Finland
From Renewable Energy to Sustainable Protein Sources: Advancement, Challenges, and Future Roadmaps
Jan 2022
Publication
The concerns over food security and protein scarcity driven by population increase and higher standards of living have pushed scientists toward finding new protein sources. A considerable proportion of resources and agricultural lands are currently dedicated to proteinaceous feed production to raise livestock and poultry for human consumption. The 1st generation of microbial protein (MP) came into the market as land-independent proteinaceous feed for livestock and aquaculture. However MP may be a less sustainable alternative to conventional feeds such as soybean meal and fishmeal because this technology currently requires natural gas and synthetic chemicals. These challenges have directed researchers toward the production of 2nd generation MP by integrating renewable energies anaerobic digestion nutrient recovery biogas cleaning and upgrading carbon-capture technologies and fermentation. The fermentation of methane-oxidizing bacteria (MOB) and hydrogen-oxidizing bacteria (HOB) i.e. two protein rich microorganisms has shown a great potential on the one hand to upcycle effluents from anaerobic digestion into protein rich biomass and on the other hand to be coupled to renewable energy systems under the concept of Power-to-X. This work compares various production routes for 2nd generation MP by reviewing the latest studies conducted in this context and introducing the state-of-the-art technologies hoping that the findings can accelerate and facilitate upscaling of MP production. The results show that 2nd generation MP depends on the expansion of renewable energies. In countries with high penetration of renewable electricity such as Nordic countries off-peak surplus electricity can be used within MP-industry by supplying electrolytic H2 which is the driving factor for both MOB and HOB-based MP production. However nutrient recovery technologies are the heart of the 2nd generation MP industry as they determine the process costs and quality of the final product. Although huge attempts have been made to date in this context some bottlenecks such as immature nutrient recovery technologies less efficient fermenters with insufficient gas-to-liquid transfer and costly electrolytic hydrogen production and storage have hindered the scale up of MP production. Furthermore further research into techno-economic feasibility and life cycle assessment (LCA) of coupled technologies is still needed to identify key points for improvement and thereby secure a sustainable production system.
Numerical Study on Tri-fuel Combustion: Ignition Properties of Hydrogen-enriched Methane-diesel and Methanol-diesel Mixtures
Jan 2020
Publication
Simultaneous and interactive combustion of three fuels with differing reactivities is investigated by numerical simulations. In the present study conventional dual-fuel (DF) ignition phenomena relevant to DF compression ignition (CI) engines are extended and explored in tri-fuel (TF) context. In the present TF setup a low reactivity fuel (LRF) methane or methanol is perfectly mixed with hydrogen and air to form the primary fuel blend at the lean equivalence ratio of 0.5. Further such primary fuel blends are ignited by a high-reactivity fuel (HRF) here n-dodecane under conditions similar to HRF spray assisted ignition. Here ignition is relevant to the HRF containing parts of the tri-fuel mixtures while flame propagation is assumed to occur in the premixed LRF/ containing end gas regions. The role of hydrogen as TF mixture reactivity modulator is explored. Mixing is characterized by n-dodecane mixture fraction ξ and molar ratio . When x < 0.6 minor changes are observed for the first- and second-stage ignition delay time (IDT) of tri-fuel compared to dual-fuel blends (x = 0). For methane when x > 0.6 first- and second-stage IDT increase by factor 1.4–2. For methanol a respective decrease by factor 1.2–2 is reported. Such contrasting trends for the two LRFs are explained by reaction sensitivity analysis indicating the importance of OH radical production/consumption in the ignition process. Observations on LRF/ end gas laminar flame speed () indicate that increases with x due to the highly diffusive features of . For methane increase with x is more significant than for methanol.
Baseload Electricity and Hydrogen Supply Based on Hybrid PV-wind Power Plants
Sep 2019
Publication
The reliable supplies of electricity and hydrogen required for 100% renewable energy systems have been found to be achievable by utilisation of a mix of different resources and storage technologies. In this paper more demanding parameter conditions than hitherto considered are used in measurement of the reliability of variable renewable energy resources. The defined conditions require that supply of baseload electricity (BLEL) and baseload hydrogen (BLH2) occurs solely using cost-optimised configurations of variable photovoltaic solar power onshore wind energy and balancing technologies. The global scenario modelling is based on hourly weather data in a 0.45° × 0.45° spatial resolution. Simulations are conducted for Onsite and Coastal Scenarios from 2020 to 2050 in 10-year time-steps. The results show that for 7% weighted average cost of capital Onsite BLEL can be generated at less than 119 54 41 and 33 €/MWhel in 2020 2030 2040 and 2050 respectively across the best sites with a maximum 20000 TWh annual cumulative generation potential. Up to 20000 TWhH2HHV Onsite BLH2 can be produced at less than 66 48 40 and 35 €/MWhH2HHV in 2020 2030 2040 and 2050 respectively. A partially flexible electricity demand at 8000 FLh could significantly reduce the costs of electricity supply in the studied scenario. Along with battery storage power-to-hydrogen-to-power is found to have a major role in supply of BLEL beyond 2030 as both a daily and seasonal balancing solution. Batteries are not expected to have a significant role in the provision of electricity to water electrolysers.
