Search Results (20)

Decarbonizing Oregon’s heavy-duty trucking sector, which accounts for 24% of the state’s transportation emissions, is essential for meeting carbon reduction targets. Drop-in fuels such as renewable diesel, biodiesel, and synthetic fuels provide an immediate and effective solution, reducing emissions by up to 80% while utilizing the existing diesel infrastructure. In 2023, Oregon’s heavy-duty trucks consumed 450 million gallons of diesel, with drop-in fuels making up 15% of the fuel mix. Renewable diesel, which is growing at a rate of 30% annually, accounted for 10% of this volume, thanks to incentives from Oregon’s Clean Fuels Program. By 2030, drop-in fuels could capture 40% of the market, reducing CO₂ emissions by 3.5 million metric tons annually, assuming continued policy support and advancements in feedstock sourcing. Meeting the projected demand of 200 million gallons annually and securing sustainable feedstock remain critical challenges. Advances in synthetic fuels, like Power-to-Liquids (PtL) from renewable energy, may further contribute to decarbonization, with costs expected to decrease by 20% over the next decade. Oregon aims for a 50% reduction in emissions from heavy-duty trucks by 2050, using a mix of drop-in fuels and emerging technologies. While hydrogen fuel cells and electric trucks face challenges, innovations in infrastructure and vehicle design will be key to the success of Oregon’s long-term decarbonization strategy. Full article

The efficiency of an electrolyzer is significantly influenced by mass, heat, and charge transport within its porous transport layer (PTL). The infeasibility of measuring them in-situ makes it challenging to study their influence experimentally, leading to the adoption of various modeling approaches. This study applies pore network (PN) modeling to investigate mass transport properties and capillary invasion behavior in three commercial titanium felt PTLs commonly used in proton exchange membrane water electrolyzers (PEMWEs). One PTL has a graded structure. Reconstructed PNs were derived from microcomputed X-ray tomography (µ-CT) data, allowing for a detailed analysis of pore size distributions, absolute and relative permeabilities, capillary pressure curves, and residual liquid saturations. The results from the PN approach are compared to literature correlations. The absolute permeability of all PTLs is between 1.1 × 10⁻¹⁰ m² and 1.5 × 10⁻¹⁰ m², with good agreement between PNM results and predictions from the Jackson and James model and the Tomadakis and Sotirchos model, the two latter involving the fiber diameter as a model parameter. The graded PTL, with fiber diameters varying between 25 µm and 40 µm, showed the best agreement with literature correlations. However, the capillary pressure curves exhibited significant deviations from the Leverett and Brooks–Corey equations at low and high liquid saturations, emphasizing the limitations of these correlations. In addition, residual liquid saturation varied strongly with PTL structure. The thicker PTL with a slightly narrower pore size distribution, demonstrated a lower residual liquid saturation (19%) and a more homogeneous invasion compared to the graded PTL (64%), which exhibited significant gas fingering. The results suggest that higher gas saturation could enhance gas removal, with much higher relative permeabilities, despite the greater PTL thickness. In contrast, the graded PTL achieves the highest relative liquid permeability (~70%) while maintaining a relative gas permeability of ~30%. These findings highlight the impact of microstructure on invasion and transport properties and suggest PN modeling as a powerful tool for their study. Full article

Background: Currently, the procedures and methods applied in biological and medical fields for the determination of reactive oxygen and nitrogen species (RONS), primarily rely on spectrophotometric techniques, which involve the use of colorimetric reagents. While these methods are widely accepted, they exhibit significant limitations from an analytical standpoint, particularly due to potential inaccuracies, artifacts, and pronounced susceptibility to matrix effects. The purpose of this Technical Note is to demonstrate the application of ion chromatography—a robust and well-established analytical technique—for the quantification of RONS produced in cell culture media through the exposure to cold atmospheric plasma (CAP), an innovative therapeutic approach for cancer treatment, known as CAP indirect treatment. In addition, the present protocol proposes to apply the pharmacokinetics principles to the RONS generated in plasma-treated liquids (PTLs) following CAP exposure. Methods: The strategy involves elucidating the kinetic profiles of certain characteristic species by evaluating their half-life in the specific media used for cell cultures and investigating their “pharmacokinetic” (PK) profile. In this approach the drug dose is represented by the plasma power and the infusion time corresponds to the exposure time of the culture medium to CAP. Volume-dependent results were shown, focusing on nitrites and nitrates activities, justifying cellular inhibition. Results: This methodology enables the correlation of the PTL biological effects on different cell lines with the PK profiles (dose/time) obtained via ion chromatography. Conclusions: In conclusion, being a simple and green method, it could be used as an alternative to toxic reactions and analytical techniques with higher detection limits, while achieving good resolution. Full article

