Biological And Thermal Pretreatment Of Lignocellulosic Materials For Enhanced Biogas Production

Samer Dahahda

doi:10.32920/ryerson.14646906.v1

Abstract

The rapid depletion of natural resources and the environmental concerns associated with the use of fossil fuels as the main source of global energy is leading to an increased interest in alternative and renewable energy sources. Lignocellulosic biomass is the most abundant source of organic materials that can be utilized as an energy source. Anaerobic digestion has been proven to be an effective technology for converting organic material into energy products such as biogas. However, the nature of lignocellulosic materials hinders the ability of microorganisms in an anaerobic digestion process to degrade and convert organic material to biogas. Therefore, a pretreatment step is necessary to improve the degradability of lignocellulosic materials and achieve higher biogas yield. Several pretreatment methods have been studied over the past few years including physical, thermal, chemical and biological pretreatment. This paper reviews biological and thermal pretreatment as two main promising methods used to improve biogas production from lignocelluloses. A greater focus is given on enzymatic pretreatment which is one of the promising yet under-researched biological pretreatment method. The paper addresses challenges in degrading lignocellulosic materials and the current status of research to improve biogas yield from lignocelluloses through biological and thermal pretreatment.

Highlights

The past decade has witnessed a surge in challenges arising from the increased consumption of fossil fuels and non-renewable energy sources such as the depletion of natural resources and the environmental impact of the use of fossil fuel that contributes to climate change and global warming
Lignocellulosic biomass could be grown as an energy crop that does not compete with food crops and can be planted in areas not suitable for food crops as several ethical concerns have arisen from using food crops such as sugarcane for biofuels production [2,6]
This paper presented a review of studies on improving the biogas yield of lignocellulosic biomass through biological and thermal pretreatment

Summary

Introduction

The past decade has witnessed a surge in challenges arising from the increased consumption of fossil fuels and non-renewable energy sources such as the depletion of natural resources and the environmental impact of the use of fossil fuel that contributes to climate change and global warming. It is estimated that more than 84% of the world’s energy demand is supplied through non-renewable sources such as fossil fuels, coal and natural gas [1]. Such challenges paved a wider way for considering and further researching the use of renewable energy sources and managing natural resources in a sustainable manner. Lignocelluloses are composed of a mixture of three main polymers: cellulose, hemicellulose, and lignin that bound together to form the rigid and protective layer of the plant cell wall [1,4]. It can be collected as a waste material from forest, agricultural, industrial, and municipal areas [5]. Lignocellulosic biomass could be grown as an energy crop that does not compete with food crops and can be planted in areas not suitable for food crops as several ethical concerns have arisen from using food crops such as sugarcane for biofuels production [2,6]

Methods

Findings

Discussion

Conclusion