Simulation and analysis of multi-stage centrifugal fractional extraction process of 4-nitrobenzene glycine enantiomers

2015 ◽  
Vol 23 (11) ◽  
pp. 1774-1781
Author(s):  
Ping Wen ◽  
Kewen Tang ◽  
Jicheng Zhou ◽  
Panliang Zhang
Keyword(s):  
Extraction Process ◽  
Multi Stage

Microwave Assisted Multi-Stage Countercurrent Extraction of Dihydromyricetin from Ampelopsis grossedentataa

2011 ◽  
Vol 7 (4) ◽  
Author(s):  
Wei Li ◽  
Cheng Zheng ◽  
Jian Zhao ◽  
Zhengxiang Ning
Keyword(s):  
Extraction Efficiency ◽  
Extraction Process ◽  
Extraction Time ◽  
Countercurrent Extraction ◽  
Bioactive Substances ◽  
Extraction Solvent ◽  
Microwave Assisted ◽  
Multi Stage ◽  
The Matrix ◽  
Substantial Concentration

A novel microwave assisted multi-stage countercurrent extraction (MAMCE) technique was developed for the extraction of dihydromyricetin from Chinese rattan tea, Ampelopsis grossedentata. The technique combined the advantages of microwave heating and dynamic multi-stage countercurrent extraction and achieved marked improvement in extraction efficiency over microwave assisted batch extraction. Analysis of dihydromyricetin concentrations in the solvent and matrix throughout the extraction process showed that by dividing the extraction into multiple stages and exchanging of solvents between stages, steady and substantial concentration gradients were established between the matrix and solvent, thus enabling the achievement of high extraction efficiency. The yield of dihydromyricetin was significantly affected by temperature, pH, solvent/material ratio and extraction time, and optimal extraction conditions were found to be 80-100°C, at acidic pH with a solvent/material ratio of 25-30 to 1 and extraction time of 5-10 min. With the high extraction efficiency and low usage of extraction solvent, MAMCE could prove to be a promising extraction technique which can be applied to the extraction of dihydromyricentin and other bioactive substances from natural materials.

An Algorithm to Extract Expressive Timing and Dynamics from Piano Recordings

2007 ◽  
Vol 11 (2) ◽  
pp. 155-182
Author(s):  
Andrew Earis
Keyword(s):  
Piano Music ◽  
Extraction Process ◽  
Morlet Wavelet ◽  
Continuous Wavelet ◽  
Musical Score ◽  
Piano Performance ◽  
Multi Stage ◽  
Keyboard Music ◽  
Audio Recordings ◽  
Recorded Performance

Measurable features of expressive piano performance include timing, dynamics, articulation and pedalling. This paper concerns the measurement of expressive timing and dynamics in audio recordings of piano music using a multi-stage semi-automated expression extraction process. A digitised version of the musical score is synchronised with the audio recording using a simple manual beat tapping system. The continuous wavelet transform (CWT) is then employed, with a Morlet wavelet, to correct the beat tapped times, and any further errors are then corrected manually. Precise note and chord onset times and dynamics of the recorded performance can then be calculated using the CWT. Sample results of the measurement of expression in keyboard music by Bach are given and the application of the algorithms to end users discussed.

scholarly journals Studies on Effect of Temperature on Asphaltene precipitation using Multi Stage Extraction

2017 ◽  
Vol 7 (1.1) ◽  
pp. 599
Author(s):  
Kethineni Chandrika ◽  
N Sampath ◽  
Jobin V J ◽  
E Seetha Ramaiah ◽  
Vishnu Vipin ◽  
...  
Keyword(s):  
Good Yield ◽  
Maximum Yield ◽  
Extraction Process ◽  
Extraction Time ◽  
Effect Of Temperature ◽  
Solvent Ratio ◽  
Multistage Process ◽  
Asphaltene Precipitation ◽  
Extraction Percentage ◽  
Multi Stage

In the case of asphaltene extraction, single stage extraction given a maximum yield at 30°c with the sample to solvent ratio of 1:25. The time taken for the extraction process is 24 hours. In the case of long step extraction process its sample to ratio is 1:4. When the temperature increased in the process the yield also started increasing. The maximum yield we could get in the temperature range of 30°c to 50°c. It is possible to reduce the extraction time by increasing the temperature and it gives a good yield of asphaltene with the usage of multistage process. It increased the asphaltene presence about 69% in the solvent. The asphaltene yield at 30°c give raise an extraction of 85% in a six-stage extraction process. It is possible to get the same extraction percentage in a temperature of 50°c with three stage extraction process.  

