Hola: 1)la expresión Volat. relat. = (pres. vapor liv./presion vapor pesado) es válida para mezcla binaria e ideales (coefic. de desviación de la idealidad, fases liq. y fase vapor = 1). Se demuestra fácilmente.
2)La expresión de comparación de volat. relativa con la relación de reflujo, se...
Thanks. Yes, the work is separate C3= from C4=. In general, this mixture is easy to distillate, but I am in searching if there were some reported or no reported cases that they were troublesome in packing columns (random or structured packing), based on the operative condition (pressure), and/or...
Hello. Somebody has experience (good or bad)to recovery monomers, from propylene-butylene recycle stream (from polymerization reactor) by distillation, in packed column?
Right! Antifoam sprays is not a good solution. A suggestion is to premix the relative small antifoam stream with a small part of the treated oil (a recycle), to give a higher rate to the injection stream, allowing a good distribution on the perforated pipe distributor. Spekuljak.
Sometime the pH change allow to diminish or avoid the foam. In my experience, methanol-water in alcaline condition produces foam, but neutralization the liquor (pH 6,9 - 7,1) the foam dissapear. Be carefully with acidification, if the column material are steel or stainless steel, because the...
The foam in distillation. If it is not produced by entraped gases but tensioactive agent (more heavy than methanol and water in this case), there are three ways to figth it, a) antifoam agent, b)a better reboiler design (falling film, recirculation), c)to break the foam by means small live steam...
More, if you increase the operating pressure, you need more energy supply to feed stream to maintain the product streams specs. The simulation is a valuable tool for such a case, because of allow to visualize the influence of the different variables in the process.
zspekul@yahoo.com
We revamped a Removal unit in ammonia plant, wich had severe foam trouble (it was impossible to operate it without antifoam injection). The original column was filled with random ceramic ring, and was revamped with structured packing and proprietary auxiliaries, specific for structured packing...
Increasing the top pressure of a topping, you will obtain a naphta with greater Reid vapor pressure, side product (Kero, G.O.) with lower Ignition and Flash point, and the bottom stream will have lower I.P. Obviously, this will be corrected with more live steam inyection, and more head venting.
A suitable method is ammonia stripped with air, circulating in a close loop, in two columns. One of them is Stripping column, and the other is Absorber column, i.e. with an acid solution (sulfuric, clorhidric, fosforic) to obtain the salt (fertilizer), and avoid to exhaution of ammonia to...
The better solutions are stripping with air or stripping with steam. The best of them depends of the ammonia conc. in water, among other variables, such as:
In case of air stripping, the installation could be made in plastics, but the gaseous effluent must be postreated,with an adsober bed or...
The ceramic packing crushes by differents causes, manly by hydraulic (flooding), by thermal cycling or by chemical attack. If we have more information about the operation of the equipment, perhaps we will have a chance to detect the cause of the problem.
spekuljak@sitingenieria.com
We have abundant and persistent smoke in a absorption-reaction packed column, where is reacted in countercurrent nitric acid (60%) with vapours rich in ammonia. What way is possible to avoid it or abbatement it?
See:
R.N. Watkins, Petroleum Refinery Distillation, Gulf.
W.L. Nelson, Petroleum refinery Engineering, McGraw,
J.Gary & G. Handwerk, Petroleum Refining, Dekker,
N. & E. Lieberman, A Working Guide to Process Equipment, McGraw.
N. Lieberman, Troubleshooting Process Operations, PennWell.
Good luck!
