Combination of Primary Measures on Flue Gas Emissions in Grate-Firing Biofuel Boiler
Increasingly stringent limits for NOx and SO<sub>2</sub> emission are forcing the investigation of new reduction methods. This study was conducted to determine the combination of primary measures, i.e., flue gas recirculation (FGR) and excess air effects on sulfur, nitrogen and hydrocarb...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-02-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/14/4/793 |
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| author | Adolfas Jančauskas Kęstutis Buinevičius |
| author_facet | Adolfas Jančauskas Kęstutis Buinevičius |
| author_sort | Adolfas Jančauskas |
| collection | DOAJ |
| description | Increasingly stringent limits for NOx and SO<sub>2</sub> emission are forcing the investigation of new reduction methods. This study was conducted to determine the combination of primary measures, i.e., flue gas recirculation (FGR) and excess air effects on sulfur, nitrogen and hydrocarbon emissions, in boiler flue gas. Experimental research was performed using an experimental, small-scale (20 kW) model of an industrial biofuel boiler. During combustion of sunflower seed hulls at different FGR ratios and incomplete combustion regimes, the composition of flue gas (NO, NO<sub>2</sub>, N<sub>2</sub>O, HCN, NH<sub>3</sub>, SO<sub>2,</sub> SO<sub>3</sub>, H<sub>2</sub>S, CO, and C<sub>x</sub>H<sub>y</sub>) was compared, allowing an explanation of the determinants of emission concentration changes to be provided. Increasing the flue gas recirculation ratio in the primary air had a positive effect on reducing NO<sub>X</sub> and CO with certain organic compounds. However, an opposite effect on SO<sub>2</sub> was observed. NO<sub>X</sub> and SO<sub>2</sub> concentrations were found to be approximately 500 mg/m<sup>3</sup> and 150 mg/m<sup>3</sup> under a regular combustion regime. When the FGR ratio of 50% NO<sub>X</sub> concentration decreased by 110 mg/m<sup>3</sup>, the SO<sub>2</sub> concentration increased by 60 mg/m<sup>3</sup>. The incomplete combustion regime reduced NO<sub>X</sub> concentration by 70 mg/m<sup>3</sup>, whereas SO<sub>2</sub> concentration increased by 100 mg/m<sup>3</sup>. The influence of primary measures presented an unclear relationship to hydrocarbon emissions, with concentrations not exceeding 18 mg/m<sup>3</sup>. |
| first_indexed | 2024-03-09T05:58:25Z |
| format | Article |
| id | doaj.art-8d1ba5c408e0421b8e15741867ad6f9b |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-09T05:58:25Z |
| publishDate | 2021-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-8d1ba5c408e0421b8e15741867ad6f9b2023-12-03T12:11:41ZengMDPI AGEnergies1996-10732021-02-0114479310.3390/en14040793Combination of Primary Measures on Flue Gas Emissions in Grate-Firing Biofuel BoilerAdolfas Jančauskas0Kęstutis Buinevičius1Department of Energy, Faculty of Mechanical Engineering and Design, Kaunas University of Technology, 51424 Kaunas, LithuaniaDepartment of Energy, Faculty of Mechanical Engineering and Design, Kaunas University of Technology, 51424 Kaunas, LithuaniaIncreasingly stringent limits for NOx and SO<sub>2</sub> emission are forcing the investigation of new reduction methods. This study was conducted to determine the combination of primary measures, i.e., flue gas recirculation (FGR) and excess air effects on sulfur, nitrogen and hydrocarbon emissions, in boiler flue gas. Experimental research was performed using an experimental, small-scale (20 kW) model of an industrial biofuel boiler. During combustion of sunflower seed hulls at different FGR ratios and incomplete combustion regimes, the composition of flue gas (NO, NO<sub>2</sub>, N<sub>2</sub>O, HCN, NH<sub>3</sub>, SO<sub>2,</sub> SO<sub>3</sub>, H<sub>2</sub>S, CO, and C<sub>x</sub>H<sub>y</sub>) was compared, allowing an explanation of the determinants of emission concentration changes to be provided. Increasing the flue gas recirculation ratio in the primary air had a positive effect on reducing NO<sub>X</sub> and CO with certain organic compounds. However, an opposite effect on SO<sub>2</sub> was observed. NO<sub>X</sub> and SO<sub>2</sub> concentrations were found to be approximately 500 mg/m<sup>3</sup> and 150 mg/m<sup>3</sup> under a regular combustion regime. When the FGR ratio of 50% NO<sub>X</sub> concentration decreased by 110 mg/m<sup>3</sup>, the SO<sub>2</sub> concentration increased by 60 mg/m<sup>3</sup>. The incomplete combustion regime reduced NO<sub>X</sub> concentration by 70 mg/m<sup>3</sup>, whereas SO<sub>2</sub> concentration increased by 100 mg/m<sup>3</sup>. The influence of primary measures presented an unclear relationship to hydrocarbon emissions, with concentrations not exceeding 18 mg/m<sup>3</sup>.https://www.mdpi.com/1996-1073/14/4/793biofuelbiomassemissionsrecirculationNO<sub>X</sub>SO<sub>2</sub> |
| spellingShingle | Adolfas Jančauskas Kęstutis Buinevičius Combination of Primary Measures on Flue Gas Emissions in Grate-Firing Biofuel Boiler Energies biofuel biomass emissions recirculation NO<sub>X</sub> SO<sub>2</sub> |
| title | Combination of Primary Measures on Flue Gas Emissions in Grate-Firing Biofuel Boiler |
| title_full | Combination of Primary Measures on Flue Gas Emissions in Grate-Firing Biofuel Boiler |
| title_fullStr | Combination of Primary Measures on Flue Gas Emissions in Grate-Firing Biofuel Boiler |
| title_full_unstemmed | Combination of Primary Measures on Flue Gas Emissions in Grate-Firing Biofuel Boiler |
| title_short | Combination of Primary Measures on Flue Gas Emissions in Grate-Firing Biofuel Boiler |
| title_sort | combination of primary measures on flue gas emissions in grate firing biofuel boiler |
| topic | biofuel biomass emissions recirculation NO<sub>X</sub> SO<sub>2</sub> |
| url | https://www.mdpi.com/1996-1073/14/4/793 |
| work_keys_str_mv | AT adolfasjancauskas combinationofprimarymeasuresonfluegasemissionsingratefiringbiofuelboiler AT kestutisbuinevicius combinationofprimarymeasuresonfluegasemissionsingratefiringbiofuelboiler |