Handbook of Biofuels Production

Rafael Luque, Carol Sze Ki Lin, Karen Wilson, James Clark

• Publisher: Woodhead Publishing
• Year: 2016
• eBook ISBN: 9780081004562
• Edition: 2
• Topic: Technology & Engineering
• Subtopic: Natural Resource Extraction Industry
• Index: Technology & Engineering

Handbook of Biofuels Production, Second Edition, discusses advanced chemical, biochemical, and thermochemical biofuels production routes that are fast being developed to address the global increase in energy usage. Research and development in this field is aimed at improving the quality and environmental impact of biofuels production, as well as the overall efficiency and output of biofuels production plants. The book provides a comprehensive and systematic reference on the range of biomass conversion processes and technology. Key changes for this second edition include increased coverage of emerging feedstocks, including microalgae, more emphasis on by-product valorization for biofuels' production, additional chapters on emerging biofuel production methods, and discussion of the emissions associated with biofuel use in engines. The editorial team is strengthened by the addition of two extra members, and a number of new contributors have been invited to work with authors from the first edition to revise existing chapters, thus offering fresh perspectives. - Provides systematic and detailed coverage of the processes and technologies being used for biofuel production - Discusses advanced chemical, biochemical, and thermochemical biofuels production routes that are fast being developed to address the global increase in energy usage - Reviews the production of both first and second generation biofuels - Addresses integrated biofuel production in biorefineries and the use of waste materials as feedstocks

Part One

Key issues and assessment of biofuels production

Outline

1. Introduction: an overview of biofuels and production technologies

2. Multiple objectives policies for biofuels production: environmental, socio-economic, and regulatory issues

3. Life cycle sustainability assessment of biofuels

4. Biofuels: technology, economics, and policy issues

5. Feedstocks and challenges to biofuel development

1

Introduction

An overview of biofuels and production technologies

C. Du¹, X. Zhao², D. Liu², C.S.K. Lin³, K. Wilson⁴, R. Luque⁵, and J. Clark^{6 1}University of Huddersfield, West Yorkshire, United Kingdom ²Tsinghua University, Beijing, China ³City University of Hong Kong, Hong Kong, China ⁴Aston University, Birmingham, United Kingdom ⁵University of Cordoba, Cordoba, Spain ⁶University of York, York, United Kingdom

Abstract

Biofuel is a rapidly growing research field and fast-moving industry. Since the publication of the first edition of Handbook of Biofuels Production in 2011, significant research progresses in biofuel production technology have been made, improved understanding of biofuel production processes has been acquired, and the industrial production of biofuels has moved forward. With this in mind, the second edition of the handbook keeps the underlying principles of various biofuel production technologies, and covers the latest progress in biofuel-related fields.

Keywords

Biodiesel; Bioethanol; Biofuel; Biomass; Biopyrolysis; Fatty acid methyl ester; Fossil fuel; Greenhouse gas emission; Lignocellulosic

1.1. Introduction

The increasing demand of renewable energy and the growing concern of global warming are still considered to be key challenges for the society worldwide. The sustainable development of the energy industry needs a continuous supply of renewable, sustainable energy. In 2013, over 90 million barrels of crude oil were consumed globally each day (US Energy Information Administration, 2014). Along with economic and population growth, the demand of energy will surge as well. Currently, 80% global energy consumption came from fossil resources, namely crude oil, natural gas, and coal. These fossil fuels are generated from organic materials that synthesized on Earth millions of years ago, and are unable to be regenerated within a short period, eg, it takes over hundreds of years for regeneration. Although the recent booming of shale gas releases the tension of the fossil fuel shortage and drags down the fossil fuel price, the finite nature of fossil fuel does not change. Based on the current daily fossil-usage data, the fossil regeneration rate (even the fossil discovery rate) will never match the consumption rate. A decade ago, some scientists warned that the fossil fuel would run out in 40 years. Our fossil fuel reserves might last for 40 or 100 years, depending upon the conditions that are put on our fossil fuel use (Dunlap, 2015). Optimists even consider that with the increasing fossil exploration, the fossil fuel would last longer than our current estimation. However, even if fossil fuel could last 300 years, this is just a short spell in human history. The exploration of new, renewable energy resources cannot wait until the depletion of fossil fuel.

