Phosphoric Acid (H3 PO4 ) Dosing in Sugar Industry | Online Calculator

Role of Phosphoric Acid (H3 PO4 ) Dosing in Sugar Process with Online Calculator

Phosphoric acid occurs in the cane juice as both soluble phosphates and in combination as protein in the cell material. But both phosphates are not participate in reaction, only the soluble phosphates take part in the reaction of defecation.

If the phosphate content is less than 200 to 250 mg/P₂O₅  in juice, it is beneficial to make additions of inorganic phosphate to raise the juice phosphate level to above 250-300 mg/kg.

The phosphoric acid added to the juice precipitates part of the colloids and coloring matter that it contains. The precipitate formed with lime is mainly Tricalcium Phosphate.

The benefits of maintaining an optimum level of phosphate in juice are as:

a) Greater colloidal elimination

b) Less calcium in clear juice;

c) Faster mud floc formation, with more rapid settling;

d) Better clarification with lighter colored clarified juice.

Disadvantages of too much phosphate addition can be higher chemical costs, higher lime consumption and higher mud volume (and hence higher filter mud sugar loss).

Action Due to phosphoric Acid Addition:

The major chemical reaction is that of the Ca⁺⁺ cation with the phosphate ion to form phosphate Intermediates and to precipitate tricalcium phosphate Ca ₃(PO₄)_2.

We have to know the activity of calcium and phosphate ions and how the phosphate components behave in the adsorption and absorption of organic colloids and other non-sugars.

It is after reacting with the available Ca⁺⁺ and then  further with lime is one of the major reaction responsible for juice clarification. In the beginning the Ca⁺⁺ ion reacts with HPO^—₄ to form CaHPO₄.  This is second order reaction & hence it is fast reaction,

Ca²⁺⁺ + HPO^{– –}₄→ CaHPO₄

Second stage phosphate ion reacts with free Ca ion to form the precipitate of tricalcium phosphate.  This a higher order reaction, hence takes time to complete

3Ca⁺⁺ + 2PO^{– —}₄ → Ca₃ (PO₄)₂      TriCalcium Phosphate

3 Ca (OH) ₂ + 2 H₃ PO₄ ———- Ca₃ (PO₄) ₂ + 6 H₂O

Steps in Calculation for required quantity of Phosphoric acid to add in Raw juice:

Required Data:

a) Crushing Rate ( M ) in T/hr

b) Percentage of mixed juice ( P ) = Take 100%

c) Density of juice ( D )(Generally take 1.06 gm/ml for raw juice)

d) Required phosphoric acid (in P₂O_{5 Content}) dosing in PPM ( R )to raw juice ( To know this analyze P₂O₅ content in mixed juice before addition than we can concluded to  how much dosing required to raw juice).

e) Percentage of Ortho phosphoric acid chemical ( H ) ( i.e Percentage of H₃PO₄ purity in used chemical)

Calculation Part:

Calculate mixed juice quantity (Q ) in Ltrs/hr.

Q = ( M x 1000)/ D

P₂O₅ requirement in ( T ) Kg/hr (1ppm=1 mg/lit)

        T = ( Q x R) / 1000000

Calculate P₂ O₅ % ( Y ) in given chemical H₃PO₄

2 H₃PO₄         →   P₂O₅ + 3H₂O

2(3+31+64)          (2*31+5*16) + (3*2+3*16)

196                             142                       54

i.e 196 parts of H₃PO₄ gives 142 parts P₂0₅)

Y = ( H x 142)/196

H₃PO₄ required quantity in kg/Hr      (T x 100)/Y

  Phosphoric Acid (H3 PO4 ) Online Calculator :

Please click here

Some Related Articles:

Flocculants Used in Sugar Processing | Flocculant Dosing Calculation.

Juice Sulphitation Process | Methods of Sugar Cane Juice Sulphitation.

Concepts of Juice Defecation Process and its Mechanization.

Sugar Industry Related Important Websites | sugar Technology.

Sugar Tech | Sugar Technology related articles .

Sugar Industry Equipment Design and Drawing Online Calculations.

Thumb Rules for Sugar factory Equipment Design Sizing.

Hi friends Thanks for reading. I Hope you liked it.  Give feed back, comments and please share it