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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

The Catalytic Reduction of Dinitrogen Under Mild Conditions (Final Report)

In order to use molecular hydrogen as an alternative to fossil fuels, large quantities of hydrogen (or protons and electrons) would have to be generated from water using a method based on solar energy and stored as a molecule in which hydrogen is a high weight percentage. The hydrogen must then be generated as needed from the form in which it is stored. An attractive molecule for this purpose is ammonia (~17% hydrogen by weight). Among the many problems that must be addressed for a successful implementation of this approach in the long term is the reduction of nitrogen catalytically to ammonia with protons and electrons under mild conditions, a goal that is addressed in this proposal. The first abiological catalytic reduction of N 2 to NH 3 by protons and electrons under mild conditions (22 °C and 1 atm) employed molybdenum catalysts, [(HIPTNCH 2 CH 2 ) 3 N]Mo (HIPTN 3 N 3- ), where HIPT (hexaisopropylterphenyl) is 3,5- (2,4,6-i-Pr 3 C 6 H 2 ) 2 C 6 H 3 . A total of approximately four turnovers (to give a maximum of eight equivalents of ammonia) along with approximately one equivalent of hydrogen per N 2 reduced, were found. A limitation of this catalytic approach is loss of the ligand from the metal. This project is aimed at developing a complex that contains a ligand that will not be removed from the metal. A macrocyclic TREN-based ligand of this type has been synthesized recently. The project is aimed at making similar ligands and molybdenum complexes that contain them and testing the new catalysts for catalytic reduction of dinitrogen. The results of these investigations will help guide further design of ligands for more efficient reduction of nitrogen to ammonia and ultimately an integrated device in which protons and electrons are generated using solar energy and employed to reduce nitrogen to ammonia using molybdenum catalysts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

In Situ Neutron Reflectometry Reveals the Interfacial Microenvironment Driving Electrochemical Ammonia Synthesis

Electrified interfaces are critical to the performance of energy systems and often demonstrate substantial complexity under operating conditions. A nanoscale understanding of the interfacial microenvironment, i.e., the solid-electrolyte interphase (SEI), in lithium-mediated nitrogen reduction (Li–N 2 R) is key for realizing efficient ammonia (NH 3 ) production. Herein, we used time-resolved neutron reflectometry (NR) to observe SEI formation under Li–N 2 R conditions. We found that the LiBF 4 -based electrolyte provided a substantially more well-defined SEI layer than previous SEI NR interrogations that used LiClO 4 , highlighting the underlying chemistry that dictates electrolyte design and enabling new NR-based studies. Using in situ NR, we found that the LiBF 4 -derived SEI under Li–N 2 R conditions comprises a thick, diffuse outer layer and a thin, compact inner layer at low current cycling (<2 mA/cm 2 ), revealing a structure which ex situ studies have not been able to probe. Increased current cycling and sustained current cycling led to the merging of the layers into a single-layer SEI. Here, we used isotope contrast methods with d 6 -EtOH and d 8 -THF to drive time-resolved tracking of SEI growth at low current cycling, revealing that the proton donor modifies the inner layer, and the solvent modifies the outer layer. Li dendritic growth was observed in the absence of a proton donor. Neutron absorption also indicated the presence of boron in the SEI, underscoring the value of neutron-based interrogation. Our results inform Li-based systems and reaction microenvironments, and these methods can be applied broadly to interfacial energy technologies.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

A CRISPRi-dCas9 System for Archaea and Its Use To Examine Gene Function during Nitrogen Fixation by Methanosarcina acetivorans

