How can one determine whether condensation can occur when using condensate water for cooling at 42?

Is 42℃ the temperature after the mixture has been cooled? Based on the data, only water has condensed; the amount of condensation for the other components is very small. These figures are not scientific

42℃ is the set temperature for the condensate produced after the mixing of steam is condensed

I would like to ask experts: why is benzene still mostly in the gas phase and not condensed at a temperature of 42 degrees Celsius? The density of benzene in the gas phase can be calculated using its saturated vapor pressure at 42°C, but it’s not clear how to determine the amount of gas produced ? Could the expert give some guidance? Thank you!

Set temperature? Was this temperature actually reached? If you set it to 42 degrees, it’s normal for the temperature to exceed 100 degrees if the cooling capacity is insufficient

Where did the data in the table in your topic come from? Aren’t they not test values but just numbers you made up on your own? Using fake numbers without relying on reliable data analysis is pure nonsense. Trying to determine mass flow rate by first checking density based on temperature and then calculating air volume is an absurd approach; there are many uncertainties involved, and it’s impossible to know where the mistakes lie. Given that a=b>0, prove that 1=2? 3) ab = bb: In step 2, multiply both sides of the “=” sign by b. 4) ab – aa = bb – aa: In step 3, subtract aa from both sides of the “=” sign. 5) a(b – a) = (b + a)(b – a): In step 4, factor out common factors from both sides. 6) a = b + a: In step 5, divide both sides of the “=” sign by (b – a). 7) a = 2a: This is obtained by substituting in steps 2 and 6. 8) a = 2a: This is achieved by adding like terms in step 7. 9) 1 = 2: In step 8, divide both sides of the “=” sign by a”

In fact, condensation does occur; when the temperature drops to a certain level, the partial pressures (concentrations) of each component remain constant at a given total pressure. The key issue is that it wasn’t completely captured, so the data you measured is incorrect. Remember: Condensation is essential, and capture is key. I’ll design a condensation collection system for you to perfectly solve the problem.

This post was last edited by Hansonwen on 2018-7-19 at 15:25. As there is an increasing emphasis on controlling VOC emissions in terms of environmental protection, GB31571-2015 sets the allowable emission level for benzene compounds at 4 mg/m3, while Sinopec requires this level to be 2 mg/m3. It is strictly prohibited to discharge such non-condensable gases directly. The relationship between the saturated vapor pressure of benzene compounds and temperature is shown in Table 1; complete condensation and separation of these compounds require a temperature of at least -75°C, and this is also the commonly used condensation process – it is not possible to achieve condensation merely through the use of circulating water alone. According to your current replacement process, the pressure of the mixture after replacement is approximately 120 kPa. The temperature of the mixture entering the cooler is 20–30°C lower than that of the steam, i.e., around 120°C. With the current mass flow rate into the cooler, the theoretically calculated vapor fraction is 0.0334; accordingly, the amount of hydrochloric acid in the vapor is about 51.7 kg/h, benzene and chlorobenzene together amount to about 40 kg/h, and water amounts to about 2.8 kg/h. These values are fairly close to those obtained from your measurements. To truly separate benzene, it is necessary to condense the regenerated gas at low temperatures (-75°C). To prevent freezing blockages, it is possible to first cool most of the water with water, using a refrigeration unit, and such a unit should be equipped with anti-icing facilities.

This post was last edited by Hansonwen on 2018-7-19 at 15:24. Brother, with liquid ammonia at -30°C that we used in the past to cool this regenerated gas, benzene couldn’t be completely condensed; so how much less can it be condensed with water cooling to +42°C? Check the saturated vapor pressure of benzene derivatives... At 42°C, the saturated vapor pressure of benzene is 26.81 kPaA. With a total pressure of 120 kPaA, the molar fraction in the gas phase is 0.223417, which corresponds to a concentration of 777.969 g/m3. If the actual gas flow rate at the site is around 50 m3/h, then the flow rate of benzene derivatives is approximately 40 kg/h, which is quite consistent with the actual conditions on site

Use the Antoine equation to calculate the saturated vapor pressure of benzene and see if it meets the emission standards; I estimate it will be well above those standards. In other words, it’s not possible to obtain your analyte solely through condensation. You need to change the process

I would like to ask why, after passing through the condenser, the mass flow rate according to the original data hardly decreases, while in your case it drops by half. In your data, the water level has almost dropped to zero, and the decline in benzene levels does not correspond at all to that of water