried. For the increase of organic load from 1,0 to 10,0 gCOD.L-1.d-1 a rise in methane productivity was observed. Maximum reached molar productivity was 123,4 molCH4.m-3.d-1, being 2767 mL-STPCH4.L-1.d-1 in volume. In regard to the yield of produced methane by consumed organic matter, the maximum was 13,8 mmolCH4.gCOD-1 (88% of the theoretical value), with applied volumetric organic load of 7,50 gCOD.L-1.d-1. Methane yield and productivity were lower in fed-batch than in batch operation (MPr = 102,5 molCH4.m-3.d-1, VPr = 2296,9 mL-STPCH4.L-1.d-1 and YM-CH4/DQO = 11,8 mmolCH4.gCOD-1, 76% of the theoretical), as well as for 45°C (MPr = 35 molCH4.m-3.d-1 and YM-CH4/DQO = 7,1 mmolCH4.gCOD-1). In general, parameters of the kinetic first-order model presented a tendency of increase with organic load and, for the fed-batch operation, values were similar to batch. The volatile acids distribution in batch and fed-batch conditions were mainly of acetic, propionic and butiric acids and for the temperature of 45°C propionic acid prevail. Vinasse showed to have an energy profit potential for applied organic loads until 10,0 gDQO.L-1.d-1 and concentration until 10000 mgCOD.L-1, which is approximately one third of the in natura concentration.

Le gaz naturel représente environ 20% de la consommation énergétique mondiale et cette part est attendue à la hausse dans les prochaines années en raison de la transition énergétique. Pour des raisons économiques et stratégiques, et afin de réguler les demandes d’énergie entre l’été et l’hiver, le gaz naturel est stocké temporairement dans des réservoirs souterrains, notamment des réservoirs aquifères. Les opérations d’injection et de soutirage du gaz mettent donc en contact des espèces gazeuses, liquides et solides, et rendent potentiellement possibles de nombreux phénomènes de transferts d’espèces chimiques d’un milieu vers un autre. Ainsi, bien que composé majoritairement de méthane (70-90%vol), le gaz naturel peut présenter des concentrations variées d’éléments trace métalliques (arsenic, mercure, plomb…). Compte tenu du caractère néfaste de ces composés, à la fois pour les installations industrielles et pour l’environnement, il est de la première importance de connaître l’impact de la composition chimique du gaz sur l’aquifère.Les travaux réalisés dans le cadre de cette thèse s’inscrivent dans ce contexte et ont eu pour objectif de caractériser les matrices gaz/eau/roche ainsi que les interactions qui existent entre elles, avec pour centre d’intérêt principal les éléments trace métalliques.Pour cela nous avons fait porter nos efforts sur l’optimisation (i) des conditions d’utilisation d’un banc de prélèvement ATEX, basé sur le principe de barbotage, et (ii) des méthodes de piégeages des métaux lourds puis d’analyses employées. Ce dispositif unique permet d’échantillonner les métaux présents dans un gaz naturel sous pression (100 bar maximum). Utilisé sur des sites industriels, ce banc a permis de mesurer et suivre sur plusieurs années la composition chimique en éléments trace métalliques du gaz naturel, mais aussi ponctuellement d’un biogaz et d’un biomethane. En effet, Ces deux derniers gaz ont vocation à réduire l’utilisation des énergies fossiles, celle du gaz naturel en particulier. Les biométhanes sont donc amenés à parcourir les mêmes réseaux de transport et à séjourner dans les mêmes sites de stockage que ceux utilisés pour le gaz naturel.En complément de la caractérisation de la phase gazeuse, nous nous sommes intéressés aux évolutions des compositions chimiques des phases aqueuse et minérale du stockage souterrain, sans pouvoir identifier de mécanisme de transfert spécifiquement lié aux activités de stockage de gaz. / Natural gas represents 20% of energy consumption in the world. This percentage is expected to increase in the next years due to the energy transition. For economic and strategic concerns, and in to regulate energy demand between summer and winter, natural gas might be stored in underground storages like aquifers. Consequently, injection and drawing operations favour contact between gaseous, liquid and solid species and make possible transfer phenomena of chemical species from one matrix to another. In addition, even though natural gases are composed essentially of methane (70-90%vol), they can also show various metallic trace element concentrations (mercury, arsenic, tin…). According harmful effects of these compounds on industrial infrastructures and on environment, knowing impacts of natural gas composition on aquifer storage is crucial.The different tasks of this thesis are incorporated within such a context with the objective to characterize gases-waters-rocks matrices and their potential interactions, focusing on metallic trace elements.Therefore, we have focused a part of this PhD thesis on the optimisation of conditions of use (i) of a in EX zone 0 sampler device, working according to the principle of bubbling and (ii) of trapping methodology as well as analytic methods. This unique device allows metal sampling from natural gases up to 100 bar pressure. Its use on industrial sites has permitted to measure and monitor during several years the metallic trace element chemical compositions of a natural gas and also more limited biogas and a biomethane analysis. Indeed, these two last gases are designed to reduce fossil fuel consumption particularly natural gas one. Biomethanes are led to use the same transportation network and to be temporarily stored in the same way as natural gaz. In addition of the gaseous phase, we have taken interest in the water and the mineral phases to characterize their chemical composition evolutions in time, without identify specific transfer mechanisms in touch with gas storage activity.