CRISPR-based systems are emerging as the premier method to manipulate many cellular processes. In this study, a simple and efficient CRISPR interference (CRISPRi) system for targeted gene repression in archaea was developed. The Methanosarcina acetivorans CRISPR-Cas9 system was repurposed by replacing Cas9 with the catalytically dead Cas9 (dCas9) to generate a CRISPRi-dCas9 system for targeted gene repression. To test the utility of the system, genes involved in nitrogen (N2) fixation were targeted for dCas9-mediated repression. First, the nif operon (nifHI 1 I 2 DKEN) that encodes molybdenum nitrogenase was targeted by separate guide RNAs (gRNAs), one targeting the promoter and the other targeting nifD. Remarkably, growth of M. acetivorans with N 2 was abolished by dCas9-mediated repression of the nif operon with each gRNA. The abundance of nif transcripts was >90% reduced in both strains expressing the gRNAs, and NifD was not detected in cell lysate. Next, we targeted NifB, which is required for nitrogenase cofactor biogenesis. Expression of a gRNA targeting the coding sequence of NifB decreased nifB transcript abundance >85% and impaired but did not abolish growth of M. acetivorans with N2. Finally, to ascertain the ability to study gene regulation using CRISPRi-dCas9, nrpR1, encoding a subunit of the repressor of the nif operon, was targeted. The nrpR1 repression strain grew normally with N2 but had increased nif operon transcript abundance, consistent with NrpR1 acting as a repressor. Furthermore, these results highlight the utility of the system, whereby a single gRNA when expressed with dCas9 can block transcription of targeted genes and operons in M. acetivorans.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Life cycle energy and environmental impacts of hydroprocessed renewable jet fuel production from pennycress

There is a growing interest in making the overall aviation industry more environmentally-friendly by developing advanced biofuels. In this context, the main driver is establishing feedstocks with lower environmental loads and higher energy use efficiency. The objective of this study was to evaluate the energy requirement and environmental impacts of hydroprocessed renewable jet fuel (HRJ) production from pennycress. The system boundary included pennycress production, logistics, oil extraction and conversion to HRJ, wastewater treatment, and electricity and steam generation. Energy allocation method was used for the analysis. The functional unit was considered to be one GJ of HRJ, and the biorefinery size was considered to be 18.9 million l/yr (5 million gal/yr) HRJ. Energy use efficiency of pennycress-based HRJ production was estimated to be 3.9–5.5 (90% central range), which was higher than that of HRJ from other oilseeds, such as canola. Global warming potential of pennycress-based HRJ (35–49 kgCO 2 eq/GJ of HRJ (90% central range)) was also lower than those of HRJ from similar oilseeds and the commercial jet fuel baseline. Pennycress production was the main contributor to the total energy use and environmental impacts of HRJ production, mainly due to the use of nitrogen fertilizer for production, and fuel combustion for farm operations. Pennycress yield was identified as the most sensitive parameter affecting the energy use efficiency and environmental impacts of HRJ production. Furthermore, the outcomes of this study are useful for identifying the performance targets towards improving energy use efficiency and environmental performance of pennycress-based HRJ production at the commercial scale.

09 BIOMASS FUELS↗
DOE OSTI2021

n-Butanol production by Rhodopseudomonas palustris TIE-1

Anthropogenic carbon dioxide (CO 2 ) release in the atmosphere from fossil fuel combustion has inspired scientists to study CO 2 to biofuel conversion. Oxygenic phototrophs such as cyanobacteria have been used to produce biofuels using CO 2 . However, oxygen generation during oxygenic photosynthesis adversely affects biofuel production efficiency. To produce n-butanol (biofuel) from CO 2 , here we introduce an n-butanol biosynthesis pathway into an anoxygenic (non-oxygen evolving) photoautotroph, Rhodopseudomonas palustris TIE-1 (TIE-1). Using different carbon, nitrogen, and electron sources, we achieve n-butanol production in wild-type TIE-1 and mutants lacking electron-consuming (nitrogen-fixing) or acetyl-CoA-consuming (polyhydroxybutyrate and glycogen synthesis) pathways. The mutant lacking the nitrogen-fixing pathway produce the highest n-butanol. Coupled with novel hybrid bioelectrochemical platforms, this mutant produces n-butanol using CO 2 , solar panel-generated electricity, and light with high electrical energy conversion efficiency. Overall, this approach showcases TIE-1 as an attractive microbial chassis for carbon-neutral n-butanol bioproduction using sustainable, renewable, and abundant resources.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Demonstration of no catalytical activity of Fe–N–C and Nb–N–C electrocatalysts toward nitrogen reduction using in–line quantification

