Effect of Temperature and Organic Load on the Performance of Anaerobic Bioreactors Treating Grasses

Spyridon Achinas,Gerrit Jan Willem Euverink

doi:10.3390/environments7100082

Abstract

The organic residues generated in grasslands can be treated by adopting anaerobic digestion technology. This technology can enhance the efforts for sustainable waste management around the world. In the northern Netherlands, there is a vast amount of ditch clippings and canal grasses that can be used as a renewable source of energy; however, optimal bioenergy production from grasses is still under research and this study aims to evaluate biogas production from grassy residues at the local level in the context of a sustainable waste management scheme. Batch tests were facilitated to investigate the impact of temperature and organic load on the anaerobic digestion performance of grass mixtures (ditch clippings and canal grasses). The results showed that high temperature favors the degradation of high lignocellulosic materials like grasses. Specifically, bioreactors at 55 °C with an organic load of 30 g volatile solids (VS) L−1 reached 360.4 mL g VSsubstrate−1. Moreover, reactors with low organic loads resulted in a lower methane yield. The kinetics study also showed good fitting of the predicted and experimental values.

Highlights

Sustainable energy production is an urgent necessity due to the depletion of fossil fuels, the continuing increase in the world population, food security, and the augmentation in environmental problems [1,2,3]
Rapid methane production began in the reactors at 25 ◦ C even though process speed did not show any clear dependence on the organic load (OL)
This study examined the effect of organic load and temperature on the methane yield from the anaerobic treatment of ditch clippings and canal grasses

Summary

Introduction

Sustainable energy production is an urgent necessity due to the depletion of fossil fuels, the continuing increase in the world population, food security, and the augmentation in environmental problems [1,2,3]. Bioenergy from agricultural and farming waste plays a major role in research efforts [4,5,6,7]. Different treatment processes are implemented to treat organic waste, with the anaerobic digestion (AD) technology having among others economic merit in large-scale utilization [8,9,10,11]. The biochemical process of AD that converts organic waste into useful products is regarded as another choice for bioenergy production [12,13,14,15,16]. Biogas is an energy carrier and its composition consists of. The biogas may probably undergo post-treatment (upgrading) to reach the natural gas properties [18]

Objectives

Methods

Results

Conclusion