# Why so much o2 left after So2 to so3 conversion

• Roy art
In summary, it seems that there is something (perhaps moisture) interfering with the conversion of so2 to so3. The so2 % & o2 % entering the first bed is mentioned above. The conversation of so3 happens in each bed. Typical adiabatic conversion. We have done analysis of so2 & o2 in each bed outlet. Found so2 % is gradually decreasing as the conversion happens. At the outlet of 4th bed the so2 % is .056% & o2 % is 10 %.Seems like something else is happening to the SO2, other than reaction with oxygen.What else could you have in the system?Either you have moisture in your gas/reactor and the SO3 is

#### Roy art

I've 12% of so2 & 12% of o2 (volume %)
This is what entering the v2o5 catalyst converter. After the last bed 4th bed we have only 560 ppm of so 2 , I.e 0.056% of so2 , but 10 % of o2 still remaining. If the equation says half mole of 02 required for 1 mole so2 . At least 6% of o2 must have consumed for 12% of so2.

First, what's the composition of the rest of the feed? Second, what are you taking off as product? Third, what methods are you using for the O2 and SO2 assays?

Bystander said:
First, what's the composition of the rest of the feed? Second, what are you taking off as product? Third, what methods are you using for the O2 and SO2 assays?
Sir, a volume of gas 150knm3 contains 12% so2 , 12% of o2 & remaining nitrogen. This enters the catalytic converter has 4 beds. Catalyst is v2o5. The so2 % & o2 % entering the first bed is mentioned above. The conversation of so3 happens in each bed. Typical adiabatic conversion. We have done analysis of so2 & o2 in each bed outlet. Found so2 % is gradually decreasing as the conversion happens. At the outlet of 4th bed the so2 % is .056% & o2 % is 10 %.

Roy art said:
Sir, a volume of gas 150knm3 contains 12% so2 , 12% of o2 & remaining nitrogen. This enters the catalytic converter has 4 beds. Catalyst is v2o5. The so2 % & o2 % entering the first bed is mentioned above. The conversation of so3 happens in each bed. Typical adiabatic conversion. We have done analysis of so2 & o2 in each bed outlet. Found so2 % is gradually decreasing as the conversion happens. At the outlet of 4th bed the so2 % is .056% & o2 % is 10 %.
Bystander said:
First, what's the composition of the rest of the feed? Second, what are you taking off as product? Third, what methods are you using for the O2 and SO2 assays?
Bystander said:
First, what's the composition of the rest of the feed? Second, what are you taking off as product? Third, what methods are you using for the O2 and SO2 assays?
If 12 % of so2 completely converts into so3 it requires atleast 6%of o2. Almost 11.5% of so2 is converted into so3. But y still 4th bed outlet has 10% OF O2 is remaining.

No water getting into the feed stream?

Bystander said:
No water getting into the feed stream?
No not at all

Bystander said:
No water getting into the feed stream?
Nowhere no oxygen & water is entering the stream

Process temperature? How much V2O5 in the catalyst beds?

Roy art said:
I've 12% of so2 & 12% of o2 (volume %)
This is what entering the v2o5 catalyst converter. After the last bed 4th bed we have only 560 ppm of so 2 , I.e 0.056% of so2 , but 10 % of o2 still remaining. If the equation says half mole of 02 required for 1 mole so2 . At least 6% of o2 must have consumed for 12% of so2.

Seems like something else is happening to the SO2, other than reaction with oxygen.

What else could you have in the system?

Either you have moisture in your gas/reactor and the SO3 is turning into H2SO4, or you have a leak and your gas is leaving. Either way, willing to bet your total flow IN is not equal to the total theoretical flow OUT. You're measuring everything in %s, which may not be comparable to initial and final conditions. Have to do stoichiometric material balances though, since mass/moles in does not equal out when it comes to reactions.

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## 1. Why is there so much O2 left after the SO2 to SO3 conversion?

The SO2 to SO3 conversion is a chemical reaction that involves the oxidation of sulfur dioxide (SO2) to sulfur trioxide (SO3). This reaction is highly exothermic, meaning it releases a large amount of heat. As a result, the reaction is typically carried out at high temperatures to increase the rate of reaction. At these high temperatures, the oxygen molecules in the air react with the SO2 to produce SO3, but there is often excess oxygen left over because it is not completely consumed in the reaction.

## 2. Is the excess O2 left over after the SO2 to SO3 conversion harmful?

No, the excess O2 left over after the SO2 to SO3 conversion is not harmful. In fact, it is necessary for the reaction to occur. Without the excess oxygen, the reaction would not be able to proceed at a fast enough rate, and the conversion of SO2 to SO3 would not be as efficient.

## 3. Can the excess O2 be reused in the reaction or in other processes?

Yes, the excess O2 can be reused in the reaction or in other processes. In industrial settings, the excess oxygen can be recycled and used in other chemical reactions or processes, reducing the need for new oxygen to be produced. This can save time, energy, and resources.

## 4. What are the potential environmental impacts of the excess O2 left over after the SO2 to SO3 conversion?

The excess O2 left over after the SO2 to SO3 conversion does not have any significant environmental impacts. It is a natural byproduct of the reaction and is not harmful to the environment. However, the SO3 produced in the reaction can contribute to acid rain if not properly treated before release into the atmosphere.

## 5. How can the amount of excess O2 in the SO2 to SO3 conversion be controlled?

The amount of excess O2 in the SO2 to SO3 conversion can be controlled by adjusting the reaction conditions, such as temperature, pressure, and reactant concentrations. By carefully controlling these factors, the reaction can be optimized to produce the desired amount of SO3 while minimizing the amount of excess O2 left over.