The cement industry is a significant contributor (around 8%) to CO₂ global emissions. About 60% of the industry’s emissions come from limestone calcination, which is essential for clinker production, while 40% are the result of fuel combustion. Reducing these emissions is challenging due to limestone’s role as the primary raw material for cement. Cement plants are required to achieve carbon neutrality by 2050, as outlined in the 13th United Nations Sustainable Goals. One strategy to achieve this goal, involves Carbon Capture and utilization (CCU). Among the options for CO₂ utilization, the Power-to-Liquid (PtL) strategy offers a means to mitigate CO₂ emissions. In PtL, the CO₂ captured from cement industrial flue gas is combined with the hydrogen generated by renewable electrolysis (green hydrogen) and is catalytically converted into renewable methanol (e-MeOH). In this sense, this review provides a comprehensive overview of the worldwide existing pilot and demonstration units and projects funded by the EU across several industries. It specifically focuses on PtL technology worldwide within cement plants. This work covers 18 locations worldwide, detailing technology existent at plants of different capacities, location, and project partners. Finally, the review analyses techno-economic assessments related to e-MeOH production processes, highlighting the potential impact on achieving carbon neutrality in the cement industry. Full article

For decades, fossil fuels have been the backbone of reliable energy systems, offering unmatched energy density and flexibility. However, as the world shifts toward renewable energy, overcoming the limitations of intermittent power sources requires a bold reimagining of energy storage and integration. Power-to-X (PtX) technologies, which convert excess renewable electricity into storable energy carriers, offer a promising solution for long-term energy storage and sector coupling. Recent advancements in machine learning (ML) have revolutionized PtX systems by enhancing efficiency, scalability, and sustainability. This review provides a detailed analysis of how ML techniques, such as deep reinforcement learning, data-driven optimization, and predictive diagnostics, are driving innovation in Power-to-Gas (PtG), Power-to-Liquid (PtL), and Power-to-Heat (PtH) systems. For example, deep reinforcement learning has improved real-time decision-making in PtG systems, reducing operational costs and improving grid stability. Additionally, predictive diagnostics powered by ML have increased system reliability by identifying early failures in critical components such as proton exchange membrane fuel cells (PEMFCs). Despite these advancements, challenges such as data quality, real-time processing, and scalability remain, presenting future research opportunities. These advancements are critical to decarbonizing hard-to-electrify sectors, such as heavy industry, transportation, and aviation, aligning with global sustainability goals. Full article

The cement industry significantly impacts the environment due to natural resource extraction and fossil fuel combustion, with carbon dioxide (CO₂) emissions being a major concern. The industry emits 0.6 tons of CO₂ per ton of cement, accounting for about 8% of global CO₂ emissions. To meet the 13th United Nations Sustainable Development Goal, cement plants aim for carbon neutrality by 2050 through reducing CO₂ emissions and adopting Carbon Capture and Utilization (CCU) technologies. A promising approach is converting CO₂ into valuable chemicals and fuels, such as methanol (MeOH), using Power-to-Liquid (PtL) technologies. This process involves capturing CO₂ from cement plant flue gas and using hydrogen from renewable sources to produce renewable methanol (e-MeOH). Advancing the development of novel, efficient catalysts for direct CO₂ hydrogenation is crucial. This comprehensive mini-review presents a holistic view of recent advancements in CO₂ catalytic conversion to MeOH, focusing on catalyst performance, selectivity, and stability. It outlines a long-term strategy for utilizing captured CO₂ emissions from cement plants to produce MeOH, offering an experimental roadmap for the decarbonization of the cement industry. Full article

Owing to the massive expansion and intermittent nature of renewable power, green hydrogen production, storage, and transportation technologies with improved economic returns need to be developed. Moreover, the slowness of the dehydrogenation reaction is a primary barrier to the commercialization of liquid organic hydrogen carrier (LOHC) technology. The present study focused on increasing the speed of dehydrogenation, resulting in the proposal of a triple-loop dehydrogenation system comprising reaction, heating, and chilling loops. The reactor has a rotating cage containing a packed bed of catalyst pellets, which is designed to enhance both heat and mass transfer by helping to detach precipitated hydrogen bubbles from the catalyst surface. In addition, the centrifugal force aids in isolating the gas phase from the LOHC liquid. A dehydrogenation experiment was conducted using the reaction and chilling loops, which revealed that the average hydrogen production rate during the first hour was 52.6 LPM (liter per minute) from 26.3 L of perhydro-dibenzyl-toluene with 1.5 kg of 0.5 wt% Pt/Al₂O₃ catalyst. This was approximately 48% more than the value predicted with the reaction kinetics measured with a small-scale plug flow dehydrogenation reactor with less than 1.0 g of 5.0 wt% Pt/Al₂O₃ catalyst. The concept, construction methods, and results of the preliminary gas infiltration, flow visualization, and reactor pumping experiments are also described in this paper. Full article

