How is the circulation rate determined for cyclic operating conditions?
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This post was last edited by yiyuguchen on 2020-8-7 at 17:36. How is the circulation rate determined for cyclic operating conditions? Raw material A → Product B. Assuming that all the unreacted raw material A in the product returns to the raw material inlet and then passes through the reactor again, this would result in an increasing amount of material circulation. Is this idea correct? How is the circulation rate determined in industry?
Assuming a conversion rate of 70% and a total flow rate of 10 t/h, you only need to maintain an input rate of 7 t/h of raw material; the remaining 3 t/h of unreacted raw material is continuously recycled
Then for the remaining 3t cycle, if another 70% reacts, won’t it stop being in a steady state?
Just keep in as much as you take out
70% of the 3 tons that are recycled undergo reaction, and 70% of the new 7 tons also undergo reaction; in the end, there are still 7 tons of product
70% of the 3 tons that are recycled undergo reaction, and 70% of the new 7 tons also undergo reaction; in the end, there are still 7 tons of product
This limits the total flow rate; however, usually when the feed rate remains constant and the circulation rate changes, the total flow rate into the reactor changes as well.
This post was last edited by kingwang81 on 2020-8-11 09:20. The determination of the cycle volume depends on the one-pass conversion rate of the raw materials. If the amount of material fed in is m and the conversion rate is f, then in order to achieve a stable state for the entire cycle, it is necessary to make the amount of product equal to the amount of material fed in. If the amount of material entering the cycle is n, then (m+n)*f = m, and thus the amount circulating can be calculated.
If the calculated amount of circulation is less than the mass of the unreacted reactants, what should be done with that excess amount of reactants?
This situation will not occur as long as there are no inert substances inside; if such substances are present, they need to be removed from the system after the reactor.