Browsing by Author "Santasalo-Aarnio, Annukka"

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  • Analysis of business model failure of engineering companies and tools to avoid it
    (2020-10-19) Bhole, Nikhil
     Insinööritieteiden korkeakoulu | Master's thesis
    Of all the companies that are formed each year, only 30% of them make it beyond 10 years or longer. This states that 70% of the companies have flaws in their business model, they do something wrong that eventually leads to failure. This thesis is an attempt to analyze the factors that are responsible for the failure of the companies (Start-ups, SME’s & Large organizations) and compare the result of the failed companies with that of a successful company. This thesis is a part of the project ‘Bridging circular economy technologies and business models to advance system-level sustainability research’ at Aalto University. The main idea behind the project was to explore a cross-disciplinary approach in different disciplines such as engineering technology, business, and art & design. Qualitative analysis was adopted as the primary research methodology for this report and the case study approach was selected for this due to the exploratory nature of the research. Overall five cases were studied and analyzed in this thesis work. Three of the five cases were failure analysis cases (Asian Electricals, Nokia, European Batteries Oy.) where the focus was on the failure engineering companies, whereas the remaining two cases were a success (Fortum) and workshop cases. Case studies explain the factors responsible for the failure and success of the respective companies. The business model canvas is used as the main tool to analyze failures and success in the case companies. The majority of the case studies were based on the fundamental of the circular economy. A thorough analysis of literatures comprised of journal papers, blogs, interviews, analysis reports, it was found that lack of a holistic approach and business model innovation failure were the main findings from failure analysis whereas successful business model Innovation and multidisciplinary approach were the success factors.
  • Application of Synthetic Renewable Methanol to Power the Future Propulsion
    (2020-09-15) Santasalo-Aarnio, Annukka; Nyari, Judit; Wojcieszyk, Michal; Kaario, Ossi; Kroyan, Yuri; Magdeldin, Mohamed; Larmi, Martti; Järvinen, Mika
     A4 Artikkeli konferenssijulkaisussa
    As CO2 emissions from traffic must be reduced and fossil-based traffic fuels need to phase out, bio-based traffic fuels alone cannot meet the future demand due to their restricted availability. Another way to support fossil phase-out is to include synthetic fuels that are produced from circular carbon sources with renewable energy. Several different fuel types have been proposed, while, methanol only requires little processing from raw materials and could be used directly or as a drop-in fuel for some of the current engine fleet. CO2 emissions arising from fuel production are significantly reduced for synthetic renewable methanol compared to the production of fossil gasoline. Methanol has numerous advantages over the currently used fossil fuels with high RON and flame speed in spark-ignition engines as well as high efficiency and low emissions in combustion ignition engines. Feasible options for engine development or upgrading for methanol have been presented separately in the past work but not considering the whole value chain. The results indicate that high concentration methanol blends will increase significantly tank-to-wheel efficiency, lower energy consumption and CO2 emissions, while their volumetric fuel consumption will increase compared to gasoline, due to the low calorific content of methanol. The work visualizes the impact on CO2 emissions for methanol-fueled transport applications and overall suitability for propulsion. For marine sector, successful demonstrations reveal high maturity of engine technology using methanol fuel. This work also highlights further development needs of synthetic renewable methanol to become a sustainable future transport fuel.
