Cupola operator re-thinks old coke substitution rates
With the help of Air Products, a cupola operator evaluates ways to improve the efficiency and profitability of their process through oxygen enrichment and reduced coke usage.
Issue: Escalating coke prices have put a lot of pressure on cupola operators to improve the efficiency of their process and companies are looking at alternative fuels and oxygen-based technologies to reduce their coke demand and improve their profitability.
Solution: Over a decade ago, substituting 5 to 10% of coke with an alternative fuel was the upper limit. Above these substitution levels, spout temperatures, melt rates, and carbon pickup were negatively impacted. Also, at that time there was only a small price differential between coke and coal, and oxygen was relatively expensive. With changing market conditions, coke can now be two or three times more expensive than alternative fuels on an equivalent BTU basis and oxygen prices have remained stable. These new dynamics, along with Air Products’ technology advancements, favor using more oxygen to reduce coke and to increase alternative fuel substitution, while maintaining stable operations.
Air Products is working with a cupola operator to increase oxygen enrichment and slowly reduce coke with the goal of achieving net savings of $200- $300 per hour. In addition, our proprietary advanced control systems will be leveraged to monitor key process variables, such as temperatures and gas compositions. By analyzing variables which are not typically measured on a continuous basis at most sites, our scientists and applications engineers will be able to quickly optimize the fuel and oxygen balance within the cupola to yield efficiency improvements and cost savings.