scholarly journals MASS TRANSFER COEFFICIENT OF EXTRACTION TANNIN COMPOUNDS FROM PAPAYA LEAVES WITH 96% ETHANOL SOLVENT

Konversi ◽  
2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Devri Eko Nurwahyuwono ◽  
Viola Eka Afrienty ◽  
Soemargono Soemargono ◽  
Nove Kartika Erliyanti
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Pest Control ◽  
Rotational Speed ◽  
Control Plant ◽  
Extraction Process ◽  
Operating Conditions ◽  
Extraction Time ◽  
Antibacterial Compounds

Papaya leaves contain antibacterial compounds such as flavonoids, terpenoids, alkaloids, tannins, and saponins.. Tannins are compounds that are often used as antibacterial, antioxidant, pest control, plant fungi, tanners and as a corrosion inhibitor.In this study, the value of the mass transfer coefficient was determined. This study used two varied operating conditions, namely stirring rotational speed (100, 200, 300 rpm) and extraction time (30, 60, 90, 120, and 150 minutes). The extraction process is carried out using a stirred extractor at a temperature of 65 ° C.The value of the mass transfer coefficient obtained is 0.00004 second-1 (100 rpm), 0.00005 second-1 (200 rpm), and 0.00007 second-1 (300 rpm) for the best concentration obtained at 150 minutes with speed turn the stirrer 300 rpm

Mass Transfer Enhancement for CO2 Absorption in Structured Packed Absorption Column

2019 ◽  
Vol 41 (5) ◽  
pp. 820-820
Author(s):  
Pongayi Ponnusamy Selvi and Rajoo Baskar Pongayi Ponnusamy Selvi and Rajoo Baskar
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Gas Flow ◽  
Aqueous Ammonia ◽  
Volume Flow Rate ◽  
Packed Column ◽  
Operating Conditions ◽  
Co2 Absorption ◽  
Absorption Column

The acidic gas, Carbon dioxide (CO2) absorption in aqueous ammonia solvent was carried as an example for industrial gaseous treatment. The packed column was provided with a novel structured BX-DX packing material. The overall mass transfer coefficient was calculated from the absorption efficiency of the various runs. Due to the high solubility of CO2, mass transfer was shown to be mainly controlled by gas side transfer rates. The effects of different operating parameters on KGav including CO2 partial pressure, total gas flow rates, volume flow rate of aqueous ammonia solution, aqueous ammonia concentration, and reaction temperature were investigated. For a particular system and operating conditions structured packing provides higher mass transfer coefficient than that of commercial random packing.

scholarly journals Determination of the ozone volumetric mass transfer coefficient in bubble column with two-fluid nozzle gas distributor

2015 ◽  
Vol 69 (5) ◽  
pp. 553-559 ◽  
Author(s):  
Milica Djekovic-Sevic ◽  
Nevenka Boskovic-Vragolovic ◽  
Ljiljana Takic ◽  
Radmila Garic-Grulovic ◽  
Srdjan Pejanovic
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Bubble Column ◽  
Operating Conditions ◽  
Volumetric Mass Transfer Coefficient ◽  
Gas Distributor ◽  
Liquid Mass Transfer ◽  
Two Fluid

Experimental investigation of gas-liquid mass transfer of ozone in water, in bubble column with two-fluid nozzle gas distributor (BKDM), under different operating conditions, are presented in this work. The main objective was to determine the ozone volumetric mass transfer coefficient, kL a, in calm uniform section of the column, under different values of gas and liquid flow rates. Obtained values of these coefficients were compared with the values in countercurrent bubble column. The critical liquid flowrate, when gas hold up reaches its maximum, was experimentally determined. It was shown that the maximum value of the ozone volumetric mass transfer coefficient is obtained just when liquid flowrate is at its critical value.

