For flue gas desulfurization in catalytic cracking, the wet (alkaline) method is used; is a sulfur transfer agent also added to the regenerator? Please share

Yes, by comparing with it, using a sulfur transfer agent in the regenerator does not increase costs; this allows for a reduction in the amount of alkali used, and as a result, the salt content in the wastewater is also reduced

What you mean is that the total operating cost will decrease, right?

For many installations, after the installation of desulfurization and denitrification equipment, the use of sulfur transfer agents or denitrification aids at the front end is usually considered for the following reasons: 1. The currently designed desulfurization and denitrification equipment fails to meet **or local environmental regulations, and thus cannot ensure compliant emissions； 2. The use of sulfur transfer agents and denitration aids can reduce the costs associated with posterior desulfurization and denitration operations to a certain extent ； At present, the efficiency and effectiveness of desulfurization and denitrification additives in China are quite good; some of them can even be made into dual-functional or multi-functional additives. Without compromising the quality of the catalytic products or the normal operation of the fluidized bed process, their efficiency can reach over 80% in some cases. This helps to address the aforementioned two problems to some extent and is beneficial for production optimization. Desulfurization and denitrification are systems that involve costs without any benefits (emission recovery methods); it’s better to save as much as possible.

Indeed, many catalytic units equipped with desulfurization systems are using flue gas sulfur transfer agents.