By the time a raw material has been transformed into a component installed in a Volkswagen, it will have passed through some 15,000 stations in the course of its production, treatment, finishing and transportation. Together with its many thousands of suppliers, Volkswagen does its best to make this long and complex process chain as environmentally compatible as possible.
Managing the aluminum cycle
Aluminum is an important staple of the automotive industry when it comes to lightweight design, but it is more energy-intensive to produce than steel. To address this issue, Audi is currently testing an innovative recycling concept designed to conserve resources.
Together with a supplier, Audi recently rolled out the Aluminum Closed Loop pilot project to identify the potential for more efficient recycling of aluminum. The aim is to set up a closed-loop recycling system between the company and its suppliers.
It works like this: Offcuts from the sheet aluminum used in the Audi press shops are returned directly to the supplier, who recycles them. The resulting secondary raw materials are then used by Audi in its production process, eliminating the need for energy-intensive production of new aluminum, which in turn benefits the environment. The bottom line is that Audi not only reduces its energy consumption, and therefore its CO₂ emissions, but at the same time also cuts its uptake of primary raw materials. To define the system requirements and constraints, Audi is currently analyzing all the relevant process steps. On this basis the company will then explore the potential for using the system across the Group.
The thinking behind the development of innovative processes like the Aluminum Closed Loop is explained by Dr. Bernd Martens, responsible for procurement on the Audi Board of Management: “Audi stands for sustainability. We are aiming to make the entire value chain of our models sustainable and have set ourselves demanding goals in this respect. Through careful resource cycle management, we aspire to conserve resources by recycling materials and raw materials.”
It’s about conserving resources by applying the principle of resource cycle management.
The Volkswagen plant in Kassel manufactures engines, gearboxes and body parts for the entire Volkswagen Group. As most of the production processes at the components plant involve the machining of metals – for example drilling, milling or grinding – large quantities of aluminum cuttings are also produced.
In the past, these cuttings were shipped to external contractors for melting and then returned to Volkswagen as a solid material. Before it could be used for the production of new parts, the aluminum had to be melted again at the Volkswagen plant.
Now Volkswagen has simplified this process. All aluminum cuttings produced from alloy Al 226 with a residual moisture level below two percent can now be melted directly on site, producing new raw material.
The specific environmental benefit is that the Kassel plant can cut the amount of aluminum alloy it purchases each year by 1,050 tonnes. As aluminum production is highly energy-intensive, this also means a considerable drop in the associated CO2 emissions. Thanks to the new approach, Volkswagen itself saves some 3,250 MWh of energy per year, representing a reduction of 1,430 tonnes in CO2 emissions.
On the logistics side, this process also reduces the distance traveled by trucks by 800,000 kilometers per year. In addition, nitrogen oxide output is cut by 0.5 tonnes per year and Volkswagen also reduces the use of many consumables such as melting salts (-1,300 tonnes p.a.) and calcium hydroxide (-16 tonnes p.a.), as well as the production of waste such as salt slag
(-2,670 tonnes p.a.) and filter dust (-130 tonnes p.a.).
1,430 tonnes less CO₂ per year.