Seasonal chemical sucrose losses in upstream and downstream products at a cane sugar factory*

Measurement of sucrose losses across a cane sugar factory are notoriously difficult to measure directly or indirectly. Six loss trials were conducted at one factory across a Louisiana processing season; per trial, 40 samples were collected across four upstream and downstream unit processes. Sucrose losses were directly measured with gas chromatography using two equations based on (1) an increase in glucose/sucrose ratios on a RDS basis across a process, or a (2) a decrease in sucrose/RDS. When actual losses were <0.5%, eq.(2) did not detect losses due to the experimental error of the method being greater than the loss. Conversely, when high sucrose losses occurred, i.e., >0.5%, sucrose losses based on eq.(1) were lower than those based on eq. (2), because concomitant acid degradation of glucose occurred. Mean season losses were 2.56% equivalent to 4.89 lbs sucrose lost per short ton of cane and USD1,404,000, with values being much higher than previously reported. Mean losses were 2%, 24.8%, 58.6%, and 14.8% across the MJ tank, clarifier, two pre-evaporators (in series), and from the pre-evaporators to the final evaporator, respectively. 53% of total season losses occurred in early season when the cane quality was worst.