scholarly journals PROSES PEMURNIAN FRAKSI KAYA RHODINOL MINYAK SEREH WANGI MENGGUNAKAN SPINNING BAND DISTILLATION

2020 ◽  
Vol 30 (2) ◽  
Author(s):  
Arum Nur Fitrah ◽  
Meika Syahbana Rusli ◽  
Dwi Setyaningsih ◽  
Arief Riyanto ◽  
Nur Hidayati
Keyword(s):  
Heat Rate ◽  
Reflux Ratio ◽  
Citronella Oil ◽  
Boiling Points ◽  
Vaporization Temperature ◽  
Oil Purification ◽  
The Stability ◽  
Feed Volume ◽  
Initial Research ◽  
Vapor Temperature

Indonesia, as one of the biggest countries which supplies citronella oil, has a high potential to produce natural rhodinol. Recent studies on rhodinol purification using fractional and mollecular distillation showed the difficulty of obtaining high purity and yield. The objective of this study was to determine the method of spinning band distillation to purify rhodinol regarding reflux ratio and vaporization temperature. Citronella oil was divided into three fractions according to its boiling points. The volume of each fraction was estimated by its ratio (according to GC analysis) to the feed volume: F1 (components before rhodinol) 21.73%, F2 (rhodinol) 61.7%, and residue 15.82%. Initial research established the best conditioning before the purification process was 3 mmHg of pressure, equilibration started at 160oC in 30 minutes, and 18–17% of heat rate, as these created the stability of the vapor temperature. The levels of reflux ratio were 3:1 and 5:1, while the evaporation temperatures of rhodinol were 230oC and 235 oC. Reflux ratio of 5:1 at 230oC obtained the highest purity (81.30%) and the highest yield (72.94%). Equilibration and reflux ratio allowed rectification inside the column because the spinning band homogenized the vapour molecules by its downwards flow and wiped the reflux on the inner surface, which in turn caused the molecules with a lower boiling point to evaporate gradually. Meanwhile the other yields were 79.81% (3:1 at 230 oC), 80.53% (3:1 at 235 oC), and 80.21% (5:1 at 23oC) with yields of  71.82%, 70.31%, and 68.23%. Keywords: citronella oil, purification, rhodinol, spinning band distillation

ECONOMY OF TIME IN LABORATORY DISTILLATION

1931 ◽  
Vol 5 (4) ◽  
pp. 455-465
Author(s):  
D. F. Stedman
Keyword(s):  
Methyl Alcohol ◽  
Critical Value ◽  
Complete Separation ◽  
Volatile Constituent ◽  
Reflux Ratio ◽  
Correction Factors ◽  
Boiling Points ◽  
Efficient Column ◽  
The Difference ◽  
Theoretical Amount

The mathematics of fractional distillation of ideal mixtures has been condensed, so that the most economical "reflux ratio" for any such mixture may be decided at once.Particular use is made of the "critical reflux ratio" for any mixture, above which even an infinite column cannot obtain complete separation; and the relation of this critical value to the most economical value for any particular case is given.Some of the conclusions with respect to the infinite column were tested by means of a mixture of methyl and ethyl alcohols using a particularly efficient column. It was found that the vapor produced in the still contained slightly more than the theoretical amount of methyl alcohol, and the magnitude of such error is illustrated from previous work on glycerine solutions.The results are given in the form of a graph of the "critical reflux ratio" for the case where the most volatile constituent boils at 100 °C., and the difference between the boiling points varies from 0.25 °C. to 32 °C., the concentration of the most volatile constituent also being included from 0.001 to 1.0.A table of correction factors is also given, showing the factor by which the "critical reflux ratio" should be varied to produce the greatest economy of time for any particular case.

What are the Molecules of Which the Samples of Metal Alkoxides do Really Consist ?

1994 ◽  
Vol 346 ◽  
Author(s):  
N.Ya. Turova ◽  
N.I. Kozlova ◽  
E.P. Turevskaya ◽  
T.V. Rogova ◽  
V.G. Kessler
Keyword(s):  
Gas Phase ◽  
Aromatic Hydrocarbons ◽  
Mass Spectra ◽  
Mixed Oxides ◽  
Metal Alkoxides ◽  
Boiling Points ◽  
Thermal Constants ◽  
Molecular Masses ◽  
Molecular Complexity ◽  
The Stability

ABSTRACTOn the basis of consideration of the properties of AI, In, Ln, Ti, Zr, Hf, NbO3+, MoO4+, WO4+, MoO22+ MO22+, Fe, Co, Ni alkoxide derivatives the main regularities in poly- and oligomerization properties have been deduced:1) The molecular complexity increases in time (aging) and on action of alcohols. This process is followed by the increase in the melting and boiling points, decrease in solubility in ROH and weakening of colour. In the mass-spectra - in connection with the temperature of transition into the gas phase - increases the stability of products with lower molecular masses. 2) oligomerization occurs on dissolution in aromatic hydrocarbons or on a short thermal treatment (melting, distillation). The oligomerization products possess lower thermal constants, higher solubility in ROH and more intense colour. Their mass- spectra are containing the fragments of higher masses corresponding to oligomers existing apparently also in the condensed phase.The mastering of these regularities permits the monitoring of molecular composition and thus physicochemical properties of the samples which are of importance for their technological application.The presence of oxoalkoxides in the “M(OR)n” samples should be taken into consideration on the preparation of solutions used in the synthesis of powders and films of pure simple and mixed oxides.