La consommation mondiale en énergie qui augmente progressivement a favorisé la recherche de ressources alternatives renouvelables. L’Europe a mis le développement de la filière de biogaz comme une priorité pour valoriser la matière organique et produire une énergie durable et un carburant propre. Plusieurs technologies ont été développées afin de produire le bio-méthane et ensuite le liquéfier. Cryo Pur a développé un procédé cryogénique où le biogaz est refroidi progressivement à 3 niveaux de température :-40 °C ; -75 °C et -120 °C. Dans un premier temps, la vapeur d’eau est extraite à -40 °C et à -75 °C, le biogaz sec ne contient plus alors que du méthane à une concentration de 65 % et du CO2 à 35 %. Le biogaz est alors refroidi jusqu’à -120 °C dans un système frigorifique en cascade intégrée pour capter le dioxyde de carbone jusqu’à une concentration résiduelle de 2 %. Une fois ce bio-méthane obtenu, il est liquéfié. A une pression de 15 bara et une température de -120 °C. Une étude énergétique et exergétique est menée et prend comme référence le pilote d’épuration et de liquéfaction Cryo Pur installé à la sortie de méthaniseurs de la station d’épuration de Valenton. Le CO2 est capté par givrage sur les ailettes d’échangeurs frigorifiques ; le dégivrage est effectué par un débit diphasique prélevé à l’étage -40 °C de la cascade intégrée. La thèse compare l’énergie récupérée par un dégivrage en phase liquide du CO2 avec donc une remontée en température jusqu’à -56 °C (température du point triple du CO2) et un dégivrage par sublimation du CO2 à une température bien inférieure à -56 °C qui fait l’objet d’une optimisation énergétique. La thèse mène aussi une étude énergétique et exergétique du procédé complet d’épuration de biogaz et de liquéfaction de bio-méthane avec récupération d’énergie par sublimation du dioxyde de carbone.Un banc d’essai est conçu pour évaluer la performance énergétique du procédé de dégivrage du CO2 par sublimation. Les différents éléments nécessaires de ce banc d’essai sont présentés avec leurs consommations énergétiques. Dans ce banc d’essai, le dégivrage du dioxyde de carbone par sublimation est effectué via un caloporteur qui récupère la froideur de sublimation du CO2 réduisant la puissance consommée par la cascade intégrée. Ce nouveau procédé a besoin d’une pompe à vide. La consommation de cette pompe à vide dépend de la pression de sublimation et fait l’objet d’une étude d’optimisation énergétique. La densité du CO2 varie énormément en fonction de la température et la pression de sublimation. Un modèle de calcul de l’évolution de l’épaisseur du givre au cours de la sublimation est présenté. Comme conclusion de cette partie, une comparaison est faite entre la consommation électrique spécifique du système installé à Valenton et celle du banc d’essai.D’autre part, la durée du cycle de givrage demande elle aussi une étude d’optimisation énergétique associée au dimensionnement de l’échangeur de captage du CO2. L’échangeur tube-ailettes avec la forme de l’ailette et les paramètres affectant le givrage du CO2 sont présentés. Une étude est effectuée pour répartir uniformément la masse de CO2 déposée sur la surface d’échange pour réduire le taux de blocage de l’échangeur et prolonger la durée de la phase de givrage. Une étude sur l’effet de la vitesse du biogaz et du glissement en température du réfrigérant sur la durée du cycle est menée ainsi qu’une étude sur les matériaux des