Microbubbles generation in pneumatic bioreactors: application in extractive ethanol fermentation using carbon dioxide as stripping gas

• Grant number: 18/24460-4
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2019
• End date: August 31, 2023
• Field of knowledge: Engineering - Chemical Engineering - Industrial Operations and Equipment for Chemical Engineering
• Principal Investigator: Alberto Colli Badino Junior
• Grantee: Rauber Daniel Pereira
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated scholarship(s): 21/06659-0 - Characterization of a new fine bubbles generator for bioprocess application, BE.EP.DR

Abstract

The microbubble generation has attracted rising scientific interest. It is known that microbubbles increase mass transfer efficiency in gas-liquid dispersions. So, the use of microbubbles is indicated for many applications at bench and industrial scales. However, the microbubbles application in extractive fermentation with ethanol removal by CO2 stripping is still unexplored. In this process, CO2 is injected into the reactor to remove part of the ethanol from the fermentation broth in order to reduce the microbiological inhibition effect caused by the product. Significant increases in ethanol productivity were achieved in this system using a specific gas flow rate of 2.5 vvm, which are impracticable in the industrial scale where the reactors have thousands of liters in capacity. The use of microbubbles is a simple way of reducing the necessary specific gas flow rate to the process. Moreover, it contributes to the operational feasibility of the extractive ethanol fermentation. In this context, the present project presents the following objectives: (i) to build and characterize the fluidic oscillator to microbubbles generation; (ii) to set up an innovative microbubbles generator and to compare its performance to the fluidic oscillator; (iii) to evaluate the best diffuser design to generate microbubbles; (iv) to evaluate the best system of microbubble generation in the extractive fermentation with ethanol stripping by CO2. A bubble column bioreactor will be used in this work and different ethanol-water mixtures and operating conditions will be tested. The best system and more adequate operational conditions will be utilized to the extractive ethanol fermentation. This project will contribute to the development of non-conventional bioreactors with a high mass transfer capacity and will turn the extractive ethanol fermentation more efficient. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SILVA, A. C. B.; ESPERANCA, M. N.; PEREIRA, R. D.; BADINO, A. C.; BETTEGA, R.. Numerical and experimental estimation of global gas holdup in a bubble column using computational fluid dynamics (CFD). Journal of the Brazilian Society of Mechanical Sciences and Engineering, v. 45, n. 10, p. 9-pg., 2023-10-01. (18/24460-4)

PEREIRA, RAUBER D.; BADINO, ALBERTO C.; CRUZ, ANTONIO J. G.. Framework Based on Artificial Intelligence to Increase Industrial Bioethanol Production. ENERGY & FUELS, v. 34, n. 4, p. 4670-4677, APR 16 2020. (18/11405-5, 18/24460-4)