This paper summarizes the findings of a detailed assessment of synthetic, electricity-based fuels for use in aviation, shipping, and road transport. The fuels considered correspond to the most promising alternatives that were analyzed as part of the German research project BEniVer (Begleitforschung Energiewende im Verkehr—Accompanying Research for the Energy Transition in Transport) initiated by the German Federal Ministry for Economic Affairs and Climate Action (BMWK). Focusing on usage, infrastructure, and ecological analyses, several e-fuels were evaluated and compared to fossil fuels according to the specific sector. It turns out that for all sectors evaluated, the existing sustainable synthetic fuels are already compatible with current technology and regulations. In shipping and road transport, the use of advanced, sustainable fuels will allow for a more distinct reduction in emissions once technology and regulations are adopted. However, standard-compliant synthetic gasoline and diesel are considered the most promising fuels for use in road transport if the transition to electricity is not realized as quickly as planned. For the aviation sector, the number of sustainable aviation fuels (SAFs) is limited. Here, the current aim is the introduction of a 100% SAF as soon as possible to also tackle non-CO₂ emissions. Full article

Developing production technology pathways of sustainable aviation fuel (SAF) that align with China’s national conditions and aviation transportation needs is crucial for promoting the SAF industry and achieving China’s carbon peak and carbon neutrality goals. This article first projects the future SAF demand in China for the coming decades. Using SAF demand data as an input, this article employs the TOPSIS analysis method to comprehensively evaluate the suitability of four SAF production technology pathways at different stages of development in China, which are Hydroprocessed Esters and Fatty Acids (HEFA), Alcohol-to-Jet (AtJ), Natural Gas + Fischer–Tropsch Synthesis (G + FT), and Power-to-Liquid (PtL). The research results reveal the following trends: HEFA-based processes are the most suitable technology pathways for China in the near term; the G + FT route, based on energy crops, appears the most likely to support civil aviation needs in the medium to long term. In the long run, the PtL route holds significant potential, especially with the decreasing costs of green electricity, advancements in carbon capture, utilization, and storage (CCUS) technology, and improvements in SAF synthesis methods. In the final section of this article, we provide recommendations to drive the development of the SAF industry in China. Full article

Sustainable aviation fuels (SAF) are needed in large quantities to reduce the negative impact of flying on the climate. So-called power-to-liquid (PtL) plants can produce SAF from renewable electricity, water, and carbon dioxide. Reactors for these processes that are suitable for flexible operation are difficult to manufacture. Metal 3D printing, also known as additive manufacturing (AM), enables the fabrication of process equipment, such as chemical reactors, with highly optimized functions. In this publication, we present an AM reactor design and conduct experiments for Fischer-Tropsch synthesis (FTS) under challenging conditions. The design includes heating, cooling, and sensing, among others, and can be easily fabricated without welding. We confirm that our reactor has excellent temperature control and high productivity of FTS products up to 800 kg_C5+ m_cat⁻³ h⁻¹ (mass flow rate of hydrocarbons, liquid or solid at ambient conditions, per catalyst volume). The typical space-time yield for conventional multi-tubular Fischer-Tropsch reactors is ~100 kg_C5+ m_cat⁻³ h⁻¹. The increased productivity is achieved by designing reactor structures in which the channels for catalyst and cooling/heating fluid are in the millimeter range. With the effective control of heat release, we observe neither the formation of hot spots nor catalyst deactivation. Full article

As the global climate crisis escalates, reductions in CO₂ emissions and the efficient utilization of carbon waste resources have become a crucial consensus. Among the various carbon mitigation technologies, the concept of power-to-liquid (PTL) has gained significant attention in recent years. Considering the lack of a timely review of the state-of-the-art progress of this PTL process, this work aims to provide a systematic summary of the advanced PTL progress. In a CO₂ capture unit, we compared the process performances of chemical absorption, physical absorption, pressure swing adsorption, and membrane separation technologies. In a water electrolysis unit, the research progress of alkaline water electrolysis, proton exchange membrane water electrolysis, and solid oxide water electrolysis technologies was summarized, and the strategies for improving the electrolysis efficiency were proposed. In a CO₂ hydrogenation unit, we compared the differences of high-temperature and low-temperature Fischer–Tropsch synthesis processes, and summarized the advanced technologies for promoting the conversion of CO₂ into high value-added hydrocarbons and achieving the efficient utilization of C₁–C₄ hydrocarbons. In addition, we critically reviewed the technical and economic performances of the PTL process. By shedding light on the current state of research and identifying its crucial factors, this work is conducive to enhancing the understanding of the PTL process and providing reliable suggestions for its future industrial application. By offering valuable insights into the PTL process, this work also contributes to paving the way for the development of more efficient and sustainable solutions to address the pressing challenges of CO₂ emissions and climate change. Full article