scholarly journals Experimental study on essential anise star oil purification in vacuum batch distillation

2021 ◽  
Vol 63 (11) ◽  
pp. 34-39
Author(s):  
Thi Thao Nguyen ◽  
◽  
Xuan Truong Do ◽  
Keyword(s):  
Essential Oil ◽  
Experimental System ◽  
Vacuum Pressure ◽  
Column Height ◽  
Gas Chromatography Mass Spectrometry ◽  
Volatile Components ◽  
Reflux Ratio ◽  
Batch Distillation ◽  
Star Anise ◽  
Oil Purification

Vietnam is one of the world’s largest annual anise harvest countries. However, products from anise are mainly in the form of dried anise fruit and crude star anise essential oil with low economic value. The main component of the star anise essential oil is trans-anethole which needs to be purified to produce higher-value products. This study focused on building an experimental system for purifying star anise essential oil by a batch distillation column working at vacuum pressure. The products obtained during the purification process were analysed by gas chromatography-mass spectrometry (GC-MS). Analytical results were used to evaluate the ability to separate volatile impurities in the crude star anise essential oil. Results showed that the bottom temperature of the tower below 150oC, corresponding to a vacuum pressure of less than 0.1 bar, can reduce the thermal decomposition of essential oils. The volatile components, such as α-pinene, β-phellandrene, limonene, and linalool, were thoroughly separated at the top of the tower. The purified star anise essential oil was from the bottom of the distillation and had the anethole composition of over 88% of mass fraction (wt.%). Anethole recovery efficiency was 98.5 and 88.8% at a pressure of 0.1 and 0.08 bar, respectively. The bottom product can have a higher anethole composition if increasing the column height, the reflux ratio, and decreasing the pressure and the quality of impurities removed at the top is increased.The experimental results are helpful for the calculation, design, manufacture, and operation of an industrial-scale essential oil purification system.

Instability of the equilibrium of a liquid below its vapour between horizontal heated plates

1992 ◽  
Vol 242 ◽  
pp. 235-247 ◽  
Author(s):  
Adam Huang ◽  
Daniel D. Joseph
Keyword(s):  
Phase Change ◽  
Water Film ◽  
Bottom Plate ◽  
Large Temperature ◽  
Basic Solution ◽  
Hot Plate ◽  
Vaporization Temperature ◽  
The Stability ◽  
Heated Plates ◽  
Vapour Film

We study the stability of a motionless liquid below its vapour between heated horizontal plates. The temperature of the bottom plate is held below the vaporization temperature and the top plate is hotter than the vaporization temperature. A water film is on the cold plate and a vapour film on the hot plate. We find a basic solution depending only on the variable y normal to the plates, with steady distributions of temperature, a null velocity and no phase change. The linear stability of this basic state is studied in the frame of incompressible fluid dynamics, without convection, but allowing for phase change. An ambiguity in the choice of the conditions to be required of the temperature at the phase-change boundary is identified and discussed. It is shown that the basic state of equilibrium is overstable under conditions of large temperature gradient, when the other parameters have suitable values. An analysis of the energy of the most dangerous disturbance shows that the source of the instability is associated with change of phase.

scholarly journals The Impact of HDPE Plastic Seeds on the Performance of Asphalt Mixtures

2021 ◽  
Vol 7 (9) ◽  
pp. 1569-1581
Author(s):  
Daud Nawir ◽  
Achmad Zultan Mansur
Keyword(s):  
Asphalt Concrete ◽  
Plastic Waste ◽  
Temperature Sensitive ◽  
Road Pavement ◽  
Seed Content ◽  
Alternative Material ◽  
Pavement Construction ◽  
The Stability ◽  
The Impact ◽  
Initial Research

