Table Of ContentPINCH ANALYSIS FOR
ENERGY AND CARBON
FOOTPRINT REDUCTION
In memoriam
Dad and Sue
Foreword to the first edition
Everynowandthen,thereemergesanapproachtotechnologywhichisbrilliant—in
conceptandinexecution.Ofcourse,itturnsouttobebothsimpleandpractical.Because
of all these things, it is a major contribution to the science and art of a profession and
discipline.
BodoLinnhoffandtheothermembersofthisteamhavemadeamajorcontributionto
chemicalengineeringthroughtheirwork.Itisalreadyrecognisedworldwide,andIhave
personal experience of the acclaim that the techniques embodied in this guide have
received in the United States.
There is no need to underline the necessity for more efficient use of energy: the
chemical industry is a very large consumer, as a fuel and as a feedstock. What is equally
importantisthatconceptualthinkingofahighorderisnecessarytoourindustrytokeep
advancing our technologies to reduce both capital and operating costs. The guide pro
vides new tools to do this, which forces the sort of imaginative thinking that leads to
major advances.
Itisalsoimportanttonotethattheemphasisintheguideisonstimulatingnewcon
cepts in process design that are easily and simply implemented with the aid of no more
thanapocketcalculator.Inthesedays,whentheteachingandpracticeofmanyapplied
sciencestendheavily towardsmathematical theoryand theneedfor sophisticatedcom
puterprogrammes,ahighlyeffective,simpletoolthatattainsprocessdesignexcellenceis
very timely.
R. Malpas
Halcon International
New Jersey, USA
ix
Foreword to the second edition
The original UserGuide waspublishedmorethan 20years ago, andit isprobably a
case of: … “from small acorns big oak trees grow.”
Innovation is fascinating. John Lennon once said: “Reasonable people adapt to the
world. Unreasonable people want the world to adapt to them. It follows that all inno
vation is due to unreasonable people.”
IneverthoughtofIanKempasunreasonable,butasayoungengineer,hedidjoinup
with those of us who innovated a (then) novel and unorthodox approach to energy
management in process design. He became one of the most committed practitioners I
remember meeting. It’sfitting that itis Ian who showedthestaying power to produce,
20yearson,thisreallabouroflove,thesecondedition,withmorethandoublethenum
ber of pages.
Detail, complexity, and sheer volume are often a sign of maturity. As a technology
develops,thebooksgetlonger.It’sacommontrendandoftenathanklesstask.Onbehalf
of many process design professionals, I thank Ian for tackling this task.
Bodo Linnhoff
Berlin, Germany
x
Preface
We live in a world of finite fossil fuel resources and an ever increasing threat of
climate change. Pinch analysis is a key tool to help us understand the heat and power
requirements of a process or site and satisfy them in a way that minimises energy con
sumption and carbon footprint.
IsaacNewtonsaidthatwhenweseefurtheritisbecauseweare“standingontheshoul
dersofgiants.”Forpinchanalysis,thegiantsareBodoLinnhoffandhiscolleaguesatICI
andUMIST(nowManchesterUniversity),whotookapromisingideaanddevelopedit
intopracticalmethodsgivingrealenergyandcostsavings.Insteadofreamsofequationsor
complex computer models, here were straightforward techniques giving fundamental
newinsightsintotheenergyuseofprocesses.Rigorousthermodynamicallybasedtargets
enabledengineerstoseeclearlywhereandwhytheirprocesseswerewastingenergyand
how toputthem right.A key insightwas theexistence ofa‘pinch’temperature,which
was the source of the term ‘pinch analysis’ to describe the new methodology.
WhenthefirsteditionoftheUserGuideonProcessIntegrationappearedin1982,it
wasinstantlyrecognisedasaclassicfortheeleganceandsimplicityofitsconceptsandthe
clarity with which they were expressed. It provides the backbone of the present book,
supplying nearly half the material, often verbatim but with judicious reordering and
expansion. The second edition of 2007 added later discoveries on process change, sep
aration systems, batch processes, and industrial applications, and this third edition
includes carbon footprint considerations and the water, hydrogen, and carbon pinch.
