scholarly journals Simulation of Mixing Intensity Profile for Bioethanol Production via Two-Step Fermentation in an Unbaffled Agitator Reactor

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5457
Author(s):  
Snunkhaem Echaroj ◽  
Hwai Chyuan Ong ◽  
Xiuhan Chen
Keyword(s):  
Ethanol Concentration ◽  
Fluid Dynamic ◽  
Scaling Up ◽  
Environmental Concerns ◽  
Bioethanol Production ◽  
Research Support ◽  
Fermentation Temperature ◽  
Ph Level ◽  
Impeller Type ◽  
Computational Fluid Dynamic Modeling

Bioethanol synthesis techniques have been studied intensively due to the energy crisis and various environmental concerns. A two-step bioethanol production process was carried out multiple times in an unbaffled agitator tank. The parameters varied, including the fermentation temperature, the pH level, the amount of yeast, and the impeller type. Then, a simulation was used to obtain an image of the agitation behavior inside the agitator tank to compare the velocity profile of each type of impeller design. The impeller with eight blades was found to produce the highest flow velocity: 0.28 m/s. The highest concentration of bioethanol generated from the fermentation was 34 g/L, which was produced by using an eight-blade impeller at 30 °C, a pH level of 5, an agitation speed of 70 rpm, and 2 wt % yeast. The two-blade impeller produced the lowest bioethanol concentration, 18 g/L, under the same conditions. Ethanol concentration was found to peak at 40 °C and a pH level of 5. The geometry of the impeller, the fermentation temperature, and the pH level were each found to have a significant effect on the resulting bioethanol concentration according to the results of an ANOVA test. The amount of yeast had no effect on the fermentation reaction. Finally, the results demonstrated the possibility of using computational fluid dynamic modeling to determine the impeller’s behavior for the development of the bioethanol fermentation process. The simulation and experimental results from this research support the scaling up of a bioethanol production facility.

scholarly journals Unpacking Brazil’s Leadership in the Global Biofuels Arena: Brazilian Ethanol Diplomacy in Africa

2016 ◽  
Vol 16 (3) ◽  
pp. 127-150 ◽  
Author(s):  
Stavros Afionis ◽  
Lindsay C. Stringer ◽  
Nicola Favretto ◽  
Julia Tomei ◽  
Marcos S. Buckeridge
Keyword(s):  
Political Leadership ◽  
Economic Recession ◽  
Scaling Up ◽  
Climatic Conditions ◽  
Global Leadership ◽  
Bioethanol Production ◽  
Land Area ◽  
African Countries ◽  
Alliance Network ◽  
The Eu

Biofuels represent an opportunity for Brazil to exert global leadership by substantially scaling up the production, consumption, and international trade of bioethanol. Africa represents an ideal venue in which to do this, given its suitable agro-climatic conditions and extensive land area. Brazil has consequently sought to establish bilateral partnerships with African countries, as well as North-South-South trilateral partnerships involving the EU and US. However, empirically grounded assessments of how Brazil’s leadership aspirations have unfolded in practice through these partnerships are limited. In this article, we examine Brazil’s potential to exert global political leadership, by analyzing its policy-based, structural, and instrumental qualities in making bilateral and trilateral inroads regarding bioethanol production in Africa. Interviews in Brazil, Africa, and Europe suggest that both the bilateral and trilateral avenues have produced meager results. Lack of domestic strategy and vision, economic recession, and a fragmented alliance network have reduced Brazil’s capacity to achieve its ethanol diplomacy objectives.

Computational fluid dynamic modeling for gas dispersion analysis during a high percentage CO2 drill stem test in deepwater, Brazil

2020 ◽  
Vol 20 (2020) ◽  
pp. 196-197
Author(s):  
Gabriel Clemente Franklin ◽  
Romulo Augusto Montovani Margotto ◽  
Jeferson de Souza Cunha ◽  
Wagner Queiroz Barros ◽  
Diego Charles Matta Fagundes ◽  
...  
Keyword(s):  
Dynamic Modeling ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Dispersion Analysis ◽  
Gas Dispersion ◽  
Drill Stem ◽  
Computational Fluid Dynamic Modeling

Contribution of inflow artery to observed flow in a vascular access: A computational fluid dynamic modeling study of an arteriovenous fistula circuit

2020 ◽  
pp. 112972982094406
Author(s):  
Jeffrey Krampf ◽  
Ramesh Agarwal ◽  
Surendra Shenoy
Keyword(s):  
Linear Relationship ◽  
Arteriovenous Fistula ◽  
Dynamic Modeling ◽  
Vascular Access ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Function Evaluation ◽  
Anastomotic Site ◽  
Flow Volume ◽  
Computational Fluid Dynamic Modeling

Introduction: The volume of blood flowing through the vascular access is an important parameter necessary to provide adequate dialysis for a functional arteriovenous fistula. Higher blood flows are seen in arteriovenous access that receive inflow from larger arteries such as brachial or axillary compared to those based on medium-caliber radial or ulnar arteries. We hypothesized that an anatomic difference in the length and the diameter of the artery is an important determinant of the flow volume in arteriovenous fistula created at different anatomic locations. Methods: Using computational fluid dynamics, we evaluated the contribution of the length and diameter of inflow artery on simulations performed with geometric models constructed to represent arteriovenous fistula circuits. Lengths and diameters of the inflow artery were altered to mimic arteriovenous fistula created at various locations of the upper extremity with standard and variant anatomy. Results: Models of arteriovenous fistula created with variable lengths and diameters of the inflow artery suggest that the length of the vessel has an inverse linear relationship and the diameter has a direct linear relationship to flow volume. Conclusion: Computational fluid dynamic modeling of arteriovenous fistula can be used to understand the physiologic basis of clinical observations of function. Evaluation of the effect of inflow artery length and diameter helps explain the higher flows seen in arteriovenous fistula created using large caliber arteries for inflow. Computational fluid dynamic modeling helps operators understand the contributions of inflow artery in access function and can guide anastomotic site selection.

Computational Fluid Dynamic Modeling For Hazardous Gas Dispersion Analysis In Deepwater, Brazil

2020 ◽  
Author(s):  
Gabriel Franklin ◽  
Wagner Barros ◽  
Marcos Ceciliano ◽  
Jeferson Cunha ◽  
Aquiles da Rocha ◽  
...  
Keyword(s):  
Dynamic Modeling ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Dispersion Analysis ◽  
Gas Dispersion ◽  
Computational Fluid Dynamic Modeling ◽  
Hazardous Gas
Sign in / Sign up

Export Citation Format

Share Document