Returnable baking waste — a new type of raw materials for distillates production (Part III. Distillation stage)

The distillation stage is a key step in distillate-based alcoholic beverage technology. The use of a new non-traditional type of raw materials to obtain distillates requires comprehensive research. The purpose of this work was to study the processes at the distillation stage of the discharged wort from the recyclable baking waste, in identifying significant factors and determining the optimal technological values of these factors. The objects of the study served 9 samples of fermented wort from various types of recyclable baking waste, distillate fractions and samples of distillates. The distillation was performed on the installation of direct distillation “KOTHE DESTILLATIONSTECHNIK” (Germany). In the objects of the study, the volume, the volume fraction of ethyl alcohol and the mass concentration of the main volatile components were determined. The composition and concentration of basic volatile components were determined using gas chromatography on the device “Thermo Trace GC Ultra” (Thermo, United States). The wide range of variation of the mass concentration of the main volatile components, depending on the composition of the initial raw materials, is revealed. It has been established that the nature of the distribution of volatile components according to distillate fractions does not depend on the physicochemical composition of the fermented wort from different types of recyclable baking waste. It is shown that the nature of the distribution of volatile components according to fractions in obtaining a distillate from the recyclable baking waste has certain differences from their distribution in the preparation of cognac and fruit distillates. A comparative assessment of distillates obtained by single fractionated distillation and double distillation showed the advantage of the first alcohol output and the composition of volatile components. It has been established that the distillation rate with a direct fractionated has a significant effect on the dynamics of the distribution of the main volatile components and the output of the distillate for anhydrous alcohol. With an optimal distillation rate (5.9 cm3 / min), an anhydrous alcohol output increases, on average, by 4% and reduced the losses of valuable aroma-forming volatile components with head and tail fractions.

Visual binary testing of methanol contained in ethyl alcohol

A method for control of methanol traces in rectified ethyl alcohol and alcoholic drinks based on visual binary testing using one reference sample was proposed. An indicator reaction of formaldehyde interaction (product of methanol oxidation) with chromotropic acid disodium salt was chosen for methanol screening. The conditions of indicator reaction proceeding are analogous as for the spectrophotometric technique of methanol determination: methanol was oxidized to formaldehyde with potassium permanganate in an acidic medium; the formaldehyde then reacts with chromotropic acid in the presence of hot concentrated sulfuric acid and forms a violet product (color of this product is stable for 12 hours). It was established that the absorption spectrum of the reaction product does not change on going from 96% ethanol to aqueous-ethanol solutions with a volume fraction of 40% ethanol. The maximum light absorption of the reaction product corresponded to 570 nm. All further studies were carried out in water-ethanol solutions with a volume fraction of ethanol of 40%. According to regulatory documents the normalized limiting content of methanol (clim) in ethyl alcohol of the “Lux” grade (the most common in the alcoholic industry) and alcoholic beverages is 0.01% by by volume counted upon anhydrous alcohol. The comparison sample (the solution of colored reaction product of indicator reaction) had to be less than the normilized level on the value which providing the risk of false-negative test result not more than 5%. To determination the threshold concentration of methanol in the comparison sample was applied the statistics of observation. For the aim the solution of colored product corresponding to the normalized limiting methanol concentration clim = 0.01% by volume was prepared and comparison samples with lower methanol concentrations were also prepared. The interval of unreliability was discovered with the help of observers. The frequency of detecting of the difference in the color of comparison samples and normalized sample (P(c)) changed from 0 to 1 in this interval. The value of methanol concentration 0.0072% by volume counted upon anhydrous alcohol was taken for the lower boundary of the interval and the value of methanol concentration 0.01% by volume counted upon anhydrous alcohol was chosen the upper border of the interval. This interval was divided on eight concentrations with step Dс = 0.0004% by volume. Three parallel series of solutions were prepared and 48 observations for each concentration were received. The experimental efficiency curve obtained was checked for compliance with the mathematical functions of the known distributions: normal, logistic, lognormal, exponential and Weibull distribution function using the statistical criterions c2 and Kolmogorov-Smirnov λ. The efficiency curve was described by the theoretical functions of the lognormal and Weibull distributions. Calculated at a confidence level of 0.95 estimation of the threshold concentration for the comparison sample was 0.0073% by volume fraction corresponding to anhydrous alcohol. The visual binary testing of methanol trace in alcoholic drinks was carried out. The accuracy of visual binary testing of methanol was confirmed by gas chromatography.

Design of a Dehydration Tower for the Obtaining of Alcohol Anhídro

The design of a dehydration tower was carried out in order to obtain anhydrous ethyl alcohol of high degree of purity by adsorption with molecular sieves, for which, we proceeded to identify the process variables by laboratory tests varying the temperature and pressure in the feeding to the molecular sieve, with these data and the flow of feeding proceeded with the design of the dehydrator, determining the variables of the equipment (diameter, volume, internal bed, flow of feeding), as well as additional devices such as a preheater that works with a temperature of 120 ºC, which is essential to increase the enthalpy of the steam, and a condenser fed with water at a temperature of 25 ºC, which makes it possible to transform the anhydrous alcohol from vapor to liquid, having a yield of 86.6% and an efficiency of 92,9%, values that help to have an alcohol of 99,5% by weight in a time of 20 minutes.

Inter-Laboratory collation testing as a method of improvement of objectivity of technical expertise

The results of the interlaboratory comparison tests of experimental laboratories that analyzed vodka produced and sold in the Russian Federation for human consumption are presented in order to demonstrate the capabilities of the comparison tests. The choice of vodka as a model object was determined, on the one hand, by its definite proximity to medicinal substances, and on the other, by its assignment as food product, for which the regulatory framework for interlaboratory comparison tests was developed in sufficient detail. The following controlled indicators were examined: strength, alkalinity, mass concentration of acetaldehyde, mass concentration of acetic aldehyde, mass concentration of fusel oil, mass concentration of esters (methyl acetate, ethyl acetate), volume fraction of methyl alcohol in terms of anhydrous alcohol. 30 experimental laboratories are involved in the interlaboratory comparison tests. All participants guided by the same regulatory documents. The test results are processed statically in accordance with the regulatory framework developed for food products. It demonstrated that the majority of participants in the interlaboratory comparison tests successfully coped with the task of testing vodka under the conditions of reproducibility of the analytical method, and recommendations were made to correct the activities of testing laboratories for the rest. The diagrams were constructed to demonstrate visually checks on the quality of tests in determining strength, in determining alkalinity, in determining the mass concentration of acetic aldehyde, in determining the mass concentration of fusel oil and in determining the volume fraction of methyl alcohol in terms of anhydrous alcohol. The results of statistical processing allowed to state that interlaboratory comparison tests correctly and visually assess the competence of the activities of experimental laboratories, allow to plan actions preventive violations in the objectivity of the work of experimental laboratories. It is shown that the introduction of the practice of experimental laboratories working in the field of production and circulation of medicinal substances, interlaboratory comparison tests can be one of the possible ways to improve the quality of medicinal substancesThe opinion was expressed that for testing interlaboratory comparison tests in the production and circulation of medicinal substances one can use the regulatory framework developed for food products.

Expanding the monomer scope of linear and branched vinyl polymerisations via copper-catalysed reversible-deactivation radical polymerisation of hydrophobic methacrylates using anhydrous alcohol solvents

The use of anhydrous alcohols for Cu-catalysed reversible-deactivation radical polymerisation of a wide range of hydrophobic methacrylates has been explored in detail.