Ammonia (NH 3 ) production via the electrochemical nitrogen reduction reaction (NRR) is a promising method for sustainable generation of this important chemical. Efforts are ongoing in finding an efficient, stable, and selective catalyst that will enable the reaction. However, progress is hindered in the field due to lack of reproducibility, most likely a consequence of reports of false-positive results due to improper measurement control and methods. In this study, we explore the NRR activity of a promising class of single atom catalysts, transition metal-nitrogen-carbon (M-N-C) electrocatalysts. Using a state-of-the-art in-line ammonia quantification methodology, with detection limit as low as 1 ppb for ammonia, we show that single atom Nb and Fe embedded in a stable carbon and nitrogen framework do not electrochemically reduce N 2 to NH 3 . Critically, this demonstrates that our experimental setup with in-line sequential injection analysis successfully excludes ammonia contamination from the gas supply and atmospheric sources, allowing for thorough and high-throughput examination of potential NRR catalysts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Solid additive engineering enables high-efficiency and eco-friendly all-polymer solar cells

Currently, morphology optimization of all-polymer solar cells (all-PSCs) strongly depends on the use of solvent additives, which are usually highly toxic and harmful to the environment and human health. Here, we report a green and volatile solid additive, 2-methoxynaphthalene (2-MN). It was found that the incorporation of 2-MN into a PM6:PY-DT blend can effectively manipulate the aggregations of PM6 and PY-DT during film depositing and thermal annealing processes and results in highly ordered molecular packing and favorable phase-separated morphology. Consequently, a record-high efficiency of 17.32% is achieved for the PM6:PY-DT device. Moreover, 2-MN-processed all-PSCs were fabricated by using non-halogenated solvent. High efficiencies of 17.03% and 16.67% are obtained for all-PSCs fabricated under nitrogen atmosphere and ambient conditions, respectively. Finally, our work shows that the utilization of 2-MN as a green and solid additive is a simple and feasible strategy to optimize the morphology and sheds new light on eco-friendly fabrication and application of all-PSCs.

14 SOLAR ENERGY↗
DOE OSTI2024

Nitrous oxide reduction by two partial denitrifying bacteria requires denitrification intermediates that cannot be respired

ABSTRACT Denitrification is a form of anaerobic respiration wherein nitrate (NO 3 − ) is sequentially reduced via nitrite (NO 2 − ), nitric oxide, and nitrous oxide (N 2 O) to dinitrogen gas (N 2 ) by four reductase enzymes. Partial denitrifying bacteria possess only one or some of these four reductases and use them as independent respiratory modules. However, it is unclear if partial denitrifiers sense and respond to denitrification intermediates outside of their reductase repertoire. Here, we tested the denitrifying capabilities of two purple nonsulfur bacteria,Rhodopseudomonas palustrisCGA0092 andRhodobacter capsulatusSB1003. Each had denitrifying capabilities that matched their genome annotation; CGA0092 reduced NO 2 − to N 2 , and SB1003 reduced N 2 O to N 2 . For each bacterium, N 2 O reduction could be used both for electron balance during growth on electron-rich organic compounds in light and for energy transformation via respiration in darkness. However, N 2 O reduction required supplementation with a denitrification intermediate, including those for which there was no associated denitrification enzyme. For CGA0092, NO 3 − served as a stable, non-catalyzable molecule that was sufficient to activate N 2 O reduction. Using a β-galactosidase reporter, we found that NO 3 − acted, at least in part, by stimulating N 2 O reductase gene expression. In SB1003, NO 2 − but not NO 3 − activated N 2 O reduction, but NO 2 − was slowly removed, likely by a promiscuous enzyme activity. Our findings reveal that partial denitrifiers can still be subject to regulation by denitrification intermediates that they cannot use. IMPORTANCE Denitrification is a form of microbial respiration wherein nitrate is converted via several nitrogen oxide intermediates into harmless dinitrogen gas. Partial denitrifying bacteria, which individually have some but not all denitrifying enzymes, can achieve complete denitrification as a community by cross-feeding nitrogen oxide intermediates. However, the last intermediate, nitrous oxide (N2O), is a potent greenhouse gas that often escapes, motivating efforts to understand and improve the efficiency of denitrification. Here, we found that at least some partial denitrifying N2O reducers can sense and respond to nitrogen oxide intermediates that they cannot otherwise use. The regulatory effects of nitrogen oxides on partial denitrifiers are thus an important consideration in understanding and applying denitrifying bacterial communities to combat greenhouse gas emissions.

