Water in the hydrogenation feed and water in the reflux can have adverse effects on the operation

Water in the raw material can cause large pressure fluctuations and a decrease in temperature as well； There are many factors that affect the water carried back by the reflux stream, and these can lead to poor separation results; even if the effects of temperature and pressure are minimal, the product will still be affected!

Water in the hydrogenation feedstock can cause large pressure fluctuations in the reaction system, as well as a decrease in temperature； Backflow of water causes significant fluctuations in tower pressure, an increase in the top temperature of the tower, and poor separation efficiency.

Personal opinion: Water in the catalytic feed has a significant impact on reaction pressure, but the effect on the pressure in hydrogenation units is not very noticeable; water in the feed has a greater impact on the catalyst. Water in the fractional distillation reflux zone has a significant impact on the tower pressure, as the space at the top of the tower is limited; when water vaporizes, the gas load in the vapor phase at the top of the tower increases.

The moisture content in the raw materials has several drawbacks: ① It causes fluctuations in the operation of the heating furnace, resulting in unstable temperature at the furnace outlet; this in turn leads to fluctuations in the reaction temperature, increased fuel consumption, and an impact on product quality； ②The large amount of water vaporizing in the raw materials causes pressure changes in the system, deteriorating the operation of various control circuits ； ③It causes damage to the catalyst; catalysts that are operated at high temperatures, if exposed to moisture for an extended period, are prone to the aggregation of the active metal components on their surface, leading to a decrease in activity and strength, as well as catalyst pulverization, which can cause blockages in the reactor. The latent heat of vaporization of water is very high, and its volume increases significantly upon vaporization. If the raw material contains a large amount of water, the following phenomena will occur: ① The load on the heating furnace increases ； ②System pressure rises and fluctuates ； ③Rise at the interface of the high-pressure separator ； ④The heat exchange temperature of the raw materials decreases. Backflow of water: The pressure at the top of the tower increases while the temperature at the top decreases.

The most significant issue caused by water in the feedstock is its impact on system pressure; the vaporization rate of water is high, and when there is a large amount of water present during distillation, the naphtha’s alkali and nitrogen content will definitely be unsatisfactory. This leads to extremely high pressures in the distillation tower along with a drop in temperature.

I see, thank you. So in other words, the raw material water means that the light components in the raw material increase, right? And the water carried back in the reflux stream means that it’s the component with a higher calorific value, is that how it can be understood?

Water in the feed stream, fluctuations in the temperature at the exit of the heating furnace, rising system pressure, and a decrease in the temperature rise of the bed layer; water carried back by the reflux can cause the pump to go into vacuum, which may lead to tower flooding.

Water content in the raw materials has a significant impact on the activity of the catalyst; in severe cases, it can cause changes in the catalyst’s micropores, thereby threatening its service life. Water vaporization inside the furnace tubes requires a large amount of heat, which increases the burden on the heating furnace. Moreover, the vaporization of water raises the pressure in the system, leading to pressure fluctuations. It has a certain impact on the pressure difference in the hydrogenation reactor

Water in the feedstock causes large pressure fluctuations in the reaction system, leading to catalyst deactivation and crushing, as well as an increase in the pressure drop across the catalyst bed.

Water in the feedstock causes large pressure fluctuations in the reaction system, leading to catalyst deactivation and crushing, as well as an increase in the pressure drop across the catalyst bed.