Effect of processing conditions on regeneration of bleaching clay

Regeneration of spent bleaching clay by heat treatment in a gas stream was performed in a thermogravimetric analysis system. Red color indices of pean ut oils unbleached and bleached with fresh or regenerated clay were determi ned to calculate regeneration efficiency. The effects of processing paramet ers such as atmosphere, temperature, time, air flow rate, and amount of cla y on the regeneration efficiency have been investigated. Weight losses, spe cific surface areas and pore volumes of clays were measured to clarify the mechanism of regeneration. Results indicate that regeneration in an air str eam is slightly more efficient than that in stagnant air, and air is more e fficient than nitrogen. The regeneration efficiency of clay is found to inc rease with temperature and time. However, it is reduced due to sintering of the clay. Air flow rate and amount of clay do not have any effect on regen eration efficiency.