Green Biorefinery of Giant Miscanthus for Growing Microalgae and Biofuel Production

Shuangning Xiu,Bo Zhang,Abolghasem Shahbazi,Nana Boakye-Boaten

doi:10.3390/fermentation3040066

Abstract

In this study, an innovative green biorefinery system was successfully developed to process the green biomass into multiple biofuels and bioproducts. In particular, fresh giant miscanthus was separated into a solid stream (press cake) and a liquid stream (press juice) using a screw press. The juice was used to cultivate microalga Chlorella vulgaris, which was further thermochemically converted via thermogravimetry analysis (TGA) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analysis, resulting in an approximately 80% conversion. In addition, the solid cake of miscanthus was pretreated with dilute sulfuric acid and used as the feedstock for bioethanol production. The results showed that the miscanthus juice could be a highly nutritious source for microalgae that are a promising feedstock for biofuels. The highest cell density was observed in the 15% juice medium. Sugars released from the miscanthus cake were efficiently fermented to ethanol using Saccharomyces cerevisiae through a simultaneous saccharification and fermentation (SSF) process, with 88.4% of the theoretical yield.

Highlights

Fossil fuels are the major source for our energy need at present, which currently contribute about 80% of the global energy demand [1]
According to the International Energy Agency (IEA), this demand will be increased by 40% by the year 2035, with fossil fuels contributing 75% [2]
Miscanthus x. giganteus (MxG) has been noted to be a good candidate for bioethanol production due to its high carbon content

Summary

Introduction

Fossil fuels are the major source for our energy need at present, which currently contribute about 80% of the global energy demand [1]. According to the International Energy Agency (IEA), this demand will be increased by 40% by the year 2035, with fossil fuels contributing 75% [2]. This over dependence and increasing use of fossil fuels in the US and globally serves as a source of worry, as it is predicted to reach a crisis point in the near future [3]. Sustainable developments requires the use of renewable biomass-based resources for fuels, chemicals and material production [4]. Considerable attention has been given to lignocellulosic biomass such as agricultural residues and energy crops for biofuel production

Methods

Results

Conclusion