Continuous improvement processes for existing plants

Automation reduces nitrous oxide emissions

One example of climate protection through greater efficiency in production at our main site in Ludwigshafen is an automation project in the nitric acid plant. It is expected to save 145,000 metric tons of CO₂ equivalents per year.

Nitrous oxide (N₂O) is a by-product of adipic acid production and 99 percent of it is decomposed or recycled. In the future, as much as 99.9 percent of the emissions are to be avoided. They will either be converted to nitrogen and oxygen or isolated and used for oxidation in the CDon plant. This is made possible by an automation project at the nitric acid plant that is nearing completion. The aim is to emit 550 metric tons less N₂O per year. Nitrous oxide has a significant global warming potential. It is 265 times more harmful to the climate than CO₂. Even small savings therefore have a major effect. The nitrous oxide saved corresponds to around 145,000 metric tons of CO₂ equivalents per year.

The significant improvement in nitrous oxide decomposition is made possible by a model-based control of the existing decomposition plant in the nitric acid cluster. To optimize the effect of the decomposers, a program with defined parameters for temperature, pressure or nitrous oxide concentration is stored in the process control system. The program specifies the plant conditions for which operation is required. It detects any change in a flash, such as an increased amount of waste gas flow from adipic acid production, and optimally adjusts operation. The special feature: The program uses models based on computer simulations. Almost nothing had to be changed in the plant itself.