scholarly journals Kinetics of Dehydration of Aroids and Developed Dehydrated Aroids Products

2010 ◽  
pp. 19-24
Author(s):  
M Kamruzzaman ◽  
MN Islam
Keyword(s):  
Mass Transfer ◽  
Rate Constant ◽  
Chemical Engineering ◽  
Raw Materials ◽  
Drying Rate ◽  
Chemical Compositions ◽  
Air Velocity ◽  
Transfer Resistance ◽  
Power Law Equation ◽  
Kinetics Of

The study was concerned with the dehydration kinetics of aroids in mechanical dryer at different dryingcondition such as variable air dry bulb temperature and air velocity. Fresh aroids with 3, 5 mm slice and 8mm cube were used as raw materials for drying. The experimental results showed that drying rate constantand thickness can be expressed as power law equation. The exponent of the equation for aroids was 1.15indicating presence of significance external mass transfer resistance. Increasing loading density gavedecreased drying rate constant and when air velocity of dryer was increased, drying rate constant was alsoincreased, as higher air velocity reduces the external resistance to mass transfer and also highertemperature gave faster drying rate. The activation energy of diffusion of water from aroids during dryingas per Arrhenius equation was found to be 5.12 k cal/g-mole. The chemical compositions of fresh and driedaroids were determined and it was observed that all the constituent remained almost constant, only fatdecreased slightly possibly due to oxidation. Organoleptic taste testing showed that “chapatti” preparedfrom aroids powder (aroids powder: wheat flour = 1:4) were adjudged to be the best by the panelists using1-9 hedonic scale and ranked as like moderately securing score 7.3.Journal of Chemical Engineering Vol.ChE 24 2006 19-24

scholarly journals Effects of Drying Parameters on Dehydration of Green Banana (Musa sepientum) and its Use in Potato (Solanum tuberosum) Chips Formulation

2012 ◽  
Vol 10 (1) ◽  
pp. 87-97 ◽  
Author(s):  
M. S. Islam ◽  
M. A. Haque ◽  
M. N. Islam
Keyword(s):  
Mass Transfer ◽  
Rate Constant ◽  
Moisture Diffusivity ◽  
Drying Rate ◽  
Drying Time ◽  
Transfer Resistance ◽  
Air Temperatures ◽  
Model Mixing ◽  
Two Parameters ◽  
Green Banana

The present study quantifies the drying kinetics of green banana during mechanical dehydration. The effect of loading density (sample thickness) and the temperature on the drying rate constant and drying time were investigated and quantified. Drying rate increased with increasing temperature but decreased with increase in loading density. The values of exponent ‘n’ of the two parameters power law model describing the drying rate constant (as a function of thickness) were less than 2 which indicated the presence of significant external resistance to mass transfer despite the dominance of internal mass transfer resistance.  Investigation with three drying air temperatures (55, 60 and 65oC) at constant air velocity (0.6 m/sec) resulted that the increase in drying air temperature increased the drying process.  The moisture diffusivity values were 1.25×10-10, 1.67×10-10 and 2.19×10-10 m2/sec at 55, 60 and 65oC respectively. The activation energy (Ea) indicating the temperature dependence of the diffusivity was 51.21 KJ/mole obtained using Arrhenius model. Mixing of green banana flour in the potato chips formulation enhanced the fiber and mineral content in the product.DOI: http://dx.doi.org/10.3329/agric.v10i1.11069The Agriculturists 2012; 10(1): 87-97

scholarly journals Study on drying kinetics of summer onion

2015 ◽  
Vol 39 (4) ◽  
pp. 661-673 ◽  
Author(s):  
Md Masud Alam ◽  
Md Nurul Islam ◽  
Md Nazrul Islam
Keyword(s):  
Activation Energy ◽  
Mass Transfer ◽  
Rate Constant ◽  
Variable Temperature ◽  
Air Flow ◽  
Drying Kinetics ◽  
Effect Of Temperature ◽  
Drying Rate ◽  
External Resistance ◽  
Kinetics Of

The present study was concerned with the kinetics of drying of summer onion. Drying was done in a mechanical dryer at constant air flow using blanched and unblanched onion with variable temperature (52, 60 and 680C) and thickness (3, 5 and 7 mm). Drying rate was increased with increase of temperature and decreased with the increase in thickness in blanched and unblanched onion. Blanched onion showed higher drying rate than unblanched onion. Drying rate constant and thickness can be expressed as power low equations. The value of index “n” were found to be 1.277 and 0.845 for onion indicating that the external resistance to mass transfer was highly significant. The effect of temperature on diffusion co-efficient follows an Arrhenius type relationship. The activation energy (Ea) for diffusion of water was found 5.781 Kcal/g-mole for unblanched and 2.46 Kcal/g-mole for blanched onion when onions were dried in mechanical dryer. DOI: http://dx.doi.org/10.3329/bjar.v39i4.22545 Bangladesh J. Agril. Res. 39(4): 661-673, December 2014

scholarly journals Modeling of the adsorption kinetics of zinc onto granular activated carbon and natural zeolite

