Increased energy efficiency is an important aspect of Gränges’ environmental strategy, as well as maximum metal yield and greater use of recycled aluminium in production.
A maximum metal yield, greater use of recycled aluminium and energy-optimising processes are absolutely crucial to Gränges financial results, while representing the company’s main contribution to reducing the environmental and climate burden.
The production facilities in Finspång and Shanghai are comparable in their high environmental standards.
Efficient transformation processes are crucial for Gränges to achieve sustainable long-term profitability. After metal procurement and personnel, energy constitutes the largest cost.
Direct energy savings are achieved partly by improving production equipment and processes, partly through the recycling of thermal energy from the processes. Waste heat is reused for heating of premises, amongst other things.
Gränges carries out regular energy surveys to identify improvement measures, that will contribute to lower use of energy and lower carbon dioxide emissions in relation to the number of tonnes of aluminium produced.
Gränges has successfully reduced its energy cost per tonne of aluminium in the past three years, thanks to efficiency improvements throughout its processes.
Recycling of metal
Gränges remelts its own process scrap, and in addition purchases scrap from external sources to reduce the use of primary ingot.
The percentage of recycled raw materials is different at the two plants in Finspång and Shanghai due to different market conditions for aluminium scrap in China and Europe.
To read more, see Aluminium
Large volumes of water are used for cooling in several stages of the process. Shanghai has a closed cooling system with a high degree of recirculation. In Finspång there is good access to lake water, and the facility uses this water in an open cooling system. The water is returned to the lake after thorough cleaning. This means that water consumption at the Shanghai plant is not comparable to the water use in Finspång, since the majority of the cooling water is returned to environment.
Life cycle perspective
Gränges uses a life cycle perspective to evaluate the environmental sustainability of the company’s products throughout their entire life cycle, from raw material to end use. The aim is to develop new alloys to recycle more scrap, and downgauge the components to enable the production of lighter, more efficient heat exchangers.
Gränges continuously reviews how it can optimise transportation and logistics flows. The average load per truck is being increased by improving finished goods inventory levels. Gränges strives to make internal logistics more efficient through process improvements and investments to reduce the use of forklifts.
By optimising the rolling process, Gränges reduced the consumption of rolling lubricants and additives at the facility.