Pinch Analysis: Process Improvement Tips From Thermodynamics, Cars, and Cooking

pinch analysis

Pinch analysis is a difficult topic to talk about, as it both has widely applicable techniques which can reduce the need for external resources, but it’s traditionally very complicated and used in a limited business sector.

That’s why today I’ll be breaking down the topic and showing how the principles behind it can be used across any and all disciplines.

You don’t have to be a thermodynamics buff to understand this; it all comes down to analyzing what you have, what by-products your processes create, and whether you can use those by-products to your advantage.

By doing this, traditional pinch analysis is able to typically result in energy savings of 10-35% – that’s a third less energy you need to generate or import to carry out your processes.

Lets’ get stuck in.

What is pinch analysis?

Pinch analysis is a technique traditionally used to assess the energy requirement of various processes and how they can be more efficiently met. This is usually achieved by assessing which existing processes produce heat, which processes require heat to take place, and how to integrate the two to use the existing heat instead of using extra energy to generate more.

In other words, it’s an energy-saving method to use the by-products of one process to fuel another.

In this way pinch analysis involves asking and answering the following questions:

  • What is the minimum energy requirement for your processes?
  • What is the ideal budget/economic cost of meeting these requirements?
  • What is the most efficient source of this energy?
  • What practical measures will need to be taken to provide this?
  • How can the systems be designed/integrated to achieve this efficiency?

Sticking with the heat context (for now), pinch analysis involves calculating an energy flow graph for each process. This shows the temperature and enthalpy for processes which generate heat and those which require it.

The point where the energy flows are closest to meeting is the “pinch point”, and from there a heat transfer system can be formulated.

To simplify, the heat generated by one process is quantified and transferred to supply at least some of the necessary energy to another process which needs heat to take place.

While the principles and techniques involved in pinch analysis traditionally deal with heat systems like those above, the same theory can be applied to almost any process which contains a useful by-product in order to make your operation more efficient.

The pros and cons of pinch analysis

Pinch technology is incredibly useful, as it provides a method for reducing the energy requirements of tasks without resorting to external sources. In this way you can turn otherwise useless by-products of your processes into something that benefits your operations.

To summarize:

  • Pinch analysis lets you quantify and measure energy savings and process improvements
  • In-depth process knowledge isn’t required to improve operations
  • Processes, plants, and operations can be made more energy (if not cost) efficient
  • Practical elements (floor plans, etc) allow realistic energy targets to be set
  • Energy efficiency is a desirable trait in a company (for both public and private audiences)
  • The principles behind pinch analysis are widely applicable

Unfortunately, traditional pinch analysis has plenty of downsides too, hence why it is perhaps more useful to apply the principles behind it to other disciplines rather than the methods themselves.

The main issues with pinch lie in its limited scope. When energy consumption is the primary target other aspects such as cost and time efficiency can be all too readily sacrificed if not carefully considered and weighed against the potential savings.

For example, although pinch analysis has allowed many processes to become more energy efficient, this doesn’t necessarily mean that the process being carried out is any cheaper. Indeed, it can often be cheaper to generate or use a new source of energy than to install the technology required to transfer the heat produced by one process to another.

Applying pinch principles beyond production

Traditional practices have pinch analysis and technology serving a very limited role in almost solely chemical production facilities. However, the principles of conserving energy and utilizing by-products of one process as part of another can be applied to almost every discipline under the sun.

Even something as simple as a change to the floor plan of a facility can allow elements of one process to lighten the resource requirement of another. In some cases this can even make certain activities possible where otherwise more impractical (and potentially deal-breaking) methods would need to be substituted.

It’s hard to describe the full extent to which the principles of pinch analysis are applicable, so let’s take a look at some real-world examples to help kick-start your imagination.

Uspenski Cathedral data center cools off by heating homes

uspenski cathedral data centre

While not internal to a single company, one of the best examples of heat-based pinch technology comes in the form of a data center set up by Finnish company Academica.

Installed in caves 30 meters below Uspenski Cathedral in downtown Helsinki, the data centre takes advantage of an old Second World War bomb shelter to keep their machines cool (along with a little seawater). By itself this is nothing special for data centres – the costs of keeping the necessary machines cool can be astronomical, so savings are always welcome.

However, the excess heat is captured by pipes in the rock which transfer the energy into a district heating system. That way, the waste energy produced by the servers provides enough heating for 500 homes at no surplus energy cost.

This is the magic of pinch analysis and technology. Instead of letting by-products go to waste, the idea is to use everything possible – in this instance going so far as to use a private company’s data requirements for the good of hundreds of Helsinki citizens.

Car batteries charge using kinetic energy from the engine

car battery charge

Most who have driven a car know that the battery charges while you drive. This is why you can have the radio on full blast for a long journey without a problem, but leaving a light on for a few hours can drain power and prevent the car from starting up again.

This is because the battery (whether an old dynamo model or a more modern alternator) is charged using a belt which is attached from the engine. That way, when the engine is turned on and power is supplied to get the car moving, the belt is turned and energy stored in the battery using that same kinetic energy.