2006 ◽  
Vol 71 (8-9) ◽  
pp. 957-967 ◽  
Author(s):  
Ljiljana Markovska ◽  
Vera Meshko ◽  
Mirko Marinkovski
Keyword(s):  
Mass Transfer ◽  
Activated Carbon ◽  
Simulation Study ◽  
Natural Zeolite ◽  
Granular Activated Carbon ◽  
Model Parameters ◽  
Mass Transfer Resistance ◽  
External Mass Transfer ◽  
Transfer Resistance ◽  
Kinetics Of

The isotherms and kinetics of zinc adsorption from aqueous solution onto granular activated carbon (GAC) and natural zeolite were studied using an agitated batch adsorber. The maximum adsorption capacities of GAC and natural zeolite towards zinc(II) from Langmuir adsorption isotherms were determined using experimental adsorption equilibrium data. The homogeneous solid diffusion model (HSD-model) combined with external mass transfer resistance was applied to fit the experimental kinetic data. The kinetics simulation study was performed using a computer program based on the proposed mathematical model and developed using gPROMS. As the two-mass transfer resistance approach was applied, two model parameters were fitted during the simulation study. External mass transfer and solid phase diffusion coefficients were obtained to predict the kinetic curves for varying initial Zn(II) concentration at constant agitation speed and constant adsorbent mass. For any particular Zn(II) - adsorbent system, k f was constant, except for the lowest initial concentration, while D s was found to increase with increasing initial Zn(II) concentration.

The Influence of Stainless Steel Mesh Porous Burner on Drying Kinetics of Nile Tilapia

2019 ◽  
Vol 805 ◽  
pp. 116-121
Author(s):  
Pathiwat Waramit ◽  
Apinunt Namkhat ◽  
Umphisak Teeboonma
Keyword(s):  
Stainless Steel ◽  
Heat Source ◽  
Nile Tilapia ◽  
Drying Kinetics ◽  
Drying Rate ◽  
Air Velocity ◽  
Stainless Steel Mesh ◽  
Steel Mesh ◽  
Porous Burner ◽  
Kinetics Of

This paper studied the influence of porous burner effect on drying kinetics of Nile tilapia drying using stainless steel mesh porous burner as heat source. Drying kinetics was analyzed by determination of drying rate (DR), drying specific energy consumption (SEC) and dryer thermal efficiency (). In this study, the stainless steel mesh was used as porous media with porosity of 10, 20 and 50 pore per inch (PPI), drying air velocity of 0.5, 1.0 and 1.5 m/s, and drying temperature of 50, 60 and 70 °C, respectively. The results were found that the application of porous burner as heat source can improve the drying kinetics. It was found, at the porosity of 50 PPI, the drying temperature of 70 °C and the air velocity of 1.5 m/s, the moisture ratio of the drying was decreased rapidly, the highest drying rate was found to be 150 g (water evap.)/hr., the lowest drying energy consumption was found to be146.75 MJ/kg, and the thermal efficiency of the dryer was found to increase by 17.79% and the CO and NOx concentration in case of applying porous burner as heat source is lower than without porous burner.

Effect of Drying on Degradation kinetics of carotenoids and color of tomato pulp

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Indu Parmar ◽  
Gurpreet Kaur Chandi ◽  
Kalika Gupta ◽  
Balmeet Singh Gill
Keyword(s):  
Rate Constant ◽  
Color Change ◽  
Degradation Kinetics ◽  
Drying Rate ◽  
Drying Temperature ◽  
Hot Air ◽  
Visual Color ◽  
Tomato Pulp ◽  
Drying Conditions ◽  
Kinetics Of

Abstract Tomato pulp was dried under various drying conditions using hot air oven (65-950C), and cabinet drier (65-950C). The drying rate constant increased with increase in drying temperature. Among different combinations of Hunter L, a and b parameters, L*a could be used to describe the visual color change in tomato pulp during dehudration process.

