Regeneration of used oil

Regeneration of used oil has been an area of great importance. In the United States, 1.23 billion pounds of used oil is discarded annually from the restaurant and food services operations (Hunter and Applegate, 1991). The spent oil is generally used in animal feed or for other industrial applications. This represents an estimated loss of US 300 million on an annual basis. 

Recent communications with industrial oil users in Mexico and Southern Europe revealed that these industries believe oil processors can take used oil and turn it into good oil. In reality, it is never possible to take any kind of used oil, reprocess it, and turn it into a product that is as good as the original. It is, however, possible to treat used oil in a specific manner to retard its degradation, and thereby prolong its useful life and reduce 

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Gourgouillon D, Schrive L, Sarrade S, and Rios G. An environmentally friendly process for the regeneration of used oil. Environ.. Sci. Technol. 2000 34 3469-3473. 

Miyagi, A. and Nakajima, M. Regeneration of used frying oils using adsorption processing. 

The usual feed is a virgin gas oil that is, the part of crude oil boiling between about 60 °F. and 1050°F. Sometimes material below 600°F will be included into the cat feed but more often, it is put into diesel fuel or home heating oil. The heavy material above 1050°F is not normally used as cat feed because it often contains metallic compounds that contaminate the catalyst. Even if metals are not present, there are sometimes tarry materials that end up on the catalyst. This deposit increases the load on the regenerator, and, hence, the 1050 °F+ material is less desirable than lower boiling feeds. 

Liquid membranes of the water-in-oil emulsion type have been extensively investigated for their applications in separation and purification procedures [6.38]. They could also allow extraction of toxic species from biological fluids and regeneration of dialysates or ultrafiltrates, as required for artificial kidneys. The substrates would diffuse through the liquid membrane and be trapped in the dispersed aqueous phase of the emulsion. Thus, the selective elimination of phosphate ions in the presence of chloride was achieved using a bis-quaternary ammonium carrier dissolved in the membrane phase of an emulsion whose internal aqueous phase contained calcium chloride leading to phosphate-chloride exchange and internal precipitation of calcium phosphate [6.1]. 

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