NOx reduction mechanism of a methane–air Smithells flame

Nishioka, Makihito; Ishigami, Y.; Horii, Hirosuke; Umeda, Yoshito; Nakamura, Yuji

doi:10.1016/j.combustflame.2006.07.008

Cited by 10 publications

(6 citation statements)

References 17 publications

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“…Figure a and formula – show the reaction pathway from NO to NO 2 for the partially premixed combustor. HONO is an intermediate product in the chain reaction (R1–R3) of NO conversion to NO 2 . As expected, both HONO and NO 2 exhibited strong load dependence consistent with NO, which was increased with higher loads (Figure S9).…”

Section: Results and Discussionsupporting

confidence: 68%

“…HONO is an intermediate product in the chain reaction (R1−R3) of NO conversion to NO 2 . 35 As expected, both HONO and NO 2 exhibited strong load dependence consistent with NO, which was increased with higher loads (Figure S9). Furthermore, we found that HONO/NO showed an increasing trend with the growing loads (Figure 4b), while both NO 2 /NO and NO 2 / HONO decreased correspondingly (Figure 4c,d), which suggested that the conversion rate of NO to HONO (R2) was enhanced, while the oxidation rates of NO to NO 2 (R1) and HONO to NO 2 (R3 and R4) were inhibited at high load.…”

Section: ■ Experimental Methodssupporting

confidence: 77%

“…Most fossil and biomass combustions associated with high NO x emissions have been shown to co-exist with HONO emissions. ,− Combustion model studies have shown that HONO is an intermediate product in the chain reaction of partial NO conversion to NO 2 . , HONO may be more sensitive to different fuel types and combustion modes than NO x during combustion. Gasoline and diesel vehicles directly emit HONO, with the emission ratios equivalent to 0.03–2.9% of NO x . , Different fuel oils and driving conditions directly affect the HONO emissions and the HONO/NO x ratio.…”

Section: Introductionmentioning

confidence: 99%

“…6,32−34 Combustion model studies have shown that HONO is an intermediate product in the chain reaction of partial NO conversion to NO 2 . 35,36 HONO may be more sensitive to different fuel types and combustion modes than NOx during combustion. Gasoline and diesel vehicles directly emit HONO, with the emission ratios equivalent to 0.03−2.9% of NOx.…”

Section: ■ Introductionmentioning

confidence: 99%

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Direct Observation of HONO Emissions from Real-World Residential Natural Gas Heating in China

Xiang

Huang

Liu

et al. 2023

Environ. Sci. Technol.

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Atmospheric nitrous acid (HONO) is an important precursor of atmospheric hydroxyl radicals. Vehicle emissions and heterogeneous reactions have been identified as major sources of urban HONO. Here, we report on HONO emissions from residential natural gas (RNG) for water and space heating in urban areas based on in situ measurements. The observed HONO emission factors (EFs) of RNG heating vary between 6.03 and 608 mg·m–3 NG, which are highly dependent on the thermal load. The highest HONO EFs are observed at a high thermal load via the thermal NO homogeneous reaction. The average HONO EFs of RNG water heating in winter are 1.8 times higher than that in summer due to the increased thermal load caused by the lower inlet water temperatures in winter. The power-based HONO EFs of the traditional RNG heaters are 1085 times and 1.7 times higher than those of gasoline and diesel vehicles that meet the latest emission standards, respectively. It is estimated that the HONO emissions from RNG heaters in a typical Chinese city are gradually close to emissions from on-road vehicles when temperatures decline. These findings highlight that RNG heating is a non-negligible source of urban HONO emissions in China. With the continuous acceleration of coal-to-gas projects and the continuous tightening of NOx emission standards for vehicle exhaust, HONO emissions from RNG heaters will become more prominent in urban areas. Hence, it is urgently needed to upgrade traditional RNG heaters with efficient emission reduction technologies such as frequency-converted blowers, secondary condensers, and low-NOx combustors.

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Section: Results and Discussionsupporting

confidence: 68%

Section: ■ Experimental Methodssupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Direct Observation of HONO Emissions from Real-World Residential Natural Gas Heating in China

Xiang

Huang

Liu

et al. 2023

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…There is abundant literature on the various pathways of NO formation in hydrocarbon-air flames in general [11][12][13][14][15][16][17]. Miller and Bowman [11] presented detailed chemical modeling of Nitrogen chemistry in combustion, outlining the various pathways of NO formation.…”

Section: Introductionmentioning

confidence: 99%