Lignocellulosic Biomass to Liquid Biofuels

Abu Yousuf, Filomena Sannino, Domenico Pirozzi

• Publisher: Academic Press
• Year: 2019
• ISBN:
  9780128162804
• Topic: Physical Sciences
• Subtopic: Energy

Lignocellulosic Biomass to Liquid Biofuels explores the existing technologies and most recent developments for the production of second generation liquid biofuels, providing an introduction to lignocellulosic biomass and the processes for its conversion into biofuels. The book demonstrates biorefinery concepts compared with petro refinery, as well as the challenges of second generation biofuels processing. In addition to current pre-treatment techniques and their technical, environmental and economic implications, chapters included also further examine the particularities of conversion processes for bioethanol, biobutanol and biodiesel through chemical, biochemical and combined approaches. Finally, the book looks into concepts and tools for techno-economic and environmental analysis, which include supply chain assessment, by-products, zero-waste techniques and process evaluation and optimization.

Lignocellulosic Biomass to Liquid Biofuels is particularly useful for researchers in the field of liquid biofuels seeking alternative chemical and biochemical pathways or those interested advanced methods to calculate maximum yield for each process and methods to simulate the implications and costs of scaling up. Furthermore, with the introduction provided by this volume, researchers and graduate students entering the field will be able to quickly get up to speed and identify knowledge gaps in existing and upcoming technology the book's comprehensive overview.

• Examines the state-of-the-art technology for liquid biofuels production from lignocellulosic biomass
• Provides a comprehensive overview of the existing chemical and biochemical processes for second generation biofuel conversion
• Presents tools for the techno-economic and environmental analysis of technologies, as well as for the scale-up simulation of conversion processes

Chapter 1

Fundamentals of lignocellulosic biomass

Abu Yousuf¹, Domenico Pirozzi² and Filomena Sannino³, ¹Department of Chemical Engineering & Polymer Science, Shahjalal University of Science and Technology, Sylhet, Bangladesh, ²Department of Chemical, Materials and Production Engineering, University of Naples “Federico II”, Naples, Italy, ³Department of Agriculture, University of Naples “Federico II”, Naples, Italy

Abstract

Liquid biofuel is a promising alternative to petroleum-based fossil fuel. Lignocellulosic biomass (LCB) is considered as a potential source of biofuel since it is not food competitive always. Moreover, it has a wide range of sources, such as agriculture residues, forest residues, grass, and energy crops. Though the resources are abundant and readily available all around the world, its contribution in energy sector is not significant. It may be due to the lacking of economically viable and industrially applicable technology. To design and develop sustainable technology, it is urgent to understand the composition, characters, and their refinery process. Therefore this chapter describes the fundamental structure, chemistry, and biorefinery of LCB.

Keywords

Lignocellulosic biomass; chemistry of LCB; biorefinery of LCB

Contents

Outline

• 1.1 Introduction 1
• 1.2 Components of lignocellulosic biomass 3
  • 1.2.1 Cellulose 3
  • 1.2.2 Hemicellulose 4
  • 1.2.3 Lignin 4
• 1.3 Sources of lignocellulosic biomass 6
  • 1.3.1 Annual and perennial energy grasses 6
  • 1.3.2 Woody biomass 6
  • 1.3.3 Nonwoody biomass 6
• 1.4 Chemistry of lignocellulosic biomass 7
• 1.5 Biorefinery of lignocellulosic biomass 11
• 1.6 Conclusion 14
• References 14

1.1 Introduction

Lignocellulosic biomass (LCB), also known as lignocellulose, is the most abundant biorenewable material on the earth [1], produced from atmospheric CO₂ and water using the sunlight energy through the photosynthesis process. It is a complex matrix, mainly made of polysaccharides, phenolic polymers, and proteins that constitute the essential part of woody cell walls of plants. LCB has a complex spatial structure, in which cellulose (a carbohydrate polymer) is wrapped by the dense structure formed by hemicellulose (another carbohydrate polymer) and lignin (aromatic polymer).

LCB is usually categorized into three types of waste: biomass, virgin biomass, and energy crops. Trees, bushes, and sand grasses are placed into virgin biomass class, whereas agricultural residue, stover, and bagasse are placed in waste biomass class. Energy crops are raw materials used for the production of second-generation biofuels as they offer high biomass productivity.

LCB has a long history as an energy source: for many centuries, wood has been the most widely used raw material to burn fire. During the Industrial Revolution, due to the increase in energy needs, wood was progressively replaced by fossil fuels. However, from the middle of the 20th century, problems rose from pollution and the exhaustion of fossil fuels has increased the demand of biomass for the production of energy [2].

The first biofuels to be developed have been bioethanol, initially obtained from starch and sugars, and biodiesel, obtained from fats and oils. However, the diffusion of these products, so-called first-generation biofuels, has been limited as they cause direct competition between biofuel and food production.

More recently, second-generation biofuels were developed, based on the conversion of LCB components to liquid fuels. Second-generation biofuels allow the utilization of the entire plants, such as woody crops, agricultural residues, or waste, as well as dedicated nonfood energy crops grown on marginal land, thus allowing a dramatic increase of the productivity.

The production of biofuels and energy from LCB is based on two main routes. Biochemical processes are typically carried out with LCB having C/N ratio lower than 30 and humidity at collection higher than 30%. These processes are based on chemical reactions carried out thanks to the exploitation of enzymes, mushrooms, and microorganisms. An alternative is offered by thermochemical processes, used when the LCB available has C/N ratio higher than 30 and humidity content below 30%. In the last years, novel biofuels have been produced from LCB, such as bio-H₂, butanol, dimethylfuran, and gamma-valerolactone [3,4].

Some technological barriers still arise in the production of biofuels from LCB, but robust research is going on to overcome those obstacles. One of such problems is that LCB has evolved to resist ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedicated
• List of contributors
• About the editors
• Preface
• Acknowledgments
• Chapter 1. Fundamentals of lignocellulosic biomass
• Chapter 2. Pretreatment of lignocellulosic biomass for efficient enzymatic saccharification of cellulose
• Chapter 3. Bioconversion of lignocellulosic biomass to bioethanol and biobutanol
• Chapter 4. Lignocellulosic biomass to biodiesel
• Chapter 5. Biobutanol from lignocellulosic biomass: bioprocess strategies
• Chapter 6. Syngas fermentation to bioethanol
• Chapter 7. Fischer–Tropsch synthesis of syngas to liquid hydrocarbons
• Chapter 8. Constraints, impacts and benefits of lignocellulose conversion pathways to liquid biofuels and biochemicals
• Chapter 9. Environmental and socioeconomic impact assessment of biofuels from lignocellulosic biomass
• Chapter 10. Pretreatment of lignocellulosic sugarcane leaves and tops for bioethanol production
• Index