EXTRACTION-HYDROGENATION, AN IDEA FOR REFINING TROUBLESOME FEEDSTOCKS

ENRIQUE TARIFA; MARIANA BUSTO; CARLOS VERA

San Luis Potosí

Congreso; VIII CONGRESO INTERNACIONAL Y XVII CONGRESO MEXICANO DE CATÁLISIS; 2021

Academia Mexicana de Catalisis

The possibility of coupling a continuous hydrogenation reactor to a continuous extraction unit was analyzed. The extract was treated to hydrogenate diluted impurities that then became less soluble in the extract. This enables a closed loop of solvent regeneration. The process can replace the regeneration of extraction solvents by distillation, which becomes prohibitive in the case of minor impurities of low volatility. Design equations are obtained for the simple case of a mixer/settler coupled to a slurry reactor. An example was studied of extraction of naphthenic acids from petroleum crudes with methanol in which the extract is regenerated to a mixture of methanol and decarboxylated hydrocarbon because of the hydrodeoxygenation of naphthenic acids over a NiMo/Al2O3 catalyst. Experimental parameters mass transfer and reaction are obtained and the process is simulated in a computer. The system has a pseudo first order reaction rate due to big dilution of the impurity in the extract. Dilution helps maintaining high ratios of dissolved hydrogen to impurity. However, dilution leads to low overall reaction rates. The biggest difficulty is finding a selective solvent that does not generate parallel undesired reactions in the reactor.