Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
ASSESSMENT OF THE FISH SCALES AND COAL BLENDS COMBUSTION IN A DROP TUBE FURNACE (DTF)
Submission Author:
Arthur Sousa Silva , SP , Brazil
Co-Authors:
Arthur Sousa Silva, Daniela Mortari, Fernando Pereira, Glauber Cruz
Presenter: Arthur Sousa Silva
doi://10.26678/ABCM.COBEM2021.COB2021-1040
Abstract
Fish production is one of the most economically representative activities on the Brazilian coast. During fish processing, the amount of organic matter discarded in the solid waste form (heads, tails, fins, viscera, skins and scales) can reach 50% by weight of the total production. The fish scales correspond to 4% of the dry residue and are considered useless and impractical, being discarded of disorderly manner in inappropriate places, such as in dumps or even thrown into the sea. It is known that the use of solid waste and biomass is a promising alternative to reduce dependence on fossil fuels, such as coal. One of the main technologies for converting biomasses into thermal energy is the co-firing of these materials with coal. This study proposed the reuse of fish scales as biofuel in co-firing processes with coal in a drop tube furnace (DTF). The samples were prepared with particle sizes < 100 µm in different proportions: 90% coal + 10% fish scales (B10), 70% coal + 30% fish scales (B30), and 50% coal + 50% fish scales (B50). The combustion processes were performed at 1100 °C, residence time of 500 ms, mass flow of 15 g h-1, airflow of 30 L min-1 and experiment time of 20 min. The combustion efficiency was measured by burnout and combustibility index (proximate analysis). The gaseous emissions of the main pollutants (CO, CO2, SO2 and NO) were evaluated by two methods: under stoichiometric conditions (theoretical emissions calculated by means of ultimate analysis) and a gas analyzer coupled to the reactor during experiments. The addition of fish scales in the blends promoted higher burnouts and combustibility rates compared to the burning of 100% coal. The sample B50 presented the highest burnout (≈ 93%), and lower carbon monoxide emissions (about 50% lower than 100% coal). However, a slight increase was observed in the CO2, SO2 and NO concentrations, related to the improvement in the combustion process and, due to the increase in the nitrogen quantity in the samples.; This behavior was also observed under stoichiometric conditions. The fish scales percentage in samples B10 and B30 were sufficient to guarantee high burnouts (close to 90%) and lower pollutants concentrations compared to B50. Therefore, the addition of fish scales favored the coal combustion process, but further studies are needed to assess its real influence on pollutant emissions, for example, in sulfur dioxide concentrations.
Keywords
fish scale, Co-firing, Coal, Blends, pollutant emissions