ailettes et des tubes choisis afin de minimiser la surface d’échange en gardant la sortie du bio-méthane avec 2 % de CO2. / Global energy consumption, which is gradually increasing, has led to the search for alternative renewable resources. Europe has put the development of the biogas sector as a priority to enhance organic matter and produce sustainable energy and clean fuel. Several technologies have been developed to produce bio-methane and then to liquefy it. Cryo Pur developed a cryogenic process where the biogas is cooled gradually to 3 temperature levels: -40 ° C; -75 ° C and -120 °C. In a first step, the steam is extracted at -40 °C and at -75 ° C, the dry biogas contains 65 % methane and 35 % CO2. The biogas is then cooled to -120 °C in a low-temperature refrigeration system to capture carbon dioxide and obtain bio-methane with 2.5 % of CO2. Once this bio-methane is obtained, it is liquefied at a pressure of 15 bara and a temperature of -120 °C. An energy and exergy study is studied and takes as reference the pilot of purification and liquefaction Cryo Pur installed at the exit of digester of the purification station of Valenton. CO2 is captured by frosting on the fins of heat exchangers. The defrosting is carried out by a two-phase flow rate taken from the -40 °C stage of the low-temperature refrigeration system. The thesis compares the energy recovered by a liquid CO2 defrosted with a rise in temperature up to -56 °C (triple point temperature of CO2) and defrosting by sublimation of CO2 at a temperature much lower than - 56 ° C which is the subject of an energy optimization. The thesis also conducts an energy and exergy study of the complete process of biogas and bio-methane liquefaction with the recovery of energy by sublimation of carbon dioxide.A test bench is designed to evaluate the energy performance of the CO2 defrosting process by sublimation. The various necessary elements of this test bench are presented with their energy consumption. In this test bench, the defrosting of the carbon dioxide by sublimation is carried out via a low-temperature heat-transfer fluid which recovers the energy sublimation of the CO2 reducing the power consumed by the low-temperature refrigeration system. This new process requires a vacuum pump. The consumption of this vacuum pump depends on the sublimation pressure and is the subject of an energy optimization study. The density of CO2 varies enormously depending on the temperature and the sublimation pressure. A model of the evolution of the thickness of the frost during the sublimation is presented. As a conclusion of this section, a comparison is made between the specific power consumption of the system installed at Valenton and that of the test bench.On the other hand, the duration of the frosting cycle also requires an energy optimization study associated with the design of the exchanger that capture the CO2. The tube-fins exchanger with the shape of the fin and the parameters affecting the CO2 frosting are presented. A study is carried out to uniformly distribution of the CO2 mass on the exchange surface to reduce the blocking rate of the exchanger and to extend the duration of the frosting phase. A study on the effect of biogas velocity and temperature slippage of the refrigerant over the cycle is carried out as well as a study on the materials of the fins and tubes selected in order to minimize the exchange surface and have the bio-methane with 2 % CO2.

