Sustainable Manufacturing Through Water Management

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Amid ongoing business transformations, OEMs and suppliers alike must consider that sustainability in the automotive industry must be achieved through specific and measurable process design and execution instead of empty promises or banal platitudes, said Gerardo Hernández, Sustainability Spokesman for Audi. 

"At Audi, we created the Mission Zero environmental program to achieve sustainability through decarbonization, biodiversity, resource efficiency and water use,” said Hernández at the International Mexican Automotive Industry Congress (CIIAM), an event organized by INA, in collaboration with Mexico Business. This extends to all other brands in the Volkswagen Group, including Seat, Porsche, Bentley and Ducati. 

Audi’s Mexico’s plant was built with the principles of a “Smart Factory.” Its construction, which covered 460ha, began in 2012 and operations started in 2016, becoming the No. 1 premium automaking spot in all of Mexico. "We currently have more than 5,000 employees in Mexico supporting the production of the Audi Q5 in all its versions," said Hernández. The company exports units to all markets except China and employs 20,000 people indirectly through a network of 180 suppliers.  

Sustainability was sought from the project’s initial planning stages, when procurement plans for specialized heavy machinery were first being drawn up “Sustainability is one of our main targets. As a German company in Mexico, we have the possibility to generate a true impact and make this a relevant topic in the industry. Water is one of our priorities, because it can be scarce during certain seasons. We are the first entity to be waste-water-free in Puebla,” said Andreas Lehe, former Executive President, Audi México, to MBN back in January 2020. 

“All machinery in the facility needed to consume resources efficiently; the equipment also needed to come with control and measurement capabilities so that consumption could be measured precisely to further cut down costs whenever possible,” said Hernández. This began with the bodywork shop, in which 800 of the latest generation of assemblage robots were acquired, all of them mounted with a modern system of energy consumption that generated electricity savings continually and was programmed to go offline at precise intervals to minimize energy consumption during downtime. “It did not take too much analysis for us to identify that an excessive amount of water was wasted at the paint shop; its processes were resource-heavy,” said Hernández.  

Sustainability led to the implementation of the EcoDryScrubber solution, which uses little to no water for finishing a paint job, applying limestone powder as a binding material instead and making the paint work through a dry separation process. “This gives us a combination of high performance with massive energy and resource savings in painting, allowing us to save copious amounts of water previously wasted in this particular segment of the manufacturing line.” This includes a general reduction of 60 percent in energy costs in the spray booth, which includes 80 percent less heat consumption, 50 percent less power consumption and 80 percent less water consumption for supply air conditioning (compared to traditional wet separation). The use of limestone powder as a natural binding material for all paint types eliminates the use of water and detackifier chemicals, not to mention the disposal of paint sludge which would severely undermine any plant’s water treatment and reuse efforts. “Meanwhile, the use of EcoPure technology results in a reduction of 95 percent in COVs”, says Hernández.

At Audi’s assembly line, all tracing and follow-ups are done digitally, which generates immense savings in the use and consumption of paper. All the water that is used throughout these processes is recycled and all trash and residues are managed and processed in-house. This has allowed the plant to be free of any kind of landfill use since it started operations in 2016. Water is managed through an artificial reservoir within the facility that Hernández refers to as an “internal lagoon,” coupled with a water treatment plant with its own reverse osmosis membranes. This treatment plant has a capacity of 3,000m3 a day and is attached to a complete set of physical-chemical equipment.    

Through these systems, Audi has managed to run a closed loop in terms of its water consumption: almost all of the water used is recycled or repurposed in a way that ensures the safety of all workers and the integrity of all materials. "Since 2018, Audi is completely free of external water discharges; we control, measure and manage the resource completely and not a drop goes unaccounted for. This has also meant that a great wealth of information has become available to us: we can now measure more exactly than ever how much water goes into making a car, which in terms of sustainability, is invaluable information," concludes Hernández.