Challenges and Outlines of Steelmaking toward the Year 2030 and Beyond—Indian Perspective
Oct 2021
Publication
In FY-20 India’s steel production was 109 MT and it is the second-largest steel producer on the planet after China. India’s per capita consumption of steel was around 75 kg which has risen from 59 kg in FY-14. Despite the increase in consumption it is much lower than the average global consumption of 230 kg. The per capita consumption of steel is one of the strongest indicators of economic development across the nation. Thus India has an ambitious plan of increasing steel production to around 250 MT and per capita consumption to around 160 kg by the year 2030. Steel manufacturers in India can be classified based on production routes as (a) oxygen route (BF/BOF route) and (b) electric route (electric arc furnace and induction furnace). One of the major issues for manufacturers of both routes is the availability of raw materials such as iron ore direct reduced iron (DRI) and scrap. To achieve the level of 250 MT steel manufacturers have to focus on improving the current process and product scenario as well as on research and development activities. The challenge to stop global warming has forced the global steel industry to strongly cut its CO2 emissions. In the case of India this target will be extremely difficult by ruling in the production duplication planned by the year 2030. This work focuses on the recent developments of various processes and challenges associated with them. Possibilities and opportunities for improving the current processes such as top gas recycling increasing pulverized coal injection and hydrogenation as well as the implementation of new processes such as HIsarna and other CO2 -lean iron production technologies are discussed. In addition the eventual transition to hydrogen ironmaking and “green” electricity in smelting are considered. By fast-acting improvements in current facilities and brave investments in new carbon-lean technologies the CO2 emissions of the Indian steel industry can peak and turn downward toward carbon-neutral production.
A General Vision for Reduction of Energy Consumption and CO2 Emissions from the Steel Industry
Aug 2020
Publication
The 2018 IPCC (The Intergovernmental Panel on Climate Change’s) report defined the goal to limit global warming to 1.5 ◦C by 2050. This will require “rapid and far-reaching transitions in land energy industry buildings transport and cities”. The challenge falls on all sectors especially energy production and industry. In this regard the recent progress and future challenges of greenhouse gas emissions and energy supply are first briefly introduced. Then the current situation of the steel industry is presented. Steel production is predicted to grow by 25–30% by 2050. The dominant iron-making route blast furnace (BF) especially is an energy-intensive process based on fossil fuel consumption; the steel sector is thus responsible for about 7% of all anthropogenic CO2 emissions. In order to take up the 2050 challenge emissions should see significant cuts. Correspondingly specific emissions (t CO2/t steel) should be radically decreased. Several large research programs in big steelmaking countries and the EU have been carried out over the last 10–15 years or are ongoing. All plausible measures to decrease CO2 emissions were explored here based on the published literature. The essential results are discussed and concluded. The specific emissions of “world steel” are currently at 1.8 t CO2/t steel. Improved energy efficiency by modernizing plants and adopting best available technologies in all process stages could decrease the emissions by 15–20%. Further reductions towards 1.0 t CO2/t steel level are achievable via novel technologies like top gas recycling in BF oxygen BF and maximal replacement of coke by biomass. These processes are however waiting for substantive industrialization. Generally substituting hydrogen for carbon in reductants and fuels like natural gas and coke gas can decrease CO2 emissions remarkably. The same holds for direct reduction processes (DR) which have spread recently exceeding 100 Mt annual capacity. More radical cut is possible via CO2 capture and storage (CCS). The technology is well-known in the oil industry; and potential applications in other sectors including the steel industry are being explored. While this might be a real solution in propitious circumstances it is hardly universally applicable in the long run. More auspicious is the concept that aims at utilizing captured carbon in the production of chemicals food or fuels e.g. methanol (CCU CCUS). The basic idea is smart but in the early phase of its application the high energy-consumption and costs are disincentives. The potential of hydrogen as a fuel and reductant is well-known but it has a supporting role in iron metallurgy. In the current fight against climate warming H2 has come into the “limelight” as a reductant fuel and energy storage. The hydrogen economy concept contains both production storage distribution and uses. In ironmaking several research programs have been launched for hydrogen production and reduction of iron oxides. Another global trend is the transfer from fossil fuel to electricity. “Green” electricity generation and hydrogen will be firmly linked together. The electrification of steel production is emphasized upon in this paper as the recycled scrap is estimated to grow from the 30% level to 50% by 2050. Finally in this review all means to reduce specific CO2 emissions have been summarized. By thorough modernization of production facilities and energy systems and by adopting new pioneering methods “world steel” could reach the level of 0.4–0.5 t CO2/t steel and thus reduce two-thirds of current annual emissions.
