Effective Partition Constant Research Articles

Effect of Coolant Temperature on Progressive Freeze Concentration of Refined, Bleached and Deodorised Palm Oil based on Process Efficiency and Heat Transfer

In this paper, raw material of refined bleached and deodorised palm oil (RBDPO) was separated into olein and stearin by applying progressive freeze concentration (PFC) as an alternative method to replace the conventional fractionation process using coil crystallizer. Overall heat transfer coefficient (U) was analyzed from the process by varying different coolant temperature values since both of them are closely related each other. In this case, heat transfer efficiency depends strongly on crystal of stearin formed on the inner wall of cooled surface and is explained theoretically from that angle. At optimum flowrate, operation time and initial iodine value (IV), the best results were observed at 28ºC of coolant temperature where high IV of olein and effective partition constant (K) obtained were 55.8 wijs and 0.27 respectively. Meanwhile, the highest U obtained at coolant temperature 28oC same as result for process efficiency at 392.9183 W/m².K and time at 55 min.

Effect of Circulation Flowrate on the Performance of a Spiral Finned Freeze Concentrator

Progressive freeze concentration (PFC) has emerged as a viable technology for concentration of liquid solution. In this study, a newly designed spiral finned crystallizer to improve productivity of PFC process was proposed. The spiral fin is presented based on the advantage of additional surface area to the spiral finned crystallizer. The performance of spiral finned crystallizer was analysed by the system efficiency and the effect of circulation flowrate. It was found that the efficiency of the system has significantly improved in terms of a lower effective partition constant and a higher recovered solute. An effective partition constant of 0.35 and a recovered solute of approximately 0.96 g of glucose per 1 g of initial glucose were obtained. Thus, spiral finned crystallizer for PFC system is evidently an effective system to concentrate solution and to produce pure ice crystal.

Progressive Freeze Concentration of Coconut Water: Effect of Coolant Temperature on Process Efficiency and Heat Transfer

In this research, coconut water was concentrated by applying progressive freeze concentration (PFC) using coil crystallizer. Overall heat transfer coefficient (U) was analyzed from the process by varying different coolant temperature values since both of them are closely related. In this case, heat transfer efficiency depends strongly on ice crystal formed on the inner cooled surface and is explained theoretically from that angle. At optimum flowrate, operation time and initial concentration best results were observed at-10oC of coolant temperature where the concentration efficiency and effective partition constant (K) obtained were 48% and 0.2 respectively. Meanwhile, U obtained at the first and second stages were 183.0046 W/m2oC but dropped at lower value at later stage at 154.9625 W/m2oC due to ice fouling.

Effect of Coolant Temperature on Desalination Process via Progressive Freeze Concentration

The world is still suffering from a shortage of clean water supply and the problem is expected to become more serious in the future. Consequently, researchers have been trying to find the best solution to address this problem by introducing new desalination technologies that are able to accommodate the demand for clean water which is increasing from time to time. One of the new technologies introduced is the desalination of seawater through freeze concentration. In this study, progressive freeze concentration (PFC) is implemented to produce pure water in the form of ice crystal block and leave behind a higher concentration solution. The effect of coolant temperature was investigated and the efficiency of the system was reviewed based on the value of effective partition constant, K which is defined by the ratio of solute in ice and liquid phase. The low value of K leads to the best efficiency for the system. Apart from that, the efficiency, E% and salinity reduction were also calculated in order to determine the system performance.

Effect of Coolant Temperature on Progressive Freeze Concentration of Refined, Bleached and Deodorised Palm Oil

This study focused on the possibility of separating refined, bleached and deodorized palm oil (RBDPO) into olein and stearin by using progressive freeze concentration (PFC) as an alternative method to replace the conventional fractionation process. PFC has the potential to be a more effective technique for olein-stearin separation, with minimal changes in the product’s quality for producing high quality edible oil. Apart from that, it requires fewer unit operations compared to conventional methods. In this research, the parameter of coolant temperature was selected to investigate the performance of PFC using stainless steel crystallizer. In order to determine the system efficiency, effective partition constant (K) was investigated, while the quality of the oil was evaluated by iodine value (IV), slip melting point (SMP) and the percentage of olein yield. From the results, all the determinant parameters were found to be optimum at the coolant temperature of 28°C. At this optimum point, K value, IV, SMP and olein yield were found to be 0.2715, 55.84 wijs, 23.10°C and 67.8537%, respectively.

