Table Of ContentAlternative Solvents for Green Chemistry
2nd Edition
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RSC Green Chemistry
Series Editors:
James H Clark, Department of Chemistry, University of York, UK
GeorgeAKraus,DepartmentofChemistry,IowaStateUniversity,Ames,Iowa,
01 USA
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P Andrzej Stankiewicz, Delft University of Technology, The Netherlands
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4- Peter Siedl, Federal University of Rio de Janeiro, Brazil
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8 Yuan Kou, Peking University, People’s Republic of China
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8 Titles in the Series:
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78 1: The Future of Glycerol: New Uses of a Versatile Raw Material
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9/ 2: Alternative Solvents for Green Chemistry
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10 3: Eco-Friendly Synthesis of Fine Chemicals
10. 4: Sustainable Solutions for Modern Economies
oi: 5: Chemical Reactions and Processes under Flow Conditions
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g | 6: Radical Reactions in Aqueous Media
or 7: Aqueous Microwave Chemistry
s.rsc. 8: The Future of Glycerol: 2nd Edition
b 9: Transportation Biofuels: Novel Pathways for the Production of Ethanol,
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http://p B10io:gAalstearnndatBivieosdtioeseClonventional Food Processing
n 11: Green Trends in Insect Control
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0 and Applications
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ary 13: Challenges in Green Analytical Chemistry
nu 14: Advanced Oil Crop Biorefineries
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. n 3 16: Natural Polymers Volume 1: Composites
d o 17: Natural Polymers Volume 2: Nanocomposites
he 18: Integrated Forest Biorefineries
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bli 19:SustainablePreparationofMetalNanoparticles:MethodsandApplications
Pu 20: Alternative Solvents for Green Chemistry: 2nd Edition
How to obtain future titles on publication:
A standing order plan is available for this series. A standing order will bring
delivery of each new volume immediately on publication.
For further information please contact:
BookSalesDepartment,RoyalSocietyofChemistry,ThomasGrahamHouse,
Science Park, Milton Road, Cambridge, CB4 0WF, UK
Telephone: +44 (0)1223 420066, Fax: +44 (0)1223 420247
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Visit our website at www.rsc.org/books
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Alternative Solvents for Green Chemistry
2nd Edition
Francesca M Kerton
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0 Department of Chemistry, Memorial University of Newfoundland, St John’s,
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8 Ray Marriott
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sc. ISSN: 1757-7039
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Chemistry or the copyright owner, or in the case of reproduction in accordance
withthetermsoflicencesissuedbytheCopyrightLicensingAgencyintheUK,or
in accordance with the terms of the licences issued by the appropriate
Reproduction Rights Organization outside the UK. Enquiries concerning
reproduction outside the terms stated here should be sent to The Royal Society
of Chemistry at the address printed on this page.
The RSC is not responsible for individual opinions expressed in this work.
Published by The Royal Society of Chemistry,
Thomas Graham House, Science Park, Milton Road,
Cambridge CB4 0WF, UK
Registered Charity Number 207890
For further information see our web site at www.rsc.org
PrintedintheUnitedKingdombyCPIGroup(UK)Ltd,Croydon,CR04YY,UK
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4- Preface
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10. Everyoneisbecomingmoreenvironmentallyconsciousandtherefore,chemical
doi: processes are being developed with their environmental burden in mind. Of
g | course, this also means that more traditional chemical methods are being
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c. replaced with new innovations. This includes new solvents.
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bs.r Solvents are everywhere, but should they be? They are used in most areas
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p://p includingsyntheticchemistry,analyticalchemistry,pharmaceuticalproduction
htt and processing, the food and flavour industry and the materials and coatings
on sectors. But, the principles of green chemistry guide us to use less of them,
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1 or to use safer, more environmentally friendly solvents if they are essential.
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u Chapter3explainssomeofthechallengesandsuccessesinthefieldofsolvent-
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. n 3 In the introductory chapter, some of the hazards of conventional solvents
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blis streamsarehighlighted.Thegeneralpropertiesofsolventsandwhyandwhere
u they are used are outlined. Additionally, EHS (Environmental, Health and
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Safety) assessments and life-cycle analyses for traditional and alternative
solvents are described. It becomes clear that often a less-hazardous VOC is
availableandthatalthoughonly‘lightgreen’(oratleast‘lessblack’)incolour,
theycanbeusedasaninterimmeasureuntilamoresatisfyingoptionbecomes
available. In each of the subsequent chapters, where possible, the use of an
alternative solvent is described for a range of chemical applications including
extractions, synthetic and materials chemistry. At the beginning of each of
these chapters,some of the advantages and disadvantages ofthat medium are
laid out.
Water is often described as Nature’s solvent; therefore Chapter 4 describes
thesolventpropertiesofwater.Itisalreadyusedquitewidelyonanindustrial
RSCGreenChemistryNo.20
AlternativeSolventsforGreenChemistry:2ndEdition
ByFrancescaMKertonandRayMarriott
#FMKertonandRMarriott2013
PublishedbytheRoyalSocietyofChemistry,www.rsc.org
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vi Preface
scale,particularlyinemulsionpolymerisationprocessesandhydrodistillations.