Treatment of Oilfield Sewage by Thermal Distillation Technology

2014 ◽  
Vol 955-959 ◽  
pp. 2911-2914
Author(s):  
Jia Bin Zhu ◽  
Shu Zhong Wang ◽  
Jian Ping Yang
Keyword(s):  
Waste Heat ◽  
Water Shortage ◽  
Extraction Process ◽  
Low Grade ◽  
Water Recovery ◽  
Vapor Compression ◽  
Steam Assisted Gravity Drainage ◽  
Multi Stage ◽  
Liaohe Oilfield ◽  
Flash Distillation

A large amount of waste heat is generated in the oil extraction process when using steam assisted gravity drainage (SAGD) technology. Thermal distillation technology is recommended to deal with the Liaohe Oilfield sewage. It not only can utilize the low-grade energy source, but also can recover the water to settle the water shortage problem. The principles and processes of multi-stage flash distillation (MSF), multi-effect distillation (MED) and vapor compression (VC) are introduced, and the tech-economic analysis is also made. It is found that it has significant advantage in heat and water recovery using the MED technology to deal with the Liaohe Oilfield sewage.

Modelling a Multi-Stage Diffuser for Sucrose Extraction in Sugarcane Biorefineries

2017 ◽  
Vol 379 ◽  
pp. 149-156
Author(s):  
Larissa de Souza Noel Simas Barbosa ◽  
Patrícia Aparecida Santiago ◽  
Paulo Seleghim Jr.
Keyword(s):  
Extraction Efficiency ◽  
Sucrose Concentration ◽  
Extraction Process ◽  
Operating Conditions ◽  
Lumped Parameter Model ◽  
Sugar Concentration ◽  
Momentum Balance ◽  
Flow Rates ◽  
Capital Costs ◽  
Multi Stage

The extraction of sugar is one of the first and main stages of sugarcane processing, and obtaining high sucrose extraction efficiencies is essential for the productivity of ethanol and sugar industries. In recent years, the number of diffusers for sucrose extraction has been increasing significantly in Brazil due to several reasons, the main ones being their higher efficiency, lower energy costs and lower maintenance and capital costs. Different factors may influence the sucrose extraction efficiency in industrial diffusers, such as operating conditions that are different from nominal equipment design conditions. Thus, the objective of this work is the modelling of a sucrose extraction process, in a multi-stage sugarcane industrial diffuser. The extraction process was first transformed into a mathematical model using phenomenological equations for the mass and momentum balance considering a lumped parameter model approach. The formulated equations were then modelled in LabVIEW and the model was tested through the analysis of the influence of the input variables in the diffuser’s extraction efficiency. Five scenarios were considered and different imbibition liquid input positions and mass flow rates, as well as different percolation liquid recirculation rates were evaluated. The results show that: (1) the insertion of imbibition liquid in more than one stage decreases the percolation velocities in most of the stages, increasing the concentration of sugar in the megasse but also increasing the concentration of sugar in the final juice; (2) higher imbibition flow rates increases the percolation velocity and, therefore, decrease sucrose concentration in the megasse. However, it dilutes the extracted juice; (3) higher recirculation rates to the same stages increase the percolation velocity and benefit sucrose extraction efficiency, decreasing the sugar concentration in the megasse and increasing the sugar concentration in the juice. Yet, a limit for the increase in recirculation must be respected in order to prevent flooding. All the obtained results were consistent and showed that the model is able to project the operation of a diffuser. In a next stage, a multi-objective optimization will be performed in order to optimize operational conditions of the equipment.

Freeze-Etch Crystal-Like Structures in Membranous Glomerulosclerosis

1969 ◽  
Vol 27 ◽  
pp. 394-395
Author(s):  
Burton B. Silver
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Sodium Hypochlorite ◽  
Kidney Tissue ◽  
Extraction Process ◽  
Donor Kidney ◽  
Unknown Substance ◽  
Etched Surface ◽  
Standard Fixation ◽  
Diseased Kidney

Tissue from a non-functional kidney affected with chronic membranous glomerulosclerosis was removed at time of trnasplantation. Recipient kidney tissue and donor kidney tissue were simultaneously fixed for electron microscopy. Primary fixation was in phosphate buffered gluteraldehyde followed by infiltration in 20 and then 40% glycerol. The tissues were frozen in liquid Freon and finally in liquid nitrogen. Fracturing and replication of the etched surface was carried out in a Denton freeze-etch device. The etched surface was coated with platinum followed by carbon. These replicas were cleaned in a 50% solution of sodium hypochlorite and mounted on 400 mesh copper grids. They were examined in an Siemens Elmiskop IA. The pictures suggested that the diseased kidney had heavy deposits of an unknown substance which might account for its inoperative state at the time of surgery. Such deposits were not as apparent in light microscopy or in the standard fixation methods used for EM. This might have been due to some extraction process which removed such granular material in the dehydration steps.

