Biogas from Lignocellulosic Materials

Abstract

Methane production via anaerobic digestion is a steadily growing industry in Europe and all over the world. Biomethane reduces the demand for fossil fuels, since it can be used for the production of power and heat or converted to vehicle fuel. Anaerobic digestion is a renewable energy technology; however, it can also be considered as a low-cost environmental-friendly waste management process, since it reduces the emission of greenhouse gases (GHGs), while it stabilizes the wastes. Currently, mainly the organic fraction of household waste, food waste, sewage sludge, manure, and energy crops is used for biogas production; nevertheless, there are a wide range of other organic substrates which can be utilized for biogas production. Among the organic matters, lignocellulosic materials have a great potential. Great abundance worldwide and carbohydrate-rich contents make them an attractive feedstock for biofuel production. Currently, anaerobic digestion of energy crops is widespread; however, biogas production from lignocellulosic residuals and wastes is still under investigation. This chapter focuses on anaerobic digestion of lignocellulosic materials. It explains the anaerobic digestion process and the current technologies used for crops digestion. It also summarizes the biogas potential of different lignocellulosic materials and the latest research on pretreatments to improve the methane yield. Finally, this chapter compares anaerobic digestion of lignocellulosic materials with energy production from these kinds of materials through thermochemical processes.

A Preliminary Study of the Effect of Bioavailable Fe and Co on the Anaerobic Digestion of Rice Straw

“…An analysis of the enzymatic activity would also offer an elegant way to better evaluate the effects of TE addition on the activity of the microbial enzymes, including cellulases that are responsible for the hydrolysis of the cellulose contained in the rice straw [41]. Zhang et al [42] and Tian et al [43] showed a positive effect of Fe and Ni in enhancing the biogas production yields from cow dung and Phragmites straw, respectively, ascribing this also to a stimulation of the cellulase activity.…”

Pretreatment of lignocelluloses for enhanced biogas production: A review on influencing mechanisms and the importance of microbial diversity

“…To date, the attempts aimed at investigating the effects of different pretreatment processes on AD were only focused on substrate characteristics [16]. In other words, so far the impacts of pretreatments on AD of lignocelluloses has only been investigated by taking into consideration the changes in main substrate properties, including composition, surface properties, crystallinity, the degree of polymerization (DP), enzymes adsorption/desorption, and accessibility [17,18].…”

Process Modeling and Optimization of Anaerobic Co-Digestion of Peanut Hulls and Swine Manure Using Response Surface Methodology

“…First of all, the optimal C/N ratio for anaerobic co-digestion of peanut hulls and swine manure may be determined by the types of biogas materials and is not possibly unified in a specific range. Because most of the biogas materials are organic wastes, the peanut hull used in this experiment is rich in recalcitrant components, such as lignocellulose (semicellulose, cellulose, and lignin), which have been proven to be hard to be utilized by anaerobic organisms in a short retention time without any special pretreatments . Hence, a large amount of “invalid carbon” existing in these materials is also included in the calculation of C/N.…”

“…Because most of the biogas materials are organic wastes, the peanut hull used in this experiment is rich in recalcitrant components, such as lignocellulose (semicellulose, cellulose, and lignin), which have been proven to be hard to be utilized by anaerobic organisms in a short retention time without any special pretreatments. 29 Hence, a large amount of "invalid carbon" existing in these materials is also included in the calculation of C/N. Thus, to be more exact, this C/N ratio should be called total C/N, which can present only the general characteristics of the biogas material but cannot indicate accurately the properties of the substrate that can be actually utilized by anaerobic organisms.…”