[acidwiz]

Is it possilble to separate organics from calcium chloride solution. Please  give some comments on this query..

[eugenedakin]

Hello acidwiz,

It depends on the solution.  If you have a hydrophobic (oil) mixture with calcium chloride (water based) then yes, the two can be easily mechanically seperated (via centrifuge, etc).

If the organics have a lower boiling point than water, then simple distillation can be used for seperation.

When you have a large molecule (such as a wax or asphaltene) then heating (to about 70 Celsius - rough estimate) and then let the solution sit - this should provide enough energy to melt the wax/asphaltene and provide the water to gather and settle on the bottom of the container. (Due to differences in Density)

There are many other ways of variations of seperation, could you provide me with a more specific example the organic material (and possibly the volume) that you are looking at seperating?

I wish you well,

Eugene

[acidwiz]

Dear Eugene,

Thanks for your reply.
To be specific, i would like to separate glycerine & dimer from CaCl₂ solution. For your clear understanding, i give the composition of solution.

--------------------------------------------------------
components                  Wt%
-------------------------------------------------------
dimer                            negligible
Glycerine                       0.4
Other organics              0.2
Water                          88.6
Ca(OH)₂                         1.1
CaCl₂                              9.3
Inorganic Solids              0.5
-----------------------------------------------------

i am thinking of placing an evaporator to separate [water + glycerine mixture] and CaCl₂ solution (concentrated). After this step, i have to separate Glycerine and water. Will you suggest me a idea?

with kind regards,
acidwiz

[eugenedakin]

hello acidwiz,

According to my reference information, here is what I have for boiling points:

--------------------------------------------------------
components                  Wt%         BP (C)
-------------------------------------------------------
dimer                            negligible
Glycerine                       0.4           290
Other organics              0.2
Water                          88.6          100
Ca(OH)2                         1.1
CaCl2                              9.3         772
Inorganic Solids              0.5
-----------------------------------------------------

I am not sure what the boiling points are for the other chemicals, and the first fraction that would be removed (in a Glycerine/water/CaCl2 system) would be water, then Glycerine, and the solids would be CaCl2.

You can try this in the laboratory:  Take the blend, and spin it in a centrifuge.  Determine what the components are and make a decision based on your results.  Next, take a laboratory sized distillation column and perform a test and base the decision on your results.

Each blend has its own unique properties and seperation problems.  This will give you some good 'starting-data'.

I hope this helps,

Eugene

[acidwiz]

Dear Eugene,

Thank you very much for your reply.

Is there any flocculant which coagulates CaCl₂ and Ca(OH)₂ completely.If a flocculant effectively works like mentioned above, i can install a clarifier to separate [ CaCl₂ + Ca(OH)₂ ] at bottom. The overflow liquid which contains [water + organics] can be separated by distillation.

please check the image for your understanding..

please give your views on this.


with kind regards
acidwiz

[eugenedakin]

Hi acidwiz,

Well, I have some good news and some bad news:  There are probably about 100 flocculants which coagulate Calcium Chloride and Calcium hydroxide and about 1500 products that are broad-spectrum flocculants which may-or may not work.

This is highly dependant on factors such as: 1) pH, 2) organic concentrations, 3) impurities, 4) solids, and other factors.

As a general rule of thumb, an inexpensive flocculant may be sodium bicarbonate (again, depending on the pH).  This would form a Calcium Carbonate precipitate which would fall to the bottom of a settling tank.  Although sodium bicarbonate is inexpensive, it is inefficient, and may cause unwanted side-effects.  Organic polymers may be better in selective situations.

Try a small sample in a beaker, and determine if this does what you want it to do.  There are MANY other options, of which, I could easily write a book just on this topic.  For most purposes, I imagine that some chemical laboratory testing would be the best way to eliminate products which do not work.

I hope this helps, and feel free to ask more questions.

Sincerely,

Eugene

[acidwiz]

Dear Eugene,

Please give me some more names of flocculants and if possible conditions to be maintained to achieve effective result.

thanks for your reply,

with kind regards,
acidwiz

[eugenedakin]

Hi acidwiz,

Since there are so many variations of flocculants, I 'googled' flocculants and clicked on the first company that came up http://www.accepta.com/Water_Treatment_Chemicals/flocculants.asp.  There are essentially 4 different classes of water treatment flocculants: organic-anionic, organic-cationic, inorganic-cationic and inorganic-anionic.  Each manufacturer will have their own set of conditions and optimum operating ranges for each chemical. 

The best that I can suggest is to talk with your suppliers, and they will be able to provide you with chemicals for your chemical-laboratory to try-out.  Really, you need to perform some tests.  That is the best way.  I have tested many chemicals and fliuds need to be fresh, at the correct temperature and you need to develop a method of chemical injection.  Again, your supplier should be able to help you out with this.  I have consulted on this type of operation many times, and I cannot stress enough that you need to perform field tests.

This becomes even more complicated if the concentration of hydrocarbons increases above 1%.  Usually, a demulsifier and a flocculant are needed.

I wish you the best.

Sincerely,

Eugene

[technologist]

If U can specify your objective probably I can help U?
I mean do U want to recover organics OR Inorganics OR its just water treatment for ETP.

[engwyk]

there are many flocculants such as aluminum ( Al2(SO4)3.18H2O ) with concentration in the clarification process 20~30 ppm.
you can also use soda ash  ( Na2CO3 ) to remove calcium chloride as follows:
       
                  CaCl2 + Na2CO3 ----> CaCO3 (Prec.) + 2 NaCl