Biotechnology & Applied Microbiology↗
DOE OSTI2023

Global nitrogen deposition inputs to cropland at national scale from 1961 to 2020

Nitrogen (N) deposition is a significant nutrient input to cropland and consequently important for the evaluation of N budgets and N use efficiency (NUE) at different scales and over time. However, the spatiotemporal coverage of N deposition measurements is limited globally, whereas modeled N deposition values carry uncertainties. Here, we reviewed existing methods and related data sources for quantifying N deposition inputs to crop production on a national scale. We utilized different data sources to estimate N deposition input to crop production at national scale and compared our estimates with 14 N budget datasets, as well as measured N deposition data from observation networks in 9 countries. We created four datasets of N deposition inputs on cropland during 1961–2020 for 236 countries. These products showed good agreement for the majority of countries and can be used in the modeling and assessment of NUE at national and global scales. One of the datasets is recommended for general use in regional to global N budget and NUE estimates.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Nitrogen fixation as NO x using air plasma coupled with heterogeneous catalysis at atmospheric pressure

Here, this study presents insights into the use of activated Al 2 O 3 catalysts to improve the energy efficiency of NO x production in atmospheric pressure air plasma. The introduction of catalysts in the direct current glow discharge system reduces the energy cost of NO x production by up to 45% at low gas flow rates. Notably, even when positioned away from the plasma zone, the catalyst enhanced NO x production, suggesting a significant role for the catalytic activation of downstream neutral species. The study also introduced a novel approach involving an air plasma jet infused with floating catalyst powder. This method significantly increased energy efficiency at higher discharge currents, with an associated energy cost of 2.9 MJ/mol for NO x production.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2024

Model associated with: "Thermodynamic control on the decomposition of organic matter across different electron acceptors"

This model data package is associated with the publication “Thermodynamic control on the decomposition of organic matter across different electron acceptors” submitted to Soil Biology and Biochemistry (Zheng et al., 2023; https://doi.org/10.1016/j.soilbio.2024.109364).In this research, a thermodynamic modeling framework is built to flexibly incorporate both organic matter (OM) molecules and electron acceptors for estimating potential free energy release from various redox reactions and to further predict reaction rates based on Microbial Transition State Theory. The model package includes scripts for thermodynamic modeling and postprocessing. Input Fourier-transform ion cyclotron resonance (FTICR) data are from a previous experimental study (Boye et al., 2018), and model outputs are free energy predictions and stoichiometric coefficients associated with all possible redox reactions.This data package is associated with the project GitHub repository found at MM_bioenergetic_modeling.This data package contains four folders (Input_FTICR, Model, Output, and Output_processing), a file-level metadata (FLMD) csv, and a data dictionary (dd) csv. Please see Zheng_bioenergetic_modeling_flmd.csv for a list of all files contained in this data package and descriptions for each. The Zheng_bioenergetic_modeling_dd.csv file describes the csv column headers. The “Model” folder contains scripts to run energy balance calculations for each electron acceptor. The “Output” folder contains csv files with stoichiometric information from model simulations. And the "Output_processing" folder contains scripts for reaction rate calculations and to generate plots.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

A low power flexible dielectric barrier discharge disinfects surfaces and improves the action of hydrogen peroxide

There is an urgent need for disinfection and sterilization devices accessible to the public that can be fulfilled by innovative strategies for using cold atmospheric pressure plasmas. Here, we demonstrate a successful novel combination of a flexible printed circuit design of a dielectric barrier discharge (flex-DBD) with an environmentally safe chemical reagent for surface decontamination from bacterial contaminants. Flex-DBD operates in ambient air, atmospheric pressure, and room temperature without any additional gas flow at a power density not exceeding 0.5 W/cm 2 . The flex-DBD activation of a 3% hydrogen peroxide solution results in the reduction in the bacterial load of a surface contaminant of > 6log 10 in 90 s, about 3log 10 and 2log 10 better than hydrogen peroxide alone or the flex-DBD alone, respectively, for the same treatment time. We propose that the synergy between plasma and hydrogen peroxide is based on the combined action of plasma-generated OH · radicals in the hydrogen peroxide solution and the reactive nitrogen species supplied by the plasma effluent. A scavenger method verified a significant increase in OH · concentration due to plasma treatment. Novel in-situ FTIR absorption spectra show the presence of O 3 , NO 2 , N 2 O, and other nitrogen species. Ozone dissolving in the H 2 O 2 solution can effectively generate OH · through a peroxone process. The addition of the reactive nitrogen species increases the disinfection efficiency of the hydroxyl radicals and other oxygen species. Hence, plasma activation of a low concentration hydrogen peroxide solution, using a hand-held flexible DBD device results in a dramatic improvement in disinfection.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2023