Progressive Freeze Concentration of Coconut Water: Effect of Circulation Flowrate and Circulation Time

Progressive freeze concentration integrated with a coil crystallizer was applied to concentrate coconut water in order to increase its sugar content. In progressive freeze concentration system, only a single ice is formed as a layer on cooled surface. It is introduced as an alternative in compensating the disadvantages of conventional method of freeze concentration, called suspension freeze concentration. In this research, the efficiency of the progressive freeze concentration system was determined through effective partition constant (K) value and percent increment of sugar content. Hence, the effect of circulation flowrate ranging from 2000 to 2800 ml/min and circulation time from 10 to 18 minutes on those two variables was then investigated through experiments designated using one factor at a time. From the experimental work, it was found that higher efficiency results at higher circulation flowrate of 2800 ml/min based on lower K and high percentage of sugar increment achieved. It was also found that the percentage of the sugar increment is high when the period given for circulating the solution is increased and the most suitable circulation time is 14 minutes.

Effect of Flowrate and Circulation Time on Fractionation of Refined Bleached and Deodorised Palm Oil using Progressive Freeze Concentration Method

This research concerns on the possibility of separating refined, bleached and deodorised palm oil (RBDPO) into olein and stearin using another alternative through Progressive Freeze Concentration (PFC) to replace the conventional process of dry fractionation. The process was carried out in stainless steel coil crystalliser and the quality of olein and stearin and the performance of crystalliser to purify the olein were analysed. The quality of oil was evaluated through iodine value (IV) and Slip Melting Point (SMP), while for the performance of PFC, effective partition constant, K, and yield of olein were used to determine the system efficiency. The purified olein were obtained for IV and SMP at higher flowrate (2800 mL/min) and longer period of time (60 min) are 55.87wijs and 23.04°C, 55.89wijs and 23.08°C, respectively. Meanwhile, the best K and yield of olein were obtained at higher flowrate and time, giving values of 0.2369, 67.99% and 0.238 and 67.93%, respectively.

Application of progressive freeze-concentration for desalination

There is a demand for new and effective desalination technologies, as water shortage is expected to spread all over the world in the future. Among many methods, the freeze desalination process has some advantages such as high energy efficiency, corrosive resistance, and easy operation. In this study, a progressive freeze-concentration, currently used in food processing, was applied for desalination. The progressive freeze-concentration is a method to concentrate impurities into a liquid phase and obtain a pure solid phase by controlling an ice front one-dimensionally. The effect of three parameters (the advance speed of the ice front (U), the circumferential velocity of the stirrer (Ur), and initial concentration (C0)) were investigated by conducting the laboratory experiments. In order to evaluate the efficiency of the desalination process, effective partition constant (K), and intrinsic partition constant (K0) were introduced by adopting the concentration gradient model. The results showed the effect of three parameters on desalination successfully. Furthermore, at a certain Co, K can be expressed as a function of U, Ur and K0. This function is useful for scaling up the system.

Process Optimization of Effective Partition Constant in Progressive Freeze Concentration of Wastewater

Response surface methodology (RSM) was employed to optimize the process parameters for effective partition constant (K) in progressive freeze concentration (PFC) of wastewater. The effects of coolant temperature, circulation flowrate, initial solution concentration and circulation time on the effective partition constant were observed. Results show that the data were adequately fitted into a second-order polynomial model. The linear and quadratic of independent variables, coolant temperature, circulation flowrate, initial solution concentration and circulation time as well as their interactions have significant effects on the effective partition constant. It was predicted that the optimum process parameters within the experimental ranges for the best K would be with coolant temperature of -8.8°C, circulation flowrate of 1051.1 ml/min, initial solution concentration of 6.59 mg/ml and circulation time of 13.9 minutes. Under these conditions, the effective partition constant is predicted to be 0.17.