Techno-economic Feasibility of Road Transport of Hydrogen Using Liquid Organic Hydrogen Carriers
Sep 2020
Publication
The cost of storing and transporting hydrogen have been one of the main challenges for the realization of the hydrogen economy. Liquid organic hydrogen carriers (LOHC) are a promising novel solution to tackle these challenges. In this paper we compare the LOHC concept to compressed gas truck delivery and on-site production of hydrogen via water electrolysis. As a case study we consider transportation of by-product hydrogen from chlor-alkali and chlorate plants to a single industrial customer which was considered to have the greatest potential for the LOHC technology to enter the markets. The results show that the LOHC delivery chain could significantly improve the economics of long distance road transport. For economic feasibility the most critical parameters identified are the heat supply method for releasing hydrogen at the end-user site and the investment costs for LOHC reactors.
Material Testing and Design Recommendations for Components Exposed to Hydrogen Enhanced Fatigue – the Mathryce Project
Sep 2013
Publication
The three years European MATHRYCE project dedicated to material testing and design recommendations for components exposed to hydrogen enhanced fatigue started in October 2012. Its main goal is to provide an “easy” to implement methodology based on lab-scale experimental tests under hydrogen gas to assess the service life of a real scale component taking into account fatigue loading under hydrogen gas. Dedicated experimental tests will be developed for this purpose. In the present paper the proposed approach is presented and compared to the methodologies currently developed elsewhere in the world.
A Numerical Performance Study of a Fixed-bed Reactor for Methanol Synthesis by CO2 Hydrogenation
Mar 2021
Publication
Synthetic fuels are needed to replace their fossil counterparts for clean transport. Presently their production is still inefficient and costly. To enhance the process of methanol production from CO2 and H2 and reduce its cost a particle-resolved numerical simulation tool is presented. A global surface reaction model based on the Langmuir-Hinshelwood-Hougen-Watson kinetics is utilized. The approach is first validated against standard benchmark problems for non-reacting and reacting cases. Next the method is applied to study the performance of methanol production in a 2D fixed-bed reactor under a range of parameters. It is found that methanol yield enhances with pressure catalyst loading reactant ratio and packing density. The yield diminishes with temperature at adiabatic conditions while it shows non-monotonic change for the studied isothermal cases. Overall the staggered and the random catalyst configurations are found to outperform the in-line system.
A Direct Synthesis of Platinum/Nickel Co-catalysts on Titanium Dioxide Nanotube Surface from Hydrometallurgical-type Process Streams
Aug 2018
Publication
Solutions that simulate hydrometallurgical base metal process streams with high nickel (Ni) and minor platinum (Pt) concentrations were used to create Pt/Ni nanoparticles on TiO2 nanotube surfaces. For this electrochemical deposition – redox replacement (EDRR) was used that also allowed to control the nanoparticle size density and Pt/Ni content of the deposited nanoparticles. The Pt/Ni nanoparticle decorated titanium dioxide nanotubes (TiO2 nanotubes) become strongly activated for photocatalytic hydrogen (H2) evolution. Moreover EDRR facilitates nanoparticle formation without the need for any additional chemicals and is more effective than electrodeposition alone. Actually a 10000-time enrichment level of Pt took place on the TiO2 surface when compared to Pt content in the solution with the EDRR method. The results show that hydrometallurgical streams offer great potential as an alternative raw material source for industrial catalyst production when coupled with redox replacement electrochemistry.