The pulp- and paper industry (PPI) faces a great challenge in finding new ways to reduce its overall carbon emissions. Large quantities of water are used in the pulp- and paper making process. In this context, a more sustainable wastewater treatment with a lower carbon footprint is of relevance for the PPI. Applied to a pulp- and paper mill (PPM) in Norway, the ongoing demonstration project “EffiSludge for LIFE” lowers the wastewater treatments (WWT) energy consumption while turning residual waste (bio sludge) into energy by implementing a new wastewater treatment concept. The aim of this study was to evaluate the current carbon footprint from a hypothetical PPM WWT plant, the potential lowering of the carbon footprint when applying the EffiSludge concept and the benefits in a larger scale assuming EffiSludge would be applied at all of the PPMs WWT in the Nordic countries represented by Sweden, Norway and Finland. An estimation of a current and future carbon footprint from one example mill was provided through the construction of one baseline and two case scenarios. Results from a laboratory biomethane potential experiment together with the responses from a survey and contributions from one example mill provided relevant input to the scenarios. The major impact on carbon emissions in the scenarios came from reducing electricity needed to aerate the biological WWT step. The maximum current carbon footprint from the parts of the WWT process included in the baseline scenario was 9.6-13 kg CO2-eq/kg pulp and the estimated future carbon footprint when implementing the EffiSludge concept was estimated as 3.6-5.9 kg CO2-eq/kg pulp. A reduction of 6-8 kg CO2-eq/kg pulp could be expected by implementing the EffiSludge concept. If the EffiSludge concept was introduced in all of the WWTP connected with Nordic PPMs a reduction of the carbon footprint with 55-180 million kg CO2-eq could be expected each year. This would reduce the total carbon emissions from the European PPI with 0.2-0.5 % annually

Esse trabalho avaliou a aplicação do reator anaeróbio operado em batelada e batelada alimentada sequenciais com agitação mecânica e biomassa imobilizada (AnSBBR) à produção de biometano pelo tratamento de vinhaça. As variáveis de interesse foram a carga orgânica volumétrica aplicada, a estratégia de alimentação e a temperatura. O volume de meio líquido do reator foi de 3 L e o volume tratado de 1 L por ciclo, com residual de 2 L. O tempo de ciclo foi de 8 h, com tempos de enchimento de 10 min para batelada e 240 min para batelada alimentada. Após a Condição Preliminar, realizaram-se as Condições 01 a 08 em batelada (30°C), a Condição 09 em batelada alimentada (30°C) e a Condição 10 em batelada (45°C). Para o aumento da carga orgânica de 1,0 até 10,0 gDQO.L-1.d-1 houve aumento na produtividade de metano, sendo o máximo valor molar atingido de 123,4 molCH4.m-3.d-1 e volumétrico de 2767 mL-CNTPCH4.L-1.d-1. Quanto ao rendimento entre metano produzido e matéria orgânica consumida, o valor máximo foi de 13,8 mmolCH4.gDQO-1 (88% do teórico), com carga orgânica de 7,50 gDQO.L-1.d-1. Para batelada alimentada, o rendimento e a produtividade foram menores (PrM = 102,5 molCH4.m-3.d-1, PrV = 2296,9 mL-CNTPCH4.L-1.d-1 e YM-CH4/DQO = 11,8 mmolCH4.gDQO-1, 76% do rendimento teórico), como também a 45°C (PrM = 35 molCH4.m-3.d-1 e YM-CH4/DQO = 7,1 mmolCH4.gDQO-1). Os parâmetros do modelo cinético de primeira ordem, de modo geral, apresentaram tendência de aumento com a carga e, para batelada alimentada, os valores foram próximos à batelada. A distribuição de ácidos voláteis nas condições em batelada e batelada alimentada foi principalmente entre ácidos acético, propiônico e butírico e a 45°C predominou o ácido propiônico. A vinhaça mostrou potencial de aproveitamento energético até a carga de 10,0 gDQO.L-1.d-1 e concentração de 10000 mgDQO.L-1, valor próximo de um terço da concentração in natura. / This study assessed the feasibility of an anaerobic sequencing batch and fed-batch biofilm reactor (AnSBBR) with agitation treating vinasse for biomethane production. Applied volumetric organic load, feed strategy and temperature were the variables of interest. The liquid medium in the reactor was 3 L, and the treated volume was 1 L per cicle, with a residual of 2 L. Time cycle length was 8 h, with feeding time of 10 min for batch and 240 min for fed-batch. After the Preliminary Condition, Conditions 01 to 08 in batch (30°C), Condition 09 in fed-batch (30°C) and Condition 10 in batch (45°C) were carried. For the increase of organic load from 1,0 to 10,0 gCOD.L-1.d-1 a rise in methane productivity was observed. Maximum reached molar productivity was 123,4 molCH4.m-3.d-1, being 2767 mL-STPCH4.L-1.d-1 in volume. In regard to the yield of produced methane by consumed organic matter, the maximum was 13,8 mmolCH4.gCOD-1 (88% of the theoretical value), with applied volumetric organic load of 7,50 gCOD.L-1.d-1. Methane yield and productivity were lower in fed-batch than in batch operation (MPr = 102,5 molCH4.m-3.d-1, VPr = 2296,9 mL-STPCH4.L-1.d-1 and YM-CH4/DQO = 11,8 mmolCH4.gCOD-1, 76% of the theoretical), as well as for 45°C (MPr = 35 molCH4.m-3.d-1 and YM-CH4/DQO = 7,1 mmolCH4.gCOD-1). In general, parameters of the kinetic first-order model presented a tendency of increase with organic load and, for the fed-batch operation, values were similar to batch. The volatile acids distribution in batch and fed-batch conditions were mainly of acetic, propionic and butiric acids and for the temperature of 45°C propionic acid prevail. Vinasse showed to have an energy profit potential for applied organic loads until 10,0 gDQO.L-1.d-1 and concentration until 10000 mgCOD.L-1, which is approximately one third of the in natura concentration.

