Fractionation of polyethylene wax by pilot-scale molecular distillation: new insights on process development

Analysis and optimization of feed liquid flow characteristics of distributor in scraping film molecular distillation equipment

The initial liquid film is the basis of material evaporation during distillation, so it is of great significance to study the distribution of the initial liquid film of distributor in the process of scraping film molecular distillation. In this paper, CFD is used to study the distribution of distributor liquid film, and the mathematical model of the triangular tooth distributor and its peripheral cylinder is established, and the effects of the triangular tooth distributor’s speed, feed rate, and feed position on initial liquid film uniformity are investigated. And the reliability of the numerical simulation model is verified by experiments. In this paper, a new feed structure that includes an intermediate feed device and inclined tooth distributor is proposed and researched by numerical simulation. And compared with the previous structure, the liquid film distribution is more uniform. This has important guiding significance to the optimization of equipment in production.

Molecular Distillation of Lavender Supercritical Extracts: Physicochemical and Antimicrobial Characterization of Feedstocks and Assessment of Distillates Enriched with Oxygenated Fragrance Components

Lavandula angustifolia is one of the most widely cultivated non-food crops used in the production of essential oil; it is used in perfumery, aromatherapy, pharmaceutical preparations, and food ingredients. In this study, supercritical fluid extraction (SFE) and molecular distillation (MD) were combined, primarily to enrich scCO2 extracts with lavender oxygenated monoterpenes, avoiding thermal degradation, hydrolysis, and solvent contamination, and maintaining the natural characteristics of the obtained oils. Molecular distillation was developed for the first time for the extraction of crucial lavender fragrance ingredients, i.e., from two scCO2 extracts obtained from dry flower stems of lavender cultivated in Poland and Bulgaria. The best results for high-quality distillates were obtained at 85 °C (EVT) and confirmed that linalyl acetate content increased from 51.54 mg/g (initial Bulgarian lavender extract, L-Bg-E) and 89.53 mg/g (initial Polish lavender extract, L-Pl-E) to 118.41 and 185.42 mg/g, respectively, corresponding to increases of 2.3 and 2.1 times in both distillate streams, respectively. The distillates, light oils, and extracts from lavender were also evaluated for their antimicrobial properties by determining the minimum inhibitory concentration (MIC) by the broth microdilution method. Generally, Gram-positive bacteria and Candida spp. were more sensitive to all distilled fractions and extracts than Escherichia coli (Gram-negative bacteria).