The Role of Lock-in Mechanisms in Transition Processes: The Case of Energy for Road Transport
Jul 2015
Publication
This paper revisits the theoretical concepts of lock-in mechanisms to analyse transition processes in energy production and road transportation in the Nordic countries focussing on three technology platforms: advanced biofuels e-mobility and hydrogen and fuel cell electrical vehicles. The paper is based on a comparative analysis of case studies.<br/>The main lock-in mechanisms analysed are learning effects economies of scale economies of scope network externalities informational increasing returns technological interrelatedness collective action institutional learning effects and the differentiation of power.<br/>We show that very different path dependencies have been reinforced by the lock-in mechanisms. Hence the characteristics of existing regimes set the preconditions for the development of new transition pathways. The incumbent socio-technical regime is not just fossil-based but may also include mature niches specialised in the exploitation of renewable sources. This implies a need to distinguish between lock-in mechanisms favouring the old fossil-based regime well-established (mature) renewable energy niches or new pathways.
Achieving Carbon-neutral Iron and Steelmaking in Europe Through the Deployment of Bioenergy with Carbon Capture and Storage
Jan 2019
Publication
The 30 integrated steel plants operating in the European Union (EU) are among the largest single-point CO2 emitters in the region. The deployment of bioenergy with carbon capture and storage (bio-CCS) could significantly reduce their emission intensities. In detail the results demonstrate that CO2 emission reduction targets of up to 20% can be met entirely by biomass deployment. A slow CCS technology introduction on top of biomass deployment is expected as the requirement for emission reduction increases further. Bio-CCS could then be a key technology particularly in terms of meeting targets above 50% with CO2 avoidance costs ranging between €60 and €100 tCO2−1 at full-scale deployment. The future of bio-CCS and its utilisation on a larger scale would therefore only be viable if such CO2 avoidance cost were to become economically appealing. Small and medium plants in particular would economically benefit from sharing CO2 pipeline networks. CO2 transport however makes a relatively small contribution to the total CO2 avoidance cost. In the future the role of bio-CCS in the European iron and steelmaking industry will also be influenced by non-economic conditions such as regulations public acceptance realistic CO2 storage capacity and the progress of other mitigation technologies.
National Hydrogen Roadmap for Finland
Nov 2020
Publication
Hydrogen has been used as an industrial chemical for more than 100 years. Today hydrogen is used to manufacture ammonia and hence fertilizers as well as methanol and hydrogen peroxide both vital feedstocks for a wide variety of different chemical products. Furthermore in oil refineries hydrogen is used for the processing of intermediate products as well as to increase the hydrogen contents of the final products that are used propel the vehicles. However hydrogen has recently achieved new attention for its capabilities in reducing carbon emissions to the atmosphere. Producing hydrogen via low or totally carbon-free ways and using this “good” low-carbon hydrogen to replace hydrogen with a larger carbon footprint we can reduce carbon emissions. Furthermore using renewable electricity and captured carbon we can synthesise many such chemical products that are currently produced from fossil raw materials. This “Power-to-X” (P2X) is often seen as the eventual incarnation of the hydrogen economy. In addition the progress in technology both in hydrogen fuel cells and in polymer electrolyte electrolysers alike has increased their efficiencies.<br/>Furthermore production costs of renewable electricity by wind or solar power have lowered significantly. Thus cost of “good” hydrogen has also decreased markedly and production volumes are expected to increase rapidly. For these reasons many countries have raised interests in “good” hydrogen and have created roadmaps and strategies for their involvement in hydrogen. Hydrogen plays a key role also in combating climate change and reaching Finland's national goal of carbon neutrality by 2035. In recent years many clean hydrogen and P2X production methods have developed significantly and become commercially viable.<br/>This report was produced by a team of VTT experts on hydrogen and hydrogen-related technologies. The focus is in an outlook for low-carbon H2 production H2 utilization for green chemicals and fuels as well as storage transport and end-use especially during the next 10 years in Finland in connection to renewed EU regulations. This roadmap is expected to serve as the knowledge-base for further work such as shaping the hydrogen policy for Finland and determining the role of hydrogen in the national energy and climate policy.