The thesis deals with the technologies upgrading the biogas to the quality of the natural gas for the following use in the gas distribution system. The main concern of the thesis is the pressure swing adsorption (PSA), which is nowadays one of the most exploited technologies. For a certain flow and composition of the biogas, completely new PSA technology was designed. Technological schema was created and the main technological devices (adsorbers) were drawn up together with the design documentation for this new technology. The important part of the thesis is also the model of the whole PSA technology in the ChemCAD programme and the evaluation of the operating and investment costs.

This thesis investigates the potential of biomethane production in India, the impact of its integration into the energy mix, and the corresponding Greenhouse Gases (GHG) emission and potential reduction. India, with its huge population and being an agriculturally rich country, produces gigantic amounts of biodegradable waste from various sources such as Municipal Solid Waste (MSW),agricultural waste, animal husbandry, sugar industry, etc. Three different end-use scenarios: electricity generation, cooking fuel, and transportation fuel—are assessed in order to determine the decree to which current fossil fuels may be replaced and the net amount of greenhouse gas emissions that are saved by using this biomethane. The total biomethane generation potential according to the study conducted by the Ministry of New and Renewable Energy (MNRE) is 25.6 Billion Metric Standard Cubic Meters (BMSCM) and with the most efficient upgrading technology available (3-stage membrane filtration) the useful potential is 25.4 BMSCM. The electricity that can be produced from the biomethane potential available is 159.1 TWh, which corresponds to the optimistic value of GHG emission reduction of 89million tons. When used as a cooking fuel, biomethane can contribute immensely to satisfying the final thermal needs of India. It can satisfy more than half the combined total thermal energy from Compressed Natural Gas (CNG) and Liquefied Petroleum Gas (LPG) consumed in India and, at the same time, reduce 46.2 million tons of GHG emissions caused by it. The transportation sectoris the most suited and easy to adapt as an end-use application for biomethane. It was observed that biomethane as a replacement for Petrol for road transportation fuel presents the best scenario, since biomethane can reduce more than 71% of its consumption and respectively reduce more than 57 million tons of GHG emission, which is the second highest after electricity production. This thesis puts up a strong case to look at biomethane as a very important fuel towards India’starget to be net zero by 2070 and its plans to be self-reliant. Moreover, biomethane production usingthe path of anaerobic digestion provides not only a renewable source of energy but also food security with digestate being used as fertilizer and an opportunity to address the impact of climate change by preventing the emission of methane in the atmosphere which has a global warming potential of28 and burning of agricultural waste in the open field. Eventually, the production of biomethane prevents soil, air and water pollution. / Denna avhandling undersöker potentialen för biometanproduktion i Indien, effekterna av dess integration i energimixen och motsvarande utsläpp och potential för växthusgaser (GHG). minskning. Indien, med sin enorma befolkning och är ett jordbruksrikt land, producerar gigantiska mängder biologiskt nedbrytbart avfall från olika källor som kommunalt fast avfall (MSW), jordbruksavfall, djurhållning, sockerindustri, etc. Tre olika slutanvändningsscenarier: el produktion,matlagningsbränsle och transportbränsle – utvärderas för att fastställa till vilket dekret nuvarande fossila bränslen får ersättas och nettomängden växthusgasutsläpp som sparas genom att använda denna biometan. Den totala biometangenereringspotentialen enligt studien utförd av ministeriet för ny och förnybarenergi (MNRE) är 25,6 miljarder metriska standardkubikmeter (BMSCM) och med den mest effektiva uppgraderingstekniken som finns tillgänglig (3-stegs membranfiltrering) är den användbara potentialen 25,4 BMSCM. Den el som kan produceras från den tillgängliga biometanpotentialen är 159,1 TWh medan det optimistiska värdet av växthusgasutsläpp som är möjligt med användning av biometan för elproduktion är 89 miljoner ton. När biometan används som matlagningsbränsle kan det bidra oerhört mycket för att tillfredsställa Indiens slutliga termiska behov. Det kan tillfredsställa mer än halva finalen termisk