Cereal Chem 65:105-109   |  VIEW ARTICLE

Reverse Osmosis and Ultrafiltration of Corn Light Steep-Water Solubles.

Y. V. Wu. Copyright 1988 by the American Association of Cereal Chemists, Inc. 

Evaporative concentration of light steep water from about 10 to 50% solids in corn wet milling uses a great deal of energy. Another more efficient process was investigated. Light steep water was separated by continuous centrifuge (45,200 x g) into light steep-water solubles (93% of total dry matter and 93% of total nitrogen) and centrifuges solids. Reverse osmosis (RO) at 1,360 kPa (200 psi) combined with ultrafiltration (UF) of light steep-water solubles yielded an RO permeate of 70% of the total volume, 8.8% of total notrogen, 10% of total solids, and 13% of total ash of light steep-water solubles. At 5,440 kPA, RO combined with UF produced a permeate that had 80% of the total volume, with residuals of 0.11% of the total nitrogen, 0.23% of the total solids, and 0.24% of the total ash initially present in the light steep-water solubles. At 6,800 kPA, RO combined with UF resulted in a permeate of 84% of the total volume, 0.09% of total nitrogen, 0.18% of total solids, and 0.18% of total ash of light steep-water solubles. Thus, RO at 5,440 or 6,800 kPa, combined with UF, appears practical to process a large volume of corn light steep-water solubles into a small volume of potentially useful concentrate and a large volume of permeate suitable for reuse or safe disposal.