Development and optimization of pyrolysis biochar production systems towards advanced carbon management
Notice bibliographique
Résumé
About 10% of the 60 Petagram (Pg)-Carbon fixed annually through worldwide photosynthetic activity ends up in agricultural residues. Through a heat-induced chemical conversion process such residues can be converted to biochar, a form of carbon that can be employed as a soil amendment, thereby providing long-term storage of carbon in soil. In this application, it has the ability to both reduce GHG emissions and enhance soil structure, moisture and nutrient retention, thereby also addressing global food security issues by improving soil fertility and crop yields.Dealing with several aspects of carbon management and resulting mitigation of GHG emissions, the current project sought to maximize biochar yield from microwave-assisted pyrolysis of maple (Acer L.) wood biomass. Microwave-assisted heating processes are known to be faster and more energy-efficient, yielding higher quality products than conventional methods. Volumetric, spectral and thermodynamic analysis of biochar developed through microwave-assisted pyrolysis showed it to exhibit greater porosity, lower reflectance and greater exothermic energy, and therefore greater overall quality than conventionally-produced biochar. This study also showed this microwave-assisted process to be capable of both producing high quality char and synthesize value-added carbon products. A three-dimensional finite element numerical model developed to optimize the primary parameters was instrumental in optimizing microwave pyrolytic process parameters so as to maximize biochar yields. The influence of selective heating phenomena on pyrolysis conditions was an important factor maximizing biochar yields arising from microwave-assisted pyrolysis of biomass. The application of a doping agent (i.e., microwave receptor) such as char enhanced the severity of the pyrolysis process by better temperature distribution within the biomassBased on numerical models and simulation data, the design of a microwave-assisted pyrolysis reactor affording optimal performance in terms of biochar yields was experimentally validated in a custom-built lab-scale unit. Biochar yield decreased with increasing pyrolysis temperature and time while doping ratio had no significant effect on biochar yields. The maximum predicted yield occurred for an microwave-assisted pyrolysis process optimized at the pyrolysis temperature of 250°C, reaction time of 1 min and doping ratio of 16%.The biochar resulting from microwave-assisted pyrolysis was characterized through various physical and chemical analyses: hyper-spectral imaging, pycnometry, proximate analyses, Scanning Electron Microscopy, Fourier Transform Infrared Radiation and Differential Scanning Calorimetry. The biochar's structural development was directly influenced by the pyrolysis conditions of temperature, residence time and doping ratio.In light of GHG emission balances and the economic feasibility of biochar production, a life cycle analysis was important in estimating the benefits of biochar systems over a wide range of biomass, process and application scenarios. The life cycle analysis determined the sustainability — in terms of reducing the undesired effects of pyrolysis biochar systems — of the proposed process for different types of agricultural residues in Quebec, Canada. This would help farmers to assess the economic vs. environmental benefits of employing this technology to put the agricultural waste they generate to optimal use. The economic viability of the pyrolysis-biochar system was found to be largely dependent on the costs of feedstock production, pyrolysis, and the value of carbon offsets. Therefore, the conclusions drawn from such a life cycle analysis would represent a useful tool in assessing the potential of biochar systems worldwide.
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 ».