Liquid-liquid mass transfer studies in various stirred vessel designs

2015 ◽  
Vol 31 (4) ◽  
Author(s):  
Reza Afshar Ghotli ◽  
Abdul Raman Abdul Aziz ◽  
Shaliza Ibrahim
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Interfacial Area ◽  
Operating Conditions ◽  
Experimental Results ◽  
Dispersed Phase ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Wide Range

AbstractA general review on correlations to evaluate mass transfer coefficients in liquid-liquid was conducted in this work. The mass transfer models can be classified into continuous and dispersed phase coefficients. The effects of drop size and interfacial area on mass transfer coefficient were investigated briefly. Published experimental results for both continuous and dispersed phase mass transfer coefficients through different hydrodynamic conditions were considered and the results were compared. The suitability and drawbacks of these correlations depend on the operating conditions and hydrodynamics. Although the results of these models are reasonably acceptable, they could not properly predict the experimental results over a wide range of designs and operating conditions. Therefore, proper understanding of various factors affecting mass transfer coefficient needs to be further extended.

scholarly journals Mass Transfer in Multiphasic Gas/Liquid/Liquid Systems. KLa Determination Using the Effectiveness-Number of Transfer Unit Method

Processes ◽  
2018 ◽  
Vol 6 (9) ◽  
pp. 156 ◽  
Author(s):  
Éric Dumont
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Gas Flow ◽  
Absorption Capacity ◽  
Operating Conditions ◽  
Transfer Unit ◽  
Liquid Systems ◽  
Overall Mass Transfer Coefficient

The Effectiveness-Number of Transfer Unit method (ε-NTU method) was applied to determine the overall mass transfer coefficient, KLa, of operating gas-liquid absorbers treating Volatile Organic Compounds (VOCs). This method requires the knowledge of the operating conditions (gas flow rate, QG; liquid flow rate, QL; scrubber volume V), the measurement of gaseous concentrations at the inlet, CGin, and at the outlet, CGout, of the contactor (in order to determine the effectiveness of the absorber ε) and the calculation of the Henry coefficient of the VOC between the gas and the liquid phases (HVOC). Coupled with the “equivalent absorption capacity” concept, the ε-NTU method was used to determine KLa of absorbers contacting a gas and a mixture of water and a Non Aqueous Phase, successfully. The method, validated from literature data for configurations countercurrent scrubbers and stirred tank reactors, could be used to simply determine the overall mass transfer coefficient of systems for which the standard KLa determination methods still remain non-reliable or inaccurate (viscous solvents, mixture of immiscible liquids, fermentation broths…).

Influence of Physical Properties of Phases on Hydrodynamics and Mass Transfer Characteristics of a Liquid-Liquid Circular Microchannel

2016 ◽  
Author(s):  
Mehdi Sattari-Najafabadi ◽  
Bengt Sundén ◽  
Zan Wu ◽  
Mohsen Nasr Esfahany
Keyword(s):  
Mass Transfer ◽  
Physical Properties ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Rate Ratio ◽  
Operating Conditions ◽  
Flow Rate Ratio ◽  
Internal Diameter ◽  
Volumetric Mass Transfer Coefficient

The influences of operating conditions and physical properties of the two phases on the hydrodynamics and mass transfer in a circular liquid-liquid microchannel have been investigated. The polytetrafluoroethylene (PTFE) microchannel has an internal diameter of 0.7 mm and a T-shaped mixing junction. Sodium hydroxide solution was used as the aqueous phase. N-hexane and toluene were employed as the organic phases to investigate the effect of physical properties. Regarding the results, at constant total flow rate, raising the flow rate ratio enhanced the overall volumetric mass transfer coefficient. Using toluene as the organic solvent enhanced the overall volumetric mass transfer coefficient in average by 64.7% and 100.27% comparing to n-hexane-water at flow rate ratio of 1 and 0.5, respectively. This increment resulted in a decrement in the required mass transfer time and length in the microchannel. The length of the slugs had no considerable variation as n-hexane was replaced with toluene. Thus, the significant improvement of the overall volumetric mass transfer coefficient was because of the increment of the overall mass transfer coefficient, not the specific interfacial area.

