Enhanced biohydrogen production from oat straw co-digested with cow dung / sewage sludge by combined aerobic digestion and anaerobic fermentation

Loretta Li,Lirong Zhou

doi:10.19040/ecocycles.v1i2.41

Abstract

Hydrogen was produced from oat straw by combined aerobic and anaerobic fermentation with fungi and cow dung. With aerobic pre-digestion, the maximum hydrogen production rate reached 133 ml/g volatile suspended solids per hour. The maximum hydrogen yield was 71.5 ml/g straw in 6 days by biological process. The lignocellulosic conversion of oak-straw waste was 39%, with the complex component converting 68% of the hemi-cellulose and 61% of the cellulose, but only 34% of lignin conversion. Aerobic pre-digestion by Trichoderma viride and Saccharomyces cerevisiae was significantly effective for lignin degradation. Combining aerobic digestion and anaerobic fermentation is a promising low-cost efficient and environmentally friendly method, not only for hydrogen production, but also for converting straw biomass.

Highlights

Production of biofuels from renewable biomass is a potentially important fuel generation technique to reduce reliance on fossil fuels and provide a more sustainable alternative (Han and Shin, 2004)
Effects of aerobic pre-digestion on hydrogen production Because chemical and physical pretreatments are often used when utilizing cellulosic materials (Antizar-Ladislao and Turrion-Gomez, 2008), the same substrate was used to compare the effects of aerobic pre-digestion with chemical and physical pretreatment on hydrogen fermentation
Aerobic digestion by T. viride and S. cerevisiae is a promising pretreatment method for hydrogen production from oat straw, and the anaerobic fermentation conditions were optimized in the following experiments

Summary

Introduction

Production of biofuels from renewable biomass is a potentially important fuel generation technique to reduce reliance on fossil fuels and provide a more sustainable alternative (Han and Shin, 2004). As hydrogen is a clean energy that could be produced from waste materials, such as organic waste crop straw (Ilgi and Fikret, 2006), some believe that hydrogen could replace fossil fuels as the generation energy carrier (Fan et al, 2004; Verhelst, 2014). A major lignocellulosic waste, is a promising source of potential candidates for energy production due to its content of approximately 70-80% carbohydrates, low cost, abundance and wide availability (Dererie et al, 2011). Harvesting of crops produces large amounts of straw annually, most of which is improperly discarded, thereby causing serious environmental problems, such as air pollution from burning (Dominguez-Escriba and Porcar, 2010). Producing hydrogen from straw could eliminate its environmental impacts, and ensure a secure renewable energy supply (Kaparaju et al, 2009)

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Results

Conclusion