Experimental Study on Tri-fuel Combustion Using Premixed Methane-hydrogen Mixtures Ignited by a Diesel Pilot
Apr 2021
Publication
A comprehensive investigation on diesel pilot spray ignited methane-hydrogen (CH4–H2) combustion tri-fuel combustion (TF) is performed in a single-cylinder compression ignition (CI) engine. The experiments provide a detailed analysis of the effect of H2 concentration (based on mole fraction MH2) and charge-air temperature (Tair) on the ignition behavior combustion stability cycle-to-cycle (CCV) and engine performance. The results indicate that adding H2 from 0 to 60% shortens the ignition delay time (IDT) and combustion duration (based on CA90) up to 33% and 45% respectively. Thereby H2 helps to increase the indicated thermal efficiency (ITE) by as much as 10%. Furthermore to gain an insight into the combustion stability and CCV the short-time Fourier transform (STFT) and continuous wavelet transform (CWT) methodologies are applied to estimate the combustion stability and CCV of the TF combustion process. The results reveal that the pressure oscillation can be reduced up to 4 dB/Hz and the CCV by 50% when MH2 < 60% and Tair < 55 °C. However when MH2 > 60% and Tair > 40 °C abnormal combustion and knocking are observed.
Cost Benefits of Optimizing Hydrogen Storage and Methanation Capacities for Power-to-Gas Plants in Dynamic Operation
Oct 2019
Publication
Power-to-Gas technologies offer a promising approach for converting renewable electricity into a molecular form (fuel) to serve the energy demands of non-electric energy applications in all end-use sectors. The technologies have been broadly developed and are at the edge of a mass roll-out. The barriers that Power-to-Gas faces are no longer technical but are foremost regulatory and economic. This study focuses on a Power-to-Gas pathway where electricity is first converted in a water electrolyzer into hydrogen which is then synthetized with carbon dioxide to produce synthetic natural gas. A key aspect of this pathway is that an intermittent electricity supply could be used which could reduce the amount of electricity curtailment from renewable energy generation. Interim storages would then be necessary to decouple the synthesized part from hydrogen production to enable (I) longer continuous operation cycles for the methanation reactor and (II) increased annual full-load hours leading to an overall reduction in gas production costs. This work optimizes a Power-to-Gas plant configuration with respect to the cost benefits using a Monte Carlo-based simulation tool. The results indicate potential cost reductions of up to 17% in synthetic natural gas production by implementing well-balanced components and interim storages. This study also evaluates three different power sources which differ greatly in their optimal system configuration. Results from time-resolved simulations and sensitivity analyses for different plant designs and electricity sources are discussed with respect to technical and economic implications so as to facilitate a plant design process for decision makers.
Replacing Fossil Fuels with Bioenergy in District Heating – Comparison of Technology Options
May 2021
Publication
We combine previously separate models of Northern European power markets local district heating and cooling (DHC2) systems and biomass supply in a single modelling framework to study local and system level impacts of bioenergy technologies in phasing out fossil fuels from a DHC system of the Finnish capital. We model multiple future scenarios and assess the impacts on energy security flexibility provision economic performance and emissions. In the case of Helsinki heat only boiler is a robust solution from economic and climate perspective but reduces local electricity self-sufficiency. Combined heat and power solution is more valuable investment for the system than for the city indicating a conflict of interest and biased results in system level models. Bringing a biorefinery near the city to utilize excess heat would reduce emissions and increase investment's profitability but biomass availability might be a bigger limiting factor. Our results show that the availability of domestic biomass resources constrains bio-based technologies in Southern Finland and further highlights the importance of considering both local and system level impacts. Novel option to boost biorefinery's production with hydrogen from excess electricity is beneficial with increasing shares of wind power.
The BioSCWG Project: Understanding the Trade-Offs in the Process and Thermal Design of Hydrogen and Synthetic Natural Gas Production
Oct 2016
Publication
This article presents a summary of the main findings from a collaborative research project between Aalto University in Finland and partner universities. A comparative process synthesis modelling and thermal assessment was conducted for the production of Bio-synthetic natural gas (SNG) and hydrogen from supercritical water refining of a lipid extracted algae feedstock integrated with onsite heat and power generation. The developed reactor models for product gas composition yield and thermal demand were validated and showed conformity with reported experimental results and the balance of plant units were designed based on established technologies or state-of-the-art pilot operations. The poly-generative cases illustrated the thermo-chemical constraints and design trade-offs presented by key process parameters such as plant organic throughput supercritical water refining temperature nature of desirable coproducts downstream indirect production and heat recovery scenarios. The evaluated cases favoring hydrogen production at 5 wt. % solid content and 600 ◦C conversion temperature allowed higher gross syngas and CHP production. However mainly due to the higher utility demands the net syngas production remained lower compared to the cases favoring BioSNG production. The latter case at 450 ◦C reactor temperature 18 wt. % solid content and presence of downstream indirect production recorded 66.5% 66.2% and 57.2% energetic fuel-equivalent and exergetic efficiencies respectively
Hydrogen Technology for Supply Chain Sustainability: The Mexican Transportation Impacts on Society
Mar 2022
Publication
This study sheds light on the Hydrogen technology in transportation for reaching the sustainability goals of societies illustrated by the case of Mexico. In terms of the affected supply chains the study explores how the packaging and distribution of a fuel-saving tool that allows the adoption of hydrogen as complementary energy for maritime transportation to improve economic and environmental performance in Mexico. This exploratory study performs interviews observations simulations and tests involving producers suppliers and users at 26 ports in Mexico. The study shows that environmental and economic performance are related to key processes in Supply Chain Management (SCM) in which packaging and distribution are critical for achieving logistics and transportation sustainability goals. Reusable packaging and the distribution of a fuel-saving tool can help decrease costs - of transport and downstream/upstream processes in SCM while at the same time increasing the environmental performance.
