Ammonia for power

Ammonia, a molecule that is gaining more interest as a fueling vector, has been considered as a candidate to power transport, produce energy, and support heating applications for decades. However, the particular characteristics of the molecule always made it a chemical with low, if any, benefit once compared to conventional fossil fuels. Still, the current need to decarbonize our economy makes the search of new methods crucial to use chemicals, such as ammonia, that can be produced and employed without incurring in the emission of carbon oxides. Therefore, current efforts in this field are leading scientists, industries, and governments to seriously invest efforts in the development of holistic solutions capable of making ammonia a viable fuel for the transition toward a clean future. On that basis, this review has approached the subject gathering inputs from scientists actively working on the topic. The review starts from the importance of ammonia as an energy vector, moving through all of the steps in the production, distribution, utilization, safety, legal considerations, and economic aspects of the use of such a molecule to support the future energy mix. Fundamentals of combustion and practical cases for the recovery of energy of ammonia are also addressed, thus providing a complete view of what potentially could become a vector of crucial importance to the mitigation of carbon emissions. Different from other works, this review seeks to provide a holistic perspective of ammonia as a chemical that presents benefits and constraints for storing energy from sustainable sources. State-of-the-art knowledge provided by academics actively engaged with the topic at various fronts also enables a clear vision of the progress in each of the branches of ammonia as an energy carrier. Further, the fundamental boundaries of the use of the molecule are expanded to real technical issues for all potential technologies capable of using it for energy purposes, legal barriers that will be faced to achieve its deployment, safety and environmental considerations that impose a critical aspect for acceptance and wellbeing, and economic implications for the use of ammonia across all aspects approached for the production and implementation of this chemical as a fueling source. Herein, this work sets the principles, research, practicalities, and future views of a transition toward a future where ammonia will be a major energy player.

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Review on ammonia as a potential fuel: from synthesis to economics

Chemical kinetic modeling of ammonia oxidation with improved reaction mechanism for ammonia/air and ammonia/hydrogen/air combustion

Liquid hydrogen, methylcyclohexane, and ammonia as potential hydrogen storage: Comparison review

Laminar burning velocity and Markstein length of ammonia/hydrogen/air premixed flames at elevated pressures

Experimental investigation of nitrogen based emissions from an ammonia fueled SI-engine

The following individuals and funding agencies are acknowledged
for their support.
The authors from DTU acknowledge the Technical University of
Denmark, Danish Strategic Research Council, and MAN Diesel &
Turbo
University of Wisconsin: Financial support provided by the Princeton
Combustion Energy Frontier Research Center.
ETH Zurich: Financial support from the Swiss Federal Office of
Energy (grant no. SI/500818-01) and the Swiss Competence Center
for Energy and Mobility (CCEM project “In-cylinder emission
reduction”) is gratefully acknowledged. Argonne National Labs: Work was funded by U.S. DOE Office of
Vehicle Technologies, Office of Energy Efficiency and Renewable
Energy under Contract No. DE-AC02-06CH11357. We also
gratefully acknowledge the computing resources provided on Fusion,
a computing cluster operated by the Laboratory Computing Resource
Center at Argonne National Laboratory.
Sandia National Labs, Combustion Research Facility: Work was
supported by the U.S. Department of Energy, Office of Vehicle
Technologies. Sandia is a multiprogram laboratory operated by
Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security
Administration under contract DEAC04-94AL85000. Chris Carlen
and Dave Cicone are gratefully acknowledged for technical
assistance.
The authors from ANL and SNL also wish to thank Gurpreet Singh
and Leo Breton, program managers at U.S. DOE, for their support.

/pdf/a-progress-review-on-soot-experiments-and-modeling-in-the-x0wea94jl7.pdf

A Progress Review on Soot Experiments and Modeling in the Engine Combustion Network (ECN)

This work presents the development of an optical setup for quantitative, high-temporal resolution line-of-sight extinction imaging in harsh optical environments. The application specifically targets measurements of automotive fuel sprays at high ambient temperature and pressure conditions where time scales are short and perceived attenuation by refractive index gradients along the optical path (i.e., beam steering) can be significant. The illumination and collection optics are optimized to abate beam steering, and the design criteria are supported by well-established theoretical relationships. The general effects of refractive steering are explained conceptually using simple ray tracing. Three isolated scenarios are analyzed to establish the lighting characteristics required to render the observed radiant flux unaffected by the steering effect. These criteria are used to optimize light throughput in the optical system, enabling minimal exposure times and high-temporal resolution capabilities. The setup uses a customized engineered diffuser to transmit a constant radiance within a limited angular range such that radiant intensity is maximized while fulfilling the lighting criteria for optimal beam-steering suppression. Methods for complete characterization of the optical system are detailed. Measurements of the liquid–vapor boundary and the soot volume fraction in an automotive spray are presented to demonstrate the resulting improved contrast and reduced uncertainty. The current optical setup reduces attenuation caused by refractive index gradients by an order of magnitude compared to previous high-temporal resolution setups.

/pdf/diffuse-back-illumination-setup-for-high-temporally-resolved-uaozmmjm81.pdf

Diffuse back-illumination setup for high temporally resolved extinction imaging.

Penetration and combustion characterization of cavitating and non-cavitating fuel injectors under diesel engine conditions

• High pressure and temperature spectroscopic data of CO2 • Pseudo-Lorentzian line profile for CO2-N2 at elevated pressure and temperature validated against spectroscopic data. • Pseudo-Lorentzian line profile correlated with high pressure and temperature data for CO2-N2 mixtures. • Pseudo-Lorentzian line profile for H2O at elevated pressure validated against spectroscopic data from literature. Radiative heat transfer affects local flame temperatures, and thus pollutant formation in high-pressure diffusion flames but the radiation properties of major gas species at pressures and temperatures relevant for combustion engines are not well known. In order to facilitate radiative transfer calculations in these types of flames, new and already published CO 2 and H 2 O absorption spectra at high pressure and temperatures have been used to validate their modelled spectra based on the HITEMP 2010 database. Corrections for non-Lorentzian behavior of collisional-broadened lines have been evaluated, where an adjustable pseudo-Lorentzian line profile has been correlated for CO 2 − N 2 mixtures over a wide range of pressure, temperature and concentration. A fixed pseudo-Lorentzian line profile was found to give similar performance to previous empirical line corrections when comparing to available experimental H 2 O data over a relatively wide pressure and temperature range. The work has led to the release of an in-house MATLAB code, named RadISpeC freely available for download. The code efficiently produces spectra for radiation calculations for both soot and gas at high pressures and temperature. 

Fredrik Ree Westlye

Papers

Experimental investigation of nitrogen based emissions from an ammonia fueled SI-engine

A Progress Review on Soot Experiments and Modeling in the Engine Combustion Network (ECN)

Diffuse back-illumination setup for high temporally resolved extinction imaging.

Penetration and combustion characterization of cavitating and non-cavitating fuel injectors under diesel engine conditions

Evaluation of spectral radiative properties of gases in high-pressure combustion