Pretreatments to enhance the digestibility of lignocellulosic biomass

Optimisation of the anaerobic digestion of agricultural resources.

Solid-state anaerobic digestion (SS-AD) generally occurs at solid concentrations higher than 15%. In contrast, liquid anaerobic digestion (AD) handles feedstocks with solid concentrations between 0.5% and 15%. Animal manure, sewage sludge, and food waste are generally treated by liquid AD, while organic fractions of municipal solid waste (OFMSW) and lignocellulosic biomass such as crop residues and energy crops can be processed through SS-AD. Some advantages of SS-AD include smaller reactor capacity requirements, less energy used for heating, and no processing energy needed for stirring. Due to its lower water content, the digestate of SS-AD is much easier to handle than the effluent of liquid AD. However, SS-AD systems also have disadvantages such as larger amounts of required inocula and much longer retention time. The principles and applications of the SS-AD process are reviewed in this paper. The variation in biogas production yields of different feedstocks is discussed as well as the need for pretreatment of lignocellulosic biomass to enhance biogas production. The effects of major operational parameters, including C/N ratio, solids content, temperature, and inoculation on the performance of SS-AD are summarized. While an increase in operating temperature can improve both the biogas yield and the production efficiency, other practices such as using AD digestate or leachate as an inoculant or decreasing the solid content, may increase the biogas yield but have negative impact on production efficiency. Different reactor configurations used in current commercial scale SS-AD systems and the impact of economics on system selection are also discussed.

Solid-state anaerobic digestion for methane production from organic waste

Pretreatment methods to enhance anaerobic digestion of organic solid waste

Hydrolysis kinetics in anaerobic degradation of particulate organic material: an overview.

1.Fundamentals of the anaerobic digestion process 2.Reactor sizing, process kinetics, and modelling of anaerobic digestionof complex waste 3.Analysis and optimisation of the anaerobic digestion of the organicfraction of municipal solid waste 4.Anaerobic digestion of the organic fraction of municipal solid waste:a perspective 5.Types of anaerobic digester for solid wastes 6.Characteristics of the OFMSW and behaviour of the anaerobic digestionprocess 7.Co-digestion of the organic fraction of municipal waste with otherwaste types 8.Pretreatments for the enhancement of anaerobic digestion of solidwastes 9.Use of hydrolysis products of the OFMSW for biological nutrientremoval in wastewater treatment plants 10.Products, impacts and economy of anaerobic digestion of OFMSW 11.Anaerobic digestion of organic solid waste in bioreactor landfills

Joan Mata-Alvarez

Papers

Biomethanization of the Organic Fraction of Municipal Solid Wastes