Analysis of the performance of an L-valve feeding spent coffee ground powders into a circulating fluidized bed

Autor(es)

Sousa, L. Massaro ^[1] ; Ferreira, M. C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Drying Ctr Pastes Suspens & Seeds, Chem Engn Dept, POB 676, BR-13565905 Sao Carlos - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Powder Technology; v. 362, p. 759-769, FEB 15 2020.
• Citações Web of Science: 0

Resumo

Waste biomass powders are appealing to generate renewable energy and to reduce the dependence on fossil fuels, however, feeding reactors in processing is still a challenge. This paper examines the performance of a non-mechanical L-valve to feed dry and moist Spent Coffee Ground (SCG) powders into a circulating fluidized bed under a broad range of conveying and aeration flowrates. The L-valve performed as a robust feeder, providing stable solids circulation rate (W-S) for most of the tested conditions. Solid mass flowrates were not affected by fluctuations in the riser air flowrate up to +/- 15%. We verified that the L-valve performance is limited by a deterioration of powders' flowability. Lower values of W-S and narrower operating ranges were observed when feeding dry SCGs powders and samples containing fine particles. Nevertheless, the feeder can be considered a good option to handle SCGs with moisture content close to 30% w.b. and a mean particle size of 400 mu m. This is an appealing result since the moisture content of SCGs burned in the soluble coffee industry ranges from 25 to 50%. Solids feeding was stable and operation was smooth in a range of 1.2 < W-S < 10.0 g/s. Finally, a correlation to predict W-S from the pressure drop in the L-valve is proposed, which fitted our data better than other equations available in the literature. (C) 2019 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 16/25946-2 - Estudo sobre o desempenho de válvulas não-mecânicas como alimentadores de pós de biomassa em reatores de leito pneumático circulante
• Beneficiário: Lucas Massaro Sousa
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 18/11031-8 - Estudo sobre o desempenho de válvulas não-mecânicas como alimentadores de pós de biomassa em reatores de leito pneumático circulante: análise via fluidodinâmica computacional (CFD)
• Beneficiário: Lucas Massaro Sousa
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado Direto