Ammonia refrigeration is best practice in McDonald&rsquo;s supply chain&nbsp;

With the release of McDonald’s report “2012 Best of Sustainable Supply”, highlighting the installation of an ammonia refrigerant plant at Northeast Foods, ammonia21.com reports on the use of ammonia in the company’s complex supply chain.

Internationally, McDonald’s is considered the largest food service retailer in the world. The production and supply of its food products requires the use of huge amounts of refrigeration machinery and coolants, including the natural refrigerant ammonia, recently honoured by McDonald’s in its “2012 Best of Sustainable Supply” report, and used by many of McDonalds suppliers.

Ammonia helps achieve 20% improvement in electricity usage at Northeast Foods

Baltimore-based Northeast Foods is a commercial baking powerhouse with 13 production facilities, supplying McDonald’s with most of their production of buns for hamburgers.

The company’s Clayton facility, designed by AM King, recently installed its first ammonia refrigeration plant. The new 103,000 sq. ft (9,569 m²) greenfield site consists of a 70,000 SF fully automated bakery and a 13,500 sq. ft (1,254 m²) freezer at 56 foot (17 m) high, a minus 10 °F (-12°C) temperature and a fully automated racking system.

The ammonia system from its freezer is used to chill glycol for the process equipment, mixers and ingredient cooling, eliminating separate equipment for the process chilling. Moreover, by utilizing a heat exchanger system, the company recovers heat from the glycol compressors. That warmed glycol is then pumped through the freezer sub floor to keep it above freezing. All of the heating and cooling requires no additional energy consumption.

The electricity usage in the new bakery is 288 kilowatts per ton of production. Compared to the company’s Virginia facility, a single roll line that also froze all of its product, that is a 20 percent improvement.

Keystone Distribution plant saves up to 15 MW a year in energy

In the UK McDonald’s supplier Keystone Distribution has installed 2,000kW two-stage ammonia refrigeration plant for its state-of the-art Hemel distribution facility, which required a new refrigeration plant after the original depot was badly damaged in the Buncefield oil storage explosion. The ammonia refrigeration system incorporates several energy saving features that contribute to 15MW yearly energy savings:

A heat recovery system that sends heat from the refrigeration compressors oil coolers to a glycol underfloor heater;
An inverter-driven compressor system that speeds up or slows down according to the duty requirements of the refrigeration system also saves energy;
An refrigeration plant management system enables fans to be cycled on and off;
Evaporator air sock collapses when the fan stops and blocks any air from entering the cooler by convection while in defrost cycle.

Earp Distribution’s energy efficient facility incorporates ammonia

Earp Distribution, whose official name is Earp Meat Company, is another distributor to McDonald’s restaurants, selling various food products, in addition to fresh hamburger. In August of 2011, the company moved to a new 184,000 sq. ft (17,094 m²) facility located in Kansas, whose energy efficient design includes an energy management system, and an ammonia refrigeration system. The physical plant consists of a 20,000 sq. ft (1,858 m²) freezer, a 17,000 sq. ft (1,578 m²) cooler, and a 26,000 sq. ft (2,415 m²) cold dock.

Suppliers of fries and pies reliant on ammonia

Bama, a leading manufacturer of donuts, fruit pies, breadsticks and biscuits, and supplier to McDonalds, has a 160,000 sq. ft (14,864 m²) facility containing the corporate offices and a manufacturing plant, cooled by a central ammonia refrigeration plant. Temperatures throughout the building vary from +50°F (10°C) to -20°F (-28°C).

The agribusiness corporation JR Simplot Company, one of the world's largest frozen potato processors, and the main supplier of French fries to McDonald's worldwide, also uses ammonia refrigeration in its processing plant.