Numerical Optimization of Spray-Guided Spark Assistance for Cold Idle Operation in a Heavy-Duty Gasoline Compression Ignition Engine

This article describes the results of a response surface model (RSM)-based numerical optimization campaign for spray-guided spark assistance at cold operations in a heavy-duty gasoline compression ignition (GCI) engine. On the basis of an earlier work on spark-assisted GCI cold combustion, a space-filling design of experiments (DoE) method was first undertaken to investigate a multitude of hardware design variables and engine operating parameters. The main design variables included the number of injector nozzles, fuel split quantities and injection timings, and spark timing. The objective variables were engine combustion efficiency (ŋ c ), maximum pressure rise rate (MPRR), and engine-out nitrogen oxide (NO x ) emissions. A total of 150 design candidates were automatically generated using the Sobol sequence method provided by the commercial software package, CAESES. Then, closed-cycle computational fluid dynamic (CFD) spark-assisted GCI simulations under cold idling operations were performed. The outcomes from the CFD-DoE design campaign were utilized to construct high-fidelity RSMs that allowed for further design optimization of the spark plug- and fuel injector-related design variables, along with fuel injection strategy parameters. A merit function with respect to objective variables was formulated with an appropriate weight assignment on each objective variable. Finally, the best design candidate was identified from the RSM-based optimization process and further validated in the CFD analysis. The best design candidate showed the potential to significantly improve combustion efficiency (ŋ c > 90%) over the baseline at cold idle while satisfying MPRR and NOx emissions constraints (MPRR < 5 bar/CAD and NO x < 4.5 g/kWh).

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2024

Graphene-supported single atom catalysts for high performance lithium-oxygen batteries

The optimal choice of d-block metals in single atom catalysts (SACs) is crucial for designing efficient electrocatalysts for activating the Oxygen reduction reaction (ORR)/ Oxygen evolution reaction (OER) in lithiumoxygen batteries (LOBs). Herein, we used the Quantum Mechanics methods to understand the origin of reactivity for a series of 16 d-block metals supported on nitrogen-doped graphene as SACs for ORR and OER in LOBs. Based on the Gibbs free energy calculations, we found that among the 16 SACs investigated, Zn-SAC exhibits the highest electrochemical activity with the lowest overpotential of 0.17 V. Here we then used machine learning (ML) to develop an intrinsic descriptor, phi, that correlates the catalytic activity with electronic and chemical properties of the catalytic centers at the M-N 4 active site on graphene surface. We established a linear relationship between phi and the catalytic activity that provides guidance for designing efficient SACs for electrocatalysis in LOBs. To validate these predictions, we report electrochemical measurements showing that Zn-SAC exhibits an ultra-stable cyclability with reduced overpotentials over Mo-SAC and nitrogen-doped graphene (NG), confirming our theoretical prediction. This fundamental work provides a deep understanding on the rational design of efficient SACs for OER/ ORR in LOBs.

25 ENERGY STORAGE↗
DOE OSTI2021

Roads less traveled: Nitrogen reduction reaction catalyst design strategies for improved selectivity

Direct electrochemical nitrogen reduction for ammonia production is necessary to reduce the use of fossil fuels from conventional Haber–Bosch methods. Applications of nitrogen reduction electrocatalysts remain inhibited by slow reaction kinetics and low faradaic efficiencies because of competitive H2 production pathways. Current strategies to address this challenge in selectivity have focused on catalyst design, reactor configuration, and electrolyte conditions. This brief review discusses the thermodynamic and kinetic challenges in the field as well as current underused approaches for selective catalyst development including bimetallic catalysts, transition metal nitrides, and carbon supports.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Renewable On-Site Nitrogen Fertilizer Production (CRADA Final Report)