  • Aspen plus-based techno-economic assessment of a solar-driven calcium looping CO2 capture system integrated with CaO sorbent reactivation
    (2024-07) Jiang, Dingyi; Li, Shouzhuang; Santasalo-Aarnio, Annukka; Järvinen, Mika
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Given the gradual nature of the energy transition, retrofitting coal-fired power plants with carbon capture technology is crucial. The calcium looping (CaL) process is a promising solution, with challenges like absorbent deactivation and reduced thermal efficiency mitigated by absorbent reactivation and heat recovery systems. This study evaluated the techno-economic feasibility of integrating a novel wet extraction and precipitation process for absorbent reactivation within a solar-assisted CaL system, alongside an existing coal power plant. The process incorporated a secondary steam cycle and an ammonia absorption chiller for enhanced heat recovery and district cooling. The integrated project could increase daily power generation by 50% and reduce CO2 emissions from 820.4 g/kWh to 54.5 g/kWh. Over its lifespan, the reactivation facility could reduce limestone extraction by 21 Mt with 90% capture efficiency. With a levelized cost of electricity (LCOE) of 116.1 €/MWh and breakeven electricity selling price (BESP) of 56.6 €/MWh, the system demonstrated promising commercial viability, with the reactor and concentrated solar heating (CSH) system making up over 60% of investment costs. CSH cost and solar abundance were identified as key factors, indicating potential feasibility even in higher latitude regions. At CO2 revenues of 150 €/t, a stand-alone capture project can break even based solely on CO2 sales, demonstrating its potential for expansion to other areas. A case study highlighted the benefits of integrating absorbent reactivation and an ammonia absorption chiller, improving both economics and carbon capture efficiency. The study also confirmed the viability of solar-assisted projects in high-latitude regions, with optimistic future CO2 revenues and advancements in carbon capture technology enhancing feasibility.
  • Aurinkotornilla tuotetun lämmön varastointi
    (2019-04-21) Lassinen, Miia-Emilia
     Insinööritieteiden korkeakoulu | Bachelor's thesis
  • Awareness increases acceptance and willingness to pay for low-carbon fuels amongst marine passengers
    (2024-02-15) Nyári, Judit; Toldy, Árpád I.; Järvinen, Mika; Santasalo-Aarnio, Annukka
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    One of the main applications discussed in decarbonising the marine sector is via alternative fuels, such as methanol and ammonia, produced from renewable hydrogen. These alternative, low-carbon fuels often come with increased prices and operational expenses for the vessel operators, which are ultimately reflected in the passengers' costs. Therefore, it is important to assess passengers' familiarity with expressions linked to decarbonisation and their willingness to pay this ‘green premium’ for alternative fuels. To assess these, we ran a survey-based study and collected close to 2000 answers through different channels from marine passengers, specifically from those travelling in the Northern European region on roll-on/roll-off passenger (RoPax) vessels. We found that most of the passengers prioritise environmental friendliness in marine fuels and are concerned about environmental issues. However, there seems to be a lack of knowledge about fuels and fuel technologies. Familiarity with certain alternative fuel-related expressions results in a more positive view of them. The observed willingness to pay is affected by the level of education, income, and place of residence, in addition to the level of concern about environmental issues, frequency of travel and spending on trips. Close to 80% of passengers are willing to increase their spending if the vessel is powered by a low-carbon, alternative fuel. As the results indicate that the more passengers know about alternative fuels and their benefits, the more willing they are to pay for them, it is recommended that RoPax operators invest in educating them.
  • Battery analytics-driven rental-like agreements for lithium-ion batteries
    (2022-01-24) Godlewski, Wojciech
     Insinööritieteiden korkeakoulu | Master's thesis
    Due to the Lithium-Ion battery’s exceptionally desirable parameters such as high energy density and low discharge rate, it has become the most popular and dynamically developing energy storage technology, both for stationary systems and as a source of power in mobile applications. Apart from the high price, one of its main downsides is degradation, which leads to loss of capacity, an increase of internal resistance, and a risk of failure. This process is very complex and strongly dependent on battery operating parameters, such as temperature, voltage, current, State-of-Charge, number, and depth of cycles. The analysis conducted using a semi-empirical, testbench data-based degradation model with e-bus in-field operating data as input shows, that the degradation rate varies significantly even for small changes in working parameters’ values. Cases with usage profiles with parameters higher or lower by 2/5/10/15% compared to mean monthly values were investigated. In extreme cases, the degradation rate was higher by 66% (15% higher parameters) or lower by 37% (15% lower parameters). Moreover, only by aggregating real monthly parameters into mean ones, the resulting degradation rate changed by 20%. In extreme cases, the difference of monthly degradation rate between minimum and maximum values was 46%. Also, the impact of considering battery degradation on revenue in stationary and mobile applications was analyzed. The authors claim that an optimal usage profile that minimizes battery degradation leads to a significant increase in battery life and results in higher revenues or savings. Both calculations and results from the literature, lead to the conclusion that by knowing usage profile one is able to better assess battery degradation, its lifetime and as a result make better decisions. These observations may be used in the battery rental business for stationary or mobile applications. Nowadays, battery analytics are not widely used in the rental business and there is no differentiation between rental prices based on users’ profiles. This may lead to inaccurate financial projections, lack of trust on both sides and result in the battery rental business being not feasible. In this work, the framework of the analytics-driven rental-like agreement was shown, with necessary stakeholders, relations between them, and methodology for conducting such agreement. Battery working parameters are collected to verify the contract and potentially adjust the rental price. Moreover, a simplified method of monthly rent calculation was proposed. Finally, this method was demonstrated in an example.
