When it comes to energy saving in Dutch industry, some low-hanging fruit remains to be picked.
The energy-guzzling giants, such as Tata Steel or Akzo Nobel, may lead the way when it comes to efficient consumption, but small and medium-sized companies show a lot of room for improvement. PepsiCo’s Lay’s crisp factory in Broek op Langedijk, the Netherlands, demonstrates how this can be done in practice.
Upon entering the hall of PepsiCo’s North-Holland factory, large media cubes hang from the ceiling making you aware of topics such as using water, saving energy, and preventing climate change. Some 250 people work here, and a million bags of crisps come off the belt every day.
‘As a factory, it is not obvious that we need to save energy,’ says Dave van Braak, Sustainability and Facility Manager at the North-Holland Lay’s factory. ‘Gas and electricity prices have only dropped, which causes there to be little incentive to save.’
Environmental Management Act
Companies such as Akzo Nobel, DSM and Tata Steel have been working towards energy efficiency for years, yet the industry as a whole is only slowly getting into gear when it comes to energy efficiency. Although, the Dutch Environmental Management Act stipulates that all energy saving measures with a payback period of less than five years must be taken, research shows that in practice only measures with a payback period of two years or less are implemented. So why does PepsiCo do it?
‘As a company, we want to take our responsibility,’ says Van Braak, mentioning the Environmental Management Act. ‘We try our best to find these projects in the company.’
Proactivity places PepsiCo ahead of other companies. ‘It’s not that entrepreneurs aren’t willing to become more sustainable, but they are lacking time and knowledge,’ says Margreet van Gastel, the Ambassador for Energy Challenges 2020 at the Ministry of Economic Affairs. Everyday activities consume management’s time completely and as a result they have little time left to delve into energy efficiency. This means they don’t capitalise on opportunities. Van Gastel gives the example of pipe insulation, which often has a payback period of several months. ‘But do entrepreneurs even know that?’ she wonders.
Compressed air
According to the Berenschot report on transition paths to electrification in the chemical industry, reuse of compressed air is an existing technique with a short payback time. PepsiCo, like many other companies, uses compressed air to control all kinds of processes: to open and close valves in machines, to clean the network of pipes, and to blow ‘bad crispies’ and potatoes out of the line on the conveyor belt. That air is led through the factory via a network of pipes that is under continuous pressure. In the North Holland Lay’s factory they already achieve energy savings as well as in the efficient use of compressed air and the proper adjustment of the process. Nevertheless, each kW of compressed air costs 7 kW of electricity to produce and Van Braak decided to reexamine the use of compressed air in the factory.
Energy guzzling monster
Geveke Energy Services redesigned the Lay’s production system, and as a result the Lay’s crisp factory now saves 60% on its electricity consumption.
‘You build a factory, the company grows, you expand it a little and you tie that together. Before you know it, you built an energy-guzzling monster,’ says Pascal van Putten, owner of VPInstruments that supplied the measuring equipment for PepsiCo’s North-Holland factory. ‘But as long as the production process is running smoothly, nobody dares touching it.’
The people at PepsiCo were brave enough to do just that. First, the entire system was checked for leaks and bottlenecks. ‘Some of the couplings were attached with a tie-wrap,’ says Van Braak. ‘A construction like this is bound to leak.’
Then they slowly reduced the pressure in the pipeline network from 7 bar to 5.3 bar. With each bar that they lowered the pressure in the system, they reduced leakage by 15% and power consumption by 7%. Instead of keeping the whole system at the highest required pressure, they put small boosters in places where higher pressure was indeed necessary.
Result
Instead of using four compressors with a total power of 315 kW of which only 250 kW was ever used, PepsiCo now has an installed power of 275 kW, of which a maximum of 140 kW is in use simultaneously. This means energy savings of 50%.
At night and during weekends, the system runs on a 15 kW compressor to keep critical processes like the water purification system running. This particular process, for instance, cannot come to a standstill but many other processes can. ‘This saves in total 2,000 hours on the large compressor,’ says Van Braak, and that in return saves an extra 10 percentage points, which reduces the energy savings to a total of 60%.
Geveke made these energy savings possible by integrating a flow pressure regulator, as well as a compressor management system and an online energy monitoring system that meets relevant ISO standards. These changes make the Broek op Langedijk factory PepsiCo’s most energy-efficient factory in Europe.
In addition the factory burns biogas from its own water treatment plant to keep the ovens at the right temperature. This accounts for 3% of the energy consumption during baking. Low-grade heat is recovered from the frying fumes –some is used to heat the buildings, and a smaller amount is returned to the production process. PepsiCo remains on the lookout for more ways that heat dissipating through the chimney can be utilised.
Payback period
‘You have to look at the life-cycle cost and challenge people to do so,’ says sustainability manager Van Braak. ‘Then it’s slightly more expensive to buy, but you earn it back.’ PepsiCo’s investment in compressed air efficiency paid for itself within a year.
The sustainability manager would like to do more, but sometimes a change in a factory elsewhere in Europe will yield more environmental benefits per euro invested, so the parent company will make a different decision. ‘But I have some great plans that are absolutely interesting, especially if energy prices were to rise,’ says Van Braak.
The article is written by Energeia, www.energeia.nl. Published 2017, May 3rd.
