BMW introduces electric exhaust air purification in paint shops
The BMW Group is introducing electric exhaust air purification in the first paint shops, thereby helping to reduce CO2 emissions in production. Series production of the use of electricity instead of gas for thermal cleaning has started.
The BMW Group is using electricity for exhaust air purification in its first paint shops: Thanks to a new process, the high temperatures required for the thermal cleaning of exhaust air from paint booths and drying rooms can be generated electrically. This means that another process in production can take place without the use of natural gas. Michele Melchiorre, Head of Production Systems, Planning, Tooling and Plant Engineering at the BMW Group: "For other energy-intensive processes in the paint shop - such as vehicle drying or hot water generation - there are already solutions for dispensing with the use of natural gas. Electric exhaust air purification is therefore the final building block on the BMW Group's path to being able to operate its paint shops with renewable energy in future."
eRTO: The natural gas-free alternative for the vehicle paint shop
eRTO stands for electrically regenerative thermal oxidation, a process that purifies gaseous and vaporous substances by burning them at temperatures of up to 1,000 degrees Celsius and - unlike in the past - requires only electricity to do so. The exhaust air from the paint booth and drying room is cleaned before it escapes via chimneys. This means that the environment is not polluted by the solvents used in the paint shop. During the cleaning process, the contaminated air flows through a ceramic bed in which the residual solvents burn off. This requires the air to be heated to a high temperature in a short space of time. An energy requirement that could previously only be met with natural gas. Thanks to the innovative eRTO system, it is now possible to dispense with fossil fuels and use electricity from renewable sources instead. The eRTO system is installed between the paint booth, drying process and chimney. An approximately two-metre-high, flat ceramic bed, in which temperatures of up to 1,000 degrees Celsius prevail, serves as a recuperator, i.e. for recovering the thermal energy. Electric heating rods heat the surrounding ceramic. As the heat is retained in the system and only a small amount escapes, a connected load of a few hundred kilowatts is sufficient to operate the system.
Series use of electrical exhaust air purification in BMW plants
The function of the eRTO system was initially tested at the BMW Group plant in Regensburg during ongoing operations in the paint shop. A system for cleaning the exhaust air from the drying system for front flaps at the Chinese BMW Brilliance plant in Lydia serves to further validate the process. The Dingolfing plant is the first European BMW Group location to use the eRTO process in series production at its paint shop. The first of four paint lines there has already been converted to electric exhaust air purification. The installation of further systems in the production network is planned. In the new plant in Debrecen, which will start production at the end of 2025, the eRTO process will be used exclusively for exhaust air purification in future (as reported by Oberfläche-Online).