  • Biomassan kestävyys ja sen osoittaminen energiantuotannossa
    (2020-05-18) Forss, Fredrik
     Insinööritieteiden korkeakoulu | Master's thesis
    EU on asettanut tavoitteekseen vähentää kasvihuonekaasupäästöjään vähintään 40 %:lla vuoden 1990 tasosta vuoteen 2030 menneessä. Jotta kasvihuonekaasupäästöjen vähennystavoitteet saavutettaisiin, EU julkaisi joulukuussa 2018 uuden direktiivin uusiutuvista lähteistä peräisin olevan energian käytön edistämisestä, joka tunnetaan nimellä RED II. RED II-direktiivi sisältää bioperäisille polttoaineille kestävyys- ja kasvihuonekaasupäästövähennyskriteereitä. Kestävyys- ja kasvihuonekaasupäästövähennyskriteerit koskevat sekä liikenteessä käytettäviä biopolttoaineita ja -nesteitä että energiantuotannossa käytettäviä biomassapolttoaineita. Energiantuotannossa biomassapolttoaineiden on täytettävä kestävyys- ja kasvihuonekaasupäästövähennyskriteerit, jotta ne laskettaisiin uusiutuviksi energianlähteiksi ja niiden käyttö olisi laskennallisesti nollapäästöistä. Energiatuottajien on myös osoitettava, että heidän käytetyt bioperäiset polttoaineet täyttävät kestävyys- ja kasvihuonekaasupäästövähennyskriteerit. Kestävyys- ja kasvihuonekaasupäästövähennyskriteereiden täyttyminen riippuu polttoaineen alkuperästä ja elinkaaren aikaisista kasvihuonekaasupäästöistä. Työssä selvitetään miten kestävyys- ja kasvihuonekaasupäästövähennyskriteerit vaikuttavat Helen Oy:n toimintaan ja nykyiseen polttoainevalikoimaan analysoimalla RED II -direktiivin sisältöä ja Helen Oy:n käyttämien bioperäisten polttoaineiden alkuperää ja elinkaaren aikaisia päästöjä. Kriteereiden täyttyminen selvitetään elinkaariarvioinnilla myös sellaisille polttoaineille, jotka eivät ole tällä hetkellä Helen Oy:llä käytössä. Tarkistettavat uudet polttoaineet ovat auringonkukansiemenestä tehty pelletti, Venäjältä hankittu hake ja suomalaisista kannoista tehty murske. Työssä hahmotellaan myös kestävyysjärjestelmää, millä Helen Oy voisi osoittaa kestävyys- ja kasvihuonekaasupäästövähennyskriteereiden noudattamisen. Tuloksien perusteella kaikki Helen Oy:n nykyiset bioperäiset polttoaineet täyttäisivät kestävyys- ja kasvihuonekaasupäästövähennyskriteerit ilman lisätoimenpiteitä. Elinkaariarvioinnin perusteella uudet, ei käytössä olevat polttoaineet täyttäisivät ainakin kasvihuonekaasupäästövähennyskriteerit. Toimivan kestävyysjärjestelmän kehittäminen on mahdollista Helen Oy:n puolesta hyödyntämällä jo käytössä olevaa toimitusketjun hallintajärjestelmää.
