[Daily Question] 20161215 – Explanation of terms related to catalytic cracking: Catalyst circulation rate (easy question)……
Thread Content
To enhance technical exchanges among users and liven up the atmosphere in the catalytic coking reforming community, this announcement is made: participating earns 4 points of wealth, while correct answers grant 10 points of wealth! ! ! It will be announced in two days that **no more scoring will take place. (Catalytic cracking term explanation) Catalyst circulation rate: The amount of catalyst that flows from the regenerator into the reactor per hour is called the catalyst circulation rate. ==============================
Baidu couldn’t find it; I’ll just wait **
A control parameter in the petroleum catalytic cracking process, representing the ratio of catalyst circulation volume to total feed volume.
Catalyst circulation rate = Carbon burning rate (kg/h) / { – } (kg/h)
Several methods for calculating the catalyst circulation rate: 1. Thermal balance method; 2. Carbon balance method. Since the carbon content in regenerated catalysts and fresh catalysts differs not significantly, it is essential that the carbon analysis be accurate. Even minor errors or poor sample representation can lead to substantial fluctuations in the calculation results. The calculation method is as follows: Catalyst circulation rate = Carbon consumption rate (kg/h) / … (kg/h). The method for calculating the carbon consumption rate is as follows: ① Calculate the carbon consumption rate using the nitrogen balance principle: Regenerated air volume × 79% = Flue gas volume × (1 – CO2% – CO% – O2%), in cubic meters per hour. Thus, the flue gas volume = (Regenerated air volume × 79%) / (1 – CO2% – CO% – O2%), in cubic meters per hour. The carbon consumption rate = 12/22.4 × Flue gas volume × (CO2% + CO%), in kg/h. Here, 12 is the atomic weight of carbon, and 22.4 (cubic meters) is the volume of 1 mole of flue gas under standard conditions. Since the combustion of coke produces CO and CO2, the total number of CO and CO2 molecules in the flue gas is equal to the number of combustible carbon molecules in the coke (assuming no burning oil is used). ②It can be estimated from the total main air volume entering the regenerator. Based on the total main air volume A (in m3/h) entering the regenerator, the coke production rate (in kg/h) can be calculated directly; according to empirical data, 10 m3 of main air is required to burn 1 kilogram of coke. ∴ Coke production = A/10. A = total main air flow rate (in m3/h), determined from the reading of the flow meter at the outlet of the main fan, after correction for the outlet temperature and pressure relative to the design values. A = Q_meter × (m3/h), where Q_meter is the reading from either the flow meter at the inlet of the main fan or the flow meter at its outlet. Tset is the design temperature in K ； T_real, the actual temperature in K ； P_actual, refers to the actual pressure ； Let P be the design pressure; the H/C ratio is calculated as H/C = CO/CO2. The carbonization rate is given by the coke production divided by (1/H/C), in kg/h. 3. The slide valve pressure drop method: The circulation rate G (in tons per hour) can be calculated using the formula ΔP = 7.65×10-7×G²/(ρA²). In the formula, P represents the pressure drop across the slide valve in kg/cm2; ρ is the density of the material in the inclined tube above the slide valve, in kg/m3; A is the flow area of the slide valve, in m2
It refers to the amount of catalyst that circulates between the regenerator and the reactor. Catalyst circulation rate = Carbon burning rate (kg/h) / { – }
Flow rate of catalyst per hour through the reflow valve
The circulation rate is the flow rate of the catalyst between the two vessels, expressed in tons per hour
The amount of catalyst that flows from the regenerator into the reactor per hour is called the catalyst circulation rate.
Ratio of catalyst dosage entering the reactor per hour to the amount of feedstock