Development of an extractive fermentation process of ethanol production by gas stripping

• Grant number: 14/07818-1
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): August 01, 2014
• Effective date (End): July 31, 2015
• Field of knowledge: Engineering - Chemical Engineering - Chemical Process Industries
• Principal researcher: Rubens Maciel Filho
• Grantee: Thuany de Brito Melo
• Home Institution: Faculdade de Engenharia Química (FEQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Alcoholic fermentation uses micro-organism S. cerevisiae to turn sugarcane extract or molasses, ethanol, is a unitary operation on a large scale in Brazil. Molasses from sugarcane which has approximately 50% by weight sugar is the main material used.During the fermentation the increase in the amount of ethanol inhibit the fermentation process. Concentrations of ethanol greater than 10-12 ° GL are not tolerated by the microorganisms. The industrial procedure to avoid this issue is to start the fermentation with a diluted solution of sugars (16 % by weight of sugars). The dilution requires large amounts of water in the process, which entails higher costs in the chemical plant. Moreover, the burdens of dilution are the additional costs of distillation and centrifugation.Considering the obstacles presented, we propose a method of extractive fermentation. The main objective is to overcome the inhibition of the process by coupling a continuous fermentation process of removing inhibitor (ethanol). Thus, the concentration of ethanol will be at acceptable levels and the impact on the metabolism of microorganisms will be minimized. The concept of extractive fermentation will be applied through the continuous removal of ethanol by using an inert carrier gas (extractive fermentation gas stripping). EFGS is a simple technique that does not require expensive chemicals and membranes. Moreover, the process uses very little energy and can be easily integrated into the fermentation process.