  • Biomechanical behaviour of scaffold materials for articulate cartilage repair
    (2017-06-13) Zühlke, Alexandra
     Kemian tekniikan korkeakoulu | Master's thesis
  • Blending Behavior of Hydrocarbon and Oxygenate Molecules to Optimize RON and MON for Modern Spark-Ignition Engines (SI)
    (2020-09-15) Knuutila, Lotta; Kaario, Ossi; Larmi, Martti; Santasalo-Aarnio, Annukka; Karvo, Anna; Kiiski, Ulla
     A4 Artikkeli konferenssijulkaisussa
    Gasoline blending is known to be complicated, because individual gasoline fractions with different octane numbers, Research Octane Number (RON) or Motor Octane Number (MON) do not always blend linearly. Instead, they may blend non-linearly, in a synergistic or antagonistic manner. Even though RON and MON are regulated properties, linear and non-linear octane blending is not a broadly understood topic. The target in the developing process of a modern SI engine is to have 100% combustion efficiency which would lead to the reduction of hydrocarbon and carbon monoxide emissions. Therefore, the properties of gasoline, especially RON and MON, need to be optimized to ensure proper ignition in the engine and prevent harmful autoignition reactions. There are hundreds of hydrocarbons in gasoline which have different octane numbers (ON). The explanations for these variations are the structural differences in hydrocarbon molecules that influence on their reactivity. For instance, longer n-paraffins have lower octane numbers compared to aromatics where electrons are delocalized around their ring which increases stability of aromatics and thus, ON. In this paper, we report and visualize qualitatively the octane blending behaviour of different hydrocarbon and oxygenate molecules to facilitate gasoline components mixing to produce high quality gasoline for clean combustion. The present study shows ethanol to blend non-linearly, but synergistically with paraffins and olefins, while the blending with aromatics is antagonistic. We also conclude that oxygenate molecules such as furans and cyclic ketones, blend synergistically with hydrocarbons. However, predicting the ON of end gasoline is challenging, as gasoline is not a blend of two components, but rather a blend of many isomers and functional groups. Therefore, in this study we highlight the need for more complex blending models than binary ones.
  • Blending strategies and process modification for the future gasoline production
    (2019-12-16) Knuutila, Lotta
     Kemian tekniikan korkeakoulu | Master's thesis
    The amount of the registered gasoline cars increased 6.5 percentage unit in Europe in 2018 that will forecast the gasoline production to continue still several decades, even though its drawbacks are the harmful CO2 emissions that accelerate the global warming. Therefore, the research needs to concentrate on the development of the renewable feed-stocks for gasoline. However, their problem could be the different properties compared to fossil gasoline. This master has collected the wide property database for the existing gasoline blending components that the gasoline blending can utilize to optimize the high-quality of gasoline also from the renewable feedstocks in the future. With the help of the gasoline blending components and their properties in the database are identified the hydrocarbon structure, physical properties and octane numbers of each gasoline component. The octane number, especially research octane number (RON) is the main property that this master thesis concentrates because it defines the behaviour of gasoline in the engine. The database reports RONs for each gasoline blending components that differ from each other. The results of the thesis show that the gasoline consist of over 100 different hydrocarbon compounds such as aromatics and paraffins and possible also of alcohols and ethers. These compounds have the highest impact on the RON that depends on their reactivity differences. Higher reactivity decreases the RON and increases the probability of knocking that could destroy the engine parts. The results show that the most viable organic compounds to avoid knocking are aromatics and ethanol. There is noticed in the results of the thesis that positions of double bond and the side groups in the carbon backbone, the length of it and the OH-groups influence on the reactivity of compound. Especially, the positions of methyl groups in aromatics influence significantly on their RON. The methyl groups in the adjacent carbons decrease the RON of aromatics compared to those that have methyl groups further each other. These structural differences of the compounds are important to concern in the gasoline production, because they could affect to the properties of final product. In the master thesis is researched the octane blending of different compound groups and noticed that ethanol blends non-linearly, but synergistic with paraffins and olefins, while the blending with aromatics is antagonistic. There is noticed the increase of methyl groups in aromatics to shift the blending more linear and even synergistic with ethanol. Moreover, thesis provides the outlook for the renewable feedstocks like terpenes and furans that the existing gasoline upgrading units could modify to fill the requirements of FQD and simultaneously produce renewable gasoline.
