TECH ADVANCES
Dan-ECO2
A closed-loop system for reducing aluminium cold-rolling emissions
To minimize the environmental impact, Danieli is committed to continuous improvement of and investment in a process that reduces the exhaust emissions of aluminum cold rolling mill to meet and exceed the requirements of environmental regulations.
For the separation of Volatile Organic Compounds (VOCs), Dan-ECO² is an ecologically effective system.
Furthermore, not only is this method ECO-logically efficient, it is also ECO-nomically efficient as it allows the recovery by distillation of the absorbed rolling oil without chemically altering its state.
Description of the process:
Each boundary layer has a chemical equilibrium on each side. This means that each time the same amount of VOC molecules goes into the gas film and leaves the gas film. A part of it goes back to the gas phase while a portion moves into the liquid film. This phenomenon is produced on the Sulzer MellapakPlus™ or equivalent packing structures that are incorporated in our system.
The process of absorption to distillation operates in an automated, closedloop cycle, continuously monitored by a range of instrumentation throughout the system and acts as a standalone unit.
The absorption process of the rolling oil into high boiling absorptive oil is heavily dependent on temperature and pressure. Therefore, the rolling oil is regenerated through the application of high temperature and low pressure in the closed-loop on the distillation unit, as shown in the diagram below.
Danieli Automation developed the automation system for Dan-ECO² in order to guarantee a strong synergy between process and software within the group.
- The exhaust air purity fulfils the highest emission standards of < 30 mg C/Nm³.
- The flexibility of the system allows for excellent efficiency, even under fluctuating inlet conditions, due to advanced condition monitoring of the inlet temperature and flow, and hence it reduces running costs.
- A by-pass line in the absorption circuit allows approximately 3- to 4-hour maintenance time to the rectification system, with no need to shut down the complete Dan-ECO² system, or to reduce the extraction from the mill and subsequently the rolling schedules.
- Because of the treatment in a distillation process, the rolling oil can be fully reused for the rolling process.
- 50% of savings in OpEx (for coolant costs)
- 97% coolant air gets purified
- Fully automated and remotely controlled from the main pulpit of rolling mills.
- Dan-ECO² can operate without fume-exhaust airflow from the mill, so it is not necessary to shut down the system when lamination is stopped.
- All pumps and heat exchangers are pre-assembled on skids for easy and quick erection and commissioning.
- Return On Investment (ROI) ~ 3,4 years