No abstract

Vegetable oil bleaching by adsorption involves the removal of color particles which are either dissolved or colloidally dispersed in the oil. This type of adsorption follows an exponential relationship and the Freundlich equation was utilized in correlating the data. In utilizing this equation, the color of the oil was assumed proportional to the concentration of the color particles, and a color measurement system based on the Beer‐Lambert Law was devised. This system involves a measurement of the transmittance of light of 475 millimicrons wave length through the oil. A Coleman, Model 11, Spectrophotometer was used for the transmittance measurements. Spectral transmittance curves for cottonseed and soybean oil, bleached and unbleached, are given. The effect of the variables of temperature, time of contact, and particle size on the activity of several adsorbents was determined. It was found that the activity of each adsorbent is at a maximum at some particular temperature. The adsorbents were grouped into three general classes: acid‐activated clays, natural earths, and materials high in silica content, and it was found that adsorbents in the same class have a temperature of maximum activity within the same range. The effectiveness of 16 different adsorbents in bleaching a refined cottonseed oil was determined by utilizing the Freundlich equation and plotting adsorption isotherms for each adsorbent. Similar data are given for 10 different adsorbents in bleaching a refined soybean oil. On the basis of adsorbent activity, acid‐activated clays were 11/s to 2 times as effective as natural earths.

No abstract

No abstract

No abstract