  • Challenging the concept of electrochemical discharge using salt solutions for lithium-ion batteries recycling
    (2018-06) Ojanen, Severi; Lundström, Mari; Santasalo-Aarnio, Annukka; Serna Guerrero, Rodrigo
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    The use of lithium-ion batteries (LIB) has grown significantly in recent years, making them a promising source of secondary raw materials due to their rich composition of valuable materials such as Co, Ni and Al. However, the high voltage and reactive components of LIBs pose safety hazards during crushing stages in recycling processes, and during storage and transportation. Electrochemical discharge by immersion of spent batteries in salt solutions has been generally accepted as a robust and straightforward discharging step to ad- dress these potential hazards. Nonetheless, there is no clear evidence in the literature to support the use of electrochemical discharge in real systems, neither are there clear indications of the real-world limitations of this practice. To that aim, this work presents a series of experiments systematically conducted to study the be- havior of LIBs during electrochemical discharge in salt solutions. In the first part of this study, a LIB sample was discharged ex-situ using Pt wires connected to the battery poles and submerged into the electrolyte solu- tion on the opposite end. The evolution of voltage in the battery was measured for solutions of NaCl, NaSO4, FeSO4, and ZnSO4. The results indicate that, among the electrolytes used in the present study, NaCl solution is the most effective for LIBs discharge. The discharge of LIB using sulfate salts is however only possible with the aid of stirring, as deposition of solid precipitated on the electrodes hinder the electrochemical discharge. Furthermore, it was found that the addition of particulates of Fe or Zn as sacrificial metal further enhances the discharging rate, likely due to an increased contact area with the electrolyte solution. While these findings support the idea of using electrochemical discharge as a pre-treatment of LIBs, severe corrosion of the battery poles was observed upon direct immersion of batteries into electrolyte solutions. Prevention of such corrosion requires further research efforts, perhaps focused on a new design-for-recycling approach of LIBs.
  • Choice of the kinetic model significantly affects the outcome of techno-economic assessments of CO2-based methanol synthesis
    (2022-11-01) Nyári, Judit; Izbassarov, Daulet; Toldy, Árpád I.; Vuorinen, Ville; Santasalo-Aarnio, Annukka
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Carbon dioxide hydrogenation to methanol is a cornerstone of the CO2 utilization toolkit, and its comparison to fossil-based methanol through techno-economic assessments (TEAs) has helped establish barriers to its commercial feasibility. TEAs are often performed in process simulation software that relies on kinetic models (KMs). The choice of KM could influence the outcome of the TEA, however, their effect has not been quantified earlier. This study quantifies this effect through TEAs performed using three different KMs in Aspen Plus™. Three KMs are selected for comparison: two of them are commonly used in TEAs while also a third, a recently published model, will be studied herein. The models are first validated in Aspen Plus™ and then compared in a series of sensitivity analyses in a one-pass reactor. Finally, a TEA study is conducted for a large-scale methanol plant to investigate the effects of the KM choice. It was found that the choice of the kinetic model significantly influences the results of TEAs as it can result in a 10% difference in the levelized cost of methanol. This can be mainly attributed to differences in one-pass yield. As CO2 utilization approaches economic viability, understanding such uncertainties will be crucial for successful project planning. Hence, these results suggest that extending a TEA's sensitivity analysis to cover the KM's contribution could increase confidence in the robustness of the TEA.
  • Cold-crystallizing erythritol-polyelectrolyte: Scaling up reliable long-term heat storage material
    (2020-05-15) Turunen, Konsta; Yazdani, Maryam Roza; Puupponen, Salla; Santasalo-Aarnio, Annukka; Seppälä, Ari
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Renewable energy usage would benefit from efficient and high-capacity long-term heat storage material. However, these types of material solutions still lack reliable and durable operation on bulk level. Previously, we showed that cold-crystallizing material (CCM), which consists of erythritol in cross-linked polymer matrix, stored heat for a long-term period in a milligram scale by supercooling stably and preventing undesired crystallization during storage. Crystallization of CCM can be triggered efficiently by re-heating the material (i.e. cold-crystallization). Supercooling and cold-crystallization are stochastic phenomena which manifest in a way that the properties in bulk scale often deviate from the microscale. In this work, we scale up CCM to a bulk size of 160 g, and analyze its supercooling and crystallization characteristics for long-term heat storage. In order to identify the impact of the scale-up on the tested compositions and to discover optimal storage conditions, CCM samples are maintained in storage mode at constant temperature between 0 and 10 °C and up to 97 days. To this end, the thermal chamber measurement procedure estimates the heat release of CCM samples based on the measured temperature data and the one-dimensional transient heat conduction model. Results indicate that the heat release in cold-crystallization is over 70% of the melting heat. This heat can be stored without reduction for at least 97 days, demonstrating the reliable performance of long-term heat storage. Analysing the thermal properties of CCM compositions indicates a maximum volumetric storage capacity of 250 MJ/m3 and excellent properties for further heat storage applications.