scholarly journals Ozone absorption in a mechanically stirred reactor

2007 ◽  
Vol 72 (8-9) ◽  
pp. 847-855 ◽  
Author(s):  
Ljiljana Takic ◽  
Vlada Veljkovic ◽  
Miodrag Lazic ◽  
Srdjan Pejanovic
Keyword(s):  
Mass Transfer ◽  
Liquid Phase ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Plug Flow ◽  
Operating Conditions ◽  
Volumetric Mass Transfer Coefficient ◽  
Pseudo First Order Reaction ◽  
Ozone Absorption ◽  
Stirred Reactor

Ozone absorption in water was investigated in a mechanically stirred reactor, using both the semi-batch and continuous mode of operation. A model for the precise determination of the volumetric mass transfer coefficient in open tanks without the necessity of the measurement the ozone concentration in the outlet gas was developed. It was found that slow ozone reactions in the liquid phase, including the decomposition of ozone, can be regarded as one pseudo-first order reaction. Under the examined operating conditions, the liquid phase was completely mixed, while mixing in a gas phase can be described as plug flow. The volumetric mass transfer coefficient was found to vary with the square of the impeller speed. .

scholarly journals A Study on the Removal of Chromium(VI) from Waste Solutions by Adsorption on to Sawdust in Stirred Vessels

1995 ◽  
Vol 12 (2) ◽  
pp. 129-138 ◽  
Author(s):  
Mahmoud A. Zarraa
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Rotational Speed ◽  
Batch Reactor ◽  
Particle Diameter ◽  
Maximum Adsorption Capacity ◽  
Volumetric Mass Transfer Coefficient ◽  
Initial Concentration ◽  
Chromium Vi

The ability of sawdust to adsorb chromium(VI) from waste solutions has been studied in a batch reactor under forced convection conditions. Variables investigated were the rotational speed of the impeller, the initial concentration of chromium(VI) in solution and the weight and particle diameter of the sawdust. Increasing both the rotational speed of the impeller and the initial concentration of chromium(VI) in solution led to an increase in the volumetric mass transfer coefficient (k) according to the relationships k ∝ ω)0.71 and k ∝ C0.26, where ω is the rotational speed of the impeller (rev./min) and C0 is the initial concentration of chromium(VI) in solution (mg/dm3). On the other hand, the volumetric mass transfer coefficient was found to decrease with increasing particle diameter of sawdust (dp) according to the relationship k ∝ dp−0.87. The removal of chromium(VI) was also found to be significantly dependent on the weight of sawdust. Analysis of the equilibrium isotherm data has been undertaken using the Freundlich and Langmuir equations. The maximum adsorption capacity of sawdust for chromium(VI) was found to be 4.44 mg/g.

scholarly journals PENENTUAN KOEFISIEN TRANSFER MASSA EKSTRAKSI KALIUM DARI ABU BATANG PISANG

Konversi ◽  
2012 ◽  
Vol 1 (1) ◽  
pp. 39
Author(s):  
Primata Mardina ◽  
Ajang Gunawan ◽  
Muhammad Imam Nugraha
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Extraction Process ◽  
Effect Of Temperature ◽  
Average Error ◽  
Time Interval ◽  
Dimensionless Equation ◽  
The One ◽  
Increasing Temperature

