Doing more with less: innovation for sustainable manufacturing
The chlor-alkali plant in Bitterfeld, Germany
AkzoNobel is a big player in the Chlor-Alkali industry, with chlorine gas and caustic lye produced by electrolysis from a solution of very pure common salt. Committed to sustainable manufacturing, innovation is key to optimize production processes.
An example: The chlor-alkali plant in Bitterfeld, Germany. For several years, it had needed more steam than other, similar facilities in AkzoNobel. The plant uses salt brine, i.e. salt dissolved in water, from a cavern nearby as raw material. However, the brine is too ‘wet’ and steam is needed to remove some of the water in this brine before the production process. This happens in an evaporation unit, which is also used to concentrate the caustic lye that is produced at the site. Highly concentrated caustic is required by the majority of customers.
In order to reduce the elevated steam consumption, a multi-functional project team was set up to research and implement mitigations.
It soon turned out that for an efficient improvement plan, further in-depth information was needed on how the evaporation unit worked. Accordingly, the team set up a staged approach for the innovation process:
- First, they developed a sophisticated mathematical model to fully understand the performance of the evaporation unit. RD&I experts for salt worked with technology experts, combining their know-how. Through this modeling, the most promising areas for improvement could be identified.
- Then, the technology experts together with AkzoNobel’s Projects & Engineering Department developed improvement ideas and planned the necessary changes in the engineering of the evaporation unit.
- Technology, production and maintenance in Bitterfeld were involved at all times and realized the proposed improvements.
The combined efforts were a success: the steam consumption was reduced by 27%. In addition, the steam contract could be changed to a more sustainable energy mix: Today, 80% of the steam comes from a waste incineration unit, reducing the CO2 footprint by 4400 tons/year, and minimizing the impact of the gas price.