Optimization of the naphtha hydro treating unit (NHT) in order to increase feed in the refinery

Increasing the capacity of this unit will cause problems such as the increase of pressure downfall, the reduction of output pressure of circulating gas compressor, the increase of the eventuality of coke formation on the catalyst, increasing the thermal load of the reboiler furnaces of unit towers and eventually reducing the catalyst life span. In this research, operating conditions have been investigated that are indicating the increase the refinery feed with the design capacity of 50,000 barrels per day, to the amount of 55,000 barrels per day. The results indicate that with increasing feed, should be increased the entrance temperature to the unit reactor. At the same time, the temperature increase caused the increasing of coke formation on the catalyst and rising the difference of entrance and output pressure of the reactor. Also, the thermal load of the furnaces of Stripper and Splitter towers increased. In this paper, with the modeling of the catalyst inactivation at the sightly temperature, as well as the troubleshooting of the system afterward, with regards to all the above conditions, it is proved that increasing the feed is an acceptable action according to the resulting profit from the sale of the products.