Global Potential of Green Ammonia Based on Hybrid PV-wind Power Plants
Apr 2021
Publication
Ammonia is one of the most commonly used feedstock chemicals globally. Therefore decarbonisation of ammonia production is of high relevance towards achieving a carbon neutral energy system. This study investigates the global potential of green ammonia production from semi-flexible ammonia plants utilising a cost-optimised configuration of hybrid PV-wind power plants as well as conversion and balancing technologies. The global weather data used is on an hourly time scale and 0.45◦ × 0.45◦ spatial resolution. The results show that by 2030 solar PV would be the dominating electricity generation technology in most parts of the world and the role of batteries would be limited while no significant role is found for hydrogen-fuelled gas turbines. Green ammonia could be generated at the best sites in the world for a cost range of 440–630 345–420 300–330 and 260–290 €/tNH3 in 2020 2030 2040 and 2050 respectively for a weighted average capital cost of 7%. Comparing this to the decade-average fossil-based ammonia cost of 300–350 €/t green ammonia could become cost-competitive in niche markets by 2030 and substitute fossil-based ammonia globally at current cost levels. A possible cost decline of natural gas and consequently fossil-based ammonia could be fully neutralised by greenhouse gas emissions cost of about 75 €/tCO2 by 2040. By 2040 green ammonia in China would be lower in cost than ammonia from new coal-based plants even at the lowest coal prices and no greenhouse gas emissions cost. The difference in green ammonia production at the least-cost sites in the world’s nine major regions is less than 50 €/tNH3 by 2040. Thus ammonia shipping cost could limit intercontinental trading and favour local or regional production beyond 2040.
Sizing Hydrogen Energy Storage in Consideration of Demand Response in Highly Renewable Generation Power Systems
May 2018
Publication
From an environment perspective the increased penetration of wind and solar generation in power systems is remarkable. However as the intermittent renewable generation briskly grows electrical grids are experiencing significant discrepancies between supply and demand as a result of limited system flexibility. This paper investigates the optimal sizing and control of the hydrogen energy storage system for increased utilization of renewable generation. Using a Finnish case study a mathematical model is presented to investigate the optimal storage capacity in a renewable power system. In addition the impact of demand response for domestic storage space heating in terms of the optimal sizing of energy storage is discussed. Finally sensitivity analyses are conducted to observe the impact of a small share of controllable baseload production as well as the oversizing of renewable generation in terms of required hydrogen storage size.
Large-eddy Simulation of Tri-fuel Combustion: Diesel Spray Assisted Ignition of Methanol-hydrogen Blends
May 2021
Publication
Development of marine engines could largely benefit from the broader usage of methanol and hydrogen which are both potential energy carriers. Here numerical results are presented on tri-fuel (TF) ignition using large-eddy simulation (LES) and finite-rate chemistry. Zero-dimensional (0D) and three-dimensional (3D) simulations for n-dodecane spray ignition of methanol/hydrogen blends are performed. 0D results reveal the beneficial role of hydrogen addition in facilitating methanol ignition. Based on LES the following findings are reported: 1) Hydrogen promotes TF ignition significantly for molar blending ratios βX = [H2]/([H2]+[CH3OH]) ≥0.8. 2) For βX = 0 unfavorable heat generation in ambient methanol is noted. We provide evidence that excessive hydrogen enrichment (βX ≥ 0.94) potentially avoids this behavior consistent with 0D results. 3) Ignition delay time is advanced by 23–26% with shorter spray vapor penetrations (10–15%) through hydrogen mass blending ratios 0.25/0.5/1.0. 4) Last adding hydrogen increases shares of lower and higher temperature chemistry modes to total heat release.
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