Pinch analysis

<h2 id="history">History</h2>
In 1971, Ed Hohmann stated in his PhD thesis that

<blockquote>one can compute the least amount of hot and cold utilities required for a process without knowing the heat exchanger network that could accomplish it. One also can estimate the heat exchange area required</blockquote>
In late 1977, Ph.D. student <a href="/facts/Bodo_Linnhoff/UTTjqHPH">Bodo Linnhoff</a> under the supervision of Dr John Flower at the <a href="/facts/University_of_Leeds/XxFJF9Qh">University of Leeds</a><a class="footnote-ref" id="fnref:1" href="#fn:1">1</a> showed the existence in many processes of a heat integration bottleneck, ‘the pinch’, which laid the basis for the technique, known today as pinch-analysis. At that time he had joined <a href="/facts/Imperial_Chemical_Industries/XECoopCt">Imperial Chemical Industries</a> (ICI) where he led practical applications and further method development.
Bodo Linnhoff developed the 'Problem Table', an algorithm for calculating the energy targets and worked out the basis for a calculation of the surface area required, known as ‘the spaghetti network’. These algorithms enabled practical application of the technique.
In 1982 he joined University of Manchester Institute of Technology (<a href="/facts/UMIST/WrPjIp82">UMIST</a>, present day <a href="/facts/University_of_Manchester/PwJzEj8h">University of Manchester</a>) to continue the work. In 1983 he set up a consultation firm known as Linnhoff March International later acquired by KBC Energy Services.
Many refinements have been developed since and used in a wide range of industries, including extension to heat and power systems and
non-process situations. The most detailed explanation of the techniques is by Linnhoff et al. (1982),<a class="footnote-ref" id="fnref:2" href="#fn:2">2</a> Shenoy (1995),<a class="footnote-ref" id="fnref:3" href="#fn:3">3</a> Kemp (2006)<a class="footnote-ref" id="fnref:4" href="#fn:4">4</a> and Kemp and Lim (2020),<a class="footnote-ref" id="fnref:5" href="#fn:5">5</a> while Smith (2005)<a class="footnote-ref" id="fnref:6" href="#fn:6">6</a> includes several chapters on them. Both detailed and simplified (spreadsheet) programs are now available to calculate the energy targets. See Pinch Analysis Software below.
Pinch analysis has been extended beyond energy applications. It now includes:

<ul><li>Mass Exchange Networks<a class="footnote-ref" id="fnref:7" href="#fn:7">7</a></li>
<li><a href="/facts/Water_pinch/qEGJazzo">Water pinch</a> <a class="footnote-ref" id="fnref:8" href="#fn:8">8</a><a class="footnote-ref" id="fnref:9" href="#fn:9">9</a><a class="footnote-ref" id="fnref:10" href="#fn:10">10</a></li>
<li><a href="/facts/Hydrogen_pinch/gQfGkC8S">Hydrogen pinch</a><a class="footnote-ref" id="fnref:11" href="#fn:11">11</a><a class="footnote-ref" id="fnref:12" href="#fn:12">12</a></li>
<li>Carbon pinch<a class="footnote-ref" id="fnref:13" href="#fn:13">13</a></li></ul>
<h2 id="weaknesses">Weaknesses</h2>
Classical pinch-analysis primarily calculates the energy costs for the heating and cooling utility. At the pinch point, where the hot and cold streams are the most constrained, large heat exchangers are required to transfer heat between the hot and cold streams. Large heat exchangers entail high investment costs. In order to reduce capital cost, in practice a minimum temperature difference (Δ T) at the pinch point is demanded, e.g., 10 °F. It is possible to estimate the heat exchanger area and capital cost, and hence the optimal Δ T minimum value. However, the cost curve is quite flat and the optimum may be affected by "topology traps". The pinch method is not always appropriate for simple networks or where severe operating constraints exist. Kemp (2006)<a class="footnote-ref" id="fnref:14" href="#fn:14">14</a> and Kemp and Lim (2019) discuss these aspects in detail.