  • Construction and optimization of SO2 depolarized electrolyser
    (2023-08-21) Narayana Prasad, Pragya
     Insinööritieteiden korkeakoulu | Master's thesis
    Green hydrogen is needed as an energy carrier in the energy transition away from fossil energy sources. For this reason, large quantities of renewable energy-based hydrogen will be required in the near future. Most of this will be produced by PEM water electrolyser technology, which has the disadvantage of requiring high overvoltage to break the water molecule into hydrogen and oxygen gas products. If SO2 is added to the anode, the reaction changes, and SO2 is oxidized to sulphuric acid, but simultaneously protons are created that can transport via a proton conductive membrane to the cathode to produce hydrogen. This reaction has the advantage of significantly lower standard potential E° ~ 0.17 V compared to conventional water electrolysis. This has two implications: a larger amount of hydrogen can be produced with the same quantity of renewable energy, and as the potential of the anode is lower, the material requirements are less demanding. However, as SO2 is introduced to the system and can carry over to the cathode, it will be reduced to elemental Sulphur or H2S gas. The thesis aims at building the setup and performing preliminary experiments that would help reduce the sulphur and H2S production, thus increasing the system's reliability. The results of the thesis show that there is enormous scope for improvement in the system, and being a complex system, it consists of multiple parameters that need to be taken into account, thus opening a window of opportunities. The effect of the addition of SO2 to the anolyte, the required system improvements, and prospects have also been discussed in detail. The thesis also emphasizes the necessity for upgraded gas analysis to precisely measure gases produced in the cathode compartment, such as hydrogen, SO2, and H2S. Gas chromatography-mass spectrometry is recommended for precise detection to address the shortcomings of gas sensors. Additionally, emphasis is placed on the significance of pH assessment, leak prevention, and tank maintenance. Future studies will involve evaluating various membranes, investigating the usage of used catholyte as anolyte, implementing various flow fields, and tackling issues with the SDE system's parasitic processes and membrane properties.
  • Cost optimization of power-to-methane process with dynamic modelling
    (2022-08-22) Konttila, Elisa
     Kemian tekniikan korkeakoulu | Master's thesis
    Two major crisis, climate change and Russian war on Ukraine, disturb the stability of the current energy system. Alternative fuels must be developed to limit the global warming and to ensure the energy security in European countries. Synthetic natural gas (SNG) can respond to these needs because of its renewable origin and its properties that match the ones of fossil natural gas. Because of the increasing amount of fluctuating renewable energy, demand response will play a large role in the future energy system. Therefore, it is important to study the dynamic properties of the production of SNG, process called Power-to-Methane, and if the process could adjust its load according to electricity prices. In this thesis, the dynamic capabilities of Power-to-Methane were reviewed, as well as the requirements that must be fulfilled in order to the participate to demand response. It was concluded that electrolysers have the best dynamic properties of the process components and are able to participate to most of the market places in the Finnish electricity system. A Simulink model was created to study the optimal dynamic operation method of the electrolyser with regards to decreasing electricity costs of the operation. In addition, an optimal intermediate hydrogen storage size was found with which the total costs of the process were the lowest. The optimal storage size was 3100 or 4650 kg depending on the electricity price scenario that was modelled. The results of the economic analysis show that the costs of the process can be significantly reduced with dynamic operation when electricity is bought with spot market prices. However, current electricity prices are too high to be able to profit from the production even with dynamic operation. When electricity prices from the beginning of 2021 were utilized, the production was profitable. The most profitable process was achieved with steady operation with average PPA-price from Finland. Dynamic operation with the most fluctuating electricity prices resulted in the largest cost reductions. When increasing the share of renewable electricity, the prices evolve to be cheaper and more volatile due to the low generation cost and intermittent nature of renewable energy. Therefore, dynamic operation can be a more cost-effective method to produce SNG in the future. Additionally, increasing natural gas prices contribute to this process becoming more feasible.