Planning and Search in Multi-Stage Risky Decision Making

2011 ◽  
Author(s):  
Jared Hotaling ◽  
Jerry Busemeyer ◽  
Richard Shiffrin
Keyword(s):  
Decision Making ◽  
Risky Decision Making ◽  
Risky Decision ◽  
Multi Stage

Effects of Cooking Oil Subsidy Removals on Related Markets in Malaysia: A Comparative Static, Multicommodity, Multi Stage Production Approach

2011 ◽  
Author(s):  
Jamal Othman ◽  
Yaghoob Jafari
Keyword(s):  
Equilibrium Model ◽  
Comparative Statics ◽  
Partial Equilibrium ◽  
Cooking Oil ◽  
Multi Stage ◽  
Supply Factor ◽  
Partial Equilibrium Model ◽  
Factor Markets ◽  
Input Markets ◽  
Production Approach

Malaysia is contemplating removal of most of her subsidy support measures including subsidies on cooking oil which is largely palm oil based. This paper aims to examine the effects of cooking oil subsidy removals on the competitiveness of the oil palm subsector and related markets. This is done by developing and applying a comparative static, multi-commodity, partial equilibrium model with multi-stages of production function for the Malaysian perennial crops subsector which explicitly links different stages of production, primary and intermediate input markets, trade, and policy linkages. Results partly suggest that export of cooking oil will increase by 0.2 per cent due to a 10 per cent cooking oil subsidy reduction, while domestic output of cooking oil may eventually see a net decline of 1.97 per cent. The results clearly point out that the effect of reducing cooking oil subsidies is relatively small at the upstream levels and therefore it only induces minute effects on factor markets. Consequently, the market for other agricultural crops is projected to change very marginally.   Keywords: Multicomodity, comparative statics, partial equilibrium model, output supply-factor markets linkages, effects of cooking oil subsidy removals.

Biorefinery implementation for recovery debottlenecking at existing pulp mills- Part II: Techno-economic evaluation

TAPPI Journal ◽  
2012 ◽  
Vol 11 (8) ◽  
pp. 17-24 ◽  
Author(s):  
HAKIM GHEZZAZ ◽  
LUC PELLETIER ◽  
PAUL R. STUART
Keyword(s):  
Cost Estimation ◽  
Process Model ◽  
Black Liquor ◽  
Pulp Mill ◽  
Value Added ◽  
Economic Assessment ◽  
Extraction Process ◽  
Estimation Methods ◽  
Precipitation Process

The evaluation and process risk assessment of (a) lignin precipitation from black liquor, and (b) the near-neutral hemicellulose pre-extraction for recovery boiler debottlenecking in an existing pulp mill is presented in Part I of this paper, which was published in the July 2012 issue of TAPPI Journal. In Part II, the economic assessment of the two biorefinery process options is presented and interpreted. A mill process model was developed using WinGEMS software and used for calculating the mass and energy balances. Investment costs, operating costs, and profitability of the two biorefinery options have been calculated using standard cost estimation methods. The results show that the two biorefinery options are profitable for the case study mill and effective at process debottlenecking. The after-tax internal rate of return (IRR) of the lignin precipitation process option was estimated to be 95%, while that of the hemicellulose pre-extraction process option was 28%. Sensitivity analysis showed that the after tax-IRR of the lignin precipitation process remains higher than that of the hemicellulose pre-extraction process option, for all changes in the selected sensitivity parameters. If we consider the after-tax IRR, as well as capital cost, as selection criteria, the results show that for the case study mill, the lignin precipitation process is more promising than the near-neutral hemicellulose pre-extraction process. However, the comparison between the two biorefinery options should include long-term evaluation criteria. The potential of high value-added products that could be produced from lignin in the case of the lignin precipitation process, or from ethanol and acetic acid in the case of the hemicellulose pre-extraction process, should also be considered in the selection of the most promising process option.

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