It still aims to be a practical tool for the engineer and does not attempt to duplicate or
replace the detailed research papers and texts on the subject that have appeared in the
last 40 years, but makes reference to them as appropriate.
Chapter 1 introduces the concepts, and Chapter 2 lays the foundations of energy,
heat, and power and their relation to carbon footprint. Chapter 3 describes the key
aspects—energy targeting, graphical representation through the composite and grand
compositecurves,andtheideaofthepinch,showinghowthisiscentraltofindingaheat
exchangernetworkthatwillmeetthetargets.Hopefully,thiswillwhetthereader’sappe
titeforthemoredetaileddiscussionoftargetingforenergy,areaandcost(Chapter4),and
network design and optimisation (Chapter 5). Chapter 6 describes the interaction with
heatandpowersystems,includingCHP,heatpumpsandrefrigeration,andtheanalysisof
totalsites.Beneficialchangestooperatingconditionscanalsobeidentified,asdescribed
in Chapter 7, especially for distillation, evaporation, drying, and other separation pro
cesses,whilstChapter8describesapplicationtobatchprocesses,start upandshutdown,
and other time dependent situations. Chapter 9 extends the techniques to water and
hydrogen networks and the carbon pinch.
xi
xii Preface
The final sections look more closely at practical application. Chapter 10 gives guid
anceonapplyingthemethodologyinrealindustrialpractice,includingthevitalbutoften
neglectedsubjectofstreamdataextraction.Chapter11showshowpinchanalysiscanbe
used in a range of industries.
Twocasestudiesrunlikeconstantthreadsthroughthebook,beingusedasappropri
ate to illustrate the various techniques in action. Six further complete case studies are
covered in Chapter 12, and others are mentioned in the text.
Itisamyththatpinchanalysisisonlyapplicabletolargecomplexprocesses,suchasoil
refineriesandbulkchemicalsplants.Evenwherecomplexheatexchangernetworksare
unnecessaryandinappropriate,pinchanalysistechniquesprovidethekeytounderstand
ingenergyflowsandensuringthebestpossibledesignandoperation.Thus,aswillbeseen
in the text and in particular the case studies, it is relevant to smaller scale chemical
processes, food and drink, consumer products, batch processing, and even non process
situationssuchasbuildings.Often,smallandsimpleplantsstillrevealworthwhilesavings,
becausenobodyhasreallysystematicallylookedforopportunitiesinthepast.Reducing
energyusagebenefitsthecompany(everypound,dollaroreurosavedreducesdirectcosts
andgoesstraightonthebottomlineasincreasedprofit)andtheenvironment(bothfrom
reduced fossil fuel usage and lower emissions). And even if no major capital projects
result, the engineer gains substantially in their understanding and ‘feel’ for their plant.
Inseveralcasesapinchstudyhasledtoimprovedoperationalmethodsgivingasubstantial
saving—at zero cost.
Formanyyearsabarriertothemorewidespreadadoptionofpinchanalysiswasalack
ofaffordablesoftware.ToremedythistheInstitutionofChemicalEngineersranacom
petition for young members in 2006 to produce a spreadsheet for pinch analysis to
accompanythesecondedition.Theentrantsshowedagreatdealofingenuityanddem
onstratedconclusivelythatthekeytargetingcalculationsandgraphscouldbegenerated
in this way, even without widespread use of programming techniques such as macros.
Special congratulationsareduetoGabrielNorwood,whoproducedthewinningentry
that is available to download free of charge with this book.
Nowadays, therefore, there is no reason why every plant should not have a pinch
analysisandaheatandmassbalance,aprocessflowsheet,andapipingandinstrumenta
tiondiagram.(Thatbeingsaid,itissalutarytoseehowmanycompaniesdonothavean
up to date, verified heat, and mass balance; this is often one of the most valuable by
products of a pinch study!)
Ourhopeisthatthislatestrevisionwillinspireanewgenerationofengineers,scien
tists, and technologists to apply the concepts in processes and situations far beyond the
areas where it was originally used, benefiting our many and varied organisations and
our one shared planet.
