6 replies to this topic

[SIVAMOORTHY]

Hello, 

 

         Can anyone suggest me any method to removal of VOC from gas stream with High volume (10000 CFM) and low concentration (usually less than 50 ppm). 

[colt16]

What do you mean by removal?

Are you considering thermal destruction? If yes, you could consider a thermal oxidizer. I can only infer that you are asking this from the viewpoint of environmental regulations.

[MrShorty]

My mentor used to hate when I would ask these kinds of "how do I..." questions. He would tell me to study the problem and come up with a possible solution, then he could critique that solution. I recommend this same approach to you. What VOC removal processes/operations are you familiar with? What are the pros and cons for each approach applied to the specific gas stream and VOC(s) that you are considering? Which operation/process would you choose based on that analysis?

 

As with your H2S removal question from last week, you have not provided any details about your gas stream or your VOC(s). I suggest that you provide some detail about your system, propose a removal solution and explain why you chose that and what your concerns are. Then someone here who is familiar with that removal process/operation will be in a position to critique your choice.

[SIVAMOORTHY]

What do you mean by removal?

Are you considering thermal destruction? If yes, you could consider a thermal oxidizer. I can only infer that you are asking this from the viewpoint of environmental regulations.

yes.. destruction only. 

[SIVAMOORTHY]

My mentor used to hate when I would ask these kinds of "how do I..." questions. He would tell me to study the problem and come up with a possible solution, then he could critique that solution. I recommend this same approach to you. What VOC removal processes/operations are you familiar with? What are the pros and cons for each approach applied to the specific gas stream and VOC(s) that you are considering? Which operation/process would you choose based on that analysis?

 

As with your H2S removal question from last week, you have not provided any details about your gas stream or your VOC(s). I suggest that you provide some detail about your system, propose a removal solution and explain why you chose that and what your concerns are. Then someone here who is familiar with that removal process/operation will be in a position to critique your choice.

Dear Mr Shorty,

 

                       My problem is to remove VOCs from gas stream coming from paint booth. Paint booth gas stream having very less amount of pollutant (This can be applicable for pharmaceutical industries also), which is also hazardous to environment. Actually, we can divide the gas stream into four categories based on volume and concentration. 1) High volume, High concentration 2) High Volume, Low concentration 3) Low volume, High concentration 4) Low volume, Low concentration.

 

Removal methods for the above categories

 

1) High volume, High concentration:  Water scrubbing, stripping, thermal oxidizer or catalytic oxidizer

 

4) Low volume, Low concentration:  Water scrubbing, stripping, thermal oxidizer or catalytic oxidizer

 

3) Low volume, High concentration: Directly, we can go for thermal oxidizer or catalytic oxidizer (Since it has high concentration)

 

 

The difficult thing here is case 2) High volume with Low concentration

 

Suppose if i apply water scrubbing method for this case. The removal efficiency will be low and it requires large amount of water

Suppose if i go for destruction directly (Thermal oxidation or catalytic oxidation), It requires more and more energy. So, this method is also not feasible.

 

One more method : Rotary Concentrator, this method first concentrate the VOC and we can destruct using thermal oxidizer. I have given working principle of this method below.

 

ROTARY CONCENTRATORS

 

A rotary zeolite or carbon concentrator, followed by a thermal oxidizer, can be a cost- effective way to control the high-volume, but very dilute solvent concentration, air emissions from large paint spray booths. The concentrator reduces the air volume by a factor of 10 in order to minimize the operating cost of the thermal oxidizer following it. The paint booth exhaust solvent emissions are first adsorbed onto a honeycomb wheel impregnated with a hydrophobic zeolite ad-sorbent. The wheel continuously rotates and the adsorbed solvents are desorbed by a very small volume of hot air in a separate desorption zone of the rotor before the wheel is saturated by the adsorbed solvents. The small volume of hot air with the concentrated solvent air emissions is then introduced into a small thermal oxidizer for final destruction of the VOCs. This type of system is used where there are mixed paint solvents in the paint spray booth exhaust that cannot be recovered and reused. A typical application of a rotary zeolite concentrator plus thermal oxidizer system would be where the mixed paint solvent concentration is less than 100 ppmv and the paint spray booth exhaust air volume is over 15,000 cfm.

 

Disadvantage:

 

A complication associated with adsorbent wheels is that there can be leakage of process gas into the regeneration section and of regeneration gas into the adsorption section. This cross-contamination leads to practical removals which are lower than can normally be achieved in fixed bed TSA processes. In addition, the mass transfer rate per unit length of bed traversed is not as high as that in packed bed of particles.

 

 Source : http://www.separatio...n/AD_Chp03e.htm

 

So, Please can you go through it, suggest me any idea to overcome this problem, 

or Suggest me any other method for this case.

[MrShorty]

As with the other question, this is beyond my personal expertise. However, it seems fairly well understood by those who specialize in it.

 

I put "adsorption wheel paint booth solvent removal" into my favorite internet search engine and found many results.

https://www.fmanet.o...s-concentrators

A publication from a Robert Kenson: https://www.scienced...026057600804444

Another paper from Kenson: http://infohouse.p2r...ef/28/27435.pdf

 

Those are just a few of the results I obtained. There were many pages that seemed potentially helpful. See what those have to say, while waiting for someone here who is familiar with paint booths.

[SIVAMOORTHY]

As with the other question, this is beyond my personal expertise. However, it seems fairly well understood by those who specialize in it.

 

I put "adsorption wheel paint booth solvent removal" into my favorite internet search engine and found many results.

https://www.fmanet.o...s-concentrators

A publication from a Robert Kenson: https://www.scienced...026057600804444

Another paper from Kenson: http://infohouse.p2r...ef/28/27435.pdf

 

Those are just a few of the results I obtained. There were many pages that seemed potentially helpful. See what those have to say, while waiting for someone here who is familiar with paint booths.

Thank you much