29 replies to this topic

[process-man]

dear all
I am now bussy designing a semi batch reaction system of XSBR(carboxylated styrene butadiene ruber) with a capacity of 30 tons per day. The emulsion reaction of XSBR (somehow so similar to SBR) is taken place in a semi batch reactor with reaction time of 10 hrs.
I really wonder if anybody can help me in design of such an emusion bach reactor.

[process-man]

for more information , please note the followings:
1-the XSBR semi batch reaction is to be done at 80-70 deg C and Press of 3-2 barg.
2-the reaction is to be mainly accomplished between 1,3 Butadiene and Styrene monomer, adding a minor amount of acrylic acid for further carboxylation of slury. The polymer molecular weight is controlled by TDM (tertiary Dodecyl mercaptane), while the other chemicals like amonium persulfate and sodium luryl sulfate play the role of reaction initiator and emulsifier , respectively.

[breizh]

Hi ,
We can support you but we are not doing your design work .
Hope you understand . let us know the several options you studied , the difficulties and we may be able to comment.
Breizh

[process-man]

Dear breizh
what I need is any guidlines or spread sheet for design of emulsion reactors. The brief of what I myself has already done is mainly confined with the process simulation of XSBR with the aim of Aspen polymer , in which the emulsion reaction kinetics as a defoult is present. The reults of such a calculation is the amount of steam for initial reactor warm up and the amount of cooling water circulation during the reaction period of 10 hrs. moreover I in parallel is to meet the best reaction formulation by an additional 10 kg pilot which is now ready to be brought in oporation.

[breizh]

Hi ,
I've attached a simple flowsheet for reference only .

Breizh

[process-man]

Dear Breizh
thank you for your information, but I was wondering if the you could reply me the followings:
1- what is the type of reaction of PFd, Semi batch, or continous?
2-what about the capcaity of each stream ?
3-at the end of reaction , in case of semibatch, what is the content of unreacted styrene and 1,3 butadiene? How do you remove the unreacted butadiene from latex, I mean simpel flash or any vacuum?
4-idea of reactor size , lengh and diameter.
best regard
Process-man

[breizh]

Hi Process ,
What I can tell you :
Batch process , using 2 reactors ( 1 for polymerisation and 1 for stripping VOC ) , Stripping done under vacuuum .
For VOC , as low as possible .
For reactor the volume is around 30 to 35 m3 , could be bigger .
Agitator high efficiency ,

Breizh

[process-man]

Dear Breizh
good information. anyway could you please tell me also the followings:
-for styrene monomer storage of 10 days (a vessel of let say 100m3), shall I inject any inhibitor to that?
-what is the function of ammonia in your PFD?
best regard

[breizh]

If I remember well , all your monomers are inhibited ( most probably TBC for styrene , HQ for others) but you need to be carefull Styrene can polymerize at the upper part of the tank . BTW I don't know which part of the world you are located but you need to manage properly the temperature of your monomers .
Ammonia is there for Ph adjustment .

Breizh

[process-man]

breizh
the plant is to be located in middle east where the climatic temperature is max 40 deg C. What about the inhibitors impurity when being carried over to reaction mixture which further could result in slury deviation from standard quality?
Really please do your best to give me more information if any?
process-man

[breizh]

Process,
Sorry but I cannot disclose the process. Too much inhibitor could lead to coloration of the latex .
I guess you have a process book to support your query .
Breizh

[breizh]

Process,
For a 30 M3 reactor , the diameter is 3.1 m and the height of the hemispherical part is 0.89 m .

Breizh

[process-man]

Breizh
I am myself experienced highly in extrusion and polymerization of polyolefins and polyesters, in particular PP and PET. I have myself simulated several spheripol (basell) and gas phase (Novolen) reactors of PP and also many calculations and design of Twin Extruders.
But it is my new job on emulsion processes and really need your help. In contrary , should you need any help and assistance from my 15 years experiences of PP and PET upstream and downstream industries, please feel free to ask me!
regarding this project , I really was wondering if you could help me more and more.
the spec of my recent calculation on this mather is as follows:
3 reactors ,each having a capacity of 14 m3. any idea of diameter and lenght??

[breizh]

Hi ,

Consider these data :
10Mt reactor for latex : Diameter : 2.388 m ; length (tangent to tangent ) :2.185 m .

You need to work around to get the best compromise , especially for heat transfer area .

Breizh

[process-man]

Briezh
thank you, I will follow with these data, I will also consider a proper jacket around each 3 reactors for initial warming up and normal cooling.
moreover I will send the products of all 3 reacotors at the end of 10 hrs to a big stirpper in which the unreacted butadiene and styrene will be removed at a vacuum of 200 mmHg A. Is it OK?
could you give me your email address?

[breizh]

For future communication , use Messenger.
Breizh

[process-man]

Briezh
Could you kindly inform me of the followings:
1-I have considered the MOC of all vessels and reactors of XSBR , as well as storage tanks of styrene and BD , all Carbon Steel. Is that OK?
2-for a reactor of 3.2m (Tl-Tl) height and 2.8 m ID , I just have calculated an agitator of 2 trubines (with distance of 1 m) , each having 6 blades. The agitator motor (final calculated) power is 10 kW. Is that OK?

best regard

[breizh]

Hi ,
Avoid CS better to use SS if you can for RM. Reactors must be in SS (316L) or duplex materials upon recipes.
Issues are corrosion (coloration) for RM and ability of latex to stick to the walls (mirror polished). BTW you will have to consider to use HP cleaning in between batches (change over).
For agitator I would advise you to contact the big guys like lightnin or Chemineer . I would advise to use high efficiency impeller from those companies as I would recommend you to add a VSD on your motor to tune the RPM .
Hope this helps
Breizh

[breizh]

Process

For a 10 Mt reactor , HP is 15 KW and RPM 1450 ;
dual aerofoil impeller from lighnin (diameter 1160 mm) ; 4 baffles

Breizh

[process-man]

Breizh
Ok, but my final reactor voume is 18 m3 (15-16 tons) for which I will follow with agitator power of 18kW. Referring to below web site of lightnin , there is no such an impeller you said??
http://www.lightninm...vices/impellers

Do you believe that such a 18 m3 reactor can be fully cooled by CW in jacket?? Do you have any spead sheet or sample for design of heating and cooling jacket?
Is the SS as MOC mandatory for XSBR reactor ??
best regard

[breizh]

Breizh
Ok, but my final reactor voume is 18 m3 (15-16 tons) for which I will follow with agitator power of 18kW. Referring to below web site of lightnin , there is no such an impeller you said??
http://www.lightninm...vices/impellers

Do you believe that such a 18 m3 reactor can be fully cooled by CW in jacket?? Do you have any spead sheet or sample for design of heating and cooling jacket?
Is the SS as MOC mandatory for XSBR reactor ??
best regard

[breizh]

Hi ,
For impeller , consider A310 from lighnin .
Yes SS is mandatory !
For heating up and cooling I don't have excel sheets..

Breizh

[process-man]

Breizh
OK, A310 with 4 blades , but as my reactor diameter is 2.8 m , shall I go with 1160 m or bigger?
moreover , I want to strip unreacted monomers from latex just in the same reactor by vacuum (no additional stripper). Ok??

best regard

[breizh]

Hi Process man ,
Consider this resource :

http://tmec.com/atta...s/27/H-150A.pdf

Breizh

[process-man]

Breizh
thank you very much, I also calculated the vacuum pump for both reactors with below spec.I was wondering if you could give me any advice on power and vacuum amount:
-max vacuum : 100 mmHgA
-power : 35 kW
-vacuum duration : 1 hr