In the present work it is evaluated the possibility of incorporating the production of hydrogen through the steam reforming of ethanol in a sugar-alcohol plant. The analysis is made using as a model an existing plant located in São Paulo, the Pioneros Distillery. An energetic and exergetic analysis is performed. Three operating scenarios were analyzed. In the first configuration the plant only generates electricity to supply its internal needs. In a second scenario the plant uses all the bagasse to generate electricity, targeting to sell electric power. Finally it was considered the possibility to incorporate the hydrogen production by ethanol steam reforming. The capacity of the plant to produce hydrogen is evaluated. The surplus bagasse is used to generate the electricity and thermal energy required for hydrogen production. A part of the anhydrous alcohol is used in the reformer for hydrogen production. An energetic study of the plant is developed based on the first law of thermodynamics. Some important parameters related to the thermal system performance are evaluated like: steam consumption in the process, specific consumption of steam turbines; and those properly related to plants of sugar-ethanol sector as: electrical or mechanical power generated from one ton of sugarcane and power generated from a given amount of bagasse burned in the boiler. It is considered the possibility of generating electricity using bagasse, which could be sold to the local energy concessionaire. Characteristic parameters of a cogeneration system (α and β) are also evaluated, these parameters depend on the characteristics of the thermodynamic system and the operating strategy. The system energy losses, excluding those located in the boiler and the electric generator, are higher in scenario 2 than in scenario 1. The efficiency is 70% in Scenario 1 and 57% in scenario 2. In scenario 3, the plant's potential for hydrogen generation is 4,467,000Nm3/year (951Nm3/h). To achieve this, the new process uses 7 % of the anhydrous ethanol produced in the plant, which implies a surplus of 37 lethanolanhydro/tcane available for sale. In this configuration all the bagasse is used for electricity and heat generation required for the hydrogen production. The hydrogen could be used for fuel cell vehicles. The plant is able to supply 68 buses with autonomy of 200 to 300 km per day. The incorporation of the hydrogen production process by steam reforming represents an attractive alternative to the sugar-alcohol sector.

This work aims an ecological and exergetic analysis of the hydrogen production by steam reforming of part of the ethanol produced in a sugar-ethanol plant. The Pioneiros Distillery, located in São Paulo, is used as model for this study. Three cases are described. In case 1 the plant produces energy only for domestic needs. A part of bagasse is not burned and it is stored. In Case 2, all available bagasse is used for production of steam. Part of the steam is used in the production process meeting the demand of the plant and the rest of steam is converted into electrical energy that can be sold at concessionaires. In Case 2 it is produced more energy than in Case 1. Case 3 includes the production of hydrogen by steam reforming of a part of the produced ethanol. Steam and energy for steam reforming is generated from combustion of bagasse. An exergetic analysis is performed. The exergy flows associated with the sugar-ethanol plant are calculated locating and quantifying the losses and irreversibility.  The ecological impact of use of the bagasse as fuel to generate thermal and electrical energy for the ethanol reformer was studied. The main pollutants that damage the atmosphere, namely: CO, CO2, NOx and PM have been taking into account. Carbon Dioxide emissions were calculated taking into account the carbon cycle (considering the absorption of carbon dioxide by the sugarcane during its growth), resulting in negative balance emissions, i.e., carbon dioxide was absorbed in higher amounts than emitted. The thermodynamics (ηsystem) and ecological (ε) efficiencies of Steam reforming of ethanol were calculated. The thermodynamic efficiency was 56% and the ecological efficiency was 80%. When the carbon cycle is taking into account the ecological efficiency is 90%. The incorporation of an ethanol reformer in a sugar-ethanol plant for hydrogen production is a very interesting option where environmental benefits are obtained. Problems related with the storage of bagasse are avoided because all the bagasse is burned for the production of steam and energy to the reformer. The amount of hydrogen that can be produced in Pioneiros Distillery could supply fuel for 68 buses with a range from 200 to 300 km per day.