As part of the Cyclotron Road program, the Nitricity Inc. research team sought to investigate the electrification of nitrogen fixation and the corresponding development of fixed nitrogen products. Nitricity’s cofounders had developed a plasma process and related technologies to cost-effectively use air, water, and electricity to convert nitrogen gas into nitrogen fertilizer (and other nitrogen products). This project explored ways to make this process more efficient and robust. Synthetic nitrogen fixation is critical for growing crops and feeding most of the world’s populace. However, the incumbent method to fix nitrogen, the Haber–Bosch process, requires unsustainable fossil fuels and ultra-centralized facilities with a supply-chain network that fails to reach many developing countries. Nitricity envisions that their process when scaled, may provide sustainable fixed nitrogen in many forms to fit the needs of the end user.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Determining the Efficiency of Nitrogen Blanketing to Mitigate Corrosion in Hanford’s Transfer Line System

The Hanford site stores large quantities of radioactive waste in underground, carbon-steel, double-shell tanks. The waste is transferred between the tanks using piping that consists of carbon-steel pipes and carbon-steel encasements. The transfer lines have shown extensive corrosion on both the interior of the casing and exterior of the carrier pipes. Nitrogen blanketing, used to displace the oxygen in the transfer lines, was hypothesized to reduce the corrosion of the transfer lines. Experimental studies were conducted to investigate the effect of oxygen concentration on the corrosion rate and the initiation of pitting on carbon steel. The results indicated that controlling the oxygen concentration to 0% effectively mitigates corrosion. However, at 5 vol% oxygen, a significant increase in the general corrosion rate and pitting corrosion is observed.

Atmospheric Corrosion↗
DOE OSTI2024

Potential Adoption and Benefits of Co-Optimized Multimode Engines and Fuels for U.S. Light-Duty Vehicles

Exploring a diverse portfolio of technologies for decarbonization is crucial to understanding the potential impacts of different technological solutions and their associated environmental implications. Using high-octane, high-sensitivity biofuel blends in co-optimized multimode engines can increase engine efficiency and reduce vehicle emissions. Here, the multimode engine research focuses on the benefits of light-duty vehicle engines, which can operate in multiple modes depending on the vehicle's load. Low-temperature combustion can improve efficiency and reduce emissions (such as those from oxides of nitrogen and particulate matter) during low-load operation, while spark ignition performance is maintained in high-load operation. These advanced engines can be optimized to run on blends of biobased fuels. This analysis models scenarios for potential market adoption of co-optimized multimode vehicles fueled by three different bioblendstocks: ethanol, isopropanol, and isobutanol. An integrated modeling approach is used to forecast the energy and environmental impacts of the deployment of co-optimized multimode vehicles and fuels in the light-duty sector over the 2020-to-2050 time horizon. The multidisciplinary approach combines vehicle sales modeling, system dynamics modeling of the biorefining industry, and life cycle assessment to estimate the emissions and energy benefits. The models consider market forces such as consumer preferences for vehicle attributes, biofuel supply and demand dynamics subject to biorefinery capacity build-out and bioresource constraints, and forecasted changes to the U.S. bulk energy system over time. Market adoption of co-optimized vehicles is evaluated across a wide parameter space for incremental vehicle cost and engine efficiency improvement. This analysis reveals that the deployment of co-optimized multimode fuels and vehicles results in up to a 5% reduction in annual sector-wide life cycle greenhouse gas (GHG) emissions by 2050, relative to a business-as-usual scenario, but is also indicates environmental trade-offs, such as higher life cycle water-use. Emission benefits could potentially increase beyond 2050, as the new technologies penetrate the market and gain a foothold. Results also show that, under certain circumstances, vehicles with engines co-optimized for use with high-octane, high-sensitivity biofuel blends can be cost-competitive with conventional gasoline, while reducing GHG emissions. Our modeling results indicate that co-optimized multimode fuels and engines can be strategically leveraged in tandem with electrification to decarbonize the light-duty sector. Co-optimized vehicles could play a role in the early years of the time horizon, while electric vehicles (EVs) could become more competitive in the later years, highlighting the complementary benefits of these technologies for GHG reductions.

Oke, Doris↗