Kinetic Modeling and Techno-economic Feasibility of Ethanol Production From Carob Extract Based Medium in Biofilm Reactor

Mustafa Germec,Irfan Turhan,Ali Demirci,Mustafa Karhan

doi:10.3390/app9102121

Mustafa Germec, Irfan Turhan + Show 2 more

Open Access

https://doi.org/10.3390/app9102121

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Abstract

In this study, different carob extract-based media containing Medium A (included all ingredients), Medium B (included yeast extract and salts), Medium C (included (NH4)2SO4 and salts), Medium D (included only salts) and Medium E (included no ingredients) were evaluated for ethanol fermentation by Saccharomyces cerevisiae in a biofilm reactor and their results were used for kinetic modeling. The logistic model for cell growth, Luedeking-Piret model for ethanol production and Modified Luedeking-Piret model for substrate consumption were studied. Kinetic parameters were determined by fitting the observed values of the models. The findings indicated that the predicted data with the suggested kinetic model for each medium fitted very well the experimental data. Estimated kinetics were also in good agreement with experimental kinetics. The techno-economic analysis was performed with the unit costs of the components used in the medium and ethanol. Medium-based process economic feasibility proved carob extract-based Medium E and subsequently Medium D as most economical for ethanol production. The present study verified the potential of carob extract-based medium for increased economical production of ethanol. In conclusion, the ethanol production in a biofilm reactor is growth-associated since α (gP/gX) was greater than β (gP/gX.h) and Media D and E increased the economic production of carob extract-based ethanol.

Highlights

Ethanol, a two-carbon aliphatic alcohol, can be produced from various renewable carbon resources such as rice hulls [1], tea processing wastes [2,3], carob pods [4,5,6,7], rice straw [8], barley husk, wheat bran, rye bran [9], waste potato mash [10,11,12], sugarcane [13], corn grain [14]
The results indicated that as a, 0 and β value was obtained very close to zero, product formation was growth-associated in PCS biofilm reactor
The results indicated that the predicted values of ∆S and SUY with modified a Luedeking-Piret (MLP) model were slightly higher than its experimental values, except for Media D and E

Summary

Introduction

A two-carbon aliphatic alcohol, can be produced from various renewable carbon resources such as rice hulls [1], tea processing wastes [2,3], carob pods [4,5,6,7], rice straw [8], barley husk, wheat bran, rye bran [9], waste potato mash [10,11,12], sugarcane [13], corn grain [14]. Carob has been suggested to be an attractive raw material in the production of bioethanol from renewable sources due to its high carbohydrate content including sucrose, glucose, and fructose [5] Bioethanol produced from these sources can be used as a fuel with high octane. It is a biodegradable product that is less toxic than methanol; its combustion causes a reduction in CO2 emissions and is associated with a lower risk of ozone formation than gasoline and diesel [15]. It creates an alternative low-cost attractive energy source that can replace fossil fuels [4]. It is a remarkable fuel as it can be used alone or with 10%–22%

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