However,some ofthemostexcitingresults havecomeinthefieldofsynthetic
chemistry. Recently, ‘on-water’ reactions have shown that hydrophobic
(water-insoluble) compounds can achieve higher rates dispersed in water
5 compared to reactions in conventional solvents or under solvent free
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68 properties are significantly altered and unusual chemistry can result. This is
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97 further discussed in Chapter 5, which describes supercritical fluids. The focus
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18 here is on the nonflammable options, that is, carbon dioxide and water.
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97 Modificationsthatareperformedonsubstratesinordertomakethemsoluble
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c.or Inadditiontowaterandcarbondioxide,thereisanincreasingavailabilityof
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p:// potential as replacements to petroleum-sourced solvents are discussed in
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n Chapter6.Renewablefeedstocksandtheirtransformationsareagrowingarea
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d o discussed in Chapter 7. The field of RTILs has grown dramatically in the last
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may be more expensive than other alternatives, the chance to make task-
specific solvents for particular processes is very exciting. RTILs, alongside
fluorous solvents, have also made a large impact in the area of recyclable
homogeneous catalysts. Fluorous solvents, as described in Chapter 8, show
interesting phase behaviour and allow the benefits of a heterogeneous and
homogeneoussystemtobeemployedbyadjustinganexternalvariablesuchas
temperature. Recent advances in this area will be discussed, for example,
supported fluorous chemistry, which avoids the use of large amounts of
fluorous solvents and might be more amenable to industrial scale processes.
Possiblytheleastexploredandnewestoptionsavailabletothegreenchemist
are liquid polymer solvents (Chapter 9) and switchable and tunable solvents
(Chapter 10). Unreactive low molecular weight polymers or those with low
glasstransitiontemperaturescanbeusedasnonvolatilesolvents.Inparticular,
poly(ethyleneglycols) and poly(propyleneglycols) have been used recently in a
range of applications. Probably the most important recent additions to our
toolboxareswitchablesolvents.Newmolecularsolventshavebeendiscovered
that can be switched from nonvolatile to volatile or between polar and
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Preface vii
nonpolar environments by the application of an external stimulus. Gas-
expandedliquidswillalsobediscussedinChapter10,ascarbondioxidecanbe
used as a solubility switch and to reduce the environmental burden of
conventional solvents.
5 Unfortunately, as will become clear to readers, there is no universal green
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68 minimise the number of solvent changes in a chemical process and therefore,
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97 the importance of solvents in product purification, extraction and separation
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18 technologies has been highlighted.
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9 There have been many in-depth books and reviews published in the area of
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3 green solvents. Hopefully, readers will find this book a readable introduction
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c.or system, readers should look to the primary literature and the many excellent
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p:// Certain solvent media can be fascinating in their own right, not just as
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n ‘green’solventalternatives!Therefore,wemustnotbeblindtoouroverallgoal
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2 readers of this book will be able to make up their own minds about the vast
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d o IwouldliketothanktheeditorsoftheRSCGreenChemistrySeries,James
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ubli group of books. Also, I would like to acknowledge Merlin Fox (the
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commissioning editor) and the staff at RSC Publishing involved with this
series, particularly, Annie Jacob, who has been advising and helping me all
alongtheway.Finally,Iwouldliketothankmyhusband,ChrisKozak,forhis
patience, support and motivational input during the writing of this book.
Francesca Kerton
St. John’s, Newfoundland, Canada
1st Edition, June 2008
Sincepublicationofthefirstedition,researchinthefieldofgreenersolvents
has continued at a pace, with special issues dedicated to field being published
in several journals (for example, issue 6 of Green Chemistry in 2012). I am
happytowelcomeaco-authortothisedition.Rayhasappliedhisexperiencein
an industrial setting to overhaul the chapter on industrial applications
(Chapter11)andprovidesanewchapteronlegislationinthisarea(Chapter2).
Allchaptershavereceivedsomeupdating–somemorethanothers.Switchable
solvents were relatively new phenomena when the first edition was published
and discoveries in this field have grown significantly. I thank Prof. Philip
Jessop for tips in this area. Also, RTIL based research has continued to grow
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viii Preface
exponentially, and significant research in the use of alternative solvents in
biomass transformations and biocatalysis has been published. More detailed
toxicological studies have been performed on RTILs and applications of
bioderivedsolventshavebecome more widespread.Anew chapter ontheuse
ofgreensolventsineducationandsolventawarenessforthegeneralpublichas
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2.2 Solvent Registration 32
2.2.1 European Union and Switzerland 32
2.2.2 United States and Canada 33
2.2.3 China and Taiwan 34
2.2.4 Japan 35
2.3 Solvent Emission Regulations 36
2.4 Applications Legislation 39
2.4.1 Food and Beverages 39
RSCGreenChemistryNo.20
AlternativeSolventsforGreenChemistry:2ndEdition
ByFrancescaMKertonandRayMarriott
#FMKertonandRMarriott2013
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x Contents
2.4.2 Pharmaceuticals, Nutraceuticals and Herbal
Medicines 41
2.4.3 Cosmetics and Personal Care 44
2.5 Natural or Organic Certification 45
2.6 Summary 47
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c. References 77
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4.5 Summary and Outlook for the Future 109
References 110
Chapter 5 Supercritical Fluids 115
5.1 Introduction 115
5.2 Chemical Examples 117
5.2.1 Supercritical and Liquid Carbon Dioxide 117
5.2.2 Supercritical Water and Near-Critical Water 132
5.2.3 Supercritical Alcohols 140
5.3 Summary and Outlook for the Future 141
References 142