  • Cost-effective Electro-Thermal Energy Storage to balance small scale renewable energy systems
    (2021-09) Tetteh, Sampson; Yazdani, Maryam Roza; Santasalo-Aarnio, Annukka
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    To decarbonise the energy production system, the share of renewable energy must increase. Particularly for small-scale stand-alone renewable energy systems, energy storage has become essential in providing electricity when the demand is high, for example, during the night. Although there are many different storage technologies, only a few are suitable for small-scale stand-alone renewable systems. Those systems must be modular and scalable to be deployed according to the capacity needed. Currently, batteries are among the leading grid storage technologies, but the demand, particularly for Lithium-ion batteries, is also high because of the electrification needs of the transportation sector. Therefore, the question of material availability might become an issue in the future, as Lithium is a scarce and critical element. As an alternative, we introduce a new modular electro-thermal energy storage (ETES) technology that is suitable for various storage needs. This storage unit can utilise various thermal storage materials (thermal oil, molten salt, and sand) at high capacities and improved efficiencies. Our design consists of the embedment of Stirling engines and an electric heater into a thermally insulated storage tank. The source electricity is first converted to heat stored in the storage tank and then converted back to electricity when needed. Among the thermal energy storage materials studied here, sand enabled the storage system's efficiency to reach 85% thanks to its wide range of operating temperatures. The cost is projected to be up to six times lower than that of current Lithium-ion batteries. This new electro-thermal energy storage provides a promising cost-efficient, high capacity alternative for stand-alone energy systems.
  • A critical review of lithium-ion battery recycling processes from a circular economy perspective
    (2019-12-01) Velázquez-Martínez, Omar; Valio, Johanna; Santasalo-Aarnio, Annukka; Reuter, Markus; Serna-Guerrero, Rodrigo
     A2 Katsausartikkeli tieteellisessä aikakauslehdessä
    Lithium-ion batteries (LIBs) are currently one of the most important electrochemical energy storage devices, powering electronic mobile devices and electric vehicles alike. However, there is a remarkable difference between their rate of production and rate of recycling. At the end of their lifecycle, only a limited number of LIBs undergo any recycling treatment, with the majority go to landfills or being hoarded in households. Further losses of LIB components occur because the the state-of-the-art LIB recycling processes are limited to components with high economic value, e.g., Co, Cu, Fe, and Al. With the increasing popularity of concepts such as “circular economy” (CE), new LIB recycling systems have been proposed that target a wider spectrum of compounds, thus reducing the environmental impact associated with LIB production. This review work presents a discussion of the current practices and some of the most promising emerging technologies for recycling LIBs. While other authoritative reviews have focused on the description of recycling processes, the aim of the present was is to offer an analysis of recycling technologies from a CE perspective. Consequently, the discussion is based on the ability of each technology to recover every component in LIBs. The gathered data depicted a direct relationship between process complexity and the variety and usability of the recovered fractions. Indeed, only processes employing a combination of mechanical processing, and hydro-and pyrometallurgical steps seemed able to obtain materials suitable for LIB (re)manufacture. On the other hand, processes relying on pyrometallurgical steps are robust, but only capable of recovering metallic components.