energi som förbrukas i Indien och samtidigt samma miljon ton i utsläpp av växthusgaser som orsakas av den. Transportsektorn är den mest lämpade och lätta att anpassa som slutanvändningsprogram för biometan. Det observerades att biometan som ersättning för bensin som transportbränsle är det bästa scenariot eftersom biometan kan minskamer än 71 % av sin förbrukning och respektive minska mer än 57 miljoner ton växthusgasutsläpp, vilket är det näst högsta efter elproduktion. Den här avhandlingen ger ett starkt argument för att se biometan som ett mycket viktigt bränslemot Indiens mål att vara nettonoll år 2070 och dess planer på att vara självförsörjande. Dessutom ger biometanproduktion genom att använda vägen för anaerob rötning inte bara en förnybar energikälla utan också livsmedelssäkerhet med rötgas som används som gödningsmedel och en möjlighet att ta itu med effekterna av klimatförändringar genom att förhindra utsläpp av metan i atmosfären som har en global uppvärmningspotential på 28 och förbränning av jordbruksavfall på det öppna fältet. Så småningom förhindrar produktionen av biometan mark-, luft- och vattenföroreningar.

Woodroll® is a gasification technology developed by Cortus that produces synthetic gas (syngas) from biomass. Syngas can be used in several different applications. One interesting option is to convert it further into biomethane, which can be used as automotive fuel or replace natural gas in gas grids. The revenues and profitability of biomethane production is heavily dependent on policy instruments and support schemes. These subsidies can be either direct, where the producer receives a feed-in tariff for biomethane production, or indirect, where consumption rather than production is stimulated. This work has investigated which revenues that can be expected from biomethane production via Woodrooll® in Sweden, the Netherlands, Germany, the UK, France and Italy, both in terms of amounts and risks. A profitability analysis have also been carried out to preliminary compare the returns in the different countries, where two different scenarios for different revenues have been analyzed for two different feedstock prices. The results showed that the Netherlands and Italy provides the potentially highest revenues. However, there are uncertainty factors associated with all cases. Sweden and Germany offers indirect support and negative market trends. The Netherlands and the UK are the only options that provide a feed-in tariff for biomethane production via gasification. In the Netherlands the tariff can be secured before making investment decision but is only disbursed for 12 years. The UK offers a fixed feed-in tariff for 20 years but the tariff is secured first after plant start-up and the tariff may be reduced on a quarterly basis. In fact, the tariff has been reduced with 40 % over the last 24 months, but there are discussions on introducing a separate tariff for gasification. Italy has the support schemes that potentially offer the highest revenues, but gasification is currently not eligible for support. The latter also holds for France, which may be an interesting case in the future. If risk is to be minimized, Cortus may either focus on the Netherlands or await the discussions in the UK and France on introducing a gasification tariff. The work on standardization of biomethane use should also be followed since Italy offers the potentially highest return of the investigated countries. It is also recommended to look further for other cases. The best-case scenario for the risk averse is the one that provides a fixed tariff for 20 years and in which the tariff can be secured before an investment decision is taken. / Woodroll® är en förgasningateknik som utvecklats av Cortus som producerar syntesgas (syngas) från biomassa. Det finns en rad olika användningsområden för gasen. Ett intressant sådant är att omvandla den till biometan, vilket kan användas som drivmedel eller ersätta naturgas i gasnät. Dock så är intäktern och lönsamheten starkt beroende av stödsystem. Dessa subventioner kan antingen vara i form av en inmatningstariff, där biometanproducenten får en fast peng för biometanproduktion, eller i form av indirekt stöd där konsumtion snarare än produktion stimuleras. I detta arbete har det utretts vilka intäkter som kan förväntas för biometan-produktion genom Woodroll® i Sverige, Nederländerna, Tyskland, Storbritanninen, Frankrike och Italien, både i termer av belopp och risk. En lönsamhetsanalys har också gjorts för att preliminärt jämföra avkastningen för de olika länderna. Två olika scenarier för olika intäkter har analyserats för två olika råvarupriser. Resultatet