Regeneration capacity of silica gel for grain drying

The research was aimed at developing a simple and inexpensive regeneration method for silica gel used in grain drying. A series of experiments were conducted. Silica gel was wetted to 30% moisture level by adding water with a sprayer while mixing. It was then divided into four batches. Each batch was dried five times using different fireplaces (closed, open), containers (big pan, small pan, rotating drum) and fuels (wheat, straw, charcoal). Following five successive regenerations as stated above, each batch was subjected to an equilibrium moisture test and compared with the original sample. A decrease in adsorption due to high temperatures and smoke was noted. The damage to silica gel during drying was minimized by using a thick (14 gauge metal sheet) with a 1/2" sand bed underneath the containers. Due to reduction in temperature and smoke contamination, the equilibrium moisture content of these samples were the same after five successive regeneration steps when compared to the original sample.