  • Critical review on Li ion battery recycling technologies
    (2017-06-13) Valio, Johanna
     Kemian tekniikan korkeakoulu | Master's thesis
    The purpose of this thesis is to offer a critical review of existing and emerging recycling technologies for lithium ion batteries (LiBs), based on a literature research. Additionally LiBs as sources of secondary raw materials are described, and the current status and possibilities of mechanical processing methods in LiBs recycling is studied. Five industrial and four emerging technologies are analysed in detail based mainly on information provided by scientific articles and patents. LiBs are used increasingly for providing energy to portable applications and electric mobility. The opera-tion principle of LiB is based on the layered active electrode materials that enable Li-ion insertion and transfer between the electrodes during discharge and charge. The performance and properties of LiB are especially dependent on the active cathode material. In present commercial LiB cells it consists of one of the five different compound types containing Co, Ni, Mn and Fe in different proportions, in addition to Li. Other materials in LiBs are graphite, Al and Cu foils, polymeric separator, electrolyte consisting of Li salt and organic materials, and the cell casing of stainless steel, Al or polymer. End-of-life batteries can have charge left, they can produce flammable and toxic gases, and they can contain flammable elemental Li – facts that have to be considered in recycling process. In the studied technologies, mechanical, pyrometallurgical and hydrometallurgical techniques are utilized in different combinations for the recovery of LiB materials. Usually pyrometallurgical or mechanical treatment starts the process, followed by hydrometallurgical recovery of the cathode materials. Pyrometallurgical treatment loses Al and Li in slag but has the capability of treating mixed feed. In mechanical treatment, more materials can be saved but extra attention is needed for safe handling of the batteries: the batteries are discharged prior to crushing, and/or comminution is carried out in protective medium. The crushed materials are separated with magnetic (Fe, SS) and density based materials (Al, Cu, polymers), and differing particle size of particular materials. Combination of several crushing and separation steps or thermal treatment can be used for improved detachment of active cathode material from the foil which is crucial for the success of the recovery of cathode materials in the following hydrometallurgical treatment. Only part of the once high-cost primary materials of the cell can be feasibly recycled to be used again. Co has been the driving force for recycling LiBs. Li is usually recovered in the end as a carbonate. For graphite and electrolyte recovery there exists methods, but the economic feasibility is questionable. Different organic materials have in general lost their value in the end-of-life of the cell. In some emerging technologies the goal is to produce cathode precursor material directly as an outcome of the mechanical and hydrometallurgical steps. This potentially saves more of the original cathode compound value, but requires also stricter processing conditions and control of the feed. Novel technologies consider the recovery other cathode compound materials than just Co, but are not able to treat the mixed cathode materials at the same time. Especially LiFePO4 is challenging material, because it has a low recycling value, and constitutes an impurity in the leaching process.
  • Decarbonisation challenges in the pulp, paper and paperboard industrial sector
    (2019-12-16) Falcon Reyes, Gerardo
     Kemian tekniikan korkeakoulu | Master's thesis
    The future panorama of the energy consumption and production looks constrained by the environmental agenda, pushing the industrial players, such as the pulp, paper and paperboard sector, to the reduction of their GHG emissions at their production facilities (reducing the carbon footprint). It is convenient to be aware what are the emissions restrictions being enforced and what are the technological options to face such challenges. This project intention is to look into this binomial: energy policies and innovations for decarbonisation. For the later one, innovation, special attention is put on reviewing the conversion technologies -under the umbrella concept of Power-to-X- that could enable synthesising liquid or gaseous fuels derived from captured CO2.
  • Demand response and electricity use optimization for battery chemical plants
    (2022-08-22) Kanerva, Jutta
     Sähkötekniikan korkeakoulu | Master's thesis
    The electricity system is currently in transition towards a more sustainable system – a greater share of electricity will be produced by nuclear and wind power in the future. This transition requires flexibility from other sources, that can be achieved for example from demand response. Even though demand response has somewhat been implemented in industry, information available on the topic is scarce. Thus, this thesis aimed to investigate the opportunities and principles of demand response and the mechanisms of demand response in large industrial projects. Additionally, concrete solutions for demand response utilization were devised. To achieve these aims, the background and principles of battery chemical plants and demand response were investigated, demand response service providers were interviewed and the Finnish electricity system was analyzed. Additionally, two battery chemical plants were examined as reference cases. Demand response was found to have several advantages for industrial projects, as it can bring economic benefits and mitigate the effects of volatile electricity prices. However, it does not have a noticeable effect on the carbon emissions from plant electricity use. For the electricity system in whole, demand response supports the transition to a greener electricity system. The possibilities of demand response participation were found to be extremely dependant on the industrial process in question – the technical de-tails of the process influence the demand response potential, available loads, plant scheduling and potential market participation. The plants examined in the thesis showed preliminary potential for demand response participation and this opportunity should be considered already in the design phase of the plants. However, the preliminary results should be confirmed by investigating the equipment and processes further.