CHLORINATION OF POWDERS BY ADSORPTION

[jaininder]

Dear collegues,

I'am a researcher based in Kenya(Africa) and I'am trying to find an effective method to produce locally the following chemicals that will be used to prevent water bourne diseases.
The water treatment chemicals are currently imported and are unaffordable to the general population who are very poor.
I'am researching on a project that will help these people attain good health thru' community based groups.
The chemicals required to manufacture are :

1) Calcium hypochlorite - 65% available chlorine
(Raw material to be used is Calcium hydroxide/slaked lime, Ca(OH)2)

2) Chlorinated sodium triphosphate - 7% available chlorine
(Raw material to be used is sodium triphosphate Na3PO4)

QUESTION :
What is the plant design and layout that is ideal for the chlorination of the above POWDERS using chlorine gas by the process of Adsorption?
(small scale plant of capacity 1MT/day)
This relates to adsorption columns and flow of powders
An elementary text book had the following process :
" The manufacture is carried out in towers designed to ensure that the upflowing chlorine mixes intimately with the finely powdered calcium hydroxide.
The reaction is exothermic and cooling below 35'C is necessary to prevent the formation of Calcium chlorate"

I would appreciate it if I could recieve help and guidance on this. Thankyou.
jaininder

 

[Montemayor]

jaininder (Chemical):

As Chemical Engineers we know that "adsorption" is a unit operation in which impurities are removed from a parent stream by concentration on the surface of a solid material. The forces which hold certain molecules at the solid surface is not thoroughly understood and are usually defined as "van der waal forces".

Calcium Hypochlorite [Ca(OCl)2]is described as being made in several ways. One way is to chlorinate calcium hydroxide by passing chlorine countercurrently through a rotating steel cylinder with inner lifting blades which shower the solid in the path of the gas. Here, what is taking place is a chemical reaction to produce the hyprochlorite - not a unit operation like "adsorption". Is this what you are meaning to say?

According to my 2nd ed. of Shreve's "Chemical Process Industries" (p.310), a stable calcium hypochlorite is also produced by the refrigerated formation of the salt, Ca(OCl)2*NaOCl*NaCl*12H2O. Perhaps you mean to say aBsorption instead of aDsorption. Is this correct? What is confusing is that aDsorption does not involve a chemical reaction, since it is a unit operation.


Art Montemayor
Spring, TX