Investigation of Mercury Transformation by HBr Addition in a Slipstream Facility with Real Flue Gas Atmospheres of Bituminous Coal and Powder River Basin Coal
Notice bibliographique
Résumé
An investigation of speciated mercury transformation with the addition of hydrogen bromide (HBr) at elevated temperatures was conducted in a slipstream reactor with real flue gas atmospheres. A real flue gas atmosphere is composed of bituminous coal (with high sulfur and high chlorine contents) and Powder River Basin (PRB) coal (with lower sulfur and chlorine contents). The average sulfur, chlorine, and mercury contents in the tested bituminous coal were 1.31% and 1328 and 0.11 ppm and 0.61% and 170 and 0.08 ppm, respectively, for tested PRB coal. The average CaO, Fe 2 O 3, and loss on ignition in collected fly ash contents of tested bituminous coal were 1.71, 17.51, and 7.13% and 22.95, 4.91, and 0.64%, respectively, for tested PRB coal. The different contents of coal chlorine, CaO, and Fe 2 O 3 in fly ash can be attributed to the different mercury speciations at baseline tests for these two coals in this study. The addition of HBr concentrations into the flue gas was controlled in the 3−15 ppm range. Semi-continuous mercury emission monitors were used to check the variation of mercury speciation at sampling locations. The Ontario Hydro Method (ASTM D6784-02) was used for data validation or comparison. For both methods, a high temperature inertial sampling probe was used to minimize the interference between vapor phase mercury and fly ash. Its temperatures were controlled consistently with flue gas temperatures at their installation locations in the slipstream reactor. Test results indicated that adding HBr into the flue gas at several parts per million strongly impacted the mercury oxidation and adsorption, which were dependent upon temperature ranges. Higher temperatures (in the range of 300−350 °C) promoted mercury oxidation by HBr addition but did not promote mercury adsorption. Lower temperatures (in a range of 150−200 °C) enhanced mercury adsorption on the fly ash by adding HBr. Test results also verified effects of flue gas atmospheres on the mercury oxidation by the addition of HBr, which included concentrations of chlorine and sulfur in the flue gas. Chlorine species seemed to be involved in the competition with bromine species in the mercury oxidation process. With the addition of HBr at 3 ppm at a temperature of about 330 °C, the additional mercury oxidation could be reached by about 55% in a flue gas atmosphere by burning PRB coal in the flue gas and by about 20% in a flue gas by burning bituminous coal. These are both greater than the maximum gaseous HgBr 2 percentage in the flue gas (35% for PRB coal and 5% for bituminous coal) by thermodynamic equilibrium analysis predictions under the same conditions. This disagreement may indicate a greater complexity of mercury oxidation mechanisms by the addition of HBr. It is possible that bromine species promote activated chlorine species generation in the flue gas, where the kinetics of elemental mercury oxidation were enhanced. However, SO 2 in the flue gas may involve the consumption of the available activated chlorine species. Thus, the higher mercury oxidation rate by adding bromine under the flue gas by burning PRB coal may be associated with its lower SO 2 concentration in the flue gas.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».