Coop Group flying high with ammonia

By Andrew Williams, May 24, 2017, 15:30 5 minute reading

Swiss retail giant the Coop Group is putting natural refrigerants at the heart of its strategy for becoming CO2-neutral by 2023. Accelerate Europe reports.

Coop Group production site, near Basel, Switzerland

Swiss retail giant the Coop Group is putting natural refrigerants at the heart of its strategy for becoming CO2-neutral by 2023. Accelerate Europe visits the group’s new production site in Pratteln to find out how ammonia is helping to deliver this target.

At its factory in the suburbs of Basel, the Coop Group produces chocolate, wine and foodstuffs such as dried fruit and nuts for sale in its own stores and for export around the world.

The group consists of a retail arm comprising Coop supermarkets and other specialist formats such as pharmacies, petrol stations and DIY stores in Switzerland, and a European wholesale and production business.

Group sales in 2016 amounted to CHF 28,322 million (EUR 26,152 million). The group employs some 85,000 people and boasts 2,250 retail stores and 226 wholesale outlets in its portfolio.

The Pratteln site is home to three of the Coop Group’s own brands: Chocolats Halba (premium Swiss chocolate), Sunray (foodstuffs) and Cave (wine). The factory produces over 13,000 tonnes of premium Swiss chocolate for retail, industry and export every year – US retail giant Walmart is a big customer.

Under the Sunray banner, 32,500 tonnes of foodstuffs sourced from around the world are processed into 600 different products including dried fruit, nuts, sugar, herbs and spices. 74 million packets per year leave the factory doors.

Cave, the Coop Group’s winery, is the largest in Switzerland. Whites, reds, rosés and dessert wines are among the 36 million bottles produced in Pratteln every year. Cave vinifies must from seven Swiss cantons, and refines and bottles wine from all over the world.

Ammonia has outstanding thermodynamic properties, and is therefore the perfect fit for high-refrigeration capacities.
– Georg Weinhofer, Coop Group

Ammonia: the factory’s beating heart

All this requires a lot of cooling. Accelerate Europe toured the site with Georg Weinhofer – assistant to the head of the logistics department at the Coop Group – and Thomas Fischer, senior project manager at Swiss refrigeration consulting and engineering company Frigo-Consulting Ltd., which has been supporting the retailer with its transition to natural refrigerants.

“The main motivation to adopt natural refrigerants was (and still is) the reduction of CO2 emissions, and hence to contribute to our ambition to become CO2-neutral by 2023,” says Weinhofer, who is responsible for sustainability in logistics.

The Coop Group has been working with natural refrigerants since the mid-2000s. In tune with its commitment to become CO2-neutral by 2023, all its new and refurbished supermarkets have used natural refrigerant CO2 since 2009.

400 of Coop’s 850 supermarkets use CO2 as the sole refrigerant. 90% of the 400 systems are CO2 transcritical.

Coop uses ammonia in all new or refurbished production sites and distribution centres in Switzerland. What led Coop to choose ammonia in particular?

“Ammonia has outstanding thermodynamic properties, and is therefore the perfect fit for high-refrigeration capacities. It has been used for over 130 years. Ammonia is also climate-neutral and reasonably priced,” Weinhofer says.

Another important factor is the availability of technology. “So far, CO2 systems haven’t been available in the capacities we need for our distribution centres and production sites,” Weinhofer says.

“We’re aware that our daughter company Transgourmet is using CO2 in some distribution centres and cash & carry markets. We’re in exchanges with colleagues there on that topic,” he said.

Six refrigeration chillers and two heat pumps, all of which use ammonia, were installed on the site in spring 2016. The cooling capacity of each chiller is 1,000 kW. Likewise, the heat pumps each contribute 1,000 kW of heating.

The six chillers are flexible enough to provide cooling for the site’s different needs. They provide cooling in temperature ranges of +2/+8°C and +6/+12°C, and heat recovery (+19/+25°C and +30/+40°C).

“In addition, we have two large cold rooms served by CO2 refrigeration installations,” Fischer says.

Producing chocolate, cooling wine storerooms, and air-conditioning and dehumidifying the premises are among the onsite processes that require cooling.

“The six refrigeration units can be run individually and their cooling energy can be passed on to two cooling grids,” Fischer explains.

Each of the six refrigeration systems runs independently from the others, helping to minimise the ammonia refrigerant charge and providing guaranteed backup.

The refrigeration units are able to recover heat at temperatures of up to 40°C. The heat pumps can achieve temperatures of up to 60°C. “This waste energy is used to heat the chocolate pipes, to heat the facility, and for dehumidification operations,” Fischer says.

The facility’s production divisions require individual cooling and customised temperature levels, for example during the conching process. A conche is a surface-scraping mixer and agitator that evenly distributes cocoa butter within chocolate. Conching is the key to giving chocolate its final flavour and texture.

‘Ammonia outruns all synthetic refrigerants’

Synthetic refrigerants were never in the picture. “Compared to ammonia, HFOs have disadvantages in terms of sustainability. Ammonia outruns all synthetic refrigerants with regard to energy efficiency, and is therefore a forward-looking and sustainable solution,” Fischer says.

The Coop Group already operates ammonia systems in other locations. This experience, together with the low charge of ammonia and round-the-clock monitoring, means that “there were never any safety concerns” in opting for an ammonia solution, Fischer says.

“At the moment, the installation is being monitored around the clock by a surveillance system from the refrigeration company. The technical service staff will be trained to do specific checks and maintenance work. Thanks to the full-service contract, the installation is serviced monthly,” he explains.

Click here to read the full version of this story in the summer issue of Accelerate Europe.

By Andrew Williams

May 24, 2017, 15:30

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