Analysis and modelling of the regeneration process of chemical solutions after brewing equipment cleaning in a Cleaning in Place system based on changes in turbidity

Abstract

Abstract The study presents the results of an analysis concerning the impact of temperature on the regeneration of the cleaning solution after cleaning the installations of a brewery in a Cleaning in Place system and based on the obtained results optimize the process of chemical solutions regeneration. The solutions were collected from a production plant after the process of cleaning and subjected to 12-h sedimentation. During the sedimentation process in different temperatures, the changes in turbidity were determined, as this represents a purity criterion for chemical solutions. The results were subjected to statistical analysis. The standard deviations of the dispersion in relation to the obtained averages were determined and Tukey's multiple comparisons test was used to identify the significance of the influence of temperature on the purity of the final solution. Based on the obtained results, a non-linear regression model was developed which constituted a mathematical description of the process of sedimentation of chemical solutions after the process of cleaning brewing installations M = f(t,T). The exponential function was assumed to describe the regeneration process. Numerical calculations were carried out based on the nonlinear least squares method using the Gauss-Newton algorithm. Finally, the surface area of the response of the relationship between the time and temperature of sedimentation and the turbidity of solutions was designated. The research results indicated that an appropriate temperature of chemical solutions during their regeneration can significantly influence their final purity degree and the duration of the regeneration process. In the case of sodium hydroxide after cleaning of mash filter, its regeneration is preferably carried out at a temperature below 40 °C, whereas in the case of sodium hydroxide after cleaning of the vessels a temperature of above 50 °C is desirable. Statistical analysis also showed that an acidic solution is best regenerated at 50 °C.