Comparing models to Neumann and Dirichlet conditions in grape seed drying

Johann, Gracielle; Menezes, Maraísa Lopes de; Pereira, Nehemias Curvelo; Silva, Edson Antônio da

doi:10.1016/j.applthermaleng.2015.10.005

Cited by 18 publications

(6 citation statements)

References 29 publications

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“…Thus, among the three models analyzed in the present study, model 1 is the most indicated to describe the convective drying of cumbeba waste. This result is in accordance with observations of previous studies on the drying of different types of biological products, where the model that considers third-kind boundary conditions also describes the experimental data better [34][35][36][37][38]. As the process parameters (D ef , Bi and h) were determined via optimization technique, Equation (9) was used in the simulations of the drying kinetics of the experimental data sets, for the temperatures of 50, 60, 70 and 80 • C, as shown in Figure 3.…”

Section: Results Obtained With the Modelsupporting

confidence: 92%

“…However, this is particularly problematic, because the underlying modeling of the drying process using this approach may result-for high mass transfer Biot numbers characteristic of the equilibrium boundary conditions-in significant truncation errors, especially in the initial instants of drying [32][33][34]. Thus, mathematical models that incorporate an appropriate number of terms from the analytical solution of the diffusion equation and/or the convective boundary condition to describe the drying process are more successful [33,[35][36][37][38].…”

Section: Introductionmentioning

confidence: 99%

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Description of Cumbeba (Tacinga inamoena) Waste Drying at Different Temperatures Using Diffusion Models

Ferreira

Silva

Queiroz

et al. 2020

Foods

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One approach to improve sustainable agro-industrial fruit production is to add value to the waste generated in pulp extraction. The processing of cumbeba (Tacinga inamoena) fruits generates a significant amount of waste, which is discarded without further application but can be a source of bioactive compounds, among other nutrients. Among the simplest and most inexpensive forms of processing, convective drying appears as the first option for the commercial utilization of fruit derivatives, but it is essential to understand the properties of mass transfer for the appropriate choice of drying conditions. In this study, cumbeba waste was dried at four temperatures (50, 60, 70 and 80 °C). Three diffusion models were fitted to the experimental data of the different drying conditions. Two boundary conditions on the sample surface were considered: equilibrium condition and convective condition. The simulations were performed simultaneously with the estimation of effective mass diffusivity coefficients (Def) and convective mass transfer coefficients (h). The validation of the models was verified by the agreement between the theoretical prediction (simulation) and the experimental results. The results showed that, for the best model, the effective mass diffusivities were 2.9285 × 10−9, 4.1695 × 10−9, 8.1395 × 10−9 and 1.2754 × 10−8 m2/s, while the convective mass transfer coefficients were 6.4362 × 10−7, 8.7273 × 10−7, 8.9445 × 10−7 and 1.0912 × 10−6 m/s. The coefficients of determination were greater than 0.995 and the chi-squares were lower than 2.2826 × 10−2 for all simulations of the experiments.

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Section: Results Obtained With the Modelsupporting

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Description of Cumbeba (Tacinga inamoena) Waste Drying at Different Temperatures Using Diffusion Models

Ferreira

Silva

Queiroz

et al. 2020

Foods

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“…As sementes de uva Bordô foram fornecidas pela Vinícola Vinhos Randon Ltda (Prineiro Preto/SC). Previamente a extração, as sementes foram lavadas para remoção de impurezas, secas à 80 o C em secador convectivo e moídas (JOHANN et al, 2016).…”

Section: Preparo Das Sementesunclassified

Aplicação Do Planejamento De Misturas Na Otimização Da Composição De Solventes Para Extrair Polifenois Dos Resíduos Da Vinificação

Diório¹,

Almeida²,

Liu³

et al. 2018

Blucher Chemical Engineering Proceedings

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RESUMO -As sementes de uva são resíduos da indústria de processamento de uvas e, se não forem descartadas corretamente, podem causar sérios problemas ambientais. Um uso nobre deste resíduo consiste na extração do seu óleo que contém polifenois benéficos à saúde do ser humano. O presente trabalho objetivou determinar a melhor composição de solventes (hexano, acetato de etila e etanol) capaz de extrair, com ultrassom, um óleo de sementes de uva Bordô rico em polifenois. A melhor extração de polifenois ocorreu utilizando 40 mL de uma mistura binária de hexano (30 %) e acetato de etila (70 %), por 30 minutos, obtendo uma concentração de 8821 mg EAG para cada 100 g semente.

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“…Clemente, Sanjuán, Cárcel, and Mulet () modeled the drying of seeds of V. vinifera , cultivar Bobal, applying the diffusive and Peleg models. More recently, Johann, Menezes, Pereira, and Silva () investigated experimentally and numerically the kinetics of grape seed drying V. vinifera cultivar Cabernet Sauvignon. They are not found in the literature studies that evaluated the influence of the drying temperature on the yield of grape seed oil content, obtained by extraction.…”

Section: Introductionmentioning

confidence: 99%

Assessment of pretreatment temperature on the oil extraction from the vinification waste

Johann

Menezes

Pereira

et al. 2018

J Food Process Preserv

Self Cite

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The study was carried out to determine the influence of hot air in drying process of grape seeds (Vitis labrusca) as well as in the oil extraction. The drying kinetics of the seeds was measured at different drying temperatures, ranging from 50 to 80 °C. The extraction experiments were conducted varying the operating pressure from 14 to 22 ton/cm 2. A phenomenological mathematical model of distributed parameters to describe the drying process was evaluated. The drying model was validated by comparison with experimental drying data and showed an average error of 2.2% in moisture profiles. In the pressing extractions experiments, the oil content was inversely proportional to the drying temperature of the seeds. The drying condition, which provided the maximum oil yield, was air temperature of 50 °C, in which the grape seed oil yield was 10%. Practical applications This article presents as contribution the filling of the scientific gap related to the evaluation of the drying kinetics and the influence of the drying temperature on the yield of grape seed oil content. For a practical application, our results revealed that the oil content was inversely proportional to the drying temperature of the grape seeds. Thus, considering the high costs related to the drying process, it can be concluded that the optimum temperature of drying the grape seeds must be directly related and the cost of energy and the oil content.

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Comparing models to Neumann and Dirichlet conditions in grape seed drying

Cited by 18 publications

References 29 publications

Description of Cumbeba (Tacinga inamoena) Waste Drying at Different Temperatures Using Diffusion Models

Description of Cumbeba (Tacinga inamoena) Waste Drying at Different Temperatures Using Diffusion Models

Aplicação Do Planejamento De Misturas Na Otimização Da Composição De Solventes Para Extrair Polifenois Dos Resíduos Da Vinificação

Assessment of pretreatment temperature on the oil extraction from the vinification waste

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