Effect of Air Velocity and Temperature on the Drying Kinetics of Drumstick Leaves (Moringa Oleifera)

2012 ◽  
Vol 8 (4) ◽  
Author(s):  
Monica Premi ◽  
Harish Sharma ◽  
Ashutosh Upadhyay
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Moringa Oleifera ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Drying Rate ◽  
Air Velocity ◽  
Drying Time ◽  
Effective Moisture ◽  
Kinetics Of

Abstract The present study examines the effect of air velocity on drying kinetics of the drumstick leaves in a forced convective dryer. The drumstick leaves were dried in the temperature range of 50–800 C, at different air velocity (Dv) of 0.5 and 1.3 m/s. The results indicated that drying temperature and air velocity are the factors in controlling the drying rate. Experimental data obtained for the samples for color, drying rate and drying time proved that air velocity of 1.3 m/s yielded the product superior in terms of both quality and energy efficiency as compared to the samples at 0.5 m/s. Activation energy for drumstick leaves dried with air velocity, 0.5 and 1.3 m/s was 12.50 and 32.74 kJ/mol respectively. The activation energy relates similarly with the effective moisture diffusivity which also increased with increase in air velocity and temperature.

scholarly journals Kinetics of Extraction of Dioscine from Vegetable Raw Materials in Vibrocavitation Homogenizer

2020 ◽  
Vol 9 (2) ◽  
pp. 77-81 ◽  
Author(s):  
E. V. Flisyuk ◽  
S. S. Belokurov ◽  
I. A. Narkevich ◽  
A. N. Shikov ◽  
O. M. Flisyuk ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Plant Material ◽  
Raw Materials ◽  
Extraction Process ◽  
Rotor Speed ◽  
Plant Materials ◽  
Periodic Action ◽  
Initial Stage ◽  
Working Volume ◽  
Kinetics Of

Introduction. In recent years, substances extracted from plant materials have been widely used in the pharmaceutical, cosmetic and food industries. Such substances are used as solutions, dry extracts for the manufacture of medicines, dietary supplements, cosmetic creams, food additives in various forms – tablets, capsules, solutions, granular powders. The extraction of valuable substances from plant materials is carried out using the extraction process, which is carried out by various methods and in apparatuses of various designs. Earlier, a comparative study of the extraction of dioscin from fenugreek by various methods was carried out: in devices with a stirrer, in an ultrasonic field, supercritical, fluid CO2 extraction, and in a vibro-cavitation homogenizer. It is shown that the most effective method is the extraction carried out in a vibrocavitation homogenizer.Aim.To analyze the kinetics of the extraction of dioscin from fenugreek seeds, to determine the optimal values of the required degree of grinding of the raw materials, working temperature, the concentration of ethyl alcohol in the solution and the rotational speed of the rotor of the vibrocavitation homogenizer. Determine the effective mass transfer coefficient responsible for the intensity of mass transfer inside the particles.Materials and methods. An experimental study of the extraction of valuable components from plant materials was carried out in a laboratory unit with a vibrocavitation homogenizer of periodic action. As raw materials were used seeds of hay fenugreek, ecotype of Morocco, acquired in the company Fitokasa, Casablanca (Morocco), which we used for research. Commodity analysis showed that raw materials comply with the requirements of the State Pharmacopoeia XIVth edition. As extractants, aqueous solutions of ethanol with an alcohol concentration of 40, 50, 60, 70, 80, and 90 %. The analysis of the kinetics of the process was based on the following ideas. Extraction begins with the surface of the particles of plant material. As the extracted component moves into the volume of the solution, the extractant penetrates into the internal pores of the particles, and the surface on which the extractant and the extracted component interact is gradually shifted into the individual particles. In this case, the resistance to mass transfer in the region between the specified surface and the outer surface of the particle increases over time.Results and discussion. An analysis of the results shows that the rotor speed significantly intensifies the process. In addition, the influence of the rotor speed is most pronounced at the initial stage of the process, when the surface layers of particles of plant material are extracted. It was also found that the resistance to mass transfer inside particles increases significantly as it approaches the final stage of the process, and with an increase in the rotor speed, it increases, especially at the initial stage of the process, which is associated with the intensity of cavitation and the weakening of its effect as the process deepens inward particles.Conclusions. The obtained dependences are necessary to determine the duration of the extraction process in a batch mode, or the average residence time of seeds in the working volume when organizing the process in a continuous mode.

scholarly journals A study on the drying behaviour of a local variety (Lalpakri) of potato (Solanum tuberosum L.)

2012 ◽  
Vol 37 (3) ◽  
pp. 505-514 ◽  
Author(s):  
Ayesha Sarker ◽  
MN Islam ◽  
MR Shaheb
Keyword(s):  
Rate Constant ◽  
Raw Materials ◽  
Solanum Tuberosum L ◽  
Absolute Temperature ◽  
Drying Rate ◽  
Exponential Relationship ◽  
Local Variety ◽  
Drying Behaviour ◽  
Rural Industries ◽  
The Relationship

