Biofuels for Aviation

Feedstocks, Technology and Implementation

Christopher Chuck

• Publisher: Academic Press
• Year: 2016
• ISBN:
  9780128032152
• Topic: Technology & Engineering
• Subtopic: Renewable Power Resources
• Index: Technology & Engineering

Biofuels for Aviation: Feedstocks, Technology and Implementation presents the issues surrounding the research and use of biofuels for aviation, such as policy, markets, certification and performance requirements, life cycle assessment, and the economic and technical barriers to their full implementation. Readers involved in bioenergy and aviation sectors—research, planning, or policy making activities—will benefit from this thorough overview.

The aviation industry's commitment to reducing GHG emissions along with increasing oil prices have sparked the need for renewable and affordable energy sources tailored to this sector's very specific needs. As jet engines cannot be readily electrified, turning to biofuels is the most viable option. However, aviation is a type of transportation for which traditional biofuels, such as bioethanol and biodiesel, do not fulfill key fuel requirements. Therefore, different solutions to this situation are being researched and tested around the globe, which makes navigating this scenario particularly challenging.

This book guides readers through this intricate subject, bringing them up to speed with its current status and future prospects both from the academic and the industry point of view. Science and technology chapters delve into the technical aspects of the currently tested and the most promising technology in development, as well as their respective feedstocks and the use of additives as a way of adapting them to meet certain specifications. Conversion processes such as hydrotreatment, synthetic biology, pyrolysis, hydrothermal liquefaction and Fisher-Tropsch are explored and their results are assessed for current and future viability.

• Presents the current status of biofuels for the aviation sector, including technologies that are currently in use and the most promising future technologies, their production processes and viability
• Explains the requirements for certification and performance of aviation fuels and how that can be achieved by biofuels
• Explores the economic and policy issues, as well as life cycle assessment, a comparative techno-economic analysis of promising technologies and a roadmap to the future
• Explores conversion processes such as hydrotreatment, synthetic biology, pyrolysis, hydrothermal liquefaction and Fisher-Tropsch

Section II

The Science and Technology of Developing Biofuels for Aviation

Outline

Chapter 4 The Suitability of Fatty Acid Methyl Esters (FAME) as Blending Agents in Jet A-1

Chapter 5 Aviation Biofuels Through Lipid Hydroprocessing

Chapter 6 Low-Carbon Aviation Fuel Through the Alcohol to Jet Pathway

Chapter 7 Metabolic Engineering Strategies to Convert Carbohydrates to Aviation Range Hydrocarbons

Chapter 8 Pyrolysis of Biomass for Aviation Fuel

Chapter 9 Towards an Aviation Fuel Through the Hydrothermal Liquefaction of Algae

Chapter 10 Aviation Turbine Fuels Through the Fischer–Tropsch Process

Chapter 11 Current and Potential Aviation Additives for Higher Biofuel Blends in Jet A-1

Chapter 4

The Suitability of Fatty Acid Methyl Esters (FAME) as Blending Agents in Jet A-1

M. Lapuerta¹ and L. Canoira², ¹Grupo de Combustibles y Motores, ETS Ingenieros Industriales, Universidad de Castilla La Mancha, Ciudad Real, Spain, ²Department of Energy & Fuels, ETS Ingenieros de Minas y Energía, Universidad Politécnica de Madrid, Madrid, Spain

Abstract

The use of biofuels in the aviation sector has economic and environmental benefits. Among the options for the production of renewable jet fuels, hydroprocessed esters, and fatty acids have received most of the attention in comparison to fatty acid methyl esters (FAME), which are not yet approved as additives for jet fuels. In this work, camelina, coconut, babassu, linseed, and palm kernel oils were transesterified with methanol by the classical homogeneous basic catalysis method with good yields. The coconut, babassu, and palm kernel FAME were subjected to fractional distillation at vacuum, and the low boiling point fractions were blended with two types of fossil kerosene, a straight-run atmospheric distillation cut (hydrotreated) and a commercial Jet A-1. The camelina and linseed FAME were blended with the fossil kerosene without previous distillation. The blends prepared met some specifications selected for study of the ASTM D1655 standard.

The presence of oxygen in methyl esters tends to reduce soot emissions and therefore particulate matter emissions. This sooting tendency was quantified in this work with an Oxygen Extended Sooting Index, based on smoke point measurements. Results showed considerable reduction in the sooting tendency for all distilled FAME with respect to fossil kerosenes. Among the tested distilled FAME, that made from palm kernel oil was the most effective, and non-distilled methyl esters (from camelina and linseed oils) showed lower effectiveness than distilled FAME to reduce sooting tendency. These results could constitute an additional argument for the use of FAME as blend components of jet fuels.

This work also describes the compatibility of distilled FAME blends of coconut, babassu, and palm kernel oils with commercial Jet A-1 testing airplane polymeric materials, metals, and composites. All material samples showed a good compatibility with the fuel blends tested.

Keywords

Distilled FAME; kerosene oxygen extended sooting index (OESI); airplane materials compatibility; cold flow properties; heating value

4.1 An Introduction to FAME in Jet A-1

4.1.1 Current Restrictions of FAME Blends in Jet Fuel

The American Society for Testing Materials (ASTM) Subcommittee J on Aviation Fuels is comprised of members of the aviation fuels community and has developed the standard ASTM D1655 [1]. Aviation turbine fuels meeting ASTM D1655 are limited to hydrocarbon distillate products derived from a limited number of fossil sources. The listed sources of feedstocks for producing aviation turbine fuel include crude oil, natural gas liquid condensates, heavy oil, shale oil, and oil sands. ASTM has been working on approval of alternative fuels as blend components for ASTM D1655 through D02.0J.06 Section J.06 on Emerging Turbine Fuel, and has recently published the approved methods for the production of alternative jet fuels that are basically the Fischer–Tropsch hydroprocessed synthesized paraffinic kerosene (FT-SPK) and the hydroprocessed esters and fatty acids (HEFA).

The group has developed the ASTM D7566 Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons, which defines specifications for alternative fuels that can be used to blend semi-synthetic jet fuel meeting ASTM D1655 requirements [2]. As aviation turbine fuels must meet a myriad of requirements, both specified and implied, this group had a very daunting task. Annex A1 to ASTM D1655 defines how fuels from non-conventional sources are to be handled. It is assumed that jet fuel from conventional sources has properties that make it fit-for-purpose, and that fuels not from these sources must be thoroughly evaluated before they can be used to blend ASTM D1655 jet fuel. These two alternative jet fuel blend components, when they meet all of the requirements of ASTM D7566, are allowed for blending ASTM D1655 jet fuel at up to 50% volumetric content. Other alternative jet fuel blend components are under evaluation by Section J.06 for inclusion in ASTM D7566. These include Alcohol-To-Jet (ATJ) fuels, alternative hydrocarbon fuels derived from pyrolysis processes, and other hydrocarbon fuels that come from other transformation technologies [3].

All of the alternative jet fuel blend components are hydrocarbons as these are the class of chemical compounds that are within the experience base of the airframe and turbine engine producers that bear the highest responsibility for aircraft design and manufacture. Other classes of chemical compounds that are not defined as fuel additives a...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of Contributors
• Preface
• Section I: An Overview of the Sector
• Section II: The Science and Technology of Developing Biofuels for Aviation
• Section III: Testing, Assessment and the Future
• Appendix A. Standard and Alternative Fuel Specifications
• Appendix B. Commercial Biofuel Flight Demonstrations (Data Collected by Innovate Washington 2013)
• Index