Affination Process in Sugar Refinery with Material balance Calculation

In this article discussed about factors involved in affination process of standalone refinery with material balance calculation.

Material Balance of Affination Process in Sugar Refinery

What is Affination Process

The affination process is a first step in the sugar refinery process when high colored raw sugar taken as a input material. This process can be defined as washing and consists of removing the adhering film of molasses from the surface of the raw sugar crystal which is input raw material of sugar refinery.

In affination process involves mingling the input high-colored raw sugar with affination liquor (Which is obtained in same process after centrifuged) and purging the mixture in the centrifugal machine with hot water washing after the syrup has been spin off. After this process obtained two products named as affinated sugar and affination liquior.

The Affinated raw sugar is directly taken to raw sugar melter and some required quantity of affinated liquor used for same process and remaining quantity sent to recovery house for massecuite boiling.

Operating Condition in Affination :

Temperature of mingling affinated liquor

The purpose of the affination is to remove the sticky high colored molasses film. Hot mingling is best practice to reduce the viscosity and maintained around 70 to 75^oC and magma temperature will be around 45 ^oC.

Parameters

Affination liquor brix 72 to 74%
Affination liquor purity 75 to 85%
Affination liquor temperature 70 to 75 ^oC
Affination magma brix 90 to 92%
Wash water temperature 85 to 90 ^oC
Quantity of wash water Depends upon required affination brix and colour of raw sugar.

Examples of Solids and Purity Balance for affination of raw sugar in refined sugar process

Example – 1

Input parameters

S.NO	Description	Values	UOM
1	Raw Suagr Quantity	100	T
2	Raw sugar Brix	99.7	%
3	Raw Sugar Purity	98.8	%
4	Affinated liquor Brix	75	%
5	Affinated liquor Purity	85	%
6	Magma Brix	90	%
7	Affinated raw sugar brix	99.7	%
8	Affinated raw sugar purity	99.5	%

Calculation:

Quantity of affination liquor for magma preparation – 64.67 T

Hint :

$\frac{( \text{Qty of raw sugar} \times \text{Raw sugar brix} ) - ( \text{Qty of raw sugar} \times \text{Magma brix} )}{ \text{Brix of magma} - \text{Brix of affination liquor} }$

(((Quantity of raw sugar X raw sugar brix) – ( Qty of raw sugar X magma brix))/ (Brix of magma – Brix of affination liquor)

Magma Quantity = 100 + 64.67 = 164.67 T

Purity of Magma = 93.38%

Hint: $frac{(Purity of raw sugar times Qty of raw sugar ) - (Purity of affi. liquor times Qty of affi. liquor )}{ Qty of magama}$

Affi. Raw sugar	99.5			8.38
		Magma	93.38
Affi. Liquor	85			6.12
				14.50

S.NO	Description	Quantity	Solids	UOM
1	Affination Magma	164.7	148.2	T
2	Affinated Raw sugar	85.91	85.7	T
3	Affinated liquor	83.39	62.5	T
4	Wash water	4.64	0	T
5	Affinated liquor for magma preparation	64.7	48.5	T
6	Affinated liquor send to recovery house	18.73	14.04	T

Example – 2

Input parameters

S.NO	Description	Values	UOM
1	Raw Sugar Quantity	100	T
2	Raw sugar Brix	99.7	%
3	Raw Sugar Purity	98.8	%
4	Affinated liquor Brix	75	%
5	Affinated liquor Purity	80	%
6	Magma Brix	92	%
7	Affinated raw sugar brix	99.7	%
8	Affinated raw sugar purity	99.5	%

Calculation:

Quantity of affination liquor for magma preparation – 45.3 T

Hint :

$\frac{( \text{Qty of raw sugar} \times \text{Raw sugar brix} ) - ( \text{Qty of raw sugar} \times \text{Magma brix} )}{ \text{Brix of magma} - \text{Brix of affination liquor} }$

(((Quantity of raw sugar X raw sugar brix) – ( Qty of raw sugar X magma brix))/ (Brix of magma – Brix of affination liquor)

Magma Quantity = 100 + 45.3 = 145.3 T

Purity of Magma = 92.24%

Hint: $\frac{ (\text{Purity of raw sugar} \times \text{Qty of raw sugar}) - (\text{Purity of affi. liquor} \times \text{Qty of affi. liquor}) }{ \text{Qty of magama} }$

Affi. Raw sugar	99.5			12.94
		Magma	92.94
Affi. Liquor	80			6.56
				19.50

S.NO	Description	Quantity	Solids	UOM
1	Affination Magma	145.3	133.671	T
2	Affinated Raw sugar	88.96	88.7	T
3	Affinated liquor	59.96	45.0	T
4	Wash water	3.63		T
5	Affinated liquor for magma preparation	45.3	33.9706	T
6	Affinated liquor was sent to recovery house	14.67	11.00	T

Conclusion : From the above examples, The quantity of solids sent to recovery house will be reduced while maintaining the proper brix of magma and control the purity of affination liquor as much as possible.

If the quantity of solids sent to the recovery house from affination process is increased then massecuite % and final molasses percentage is also increased.

Colour reduction in this process will be obtained around 50 to 60% on input raw sugar color. Sometimes more percent reduction is required for input raw sugar colour having higher side. For this we go for more washing in centrifugal section and at the same time, losses also will be increased.

For online calculator of the Material Balance of Affination Process purpose please go through the below link

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