EVALUATION OF CORROSION INHIBITORS OBTAINED FROM THE RESIDUAL VINAZA DISTILLERIES ETHYL ALCOHOL WITH ADDITIVES

Abstract

In this paper a study of solids extracted from the residual vinasse from the fermentation of molasses to obtain ethanol, as corrosion inhibitors. The vinasse is subjected to electrocoagulation process, which was carried out under different conditions in order to increase the performance of the solids obtained, these conditions are: adding NaCl to the residual vinasse to increase its conductivity, adding NaOH to the residual vinasse to increase the pH, without any additives and the natural pH of residual vinasse which is slightly acidic. After electrocoagulation process, you get the sludge solids that precipitate in the bottom of the liquid and solids that rise to the surface with foam. The study was conducted with both solid at 60 ° C and found that conditions Nº 1, the addition of NaCl, solid L1 and E1 is unfavorable for the 4 metallic materials studied, namely: carbon steel, zinc, aluminum and brass. The solids obtained increasing to 9 the pH of vinasse before being subjected to the process of electrocoagulation (L5 and E5), and the solids obtained with the natural pH of vinasse (L2 and E2) are comparable in their inhibitory properties, although depending on the metallic material, one of them can be slightly better than the other. Are presented mathematical models that correlate the corrosion rate with pH, the inhibitor concentration and temperature. Finally, do not recommend adding any additives to the residual vinasse before the electrocoagulation process.