<h2 id="recent-developments">Recent developments</h2>
The problem of integrating heat between hot and cold streams, and finding the optimal network, in particular in terms of costs, may today be solved with numerical <a href="/facts/Algorithm/fnl5NmRt">algorithms</a>. The network can be formulated as a so-called <a href="/facts/Mixed_integer_programming/GduXFQxT">mixed integer</a> non-linear programming (MINLP) problem and solved with an appropriate numerical <a href="/facts/Solver/S8LurhlM">solver</a>. Nevertheless, large-scale MINLP problems can still be hard to solve for today's numerical algorithms. Alternatively, some attempts were made to formulate the MINLP problems to mixed integer linear problems, where then possible networks are screened and optimized. For simple networks of a few streams and heat exchangers, hand design methods with simple targeting software are often adequate, and aid the engineer in understanding the process.<a class="footnote-ref" id="fnref:15" href="#fn:15">15</a>

<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/CHP_Directive/s3UteVBB">CHP Directive</a> – EU Directive on cogeneration of heat and power</li>
<li><a href="/facts/Energy_policy_of_the_European_Union/WksPLw00">Energy policy of the European Union</a> – Legislation in the area of energetics in the European Union</li>
<li><a href="/facts/Relative_cost_of_electricity_generated_by_different_sources/xjHw32M9">Relative cost of electricity generated by different sources</a> – Comparison of costs of different electricity generation sourcesPages displaying short descriptions of redirect targets</li>
<li><a href="/facts/Cogeneration/nuSxEoqP">Cogeneration</a> – Simultaneous generation of electricity and useful heat</li>
<li><a href="/facts/Process_flowsheeting/vPaRDA4Y">Process flowsheeting</a> – use of computer aids to perform calculations for a chemical processPages displaying wikidata descriptions as a fallback</li></ul>