 Abstrak-Kalium sebagai mineral alam bisa didapatkan dari batang pisang dengan cara ekstraksi padat-cair pada abu batang pisang menggunakan pelarut methanol. Penelitian ini bertujuan untuk mengetahui pengaruh suhu pada proses ekstraksi kalium dari abu batang pisang koefisien transfer massa proses tersebut. Proses ekstraksi ini dilakukan secara batch pada labu leher tiga yang dilengkapi dengan motor pengaduk, pendingin balik, termometer dan media pemanas. Abu batang pisang sebanyak 25 gram dan metanol 250 mL dimasukkan ke dalam labu leher tiga sebagai sampel. Ekstraksi dimulai dengan memanaskan sampel sampai suhu yang diinginkan, yaitu 30oC, 45 oC dan 60 oC, kemudian motor pengaduk dijalankan pada kecepatan yang telah ditentukan. Sampel diambil dalam selang waktu tertentu 0, 15, 30, 60, 120 180 dan 240 menit. Dari proses ekstraksi kalium dapat diketahui koefisien transfer massa. Hasil penelitian menunjukkan bahwa koefisien transfer massa semakin besar dengan semakin tinggi suhu operasi. Nilai koefisien transfer massa terbesar adalah 0,0235/menit pada suhu 60oC. Hubungan antara koefisien transfer massa dengan variabel-variabel yang mempengaruhinya dapat dinyatakan dengan persamaan dalam bentuk kelompok tak berdimensi sebagai berikut: Dengan ralat rata-rata 6,56 % Keywords: Ekstraksi, kalium, abu batang pisang,  Abstract-Potassium is the one of chemical compounds which can be extracted from ash of pseudo stem of banana by methanol solid-liquid extraction method. The experiment investigated the effect of temperature on mass transfer coefficient of potassium extraction process from ash of banana’s pseudo stem. This experiment conducted in a three necks flask which equipped with mechanical stirrer, condenser, thermometer and heating mantle. The sample was heated to desired temperature, 30oC, 45 oC and 60 oC. and maintained constant while reaction time. The reaction was timed as soon as the mechanical stirrer was turned on. Samples were drawn at specified time interval 0, 15, 30, 60, 120, 180 and 240 minutes. The result showed increasing temperature increased mass-transfer coefficient. The highest value of mass-transfer coefficient was 0,0235 /minute at 60oC.The correlation between mass transfer coefficient and investigated variables is shown in the dimensionless equation below: The average error is 6.56 % Keywords: Extraction, potassium, ash of banana’s pseudo stem.

scholarly journals Effects of geometric parameters on volumetric mass transfer coefficient of non-Newtonian fluids in stirred tanks

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Haider Ali ◽  
Sofia Zhu ◽  
Jannike Solsvik
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Gas Flow ◽  
Scale Up ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Volumetric Mass Transfer Coefficient ◽  
Transfer Coefficients ◽  
Stirred Tanks

Abstract Scaling up stirred tanks is a significant challenge because of the research gaps between laboratory and industrial-scale setups. It is necessary to understand the effects of scale-up on the mass transfer in stirred tanks, and this requires meticulous experimental analysis. The present study investigates the effects of tank size and aspect ratio ( H L T ${H}_{L}}{T}$ ) on the volumetric mass transfer coefficients of shear-thinning fluids. The experiments were conducted in three stirred tanks of different sizes (laboratory and pilot scale) and geometries (standard and nonstandard). H L T ${H}_{L}}{T}$ was 1 for the standard tanks and 3.5 for the nonstandard stirred tanks. Three sizes of stirred tanks were used: 11 L with H L T ${H}_{L}}{T}$ of 1, 40 L with H L T ${H}_{L}}{T}$ of 3.5, and 47 L with H L T ${H}_{L}}{T}$ of 1. Impeller stirring speeds and gas flow rates were in the range of 800–900 rev min−1 and 8–10 L min−1, respectively. The volumetric mass transfer coefficient was estimated based on the dissolved oxygen concentration in the fluids, and the effects of rheology and operating conditions on the volumetric mass transfer coefficient were observed. The volumetric mass transfer coefficient decreased as tank size increased and increased with an increase in operating conditions, but these effects were also clearly influenced by fluid rheology. The impacts of scale-up and operating conditions on the volumetric mass transfer coefficient decreased as liquid viscosity increased.

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