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.

A Low-Cost Assembly for Extraction of Hot Calcium Chloride Extractable Boron from Soil Samples

Among micronutrients, boron (B) occupies a prime place next to zinc (Zn) in Indian Agriculture. Acidic soils, coarse-textured soils subjected to leaching in high rainfall areas, and calcareous soils are likely to be deficient in B (Srivastava and Gupta 1996). According to an estimate based on soil testing of more than two lakh samples drawn from 508 districts of India indicated that 23.2 percent of soil samples are deficient in B (Shukla et al. 2019). Though there are several methods for the analysis of B in soils yet hot water-soluble B (Berger and Truog 1940; Gupta 1967) or dilute CaCl2 extractable B (Cartwright et al. 1983; Adams et al. 1991) are widely adopted for different soils all over the World (Diana 2008). The assembly adopted for the extraction of hot water soluble or dilute CaCl2 extractable B is costly as it requires the use of low B glass or quartz boiling flask equipped with a condenser tube for refluxing (Parker and Gardner 1981) which generally poses difficulty in handling and maintenance. Schuppli (1986) used a Teflon Erlenmeyer flask (125 ml) capacity attached to a Teflon reflux condenser to extract hot water-soluble B from soils, and an asbestos mat was placed between the hot plate and the flask to prevent damage to the Teflon flask. This publication proposes a low-cost assembly to extract hot water-soluble or hot CaCl2 extractable B in soils.

MODELING OF THERMAL MODES OF THE REFLUX CONDENSER OF THE ABSORPTION REFRIGERATION UNIT

Currently, developers of modern refrigeration equipment, in accordance with the plans of the UN, are moving to natural refrigerants (hydrocarbons, carbon dioxide and ammonia) that do not have an adverse technological impact on the ecosystem of the planet. In domestic refrigeration technology, one of the options is absorption refrigeration units, the working body of which is an aqueous ammonia mixture with the hydrogen addition. Having a number of unique advantages over compression analogs, absorption systems are characterized by lower energy characteristics. As the analysis shows, the maximum thermodynamic losses in the absorption aggregates are concentrated in the generating unit when the ammonia is evaporated, it is purified from water vapor and transported to the evaporator. In this connection, the mathematical modeling of the thermal regimes of the reflux condenser is performed, which is responsible for purification and transportation of ammonia vapor. Modeling is carried out on standard designs of absorption refrigeration units taking into account reasonable assumptions and results of own experimental researches. A cellular model is used. Stationary operating modes are modeled due to the high thermal inertia of the processes in the reflux condenser. As a result, the perspective of the thermal insulation installation throughout the reflux section is shown, which makes it possible to increase the energy efficiency by 17 ... 22 %

Oil Production from Polyethylene Plastics by Thermal Pyrolysis Using a Reflux Condenser

Polyethylene (HDPE) was pyrolyzed at 450 °C using a reflux condenser to produce oil for recycling of waste plastics. HDPE was pyrolyzed in the glass reactor with a reflux condenser, and the reflux condenser was varied from 150 °C to 200 °C. With increasing the temperature of reflux condenser, the yield of oil increases and the product oil contains the components with higher molecular weight.

Functionalization by Acidic Treatment in the Purification of Multiwalled Carbon Nanotubes (MWCNTs)

Comparative studies of two multi-walled carbon nanotubes (MWCNT) from different manufacturers were reported. The purification and functionalization of commercial multiwall carbon nanotubes were investigated. MWCNTs were treated with boiling concentrated HNO3 under a reflux condenser for 2 hours at 100 °C in order to purify and oxidize the raw material. The oxidized MWCNTs were rinsed with deionized water until stabilization of the filtrate pH. The measurement technique was by thermogravimetric analysis (TGA) for thermal analysis decomposition products. Meanwhile, the chemical shifted in MWCNTs can be determined by using Raman Spectroscopy.

PRODUKSI BIODIESEL DARI LEMAK SAPI DENGAN PROSES TRANSESTERIFIKASI DENGAN KATALIS BASA NaOH

Biodiesel is an alternative fuel commonly produced from vegetable oil or animal fat with methanol through transesterification. Beef tallow was used as a raw material of transesterification to make biodiesel, because the price of beef tallow was driven down by the market and to reduce the pollution to the surrounding. In this research variable observed were reaction temperature, reaction time and amount of catalyst. Transesterification was carried out in a three necked spherical Pyrex vessel equipped with reflux condenser, stirrer and thermometer. In the present investigation an attempt has been made to use beef tallow as low cost sustainable potential feedstock for biodiesel production by single step transesterification process. Under optimal condition, the maximum yield of 95,67 % beef tallow methyl ester was obtained by using 6 : 1 molar ratio of beef tallow to methanol at 50 oC for a reaction time 30 minutes in the presence of 0,8 wt% of NaOH catalyst. The biodiesel properties were comparable to Indonesian National Standard (SNI). The results of this work showed that the use of beef tallow is suitable for feedstock of biodiesel production with low cost.