Further Insight into the Possibility to Fuel a SI Engine with Ammonia plus Hydrogen

Frigo, Stefano; Gentili, Roberto; Angelis, Franco De

doi:10.4271/2014-32-0082

Cited by 28 publications

(8 citation statements)

References 9 publications

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“…The use of hydrogen–ammonia blends was central in the development of ICE using ammonia. Frigo et al − demonstrated the use of ammonia and cracked hydrogen to power a converted Lombardi 505 cm 3 engine for waste trucks. The introduction of a new cracker device capable of converting almost all ammonia intake (at temperatures above 500 °C) enabled the generation of 10.5 kW with emissions below 3500 ppm of NO x .…”

Section: Applications Of Nitrogen-based Fuelsmentioning

confidence: 99%

Progress and Prospective of Nitrogen-Based Alternative Fuels

et al. 2020

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Alternative fuels are essential to enable the transition to a sustainable and environmentally friendly energy supply. Synthetic fuels derived from renewable energies can act as energy storage media, thus mitigating the effects of fossil fuels on environment and health. Their economic viability, environmental impact, and compatibility with current infrastructure and technologies are fuel and power source specific. Nitrogen-based fuels pose one possible synthetic fuel pathway. In this review, we discuss the progress and current research on utilization of nitrogen-based fuels in power applications, covering the complete fuel cycle. We cover the production, distribution, and storage of nitrogen-based fuels. We assess much of the existing literature on the reactions involved in the ammonia to nitrogen atom pathway in nitrogen-based fuel combustion. Furthermore, we discuss nitrogen-based fuel applications ranging from combustion engines to gas turbines, as well as their exploitation by suggested end-uses. Thereby, we evaluate the potential opportunities and challenges of expanding the role of nitrogen-based molecules in the energy sector, outlining their use as energy carriers in relevant fields.

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Section: Applications Of Nitrogen-based Fuelsmentioning

confidence: 99%

Progress and Prospective of Nitrogen-Based Alternative Fuels

et al. 2020

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“…Ammonia combustion in engines can be enhanced by mixing it with fuels that exhibit higher reactivity and flame temperature. Use of ammonia as the primary fuel for sparkignited engines has been demonstrated in the literature and has been shown to benefit from some degree of mixing with gasoline or other ignition enhancers to increase the flame speed [18,[27][28][29][30] Ammonia combustion in compression ignition engines requires dual-fuel operation where ammonia is fumigated into the intake air and direct diesel fuel injection near the end of compression provides sufficient reactivity for ignition [15,16,29,31]. Prior studies on dual-fuel operation using diesel and ammonia have shown that on a lower heating value basis, ammonia may replace up to 95% of diesel fuel for stable operation, and up to 80% while maintaining reasonable engine fuel efficiency.…”

Section: Introductionmentioning

confidence: 99%

“…Mixing ammonia with hydrogen has promise to improve reactivity in dual-fuel combustion because only small amounts are necessary to yield significant improvements [12,14,17,24,30,33,34]. Mixing as little as 30% H 2 with ammonia by volume has shown to increase the laminar flame speed of ammonia to nearly the same as that of gasoline [14].…”

Section: Introductionmentioning

confidence: 99%

Thermochemical Recuperation to Enable Efficient Ammonia-Diesel Dual-Fuel Combustion in a Compression Ignition Engine

Kane

Northrop

2021

Energies

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A thermochemical recuperation (TCR) reactor was developed and experimentally evaluated with the objective to improve dual-fuel diesel–ammonia compression ignition engines. The novel system simultaneously decomposed ammonia into a hydrogen-containing mixture to allow high diesel fuel replacement ratios and oxidized unburned ammonia emissions in the exhaust, overcoming two key shortcomings of ammonia combustion in engines from the previous literature. In the experimental work, a multi-cylinder compression ignition engine was operated in dual-fuel mode using intake-fumigated ammonia and hydrogen mixtures as the secondary fuel. A full-scale catalytic TCR reactor was constructed and generated the fuel used in the engine experiments. The results show that up to 55% of the total fuel energy was provided by ammonia on a lower heating value basis. Overall engine brake thermal efficiency increased for modes with a high exhaust temperature where ammonia decomposition conversion in the TCR reactor was high but decreased for all other modes due to poor combustion efficiency. Hydrocarbon and soot emissions were shown to increase with the replacement ratio for all modes due to lower combustion temperatures and in-cylinder oxidation processes in the late part of heat release. Engine-out oxides of nitrogen (NOx) emissions decreased with increasing diesel replacement levels for all engine modes. A higher concentration of unburned ammonia was measured in the exhaust with increasing replacement ratios. This unburned ammonia predominantly oxidized to NOx species over the oxidation catalyst used within the TCR reactor. Ammonia substitution thus increased post-TCR reactor ammonia and NOx emissions in this work. The results show, however, that engine-out NH3-to-NOx ratios were suitable for passive selective catalytic reduction, thus demonstrating that both ammonia and NOx from the engine could be readily converted to N2 if the appropriate catalyst were used in the TCR reactor.

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“…Furthermore, slip NH3 and carbon monoxide (CO) emissions for the former were lowered by 2.5 g/kWh and 8 g/kWh, respectively. Frigo [27,30] developed a Hydrogen Generation System (HGS) for NH3 dissociation, as depicted in Fig. 4a.…”

Section: Ammonia In Spark Ignition (Si) Enginementioning

confidence: 99%