Research into the influence of ethoxylated alcohols on the citric acid transport through polymer inclusion membranes (PIMs) has been carried out. This process may be used in the future as one of the methods of citric acid isolation. Ethoxylated alcohols, which were GENAPOL® X020, X060 and X150, served as both: plasticizer and carrier. The results showed that the maximum values of citric acid fl ux [mol/(m2.s)] were equal to: 1.02.10-4 (X020), 1.57.10-4 (X060) and 1.77.10-4 (X150). The obtained results allow proceeding further study on using the polymer inclusion membranes, as an alternative to traditional methods of citric acid separation, which are precipitation and extraction.
The effect of time, temperature, the catalyst particle size and the ratio of the catalyst weight to the leaching solution volume (S:L) on the treatment of spent vanadium catalyst components was determined using citric acid solutions at atmospheric pressure. The optimal parameters of catalyst leaching in 10% acid solutions at atmospheric pressure are: T = 323 K, t = 4 h, the particle size of less than 0.160 mm, the S:L ratio below 0.1. Under these conditions it was possible to dissolve about 90% of vanadium and potassium compounds and more than 60% of iron compounds contained in the catalyst. These results fall within the scope of research on a comprehensive method for recovering spent vanadium catalyst components.