The study was carried out in the laboratory of the Department of Food Technology and Rural Industries, Bangladesh Agricultural University, Mymensingh during 2008-09 to analyze the drying behaviour of potato (var. Lalpakri) at variable air dry bulb temperature using a mechanical dryer. Fresh potatoes with 3, 5, 7 mm slices were used as raw materials for drying. The experiment showed that drying rate constant decreases with the increases in thickness and increasing loading density of potato slice, the rate of drying decreases but drying rate constant does not decrease proportionately. From the relationship between drying rate constant and thickness, the value of exponent ‘n’ of the power law equations was recorded 0.4586. It was observed that higher temperatures gave faster drying rate. From the exponential relationship between diffusion co-efficient (De) versus inverse absolute temperature (Tabs -1), activation energy (Ea) for diffusion of water from local variety of potato (var. Lalpakri) was found to be 5.60 Kcal/gm-mole. Bangladesh J. Agril. Res. 37(3): 505-514, September 2012 DOI: http://dx.doi.org/10.3329/bjar.v37i3.12127

Effect of temperature on the equilibrium and kinetics of galactose, glucose, and lactose adsorption on a cation exchanger

2014 ◽  
Vol 68 (12) ◽  
Author(s):  
Łukasz Wiśniewski ◽  
Katarína Vaňková ◽  
Pavel Ačai ◽  
Milan Polakovič
Keyword(s):  
Mass Transfer ◽  
Cation Exchanger ◽  
Enzymatic Reaction ◽  
Breakthrough Curves ◽  
Axial Dispersion ◽  
Effect Of Temperature ◽  
Transfer Resistance ◽  
Adsorption Equilibria ◽  
Intraparticle Mass Transfer ◽  
Kinetics Of

AbstractGalacto-oligosaccharides are typically produced by an enzymatic reaction when the post-reaction mixture contains considerable amounts of lactose and glucose and a smaller amount of galactose. In order to develop a process of chromatographic removal of saccharide impurities, adsorption equilibria and kinetics of these di- and monosaccharides were investigated for Diaion UBK 530, an industrialgrade strong cation-exchanger in the Na+ form. Frontal chromatographic experiments were carried out in the temperature range of 30–70°C and a broad interval of saccharide concentrations up to 350 g L−1. Breakthrough curves were described using the equilibrium-dispersive model with the linear adsorption isotherm. Both the distribution and the axial dispersion coefficient values depended on the saccharide molecule type and size. No significant effect of temperature or concentration on the distribution coefficient was observed. The apparent dispersion coefficients of all saccharides exhibited some decrease with the temperature, which was caused by the decrease of the intraparticle mass transfer resistance. An analysis showed that both the intraparticle mass transfer and the axial dispersion had a significant influence on the front dispersion.

scholarly journals Pengaruh Kecepatan Alir Udara dan Temperatur Terhadap Perpindahan Massa Padat dan Gas (Disk Naftalen-Udara) Dalam Sistem Kolom Akrilik

2018 ◽  
Vol 2 (3) ◽  
Author(s):  
Hadyan Hilman Radifan ◽  
Lindawati Lindawati
Keyword(s):  
Mass Transfer ◽  
Chemical Engineering ◽  
Effect Of Temperature ◽  
Gas Temperature ◽  
Air Velocity ◽  
Flow Temperature ◽  
Fundamental Knowledge ◽  
Column System ◽  
Observation Method ◽  
Observation Results

ABSTRAKPerpindahan massa merupakan salah satu fundamental penting yang harus dikuasai oleh seorang sarjana teknik kimia. Sublimasi, adsorbsi, serta pengeringan merupakan salah satu contoh penerapan dari perpindahan massa padat-dan gas di bidang Industri. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh temperatur dan kecepatan udara terhadap koefisien perpindahan massa padat - gas (sistem disk naftalen – udara) dalam sebuah kolom akrilik silinder. Penelitian dilakukan dengan metode observasi. Variasi yang digunakan untuk temperatur adalah 318K; 330K dan 348K dan untuk kecepatan alir udara adalah 1,840 m/s; 3,620 m/s; dan 4,980 m/s. Hasil observasi menunjukkan bahwa peningkatan kecepatan udara dan suhu yang masuk ke dalam sistem kolom akan menyebabkan peningkatan nilai terhadap koefisien perpindahan massa padat-gas (KG).Kata kunci: Perpindahan Massa, Padat-Gas, Temperatur, Kecepatan UdaraABSTRACTMass transfer is one of the fundamental knowledge that must be mastered by a bachelor in chemical engineering. Sublimation, adsorption, and drying are examples of the application of solid-gas mass transfer in the industrial fields. The purpose of this study was to determine the effect of temperature and air velocity on the coefficient of solid - gas mass transfer (disc naphthalene-air system) in a cylindrical acrylic column. The air flow temperature used are 318K; 330K and 348K with the air velocity of 1,840 m/s; 3,620 m/ s; and 4,980 m/s. The research was done by observation method. The observation results show that the increase of air velocity and temperature entering the column system will cause the increase of value to the solid-gas mass transfer coefficient (KG)Keywords: Mass Transfer, Solid- Gas, Temperature, Air Velocity

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