Ian C. Kempa, Jeng Shiun Limb
aWare, Hertfordshire, United Kingdom
bJohor Bahru, Malaysia
Acknowledgements
Much of the material in the original User Guide has stood the test of time, and it
is pointless to reinvent the wheel. A significant proportion of the text and figures in
Chapters1,3–6,and12ofthisbookisreproducedfromthefirstedition.Wearegrateful
totheIChemEandProfessorLinnhofffor givingusthepermissiontousethismaterial,
whichmadethewritingofsubsequenteditionsamanageabletaskratherthananimpos
sible one, and we are only too happy to acknowledge our debt to the original team of
authors: B. Linnhoff, D.W. Townsend, D. Boland, G.F. Hewitt, B.E.A. Thomas,
A.R. Guy, and R.H. Marsland, plus the additional contributors.
Many other people have had an influence on this book. Ian Kemp was fortunate
enough to attend one of Bodo Linnhoff’s early courses at UMIST and to be trained
by several members of the pioneering ICI research and applications teams, particularly
Jim Hill, Ajit Patel, and Eric Hindmarsh. I am profoundly grateful to them and also
to my colleagues at Harwell Research Centre, particularly Ewan Macdonald who gave
me much valuable guidance as a young engineer. Of the many others who have influ
enced me over the years, I would particularly like to mention John Flower and
Peter Heggs.
RobinSmith,GeoffHewitt,GrahamPolley,andAlanDeakinmadesignificantcon
tributionswhenthesecondeditionwasfirstmooted.Ourthanksalsogotooureditorsat
Elsevier for their assistance through the publishing process.
Lastbutnotleast,wewouldliketothankourfamilies fortheir unwaveringsupport
and patience during the writing and preparation.
Figure acknowledgements
The authors acknowledge with thanks the assistance given by the following companies
and publishers in permitting the reproduction of illustrations from their publications:
AmericanChemicalSocietyforFigs9.11–9.13fromEl Halwagi,M.M.etal.(2003),
Industrial & Engineering Chemistry Research, vol. 42, pp. 4319–4328, Figs 9.17–9.21
fromWanAlwi,S.R.andManan,Z.A.(2008),Industrial&EngineeringChemistryResearch,
vol.47,pp.2762–2777,Fig.9.29fromFoo,D.C.Y.andManan,Z.A.(2006),Industrial&
EngineeringChemistryResearch,vol.45,pp.5986–5995andFig.9.38fromLee,S.C.etal.
(2009),AppliedEnergy,vol.86,pp.60–67.
Elsevier Ltd for Fig. 4.20 from Linnhoff, B. and Ahmad, S. (1990), Computers and
Chemical Engineering, vol. 7, p. 729, Fig. 6.19 from Klemes, J. et al. (1997), Applied
Thermal Engineering, vol. 17, p. 993, Fig. 9.22 from Wan Alwi, S.R. et al. (2009),
xiii
xiv Acknowledgements
Resources,Conservation&Recycling,vol.53,pp.588–591andFigs9.23and9.24from
Prakash, R. and Shenoy, U.V. (2005), Chemical Engineering Science, vol. 60,
pp. 255–268.
John Wiley and Sons for Figs 6.20, 6.21, 6.24, and 7.16 from Smith, R. (2005),
Chemical Process Design and Integration, Figs 9.4–9.7 from Manan, Z.A. et al.
(2004), AIChE Journal, vol. 50, pp. 3169–3183 and Fig. 9.25 from Agrawal, V.
and Shenoy, U.V. (2006), AIChE Journal, vol. 52, pp. 1071–1082.
SpringerNatureforFig.2.3fromAndersNordelo€fetal.(2014),TheInternationalJour-
nal of Life Cycle Assessment, vol. 19, pp. 1866–1890.
The Institution of Chemical Engineers (IChemE) for Fig. 7.15 from Smith, R. and
Linnhoff, B. (1988), TransIChemE Part A, vol. 66, p. 195.
Woodhead Publishing Limited for Figs 9.1, 9.8, and 9.9 from Wan Alwi, S.R. and
Manan, Z.A. (2013), Handbook of Process Integration (PI).
And special thanks to the IChemE and Professor Bodo Linnhoff for giving us the
permission to use many of the figures from the first edition.