Performance Investigation on a New Design for Progressive Freeze Concentration System

Freeze concentration freezes or crystallizes water component in a solution out as ice crystals and leaves behind a highly concentrated solution. Conventional Suspension Freeze Concentration (SFC) system has to deal with difficult separation of ice formed in a suspension of the mother liquor, which leads to a high cost of operation. Scraped surface heat exchanger used to form seed ice to ensure production of large ice crystals also hiked up the capital cost involved. Progressive Freeze Concentration (PFC) is believed to be able to reduce the capital and operation cost by eliminating some unit operations used. In PFC, ice crystals were formed progressively as a single block of ice, on the surface where cooling is supplied. In this particular study, a new helical structured copper Crystallization Chamber (CC) was designed and fabricated. Three operating parameters which affect the performance of the system were investigated namely the circulation period, circulation flow rate and coolant temperature. Effective partition constant, K was used as an indication of the system efficiency and to assess its performance, calculated from the volume and concentration of the solid and liquid phase. Circulation period was found to produce a constant value of K at each period tested with the CC. It was also discovered that higher flowrate resulted in a lower K, which translated into high efficiency. The efficiency is the highest at 1000 mL min-1. The process also gives the highest efficiency at a coolant temperature of -6°C.

Tubular ice system for scale-up of progressive freeze-concentration

Progressive freeze-concentration is a method of freeze concentration with a single ice crystal formed on the cooling plate in the system. This makes the separation of ice crystal formed from the concentrated mother solution much easier than the conventional suspension crystallization method, in which many small ice crystals are formed. Tubular ice system with a large cooling surface area was shown to be effective as a method for scale-up of progressive freeze-concentration with an increased productivity and a high yield. In this method, the slower growth rate of ice and the higher circulation rate gave the lower effective partition constant as was expected theoretically by the concentration polarization model. The effective partition constant was also dependent on the initial solute concentration; the higher concentration gave the higher partition constant of solute. By tubular ice system, coffee extract, tomato juice, and sucrose solution were very effectively concentrated to high concentrations with good yields, showing the high potential of progressive freeze-concentration for practical applications.

Acid-Base and Complex-Forming Properties of 2-Dialkylaminomethylphenols with respect to Copper(II) in a Tetrachloromethane-Water Two-Phase System

The protolytic properties of 2-dialkylaminomethylphenols were characterized by effective partition constants in the tetrachloromethane-water medium at 298 K by means of two-phase potentiometric titration. A correlation was found between the effective partition constant including the dissociation constant of the protonated form of 2-dialkylaminomethylphenol and the π constants of the substituents. The partition constants of the compounds were calculated. The formation of 1:1 charged copper(II) complexes in aqueous solution and of 2:1 neutral complexes in the organic phase was revealed. The stability constants of the complexes in aqueous solution and the partition constants of the 2:1 complexes were estimated.

Progressive Freeze-Concentration of Tomato Juice.

Progressive freeze-concentration was applied to concentrate tomato juice. Effective partition constants of the solute between the solid and liquid phases were experimentally determined for total solid and potassium chloride (KCl)-equivalent salts. The partition constants were strongly dependent on the stirring rate at the ice front and the advance rate of that front. Increasing stirring rate and reducing advance rate of the ice front lowered the effective partition constant and improved freeze concentration performance. The partition constant was different between total solid and salts suggesting a different mechanism in the partition phenomena between the two components. Tomato juice of 4.3 wt% in solid content was concentrated up to 18.8 wt%. After the reconstitution of freeze concentrated tomato juice based on Brix, no substantial differences, except for salt content, were observed in acidity, vitamin C content, or color quality compared with before the concentration.

Effective Partition Constant of Solute between Ice and Liquid Phases in Progressive Freeze‐Concentration

ABSTRACTProgressive freeze‐concentration was effectively applied to concentrate glucose in a model solution. Effective partition constants of the solute between the liquid and solid phases were determined experimentally. The constant was strongly dependent on the stirring rate at the ice front and the advance rate of the ice front. Increasing stirring rate and reduced rate of advance lowered the effective partition constant: an improvement in freeze concentration performance. A concentration polarization model was useful to describe the effects of the operating conditions on the effective partition constant.