CONSTRUCTION OF ULTRAFILTRATION MEMBRANE UNIT IN PILOT SCALE
FOR CLEAR JUICE PURIFICATION AT SUGAR FACTORY

Toto Martoyo* dan Agus Bachtiar*
*Pusat Penelitian Perkebunan Gula Indonesia


ABSTRACT
Cane juice purification at sugar factory (SF) is the important step because it affects the performance of the following processing steps. Many SF’s (> 90%) in Indonesia utilize sulphitation process for cane juice purification, which includes continuous settling process in a clarifier tank to separate the clear juice from the scum. In general, the quality of clear juice is low, because it still contains suspended particles and macromolecules such as polysaccharides and proteins. The juice impurities will cause some problems in further juice processing steps, such as colour formation, viscous massecuites and finally lowering sugar recovery. Therefore, ultrafiltration (UF) membrane as a new technology is introduced to solve those problems. This technology has been applied and widely used in other industries such as HFCS (high fructose corn syrup) and pharmaceutical industry. This research project was conducted to study the performance of UF membrane in pilot scale as an in-line unitat SF hence the unit was able to process continuously. The objective of this research projects was to study the characteristics of permeate juice, retentate juice as well as the unit of ultrafiltration. The results showed that the quality of permeate juice was increased. It was showed that turbidity, colour and CaO content can decrease by 95%, 50%, 20 %, respectively and juice purity increases by 1.3 point. That means more sugar will be recovered when the cane juice from UF membrane is further processed. It is estimated that 4 ton more sugar with better quality is able to be recovered per day from SF with capacity 3000 ton cane per day (TCD). Furthermore,the results from membrane UF characteristic showed that flux achieves about 33 L/ m2.h , 44 L/ m2.h and 30 L/ m2.h at VCR 5, VCR 10 and VCR 15, respectively.

Keywords: technology, membrane, ultrafiltration, clear juices, sugar factory