Q & A > Question Details
Which is preferable for naphtha hydrotreater catalyst regeneration in situ or off situ , and if in situ what are requirements and steps for that process?
05/06/2015 A: Saleh Daryabari, Senior Process Engineer of RCD and RFCC, Arak Refinery, daryabari@gmail.com
Generally in ex-situ regeneration catalyst recover better activity because of uniform and homogenize coke burn. Also temperature control is more accurate in ex-situ and by preventing hot spot and temperature run away during regeneration, catalyst structure remain in good condition. In ex-situ regeneration there are no air pollution with acid gases and no discharge of neutralization products and caustic to the water stream and in addition it increases time available for reactor inspection and maintenance.
In in-situ regeneration recycle gas contain controlled amount of oxygen and in different temperature level, oxygen reacts with carbon, sulfur and nitrogen forming CO, CO2, SOx, NOx. These gases should be neutralized in close loop. Neutralization is a demanding and time consuming process; requiring injection systems, trained operators and time. In-situ regeneration is generally time consuming.
02/06/2015 A: Sarath Konda, DuPont India, sharathsatya@gmail.com
Ex-Situ is regeneration is preferable now a days. Specialist Vendors are available to perform the job diligently. Regeneration temperature control is a must to protect the catalyst from getting damged, which some times difficult in insitu regeneration. In Insitu regeneration most of the time it is carbon burning only and other contaminants on the catalyst remains as it is.