FCC Emissions Reduction


A partnership half-a-century in the making

For over 50 years, our specialists have collaborated with leading refiners. And this partnership has led to extensive operations experience gained through over 20 refinery oxygen enrichment installations and groundbreaking oxygen applications in Fluid Catalytic Cracker (FCC) units. Today, we have developed a practical, low-capital technology for refiners looking for a way to improve operational flexibility and reduce emissions. Our proprietary CONOx control system can improve flexibility by providing options to modify the operation of the FCC unit to meet environmental limits or improve profitability.

The key to our CONOx technology is a high velocity jet of heated oxygen that rapidly mixes with process gases. Due to the extraordinary jet mixing characteristics, CONOx technology is significantly more efficient than a standard oxygen jet. Carbon monoxide (CO) levels are significantly reduced, and nitrogen oxide (NOx) emissions can be reduced up to 60%. Even higher levels of NOx reduction are possible when the system is used in conjunction with other low capital control methods like SNCR or NOx reduction additives.

Operators are able to improve yields by taking advantage of lower regenerator temperatures or by increasing charge rates through the elimination of regenerator or CO boiler constraints. In addition, the CONOx system can reduce or even eliminate the need for CO boiler supplemental firing. Other benefits can include lower velocity and reduced combustion promoter use. Operational synergies can exist where oxygen enrichment is already in use. Praxair designs each CONOx system with the necessary controls to provide a high level of safety.