Energy-saving technology for betulin extraction from birch bark waste

The paper presents experimental studies on the extraction of betulin from birch bark by one-stage extraction method in a flask with a reflux condenser and extraction in a Soxhlet apparatus. It is found that the highest betulin yield (up to 40 %) is achieved by extraction in a Soxhlet apparatus with periodic renewal of the extractant. The kinetic dependences obtained in the course of the research allows constructing an equilibrium dependence necessary to determine the rational number of phase contact stages when designing an industrial continuous extraction plant. On the basis of the studies carried out, a scheme of energy and resource-saving technology for extracting betulin from birch wood waste is proposed and a pilot plant is developed, which can be used to work out the modes of obtaining high-purity betulin. The absence of losses of organic extractants and the reuse of Florentine water determines the ecological purity of production. Refined birch bark can be used for the production of wood-polymer composite materials or as a fuel for generating thermal energy, which reflects the energy and resource-saving potential of this technology.

Improvement of the gas chromatographic method for diagnosing developing defects in oil-filled electrical equipment based on the analysis of furan compounds

During the operation of oil-filled electrical equipment under the influence of temperature, humidity and other negative factors, the destruction of paper insulation occurs. As a result of this destruction, furan compounds are formed, which get into the transformer oil. To identify the process of destruction of paper insulation, control of furan compounds in transformer oil is carried out by instrumental methods. Of these methods, the most widely used is gas chromatography using packed chromatographic columns, on the basis of which guidelines have been developed. To improve gas chromatographic methods for monitoring furan compounds, we used a highly efficient quartz capillary column filled with a polar stationary phase based on polyethylene glycol. The sample was injected into the injector of the chromatograph Chromos-GC1000 using an automated dosing system with a vial for 23 samples. Used transformer oil of the GK-1 brand of Almetyevsk electrical networks was taken as the object of research; The optimal retention characteristics of standard sorbates were preliminary determined, which were used as organic extractants of transformer oil and furan compounds. The effect of temperature on the process of chromatographic analysis of furfuryl alcohol and organic extractants was determined, on the basis of which it was established that the selectivity of separation is determined by the nature of intermolecular interactions in the sorbate-sorbent system, in particular, the formation of a hydrogen bond. It has been shown that the selectivity coefficient for the separation of furfuryl alcohol depends on the physicochemical nature of organic extractants, their boiling points and dipole moments and has the highest values for the analyzed pair of components: furfuryl alcohol - ethanol.

Determination of the antioxidant additive “Ionol” in transformer oil by gas chromatographic method

Transformer oil is widely used in power oil-filled electrical equipment, which is an insulating and diagnostic medium. During the operation of power transformers, its operational and dielectric properties deteriorate. To increase the operating time of transformer oil, it is inhibited by an antioxidant additive, which is most often used as ionol and the ionol concentration must be constantly monitored. This control is carried out by chromatographic methods. The main problem of controlling the antioxidant additive in transformer oil is its extraction with organic extractants, which are ethyl alcohol, which contains water, which has a negative effect on the extraction process. Thus, a search for more effective extractants for the extraction of ionol from transformer oil was undertaken. The retention characteristics of individual organic extractants and antioxidant additives were determined by the method of high-performance gas-liquid chromatography using a quartz capillary column and an automated system for dosing a sample into the chromatograph under various experimental conditions. Both the isothermal mode of the experiment and under linear programming conditions of the chromatographic column have been used. The dependence of the retention characteristics of organic extractants and ionol on the temperature of analysis was established, which has a linear form.

Evaluation of MIP-OES as a detector in DLLME procedures: application to Cd determination in water samples

This work evaluates the feasibility of coupling DLLME to MIP-OES for elemental analysis. To this end, the potential spectral and non-spectral interferences caused by different organic extractants on the emission signal in MIP-OES have been studied.