On the other hand, the appeal of the reduction of greenhouse gas (GHG) emission has been the hottest topic in every recent United Nations Climate Change Conference. In 1997, the Kyoto Protocol was signed by most of the industrialized countries with the aim of reducing the global GHG emission. After the Kyoto Protocol's first commitment period expired on 2012, 37 countries, including 28 members of the European Union, agreed to a second commitment period of GHG emission reduction in Doha. Although the two largest GHG emission countries did not participate in the Kyoto Protocol, they both set their own CO₂ emission targets (UNFCCC, 2015). According to the latest report of the Intergovernmental Panel on Climate Change (IPCC, 2014), the GHG concentration in the atmosphere could reach from 750 to 1300-ppm CO₂ equivalents. As a consequence, the global average surface temperature could increase by 3.7–4.8°C. If we would like to control the temperature change within 3°C in 2100 compared to that of preindustrial levels, the GHG concentration in the atmosphere should be controlled to lower than 650-ppm CO₂ equivalents. This means a change of GHG emission should at least not exceed 24% of the 2010 emission level (IPCC, 2014). Since 78% of GHG emissions in recent decades came from fossil fuel combustion and industrial processes, the development of a low-carbon economic system to replace the fossil fuel–based system is urgent.

Along with several other renewable technologies, biofuel has made and will continuously make a significant contribution to meet targets on the usage of renewable energy resources and the reduction of GHG emission. Besides the above-mentioned major reasons, the advantages of development and application of biofuels also include: improving national energy security, utilizing existing transportation system, utilizing existing fuel distribution system, and facilitating rural development.

Currently, in the first generation of bioethanol, food crops such as corn, sugar cane, and wheat are used for the production of energy. These are starch- or sucrose-rich feedstocks that are readily fermented by microorganisms. However, these crops are also used for food and feed production, resulting in competition. At present, commercial production of the first-generation biomass utilizes readily-available sugars from these food plants for the fermentation process of biofuel production.

However, the second generation of bioethanol uses lignocellulosic raw materials as the main substrate, which has a more complex composition as compared to the first-generation feedstocks. Lignocellulosic feedstocks are high in cellulose, hemicellulose, and lignin. Second-generation feedstocks avoid competition with food and feed products. Examples are waste streams from food- or feed-crops such as wheat straw or corn stover, also municipal or industrial waste streams, or energy crops that grow on marginal lands that are unsuitable for regular agriculture. To use the preferred second-generation feedstocks, further advances in technological development are needed to unlock the more hidden sugars in the crop residues or woody plant materials. Significant research efforts and investment have been spent to improve the technology in order to enable the commercial use of the second-generation feedstocks.

Different generations of biofuels also differ in other characteristics. While the food part of the food crops is made of easily digestible sugars, the sugars captured in lignocellulosic compositions of the second-generation feedstocks are more difficult to utilize. So why do we want to use these more challenging second-generation feedstocks? This is to reduce competition with food, arable land, and water. Using residues can help to avoid land-use changes, and energy crops can be genetically engineered to reduce water usage. It can also bring in extra income for farmers. In the future, water-based feedstocks such as algae may become as important as the third-generation feedstocks. The third-generation feedstock is used for processes where CO₂ is utilized as one of the substrates. A common example would be photosynthetic algae that use sunlight and CO₂ to produce useful organic molecules. These third-generation systems would completely eliminate the need for agricultural land.

This book aims to provide an overview of the latest progresses in various technologies for biofuel production. The special emphasis has been focused on the advanced generation of biofuels, which produce biofuels from nonfood materials. We keep the same the classification method, dividing different technologies into three main sections: chemical, biological, and thermochemical conversions.

In the first few introductory chapters, details on policies, socioeconomic, and environmental implications of the implementation of biofuels (chapter: Multiple objectives policies for biofuels production: environmental, socioeconomic and regulatory issues), life-cycle assessment (LCA) (chapter: Life cycle sustainability assessment of biofuels), techno-economic assessment (chapter: Techno-economic studies of biofuels), environmental concern (chapter: Multiple objectives policies for biofuels production: environmental, socio-economic and regulatory issues), and t...

Table of contents

• Cover image
• Title page
• Table of Contents
• Related titles
• Copyright
• List of contributors
• Woodhead Publishing Series in Energy
• Part One. Key issues and assessment of biofuels production
• Part Two. Biofuels from chemical and biochemical conversion processes and technologies
• Part Three. Biofuels from thermal and thermo-chemical conversion processes and technologies
• Part Four. Integrated production and application of biofuels
• Index