A large number of CO₂ emissions caused a serious greenhouse effect, aggravating global warming and climate change. Therefore, CO₂ utilization has been a research hotspot, especially after the Paris Agreement, and among the various CO₂ utilization technologies, the power-to-gas (PTG) and power-to-liquid (PTL) processes have recently attracted significant attention because they can transform CO₂ into fuels and/or chemicals. Considering the lack of detailed information in the literature with regard to process design and economic analysis, we have critically and comprehensively summarized the recent research progresses concerning the PTG and PTL processes. Herein, we mainly focus on the power-to-methane in the case of PTG and the power-to-syncrude, power-to-methanol, and power-to-ethers in the case of PTL. From the technical point of view, the bottleneck problem of PTG and PTL processes is the low system efficiency, which can be improved by heat integration and/or process integration. Meanwhile, from the economic point of view, the production cost of PTG and PTL processes needs to be further reduced by the following measures, such as by increasing the carbon tax, lowering the electricity price, improving the electrolysis efficiency, reducing the capital expenditure of the electrolytic cell, and formulating sustainable incentive policies. The main purpose of the paper is to present a comprehensive updated review of CO₂ utilization in PTG and PTL processes from process system integration, the techno-economic aspects, such as, state-of-the-art synthesis technologies, process system integration and the production cost, and provide useful information and reliable suggestions for the future development trends of the PTG and PTL processes. Full article

Mitigating climate change requires the development of technologies that combine energy and transport sectors. One of them is the production of sustainable fuels from electricity and carbon dioxide (CO₂) via power-to-liquid (PtL) plants. As one option for splitting CO₂, plasma-based processes promise a high potential due to their flexibility, scalability, and theoretically high efficiencies. This work includes a modeling and techno-economic analysis. A crucial element is the process of the joint project PlasmaFuel, in which two plasma technologies are included in a PtL plant to produce synthetically sulfur-free marine diesel. The results are divided into three scenarios, which differ in the use of different boundary conditions and thus represent different degrees of technology development. The evaluation results in process efficiencies from 16.5% for scenario 2018/20 to 27.5% for scenario 2050, and net production costs between EUR 8.5/L and EUR 3.5/L. Furthermore, the techno-economic potential is mapped in order to open up development steps in the direction of costs below EUR 2.0/L. The present work allows statements regarding system integration and the industrial use of the plasma-based process.; moreover, conclusions can be drawn towards the most important levers in terms of process optimization. Full article

Decarbonization of the aviation sector is crucial to reaching the global climate targets. We quantified the environmental impacts of Power-to-Liquid kerosene produced via Fischer-Tropsch Synthesis from electricity and carbon dioxide from air as one broadly discussed alternative liquid jet fuel. We applied a life-cycle assessment considering a well-to-wake boundary for five impact categories including climate change and two inventory indicators. Three different electricity production mixes and four different kerosene production pathways in Germany were analyzed, including two Direct Air Capture technologies, and compared to fossil jet fuel. The environmental impacts of Power-to-Liquid kerosene varied significantly across the production pathways. E.g., when electricity from wind power was used, the reduction in CO₂-eq. compared to fossil jet fuel varied between 27.6–46.2% (with non-CO₂ effects) and between 52.6–88.9% (without non-CO₂ effects). The reduction potential regarding CO₂-eq. of the layout using low-temperature electrolysis and high-temperature Direct Air Capture was lower compared to the high-temperature electrolysis and low-temperature Direct Air Capture. Overall, the layout causing the lowest environmental impacts uses high-temperature electrolysis, low-temperature Direct Air Capture and electricity from wind power. This paper showed that PtL-kerosene produced with renewable energy could play an important role in decarbonizing the aviation sector. Full article

Power-to-Liquid (PtL) plants can viably implement carbon capture and utilization technologies in Europe. In addition, local CO₂ sources can be valorized to substitute oil and gas imports. This work’s aim was to determine the PtL efficiency obtained by combining a solid oxide electrolyzer (SOEC) and Fischer–Tropsch synthesis. In addition, a recommended plant configuration to produce synthetic fuel and wax at pilot scale is established. The presented process configurations with and without a tail gas reformer were modeled and analyzed using IPSEpro as simulation software. A maximum mass flow rate of naphtha, middle distillate and wax of 57.8 kg/h can be realized by using a SOEC unit operated in co-electrolysis mode, with a rated power of 1 MW_el.. A maximum PtL efficiency of 50.8% was found for the process configuration without a tail gas reformer. Implementing a tail gas reformer resulted in a maximum PtL efficiency of 62.7%. Hence, the reforming of tail gas is highly beneficial for the PtL plant’s productivity and efficiency. Nevertheless, a process configuration based on the recirculation of tail gas without a reformer is recommended as a feasible solution to manage the transition from laboratory scale to industrial applications. Full article