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

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.

Review and perspectives of enhanced volatile fatty acids production from acidogenic fermentation of lignocellulosic biomass wastes

“…Cavinato et al ( 2017 ) compared the acidogenic co-fermentation from cow manure and maize silage at mesophilic and thermophilic conditions, and found fermentation at 37 °C range leading to 30% higher VFA production while about 50% higher solubilization yield at 55 °C range. However, due to this enhanced hydrolysis ability at higher temperature, thermophilic condition was found in favor of the fermentation with solid-state or high solid concentration, i.e., 30 g volatile solids (VS)/L (Achinas and Euverink 2020 ; Shi et al 2013 ).…”

High-Solid Anaerobic Digestion: Reviewing Strategies for Increasing Reactor Performance

“…These strategies may increase productivity and reduce reactor size without causing significant detriments in biogas yields, favorably affecting capital investment costs and plant economic feasibility. In addition, increasing the temperature favors the degradation of highly lignocellulosic materials such as grasses [171] and other agricultural wastes, in which anaerobic digestion finds wide applicability, but on the other hand, may increase the risk of compaction and uneven degradation. Wang et al [90] demonstrated the greater capacity of thermophilic systems to operate under higher organic loading rates when biochar was added to the reactor, due to the improvement in VFA degradation.…”

Analysis of the Efficiency of Landfill Gas Treatment for Power Generation in a Cogeneration System in Terms of the European Green Deal

“…LFG generated in the landfill waste bed is a renewable source of energy, while electricity and heat that are the product of cogeneration are counted from the so-called "green energy", which is part of the closed-loop economy and green energy transition [35,36]. In recent years, the European Union has been placing a heavy emphasis on the energy transition, pointing to the need for intensive development of renewable energy generation technologies, reducing the use of fossil fuels [37,38].…”