Cane Sugar Refining - Purolite

Cane Sugar Refining with Ion Exchange Resins
Liquid Invert
22
Inversion (%)
Sucrose Inversion
The hydrolysis of sucrose, a disaccharide, to form invert sugar produces an equimolar
mixture of fructose and glucose, two monosaccharides as follows:
Sucrose Fructose Glucose
H+
C 12 H 22 O 11 + H 2 O C 6 H 12 O 6 + C 6 H 12 O 6
Sucrose inversion can be accomplished in a homogeneous fashion by bulk addition of
acid to the syrup with addition of base for neutralization at the completion of the
reaction. However, this produces an additional amount of ash which may exceed the
liquid invert specifications and possibly create significant amounts of HMF (Hydroxymethyl-furfural)
which is associated with color formation. Heterogeneous inversion of
sucrose can be accomplished using a strong acid cation resin (H+ form) such as Purolite
CT124SH and neutralization of the acids produced from the existing ash in the syrup
with a weak base anion resin, resulting in color and ash removal.
The variation of 65° Brix sucrose inversion as a function of temperature and flow
rate (residence time) are shown below.
Sucrose Inversion Using Purolite C124SH and 65 Brix Syrup
90
80
70
60
50
40
30
20
10
0
40°C
35°C
30°C
25°C
1 2 3
Flow Rate (BV/hr)
4 5 6
HMF formation
HMF is an invert sugar dehydration degradation reaction product which must be
minimized in order to avoid color formation. For a given syrup, the formation of HMF,
like sucrose inversion itself, is controlled primarily by a combination of the temperature
and flow rate. As a result, it is advisable to limit the temperature of inversion to 40-45°C
in order to minimize HMF production.