Now, it’s worth noting that this isn’t a typical example of pinch technology. There’s no heat transfer taking place, the energy being shared isn’t a by-product, and the integration of the battery charging mechanic with the regular engine function is more of a necessity than an energy-saving function. However, the same principles behind pinch analysis and technology are present.

Energy produced in one process is being used to power a secondary process (which isn’t the primary objective). In this case, the same kinetic energy produced to power the car is also being used to charge the battery and power the electronics.

Regenerative breaking extends the battery life of hybrid and electric cars

regenerative brakes

Hybrid and electric cars rely much more heavily on battery power to run, so it makes sense to apply pinch technology and principles wherever possible to use by-products to extend the battery life. Regenerative brakes are one such measure.

While traditional braking systems use friction to slow down the car, regenerative braking instead puts the vehicle’s electric motor into reverse. This means the motor runs backwards and slows down the car as such, while also charging the battery.

Ingenious as this is, however, it comes with its own drawbacks. The power of this braking system isn’t nearly the same as a traditional friction brake, and is only particularly suitable for stop-and-start driving. As such, both regenerative and friction braking systems are typically installed so that the friction brakes can kick in as a backup when extra stopping power is required.

This is a drawback not only due to the need to install two separate braking systems, but also because this can cause the brake pedal to have a varying feel to the driver based on the situation they’re in. On the whole, however, regenerative brakes help to minimize the issue of battery life in hybrid and fully electric vehicles.

Bubble and squeak makes a meal out of process leftovers

Making a meal of leftovers isn’t anything special, but it does provide a great example of the principles behind pinch analysis in as simple and common a setting as possible. The process of cooking can easily produce more food than is necessary but, rather than throwing it away and starting from scratch the next day, those leftovers can be used to provide all the necessary food for the next meal.

leftovers

One great example of this is bubble and squeak – a staple food in the UK made from leftover vegetables from a Sunday roast. Instead of trashing the potatoes, carrots, peas, and whatever else was used, all of it can be re-fried to a form a kind of vegetable hash named bubble and squeak.

Other examples of pinch principles exist in cooking, such as tiered steamers which use the same pot of water to cook several items at once, but you get the idea. After all, waste not want not.

How we Implement Pinch Principles at Process Street

Here at Process Street, we hate to waste resources or a good opportunity. That’s why we’ve taken the principles of pinch analysis to heart and use them to achieve multiple tasks at once.

In other words, rather than having to work twice as hard, we often combine our activities to achieve multiple goals with the same resources.

Here are a few examples of how we combine our efforts:

  • Support duty is included in employee onboarding
  • Blog post series are turned into ebooks
  • Guest posting allows us to grow our audience and network of contacts while targeting certain keywords
  • Our influencer outreach includes a guest posting offer to maximize our opportunities
  • Inside SaaS Sales’ data was used to analyze sales cadences, create a new website, and provide guest posting opportunities
  • The Consultant’s Guide to Process Street explains our product, shows what’s possible, and promotes signups via consultant recommendations

To expand on this a little, let’s break down why we put new employees on support duty as part of their training.

The issue isn’t that we don’t have enough support technicians; we’ll always have a higher level support technician to hand ready to answer any questions, and supply a strict support process to follow for each ticket to make sure that nothing is replied to erroneously. However, by allowing new employees to tackle some of the easier user tickets we can kill two birds with one stone.

In answering basic questions, new hires have an opportunity to become thoroughly familiar with every aspect of our product, from the most commons issues to potentially useful user examples. They can also talk to our users and get familiar with the more common user profiles – what they value, some common processes that they use, and so on.

By doing this we not only get them on board faster, but provide extra support to our user base, increase the number of people able to field support requests (in the event of a ticket rush) and ensure that they have fully explored our product in far less time than would be achievable otherwise.

Don’t be afraid to apply techniques beyond their original context

While pinch technology is traditionally used for heat transfer in chemical processes and production, the principle of saving energy by using the by-products of other processes is applicable to so much more.

The key is to analyze your processes and figure out what you’re wasting with your current setup, and where there is potential to combine activities to save time and effort. While it might take some shifting in terms of task location, timing, and resource storage, the opportunities can allow you to achieve tasks that were otherwise impossible or inefficient due to their requirements.

Whether you’re looking to improve your HR processes, marketing opportunities or, indeed, your production methods, take the time to quantify and calculate how you can use every last aspect of your processes. Even if it turns out to be more costly to reuse elements instead of having separate resources for each, at the very least you’ll be able to see precisely what you’re doing and how those activities can be used to their fullest potential.

How do you make the most out of your tasks and processes? I’d love to hear from you in the comments below!

Get our posts & product updates earlier by simply subscribing

Ben Mulholland

Ben Mulholland is a Content Marketer at Process Street, and winds down with a casual article or two on Mulholland Writing. Find him on Twitter here.


Leave a comment

Your email address will not be published. Required fields are marked.

Get a free Process Street account
and take control of your workflows today.

No Credit Card Required