visade att samtliga länder kan erbjuda attraktiv avkastning. Dock är samtliga fall förknippade med osäkerhetsfaktorer. Sverige och Tyskland erbjuder indirekt stöd och negativa marknadstrender. Nederländerna och Storbritannien är de enda alternativen som ger en feed-in-tariff för biometanproduktion. I Nederländerna kan tariffen säkras innan investeringsbeslut fattats men betalas endast i 12 år. Storbritannien ger en fast tariff i 20 år men kan justeras kvarstalsvis och nivån säkras först efter uppstart av anläggningen. Tariffen har reducerats med 40 % de senaste 24 månaderna, men det pågår diskussioner om att introducera en särskild tariff för förgasning. Italien erbjuder stödsystemet som ger högst potentiella intäkter men biometan från förgasning är inte berättigat för stödet. Det senare gäller också för Frankrike som kan bli ett intressant fall i framtiden. Om det önskas att minimera risken så bör Cortus fokusera antingen på Nederländerna eller invänta diskussionerna om förgasningstariffen i Storbritannien och Frankrike. Arbetet kring standardisering av biometan-användning bör också följas eftersom Italien erbjuder de potentiellt högsta intäkterna. Det rekommenderas också att Cortus tittar vidare på andra alternativ. Det bästa fallet för den risk-aversiva är fallet som ger en fast tariff i 20 år och där stödet kan säkras innan investeringsbeslut fattas.

The prevalence of antibiotics on farms for therapeutic and prophylactic use in animals can cause negative effects on biomethane production during anaerobic digestion. Previous literature has found decreased biomethane production rates from a variety of antibiotics, but biogas inhibition differs between studies of continuous and batch reactors and the type of antibiotic studied. Cephalosporin drugs are the most common antibiotic class used to treat mastitis in dairy cows and can retain most of their bioactivity after excretion. Ceftiofur is a commonly used cephalosporin drug but no previous study investigating the effect of Ceftiofur on biomethane during continuous anaerobic digestion has been performed. The aim of this study was to examine the effect on biomethane production when manure from cows treated with Ceftiofur was anaerobically digested. Laboratory sized anaerobic digesters (AD) were run at thermophilic (55°C) temperatures and a 10 day hydraulic retention time. Manure from cows treated with Ceftiofur were fed to the antibiotic treatment reactors for 50 days. The reactor performance was measured by i) biomethane production, ii) waste stabilization in terms of solids and chemical oxygen demand, iii) change in mass of Ceftiofur and iv) change in concentration of antibiotic resistant genes, specifically cfx(A), mef(A), and tet(Q). There was statistically significant decrease in cumulative gas production due to the addition of Ceftiofur into the reactors, but no significant difference between treatments in waste stabilization in terms of percent volatile solids (VS) and total chemical oxygen demand (TCOD) reduction. Anaerobic digestion decreased the amount of Ceftiofur in manure, and the amount of Ceftiofur in the reactors reduced over the time of the experiment. Change in antibiotic resistant genes (ARGs) were gene dependent over time. Concentrations of tet(Q) reduced significantly between feed and effluent of both treatments, and cfx(A) reduced significantly for the control treatment but not the Ceftiofur treatment. Concentrations of mef(A) increased over time in both treatments. Overall, the addition of Ceftiofur in continuously operated anaerobic digesters negatively affected biomethane production, a value-added product responsible for on-farm renewable energy. However, anaerobic digestion does decrease the mass of Ceftiofur within manure, thereby reducing the environmental loading from run-off from farms. / Master of Science / Anaerobic digestion is a biological treatment technology used on farms to treat manure. It can be used to reduce potential environmental damage from contaminants and manure, homogenize manure for fertilizer, and produce methane gas for renewable energy. An emerging challenge in manure management is the presence of antibiotics such as ceftiofur used in animal production to prevent and treat illnesses. When antibiotics are used on livestock, they are excreted from the animal in manure. When the manure is added to the digester, the antibiotic molecules within the manure can kill the bacteria responsible for manure homogenization and gas production. Ceftiofur is a type of cephalosporin antibiotic used to treat dairy cows for mastitis, a bacterial infection of the udder. When the cows