Operation of the cyclic hydrogen compressor
Thread Content
Suddenly, an idea came to mind; I’m not sure if it’s feasible. At the outlet of the cycle compressor in the hydrogenation unit, there are branches that lead to the inlet of Reactor 1 and another branch that is used for quench hydrogen. My idea is that, toward the end of catalyst operation, it might be possible to reduce the amount of cycle hydrogen flowing into Reactor 1, and channel the reduced amount to the quench hydrogen branch in order to lower the temperature of the catalyst bed. This allows the reaction temperature of the catalyst at the inlet to increase appropriately, while reducing the reaction temperature of the catalyst at the rear, thereby enabling the catalyst to perform better. I’m not sure if this approach will work; could everyone share some suggestions? :handshake
Towards the end of the device’s operation, the catalyst’s activity declines; at this point it is necessary to increase the reaction temperature to compensate for this loss in activity. If the temperature of the subsequent beds is deliberately reduced, then how can the conversion rate in those beds be maintained? A very important function of the cold hydrogen in each bed layer is to lower the temperature when the bed layer overheats. Although the valve position range of 0–20% is the same as that of 20–40%, the effect achieved by the latter is definitely not as good as that of the former
I think this method is not feasible, because the hydrogen-to-oil ratio at the end of the catalyst’s life is very important; by that point the catalyst has already begun to coking. To prevent further coking, it is necessary to maintain a certain hydrogen-to-oil ratio. As for the bed temperature, measures can be taken to increase it, such as raising the temperature of the heater or reducing the amount of cold hydrogen used. If necessary, the feed rate can also be reduced in order to raise the reaction temperature
It can be adjusted slowly! The temperature at the inlet can be adjusted through the furnace outlet; the method you mentioned is not easy to implement. Additionally, reducing the amount of circulating hydrogen at the inlet means reducing the hydrogen-to-oil ratio!
1. During normal production, the opening degree of the cold hydrogen control valve is 60%; I think it can be increased slightly toward the end of production, but not too much, to avoid difficulties in handling situations of excessive temperature rise! 2. An increase in the reactor inlet temperature inevitably generates more heat. Hydrogen carries this heat into the cracking reactor; an increased amount of cold hydrogen means a higher hydrogen-to-oil ratio in the cracking reactor, which in turn results in more heat generation. This leads to a cumulative heat effect that is unfavorable for production.
I agree with the view from the 4th floor. It is necessary to calculate the hydrogen-to-oil ratio first; if this ratio is lower than the designed value, the coking rate of the upper catalyst increases and the pressure difference across the bed rises.
Your consciousness understands that what’s intended is to make use of the catalyst located in front of the reactor; it’s not necessary to reduce the circulation rate – in any case, fuel should be increased, and as a result the temperature downstream as well as the temperature for heat exchange will decrease.
A change in one aspect can have an impact on the whole system; it cannot be considered in isolation. Even if adjustments are made, they need to be done slowly, otherwise the consequences you might expect will occur – such as excessive temperature rises and substandard products