Heidenheim pilot plant tests pure-oxygen clinker production to slash cement CO2 emissions

A new approach to cement production

The pilot plant in the Mergelstetten district of Heidenheim, roughly 50 kilometres north of Ulm, is designed to produce up to 450 tonnes of clinker per day. Traditional cement manufacture heats limestone with air to around 1,450 degrees Celsius, releasing a mix of CO2 and nitrogen that is hard to separate. The new rotary kiln replaces air with pure oxygen, so the exhaust is an almost pure CO2 stream that can be captured directly. The operators are Thyssenkrupp Calvion, a subsidiary of thyssenkrupp Polysius GmbH.

From pilot to industrial scale

The facility is a research and development plant backed by four European cement manufacturers, who together invested more than 120 million euros. Its purpose is to test the technology under realistic conditions and gather know-how for later large-scale plants. Hannah Berse, spokeswoman for Thyssenkrupp Calvion, describes it as the first research installation of its kind anywhere to include its own clinker line.

The plant was built specifically for research and development and makes it possible to test the process under realistic conditions.

The basic functionality has been demonstrated. The next step is to prove whether the method is suitable for industrial deployment. At present no specific use is planned for the CO2 captured by the pilot. Whether the gas can later be stored under the North Sea or delivered to other storage sites depends on legal frameworks and the construction of pipelines and terminals.

Climate policy backdrop

Cement making is one of the industrial sectors where CO2 emissions are especially hard to avoid. The European Union has agreed a binding climate target for 2040: greenhouse gas emissions must be cut by 90 percent compared with 1990 levels. Baden-Württemberg’s own climate law requires a reduction of at least 65 percent by 2030 and demands that the state become climate-neutral by 2040, meaning only as much CO2 may be emitted as can be offset. The Heidenheim pilot could contribute to meeting those goals by testing a path to capture process emissions that have so far been difficult to abate.

What happens to the captured CO2

The captured carbon dioxide could in theory be re-used in the beverage industry or in fire extinguishers, or stored permanently in geological formations. But the lack of transport infrastructure and clear regulation means no decisions have been made. The immediate focus is on the plant’s operational performance and the data it generates for scaling the technology.