are treated with Ceftiofur, it can remain in the excreted manure and enter the digester. The use of antibiotics on farms is also leading to a global phenomenon known as antibiotic resistance. The bacteria that are exposed to antibiotics can develop mutations to become immune to the antibiotic, and can spread the mutations through antibiotic resistant genes (ARGs). ARGs can spread to bacteria which have never been exposed to antibiotics, making them resistant. This causes a significant concern in regards to disease treatment across the world as the efficacy of antibiotics is threatened. Understanding how ARGs move and how they can be eliminated is crucial to preventing global antibiotic resistance. The purpose of this study was to assess the effect of anaerobic digestion on Ceftiofur and ARGs. Four continuous lab-scale anaerobic digesters, two using control manure and two using manure from cows treated with Ceftiofur, were run at 55˚C for a period of 50 days. Over time, the reactor with manure from cows treated with the Ceftiofur antibiotic produced less gas as compared to the control digesters. The amount of Ceftiofur within the digesters decreased over time, demonstrating anaerobic digestion’s ability to degrade the antibiotic molecule. The effect of anaerobic digestion on the ARG concentration was gene specific. The concentration of the tet(Q) gene, a gene responsible for resistance against the very common antibiotic tetracycline, was reduced by anaerobic digestion. These results demonstrate that anaerobic digestion is a technology which can reduce the environmental impact of manure from Ceftiofur-treated cows. This shows that manure treatment can be a first step in combating antibiotic resistance across the globe.

Au cours de la dernière décennie, nous avons pu assister à l’expérimentation de plusieurs nouvelles filières pour contribuer aux objectifs nationaux de décarbonation du système énergétique français : biométhane, méthane de synthèse produit par du Power-to-Gas, hydrogène, Capture et Séquestration du Carbone (CSC)… Dans quels contextes ces filières pourraient-elles se développer ? Quelles seraient le cas échéant leurs perspectives de compétition/coopération ?Ce travail de thèse évalue le positionnement de ces nouvelles filières technologiques au sein des systèmes gaz et électrique. Il propose une estimation technico-économique des choix de long terme à l’horizon 2050 dans le cadre d’un paradigme d’optimalité. L’analyse de l’équilibre offre-demande pluriannuel est complétée par celle des dynamiques de production à une échelle intra-journalière et des enjeux de flexibilité associés.Pour ce faire, le modèle TIMES-FR-GAZEL développé dans cette thèse décrit le couplage des systèmes gaz et électrique à travers une représentation explicite des chaînes technologiques. Il permet une optimisation conjointe des deux systèmes sous contraintes environnementales.A l’aide de ce modèle, le positionnement des nouvelles filières gazières et électriques en France est étudié en prenant en compte les trajectoires pour parvenir à l’horizon 2050. Les analyses sont réalisées sur la base de scénarios de demande finale qui intègrent des jeux d’hypothèses contrastés concernant la disponibilité des technologies, les stratégies de décarbonation et la demande. / Over the past decade, several new technological pathways have been experimented with a view to reaching national decarbonization targets in France. These include biomethane, synthetic methane from Power-to-Gas, hydrogen, and Carbon Capture and Sequestration (CCS). The potential contributions of these technologies could make it more difficult for stakeholders and public authorities to choose the appropriate solution. In what contexts could these technologies be developed and what are their potential competition/cooperation perspectives?This research analyzes the role of these new technological pathways within the French gas and electricity systems. We propose a long-term, techno-economic assessment of the options at a 2050 horizon applying an optimal paradigm. We analyze the systems balance over several years while addressing the issue of intraday flexibility constraints.To this end, the bottom-up TIMES-FR-GAZEL model has been developed in order to study joint gas and electricity systems optimization with explicit representation of technologies (biomethane production, Power-to-Gas, CCS, etc.).This model allows us to embed trajectory constraints to reach the 2050 horizon. Assessments are conducted based on final energy demand scenarios with contrasted hypotheses on technology availability, decarbonization strategies and energy demand.