Evaluation of Production of Hydrogen in a Batch Bioreactor Using Clostridium Butyricum Dsm 2478 from Banana Peel

Abstract

Production of banana in the world was 20 million tons in 2018; this means that around 6 million tons of banana peel is converted in agricultural waste worldwide. Different methods have been evaluated for using this type of waste; one alternative use is the conversion to hydrogen by biotechnological processes. The high calorific value and clear combustion are attributes that makes hydrogen a solution to replace fossil fuels. One way to obtain hydrogen is by biological methods as fermentative pathway by bacteria. In this paper it was evaluated the production of hydrogen with Clostridium butyricum DSM 2478 from banana peel (BP). BP was collected and pretreated by washed, dried, grounded and sieved for the adaptation and selection of the particle size for fermentation. The fermentation was carried out at 100 ml in RCM (Reinforced Clostridial Medium) medium with the pretreated BP using initial concentrations: 2.5%, 5% and a control test (0%). The medium with 5% of BP showed the best results, obtaining 157.54 mmol H₂/l with a scale of 10 ml and a degradation percentage of 29.12% of BP. Process was scaled up in bioreactor (2.5 l). Operation conditions were temperature 37°C, pH 7, an initial concentration of BP at 5% (which was the best at laboratory scale) and agitation of 200 rpm. The hydrogen production in the bioreactor was evaluated obtaining a maximum concentration of 668.4 mmol H₂/L with a degradation percentage of 94.97% of the initial BP in the medium. These results indicate that hydrogen production through BP using C. butyricum is possible.