Plastic waste processing is a problem that almost several countries in the Asian region are unable to overcome. One of the latest innovations carried out in the field of road pavement construction is mixing HDPE type plastic waste that has been processed into plastic seeds into the asphalt concrete mixture. Previous research has shown that HDPE plastic waste may be reused to improve the physical properties of temperature-sensitive asphalt and improve the stability of asphalt concrete. This study was conducted to determine the effect of using HDPE plastic ore as a mixed additive on the Asphalt Concrete-Wearing Course (AC-WC) using Marshall parameters. Marshall Parameters used are stability, flow, VIM, VMA, VFA, and MQ. The study was conducted in a laboratory by testing 42 samples with different levels of HDPE plastic seeds, mixed using wet methods to determine Marshall Characteristics. Manufacture of test objects using asphalt type, which has a penetration rate of 60/70. The initial research results showed that the optimal asphalt content (OAC) is 5.5%, with the percentage content of HDPE plastic seeds around 0, 1, 2, 3, 4, 5, 6, and 7% compared to asphalt weight. The results showed that the effect of HDPE plastic seed content on the AC-WC mixture increased the value of Marshall Characteristics and met all the requirements of SNI 06-2489-1991. This finding shows that HDPE plastic seeds deserve to be an alternative material for road pavements. Doi: 10.28991/cej-2021-03091744 Full Text: PDF

Simulation of Citronellal Extraction Tower Based on Aspen Plus Software

2015 ◽  
Vol 1090 ◽  
pp. 148-153
Author(s):  
Qiu Chen
Keyword(s):  
Large Scale ◽  
Continuous Production ◽  
High Vacuum ◽  
Aspen Plus ◽  
Temperature Sensitive ◽  
Reflux Ratio ◽  
Distillation Process ◽  
Citronella Oil ◽  
Extraction Tower ◽  
Main Component

Aspen Plus is a simulation system of large-scale generalized flowsheet. It is to describe the chemical process by using a digital model, and to obtain the desired results on the computer by changing various effective conditions. The main component with higher value in citronella oil is high purity citronellal. Due to its boiling point, temperature-sensitive and other issues, the difficulty of distillation process increases. This paper conducts process design and simulation on citronella oil high vacuum distillation process by using Aspen Plus software, obtains the process parameters of citronellal extraction tower, explores the relationship between reflux ratio and the number of theoretical plates, and provides data support for the continuous production of citronellal in citronella oil system.

Open discussion

1982 ◽  
Vol 99 ◽  
pp. 605-613
Author(s):  
P. S. Conti
Keyword(s):  
Buenos Aires ◽  
Large Mass ◽  
List Type ◽  
Common Phenomenon ◽  
Open Discussion ◽  
The Stability ◽  
Ring Nebulae

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.

Symmetric Multistep Methods Revisited: II. Numerical Experiments

1999 ◽  
Vol 173 ◽  
pp. 309-314 ◽  
Author(s):  
T. Fukushima
Keyword(s):  
Multistep Methods ◽  
Computational Time ◽  
Integration Time ◽  
Implicit Methods ◽  
Symmetric Methods ◽  
Celestial Bodies ◽  
The Stability ◽  
Predictor Corrector ◽  
Symmetric Multistep Methods ◽  
Integration Errors

AbstractBy using the stability condition and general formulas developed by Fukushima (1998 = Paper I) we discovered that, just as in the case of the explicit symmetric multistep methods (Quinlan and Tremaine, 1990), when integrating orbital motions of celestial bodies, the implicit symmetric multistep methods used in the predictor-corrector manner lead to integration errors in position which grow linearly with the integration time if the stepsizes adopted are sufficiently small and if the number of corrections is sufficiently large, say two or three. We confirmed also that the symmetric methods (explicit or implicit) would produce the stepsize-dependent instabilities/resonances, which was discovered by A. Toomre in 1991 and confirmed by G.D. Quinlan for some high order explicit methods. Although the implicit methods require twice or more computational time for the same stepsize than the explicit symmetric ones do, they seem to be preferable since they reduce these undesirable features significantly.

Uniformity of Magnification from Different Electron Microscopes

1967 ◽  
Vol 25 ◽  
pp. 32-33
Author(s):  
Godfrey C. Hoskins ◽  
V. Williams ◽  
V. Allison
Keyword(s):  
Diffraction Grating ◽  
The Other ◽  
Carbon Replica ◽  
Electron Microscopes ◽  
The Stability

The method demonstrated is an adaptation of a proven procedure for accurately determining the magnification of light photomicrographs. Because of the stability of modern electrical lenses, the method is shown to be directly applicable for providing precise reproducibility of magnification in various models of electron microscopes.A readily recognizable area of a carbon replica of a crossed-line diffraction grating is used as a standard. The same area of the standard was photographed in Phillips EM 200, Hitachi HU-11B2, and RCA EMU 3F electron microscopes at taps representative of the range of magnification of each. Negatives from one microscope were selected as guides and printed at convenient magnifications; then negatives from each of the other microscopes were projected to register with these prints. By deferring measurement to the print rather than comparing negatives, correspondence of magnification of the specimen in the three microscopes could be brought to within 2%.

Effect of Improved ThO2 Particle Dispersion in Nickel on High-Temperature Strength

1970 ◽  
Vol 28 ◽  
pp. 444-445
Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer
Keyword(s):  
High Temperature ◽  
Metal Matrix ◽  
Oxide Particle ◽  
Oxide Phase ◽  
Dislocation Motion ◽  
Particle Dispersion ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Oxide Particles ◽  
The Stability

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.

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