scholarly journals Optimization of liquid-phase α-pinene oxidation with oxygen in presence of cobalt (II) stearate

2019 ◽  
Vol 55 (2) ◽  
pp. 233-239
Author(s):  
A. A. Sosnovskaya ◽  
V. L. Fleisher ◽  
Y. V. Borkina
Keyword(s):  
Liquid Phase ◽  
Flow Rate ◽  
Air Flow ◽  
Maximum Yield ◽  
Oxidation Products ◽  
High Conversion ◽  
Optimum Process ◽  
Process Conditions ◽  
Air Flow Rate ◽  
Quantitative Content

Optimization of the liquid-phase oxidation of α-pinene was carried out using the Box plan. It was found that an increase in the temperature of the oxidation process in the interval 55–85 °C leads to an increase in the amount of polymers from 45 to 55 %, and a decrease in the air flow rate from 1000 to 600 ml/min – to a 10 % decrease in terpenic oxygencontaining compounds (verbenol, verbenon, epoxy α-pinene). Increasing the duration of oxidation from 5 to 15 h leads to a reduction in the content of α-pinene from 70 to 48 %, which indicates its high conversion. The results of the experimental plan have been processed, the optimum process conditions found, which ensure the maximum yield terpenic oxygencontaining compounds and a high conversion α-pinene with the minimum content of polymers in the oxidation products, have been calculated and confirmed in practice. It was established that at a temperature of 70–75 °C, an air flow rate of 1000 ml/min and an oxidation time of 5 h, the quantitative content of the main products was: terpenic oxygen-containing compounds – 27.04 %, monomers – 69.70 %, polymers – 30.30 %.

Optimization of Virgin Coconut Oil (VCO) Production with Diffuser Type Aeration Method

2021 ◽  
Vol 6 (4) ◽  
pp. 139-143
Author(s):  
Nyoman Sri Widari ◽  
Rahaju Saraswati ◽  
Bambang Sutejo
Keyword(s):  
Fatty Acid ◽  
Flow Rate ◽  
Acid Content ◽  
Air Flow ◽  
Fatty Acid Content ◽  
Maximum Yield ◽  
Coconut Oil ◽  
Efficient Production ◽  
Air Flow Rate ◽  
Virgin Coconut Oil

Virgin coconut oil (VCO) is pure coconut oil with low free fatty acid content and high lauric acid content. VCO has been produced in many home industries where the yield obtained is still very small. So, the researchers tried to find a more efficient production process so that they could obtain high process yields. Researchers made VCO using the aeration method with a diffuser type aerator. The experimental variables were air flow rate (L / min): 0.6; 1.8; 4.0; 4,5 and the duration of the aeration process (hours): 2; 3; 4; 5, by using coconut milk from 1 kg of grated coconut in 1 liter of water, the maximum yield is 33.5% at an air flow rate of 4.0 L / min with an aeration time of 4 hours. The quality of VCO obtained were: water content of 0.02%; iodine number 5,54%; peroxidation number 1.36 g.iod / 100 g; 0.19% free fatty acids; saturated fatty acid content of 93.71% and unsaturated fatty acid 6.24% and the color is very clear. The quality test results obtained are in accordance with the quality standards required by SNI 7381-2008.

scholarly journals Model of thermal buoyancy in cavity-ventilated roof constructions

2021 ◽  
pp. 174425912098418
Author(s):  
Toivo Säwén ◽  
Martina Stockhaus ◽  
Carl-Eric Hagentoft ◽  
Nora Schjøth Bunkholt ◽  
Paula Wahlgren
Keyword(s):  
Analytical Model ◽  
Flow Rate ◽  
Numerical Study ◽  
Air Flow ◽  
Wind Pressure ◽  
Air Flow Rate ◽  
Test Set ◽  
Air Cavity ◽  
Thermal Buoyancy ◽  
The Impact

Timber roof constructions are commonly ventilated through an air cavity beneath the roof sheathing in order to remove heat and moisture from the construction. The driving forces for this ventilation are wind pressure and thermal buoyancy. The wind driven ventilation has been studied extensively, while models for predicting buoyant flow are less developed. In the present study, a novel analytical model is presented to predict the air flow caused by thermal buoyancy in a ventilated roof construction. The model provides means to calculate the cavity Rayleigh number for the roof construction, which is then correlated with the air flow rate. The model predictions are compared to the results of an experimental and a numerical study examining the effect of different cavity designs and inclinations on the air flow rate in a ventilated roof subjected to varying heat loads. Over 80 different test set-ups, the analytical model was found to replicate both experimental and numerical results within an acceptable margin. The effect of an increased total roof height, air cavity height and solar heat load for a given construction is an increased air flow rate through the air cavity. On average, the analytical model predicts a 3% higher air flow rate than found in the numerical study, and a 20% lower air flow rate than found in the experimental study, for comparable test set-ups. The model provided can be used to predict the air flow rate in cavities of varying design, and to quantify the impact of suggested roof design changes. The result can be used as a basis for estimating the moisture safety of a roof construction.

