Commercial Deodorizer Systems

In addition to equipment suppliers already mentioned in this chapter (Alfa-Laval, De Smet, Tirtiaux), there are a number of other suppliers of commercial-deodorizer systems for oils and fats (e.g., Andreotti, CMB, Crown, Kirchfeld, Krupp, Lipico, Oiltek, etc.). 

Experience has shown that edible fats and oils flavor and odor removal correlates well with the reduction of FFA. The odor and flavor of an oil with a 0.1 % FFA will be eliminated when the FFA is reduced to 0.01% to 0.03%, assuming a zero peroxide value. Therefore, all commercial deodorization consists of steam stripping the oil for FFA removal. Typical conditions practiced in the United States for the three deodorizer system types are shown in Table 23. The four interrelated operating variables that influence deodorizer design are vacuum, temperature, stripping rate, and retention time at deodorization temperatures. 

The oxidative degradation of organic pollutants in water and air streams is considered as one of the so-called advanced oxidation processes. Photocatalytic decomposition of organics found widespread industrial interest for air purification (e.g., decomposition of aldehydes, removal of NO , ), deodorization, sterilization, and disinfection. Domestic applications based on Ti02 photocatalysts such as window self-cleaning, bathroom paints that work under illumination with room light, or filters for air conditioners operating under UV lamp illumination have already been commercialized. Literature-based information on the multidisciplinary field of photocatalytic anti-pollutant systems can be found in a number of publications, such as Bahnemann s [237, 238] (and references therein). 

Ozone in the lower atmosphere is also produced as a result of modem technology. Equipment that produce sparks, arcs, or static discharge ultraviolet and other ionizing radiation commercial applications such as air purifiers and deodorizers in homes, hospitals, and offices and closed environmental systems such as aerospace cabins and submarine chambers due to electric discharge from equipment or ionizing radiation, are some examples. 

It can be seen from Equation (5.1) that the volume of steam required for deodorization is directly proportional to the system pressure and inversely proportional to the vapour pressure of the free fatty acid. Thus, a reduction in the former and an increase in the latter, brought about by increasing temperature, result in a reduction of time on temperature for a set steaming rate. This is correct for the simple reduction of fatty acid levels. However, oils vary in their content of pigments and oxidation products. Practical experience has shown that, whereas these products can be removed in the time required to reduce free fatty acid to the desired level from a good-quality feed oil, this is not so with oxidized oils. For such oils, an extended time at the selected temperature is required to allow thermal reactions to take place in which some of the oxidation products are further decomposed and the derivatives removed from the oil (Andersen, 1962 Brekke, 1980). If such oxidation products are not removed, the deodorized product will have a poorer taste and reduced oxidative stability. The limitations of this aspect of the deodorization process can be noted in the fact that to date the anisidine value, which is a measure of secondary oxidation products in the oil, is not reduced to zero. Commercial plants are currently designed for holding time on temperature of 30-120 min, but all are capable of extension. 

Chem. Descrip. Blend of nat. bacteria, surfactants, preservatives Uses Cleaner, deodorizer for toilets, drains, traps, plumbing/sewer/lrealment systems In restaurants, kitchens, commercial buildings, and institutions Properties Greenish-blue opaque liq. susp. 

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