Renewable energies are fluctuating and the bigger its share on the Swedish energy market, the more fluctuating are the prices. Therefore, CHP plant operators as VEAB in Växjö, are more and more struggling to be competitive. There is, hence, a need of alternative options for the use of produced electricity, rather than being dependent on such a volatile and unclear market. Hydrogen production through water electrolysis could therefore be an alternative to be decoupled from the electricity business and instead being part of a promising, future hydrogen economy. Since state-of-the-art electrolysers have efficiencies between 51% and 75%, it was assessed that some of the efficiency losses could be recuperated by implementing the excess heat in an existing District heating (DH) grid. Calculations of the base scenario electrolyser with a power input of 870 kW showed, that an increase of the overall temperatures of the returning mass flow of the DH grid from 0,05°C to 0,23°C should be achievable. The economic analysis showed, that for this size of hydrogen production unit, the minimum hydrogen selling price (MHSP) would be 6,64 €/kg, which is not competitive on today’s market. However, the sensitivity analysis showed, that by a decreased investment cost, lower electricity prices and especially by scaling up the base scenario, the MHSP could be lowered significantly. Assuming a reduction of investment costs of 20% and scaling up the electrolyser by 1000% to 8700 kW, the MHSP resulted in 1,9 €/kg, a competitive price on the market. This study revealed that hydrogen production could be part of the future business model of CHP plant operators and provides a guideline on the feasibility of such a project.

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This work presents a techno-economic analysis of multiple direct hydrogen production technologies using different blends of Arabian crude oil and natural gas as feedstock: Auto thermal reforming, steam reforming, and combined reforming technologies are thermodynamically and technically evaluated through development of process flowsheets. Comparative analysis indicates that combined reforming using Arabian light crude oil achieves a 22.69 % of hydrogen recovery with carbon capture, which is higher than auto thermal reforming and steam reforming by 0.7 %. At the same time, auto thermal reforming achieves a 26.70 % of hydrogen recovery without carbon capture, which is higher than steam reforming and combined reforming by 4 %. Arabian heavy, medium, light, and extra light are evaluated using auto thermal reforming technology to estimate hydrogen recovery values. A wide range of crude oil and natural gas prices are included in the analysis to calculate hydrogen production cost. With crude oil price at 90 USD/bb, the hydrogen production cost is 2.9 USD/kg, and natural gas prices at 30 USD/MMBtu (Europe), 20 USD/MMBtu (Japan), and 2.5 USD/MMBtu (GCC region), the hydrogen production cost is 4.5, 3.0, and 0.4 USD/kg respectively.

Humanity faces challenge to satisfy its growing energy demand while simultaneously transitioning into a sustainable society. Reducing carbon emissions from the industrial and transportation sector are met with difficulties. To help decarbonisation efforts EU members like Sweden have recognised the use of hydrogen as a viable solution. In 2021, Sweden laid out its national hydrogen strategy, containing desires to out-phase fossil-based hydrogen production with new sustainably alternatives. The question is whether Sweden has any prospect of domestically producing hydrogen in the future.  The purpose of the thesis is to lay out what hydrogen producing techniques could have a future prospect in Sweden, basing their performance on the amount of carbon emitted and energy consumption in a lifecycle perspective. To fulfil the thesis’ purpose, a literature review, and a comparative lifecycle assessment study that covers cradle-to-gate was conducted.  The literature study indicates that several mature options for producing hydrogen exists today and several upcoming techniques could be available in the future. Techniques recognised as mature today covers several process categories: steam reforming, gasifier, electrolyser, biolysis, and thermochemical hybrid.  Techniques that progressed to the LCA study were thermochemical techniques SMR (steam methane reforming) and CG (coal gasification), and electrolysers ALK (alkaline), PEM (proton exchange membrane), and SOEC (solid-oxide electrolyser cell). The techniques’ performance were tested in four scenarios: one in the present and three in the future. The Present scenario indicates that electrolysers were more benign towards global warming impact category than the thermochemical tehcniques’. The future scenario indicates that depending on the scenarios, electrolysers performed either better or worse regarding global warming impact category compared to SMR and SMR with CCS. Regardless of scenario, the LCA study indicates that a shift in burden from climate change to other impact categories could occur by replacing thermochemical techniques with electrolysers.  In conclusion, with the condition set for this thesis, Sweden has a future prospect for domestic hydrogen production, where more environmental benign techniques like electrolysers are possible. It is up to relevant stakeholders to decide whether possible shift in burden is acceptable. / Mänskligheten står inför behovet av att behöva tillgodose sitt växande energibehov samtidigt som transaktionen till ett hållbart samhälle pågår. Minskandet av koldioxidutsläpp från industri- och transportsektorn har mötts med svårigheter. För att minska koldioxidutsläppen har EU medlemmar däribland Sverige accepterat användandet av vätgas som en lösning. 2021 lade Sverige fram sin nationella vätgasstrategi vars innehåll indikerar på en önskan att ersätta nuvarande fossilbaserad vätgasproduktion med hållbara alternativ. Frågan blir ifall Sverige har förutsättningar för inhemsk vätgasproduktion i framtiden.  Syftet med examensarbetet är att presentera vilka vätgasproducerande tekniker som har framtida förutsättningar i Sverige, baserat på deras prestanda gentemot koldioxidutsläpp samt energikonsumtion i ett livscykelperspektiv. För att uppnå syftet med examensarbetet har en litteratur- och komparativ LCA studie som täcker vagga-till-port utförts.  Litteraturstudien indikerar att ett flertal mogna tekniker för att producera vätgas existerar redan idag och att ett flertal tekniker kan komma att vara tillgängliga i framtiden. Tekniker som anses vara mogna idag tillhör flera processkategorier: ångreformering, förgasning, elektrolys, biolys samt termokemisk hybrid.  Tekniker som fortsatte vidare till LCA studien var termokemiska tekniker som SMR och CG, samt elektrolysörer ALK, PEM, och SOEC. Teknikernas förmågor testades i fyra scenarion: en i nutiden och tre i framtiden. Den nutida scenariot indikerar att elektrolysörerna är mer gynnsam mot klimatförändring jämfört med termokemiska tekniker. De framtida scenarion indikerar att beroende på elmix kan elektrolysörerna vara antingen gynnsamma eller missgynnande gentemot global uppvärmning. Oavsett scenario indikerar LCA studien potential till skifte i börda från global uppvärmning kategorin till andra kategorier om ersättandet av terkmokemiska tekniker med elektrolysörer sker.  Sammanfattningsvis, med de inställningar som examensarbetet utgick ifrån har Sverige förutsättningar för inhemsk vätgasproduktion, varav hållbara alternativ som elektrolysörer är möjliga. Det är upp till relevanta aktörer att bedöma utifall skiftandet i börda är acceptabla.