scholarly journals Modeling and optimization of radish root extract drying as peroxidase source using spouted bed dryer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shahrbanoo Hamedi ◽  
M. Mehdi Afsahi ◽  
Ali Riahi-Madvar ◽  
Ali Mohebbi
Keyword(s):  
Kinetic Parameters ◽  
Flow Rate ◽  
Air Flow ◽  
Cost Effective ◽  
Industrial Applications ◽  
Interactive Effects ◽  
Root Extract ◽  
Air Flow Rate ◽  
Spouted Bed ◽  
Radish Root

AbstractThe main advantages of the dried enzymes are the lower cost of storage and longer time of preservation for industrial applications. In this study, the spouted bed dryer was utilized for drying the garden radish (Raphanus sativus L.) root extract as a cost-effective source of the peroxidase enzyme. The response surface methodology (RSM) was used to evaluate the individual and interactive effects of main parameters (the inlet air temperature (T) and the ratio of air flow rate to the minimum spouting air flow rate (Q)) on the residual enzyme activity (REA). The maximum REA of 38.7% was obtained at T = 50 °C and Q = 1.4. To investigate the drying effect on the catalytic activity, the optimum reaction conditions (pH and temperature), as well as kinetic parameters, were investigated for the fresh and dried enzyme extracts (FEE and DEE). The obtained results showed that the optimum pH of DEE was decreased by 12.3% compared to FEE, while the optimum temperature of DEE compared to FEE increased by a factor of 85.7%. Moreover, kinetic parameters, thermal-stability, and shelf life of the enzyme were considerably improved after drying by the spouted bed. Overall, the results confirmed that a spouted bed reactor can be used as a promising method for drying heat-sensitive materials such as peroxidase enzyme.

Method to Determine an Optimal Air-Flow Rate in Solar Collectors

1979 ◽  
Vol 3 (6) ◽  
pp. 357-362
Author(s):  
H. C. Hewitt ◽  
E. I. Griggs
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Solar Collectors ◽  
Air Flow Rate

Model-Based Analysis of Transient Behavior of Large Scale CFB Boilers

2003 ◽  
Author(s):  
Ari Kettunen ◽  
Timo Hyppa¨nen ◽  
Ari-Pekka Kirkinen ◽  
Esa Maikkola
Keyword(s):  
Flow Rate ◽  
Large Scale ◽  
Air Flow ◽  
Model Parameters ◽  
Air Flow Rate ◽  
Process Data ◽  
Cfb Boiler ◽  
Flow Rates ◽  
Load Change ◽  
Secondary Air

The main objective of this study was to investigate the load change capability and effect of the individual control variables, such as fuel, primary air and secondary air flow rates, on the dynamics of large-scale CFB boilers. The dynamics of the CFB process were examined by dynamic process tests and by simulation studies. A multi-faceted set of transient process tests were performed at a commercial 235 MWe CFB unit. Fuel reactivity and interaction between gas flow rates, solid concentration profiles and heat transfer were studied by step changes of the following controllable variables: fuel feed rate, primary air flow rate, secondary air flow rate and primary to secondary air flow ratio. Load change performance was tested using two different types of tests: open and closed loop load changes. A tailored dynamic simulator for the CFB boiler was built and fine-tuned by determining the model parameters and by validating the models of each process component against measured process data of the transient test program. The know-how about the boiler dynamics obtained from the model analysis and the developed CFB simulator were utilized in designing the control systems of three new 262 MWe CFB units, which are now under construction. Further, the simulator was applied for the control system development and transient analysis of the supercritical OTU CFB boiler.

scholarly journals Experimental Investigation on Improvement of Wet Cooling Tower Efficiency with Diverse Packing Compaction Using ANN-PSO Algorithm

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 167
Author(s):  
Hasan Alimoradi ◽  
Madjid Soltani ◽  
Pooriya Shahali ◽  
Farshad Moradi Kashkooli ◽  
Razieh Larizadeh ◽  
...  
Keyword(s):  
Neural Network ◽  
Water Temperature ◽  
Water Flow ◽  
Flow Rate ◽  
Cooling Tower ◽  
Air Flow ◽  
Water Flow Rate ◽  
Pso Algorithm ◽  
Outlet Temperature ◽  
Air Flow Rate

In this study, a numerical and empirical scheme for increasing cooling tower performance is developed by combining the particle swarm optimization (PSO) algorithm with a neural network and considering the packing’s compaction as an effective factor for higher accuracies. An experimental setup is used to analyze the effects of packing compaction on the performance. The neural network is optimized by the PSO algorithm in order to predict the precise temperature difference, efficiency, and outlet temperature, which are functions of air flow rate, water flow rate, inlet water temperature, inlet air temperature, inlet air relative humidity, and packing compaction. The effects of water flow rate, air flow rate, inlet water temperature, and packing compaction on the performance are examined. A new empirical model for the cooling tower performance and efficiency is also developed. Finally, the optimized performance conditions of the cooling tower are obtained by the presented correlations. The results reveal that cooling tower efficiency is increased by increasing the air flow rate, water flow rate, and packing compaction.

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