Rapid method for determining the composition of crude alcohol using diagrams composition – property

Abstract

The preparation of a raw alcohol in a beer still is a periodic process which is accompanied by a flood, the reflux-to-product ratio and speed of sampling changes, unexpected temperature jumps etc. As the result, at formal conformity with the sampling temperature, the main product is polluted by fusel oils. The degree of pollution by fusel oils is above the requirements needed for further treatment which in turn requires an ad-ditional rectification. For this reason the process of periodic rectification needs continuous express control. The rapid method of the determination of the com position of crude alcohol using diagrams composition-properties was developed. There fractive index, the density and su rface tension were chosen as the physical properties characterizing the mixture. The re fractive index was measured on a digital portable refractometer PAL-RI made by the company ATAGO (Japan), the density was measured using a pick-nometer, the surface tension was measured at stallagometеr with a falling drop method. Experimental plan was realized on a simplex la ttice. The third-degree polynomial was used as a model. All calculations were made using the “Simplex” program. The adequate mathematical models (diagrams) were made which allowed us to determine the composition of crude alcohol using only three physical con-stants: density, refractive index, surface tension. Validity check of the model has shown that the error of the results does not exceed 3% rel. (ethanol concen tration) and 7% rel. (fusel oil concentration).