<ul><li>de Klerk, LW, de Klerk, MP and van der Westhuizen, D "Improvements in hydrometallurgical uranium circuit capital and operating costs by water management and integration of utility and process energy targets" AusImm Conference, U <a href="http://www.projectandprocessdevelopment.com/#!process-publications/fa1qi">2015</a></li></ul>
<h2 id="external-links">External links</h2>
<ul><li><a href="https://pinch-analyse.ch/en">PinCH</a> - Software for continuous and batch processes including indirect heat recovery loops and energy storages. Free manuals, tutorials, case studies and success stories available</li>
<li><a href="http://www.pinchco.com/images/site/heatit_v5.2.4_2014_12_07-basic.xlsm">HeatIT</a> - Free (light) version of Pinch Analysis software that runs in Excel - developed by <a href="http://www.pinchco.com">Pinchco</a>, a consultancy company offering expert advice on energy related matters</li>
<li><a href="https://www.prosim.net/en/product/simulis-pinch-energy-integration-of-processes-in-excel/">Simulis Pinch </a>- Tool from ProSim SA that can be used directly in Excel and that is dedicated to the diagnosis and the energy integration of the processes.</li>
<li><a href="http://www.nrcan.gc.ca/energy/efficiency/industry/processes/systems-optimization/process-integration/products-services/5529">Integration</a> - A practical and low-cost process integration computation tool developed by <a href="http://www.nrcan.gc.ca/energy/offices-labs/canmet/5715">CanmetENERGY</a>, Canada's leading research and technology organization in the field of clean energy.</li>
<li><a href="https://tlk-energy.de/en/tools/pinch-analysis-online">Pinch Analysis Tool</a> - TLK-Energy's online pinch analysis software enables you to swiftly identify efficiency potential in unused waste heat flows and optimally integrate heat pumps for your industrial operation.</li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1">Ebrahim, M.; Kawari, Al- (2000). "Pinch technology: an efficient tool for chemical-plant energy and capital-cost saving". Applied Energy. 65 (1–4): 45–49. doi:10.1016/S0306-2619(99)00057-4. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">Linnhoff, B., D.W. Townsend, D. Boland, G.F. Hewitt, B.E.A. Thomas, A.R. Guy and R.H. Marsland, (1982) A User Guide on Process Integration for the Efficient Use of Energy. IChemE, UK. <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">Shenoy, U.V. (1995). Heat Exchanger Network Synthesis: Process Optimization by Energy and Resource Analysis. Includes two computer disks. Gulf Publishing Company, Houston, TX, USA. ISBN 0-88415-391-6. <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">Kemp, I.C. (2006). Pinch Analysis and Process Integration: A User Guide on Process Integration for the Efficient Use of Energy, 2nd edition. Includes spreadsheet software. Butterworth-Heinemann. ISBN 0-7506-8260-4. (1st edition: Linnhoff et al., 1982) <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
<li id="fn:5">Kemp, I.C. and Lim, J.S. (2020). Pinch Analysis for Energy and Carbon Footprint Reduction: A User Guide on Process Integration for the Efficient Use of Energy, 3rd edition. Includes spreadsheet software. Butterworth-Heinemann. ISBN 978-0-08-102536-9. <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></li>
<li id="fn:6">Smith, R. (2005). Chemical Process Design and Integration. John Wiley and Sons. ISBN 0-471-48680-9 <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></li>
<li id="fn:7">El-Halwagi, M. M. and V. Manousiouthakis, 1989, "Synthesis of Mass Exchange Networks", AIChE J., 35(8), 1233–1244 <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
<li id="fn:8">Wang, Y. P. and Smith, R. (1994). Wastewater Minimisation. Chemical Engineering Science. 49: 981-1006 <a href="#fnref:8" class="footnote-back-ref">↩</a></li>
<li id="fn:9">Prakash, R. and Shenoy, U.V. (2005) Targeting and Design of Water Networks for Fixed Flowrate and Fixed Contaminant Load Operations. Chemical Engineering Science. 60(1), 255-268 <a href="#fnref:9" class="footnote-back-ref">↩</a></li>
<li id="fn:10">Hallale, Nick. (2002). A New Graphical Targeting Method for Water Minimisation. Advances in Environmental Research. 6(3): 377-390 <a href="#fnref:10" class="footnote-back-ref">↩</a></li>
<li id="fn:11">Nick Hallale, Ian Moore, Dennis Vauk, "Hydrogen optimization at minimal investment", Petroleum Technology Quarterly (PTQ), Spring (2003) <a href="#fnref:11" class="footnote-back-ref">↩</a></li>
<li id="fn:12">Agrawal, V. and U. V. Shenoy, 2006, "Unified Conceptual Approach to Targeting and Design of Water and Hydrogen Networks", AIChE J., 52(3), 1071–1082. <a href="#fnref:12" class="footnote-back-ref">↩</a></li>
<li id="fn:13">Kemp, I.C. and Lim, J.S. (2020). Pinch Analysis for Energy and Carbon Footprint Reduction: A User Guide on Process Integration for the Efficient Use of Energy, 3rd edition. Includes spreadsheet software. Butterworth-Heinemann. ISBN 978-0-08-102536-9. <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></li>
<li id="fn:14">Kemp, I.C. (2006). Pinch Analysis and Process Integration: A User Guide on Process Integration for the Efficient Use of Energy, 2nd edition. Includes spreadsheet software. Butterworth-Heinemann. ISBN 0-7506-8260-4. (1st edition: Linnhoff et al., 1982) <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></li>
<li id="fn:15">Furman, Kevin C.; Sahinidis, Nikolaos V. (2002-03-09). "A Critical Review and Annotated Bibliography for Heat Exchanger Network Synthesis in the 20th Century". Industrial & Engineering Chemistry Research. 41 (10): 2335–2370. doi:10.1021/ie010389e. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></li>
</ol>

Pinch analysis open-in-new

Pinch analysis