The world energy production, transformation, storage, and usage are under a dramatic change. Actions are being taken by Governments to slow down the effects of the climate change. Wind energy is expected to be a central pillar for this change. However, a key issue facing the expansion of wind energy, especially in Sweden, is the integration of the massive amounts of new generation into the electricity grid (Energinet et al., 2021; Ingeberg, 2019; IVA, 2020). Another challenge facing the expansion of the wind energy is that it can’t be used by end-sector which rely on energy-dens carriers (IRENA, 2020b). In the pursuit of solutions to these challenges, green hydrogen produced by offshore wind energy emerges an alternative. Motivated by the recent Swedish plans to develop offshore wind power capacity in the Baltic Sea, as well as the problematic environmental statues in the Baltic Sea, this work investigate the cost of green hydrogen produced from offshore wind energy in Sweden and evaluates the environmental impacts of utilizing by-product oxygen on the marine ecosystem in the Baltic Sea.  The first step of this work considers the economic feasibility of a 2 GW offshore wind energy dedicated for hydrogen production in the Baltic Sea outside Sweden, with three alternative electrolyzer placement: onshore electrolyzer (III), centralized offshore electrolyzer (II), and decentralized offshore electrolyzer (I). The proposed assessment of this work investigated the hydrogen production cost using electricity from offshore wind energy in the Baltic Sea in Sweden. The LCoE and LCoH in relation to three configurations reflecting the electrolyzer placement were analyzed and compared. The electrolyzer operation at nominal capacities of 06%, 65%, and 70% were considered for the three configurations. The results shows that the LCoE and LCoH differed between the three configurations. The results showed that the lowest LCoE and LCoH is achieved by the configuration where the electrolyzer system decentralized at the turbine platform at a price of 1.7 €/kg. Reflecting the impact of the electrolyzer nominal capacities, which are at 60%, 65%, and 70%, on the LCoH, the result showed that the three configurations are equally competitive. However, when the nominal capacity of 65% were compared among the three configurations, it was showed that the LCoH at the onshore electrolyzer were 2.6 €/kg compared to the LCoH at the centralized electrolyzer which resulted in LCoH of 2.7 €/kg. The second step of this work considers the evaluation of the environmental impact of artificial oxygenation by reviewing existing studies. The results of the reviewed studies on the environmental impacts of artificial oxygenation indicate that the utilization of the by-product oxygen would contribute to important environmental benefits for the Baltic Sea. The use of the by-product oxygen to oxygenate would maintain the processes that removes nutrients, keep the sea water oxygenated, and the seabed habitable for marine animal. There are, however, some aspects that need to be considered and understood when planning for oxygenation, such as the complicated physical and biogeochemical interactions. Hence, this requires further studies and investigations.

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