Jusoh Mazura

Bio: Jusoh Mazura is an academic researcher from Universiti Teknologi Malaysia. The author has contributed to research in topics: Ice crystals & Response surface methodology. The author has an hindex of 2, co-authored 6 publications receiving 9 citations.

Preparation of ti-so3h/icg using microwave-assisted for esterification of palm fatty acid distillate to methyl ester

Abstract: The utilisation of low-cost yet valuable feedstock such as palm fatty acid distillate (PFAD) in the replacement of edible oils have a great potential in solving high-cost problem in biodiesel industries. Heterogeneous solid acid catalyst is the most proficient to esterify the feedstock containing high free fatty acid (FFA). Most of the prepared catalysts from the previous studies were produced using a conventional heating method which is basically time and energy consuming. The development of heterogeneous solid acid catalyst from sulfonated glucose and impregnation with titanium (Ti-SO3H/ICG) was prepared by using a microwave-assisted heating method with various heating time during the sulfonation process. The heating times taken were 3, 5, 7 and 9 min for acid treatment using H2SO4. The catalysts showed an outstanding result in reducing the catalyst separation problem and efficiently producing high percentage yield of biodiesel. The physical and chemical properties of the modified catalyst were analysed by using Temperature Programmed Desorption-Ammonia (TPD-NH3) and Brunauer-Emmett-Teller (BET). 7 min Ti-SO3/ICG showed the best performance catalyst due to its high surface area and acid site density, which were 78.37 m2/g and 15.16 mmol/g. The catalyst showed highest percentage yield and conversion of 98.92 % and 80.24 % at 70 °C, with a molar ratio of methanol to PFAD of 10 : 1, 2.5 wt% of catalyst loading and 90 min of reaction time. A kinetic model was studied and the activation energy (Ea) obtained was 13.43 kJ/mol.K, the lowest value recorded as compared with the activation energy from previous studies in related field.

Process Optimisation of Effective Partition Constant in Coconut Water via Progressive Freeze Concentration

Abstract: Concentration technique via progressive freeze concentration was applied to increase the concentration of coconut water for commercialisation. The process will eliminate portion of water from coconut water and retain pure nutritional compound with high sugar content. To obtain the optimum condition, which is the objective of this study, optimisation process was conducted using Response Surface Methodology (RSM) through STATISTICA Software. RSM was utilised to optimise the process parameters for effective partition constant(K) in progressive freeze concentration (PFC) of the coconut water. The effects of circulation flowrate, circulation time, initial solution concentration and coolant temperature on effective partition constant were observed. Results show that the data adequately fit the second-order polynomial model. The linear and quadratic independent variables, circulation flowrate, circulation time, initial concentration and coolant temperature have significant effects as well as interactions on the effective partition constant. It was observed that the optimum process parameters within the experimental range for the best K would be with circulation flowrate of 3,400 mL/min, circulation time of 23 min, initial concentration of 3.4 % Brix and coolant temperature of -7 °C. Under these conditions, the K can be enhanced up to 0.3.

Behaviour of Ice Crystal Growth in a Vertical Finned Cylindrical Freeze Concentrator

Abstract: Behaviours of ice crystal growth at two different operating parameters namely coolant temperature and circulation time were investigated for progressive freeze concentration (PFC) of glucose solution through a vertical finned crystallizer (VFC). Two determinant parameters which are ice production rate (mu), and water recovery (WR) were used to illustrate the behaviours of ice crystal growth in this study. From the result, higher ice production rate (mu) and water recovery (WR) were achieved at lower coolant temperature. On the other hand, longer circulation time resulted in lower ice production rate (mu), but at the same time increased the water recovery (WR). The maximum ice production rate (mu) and water recovery (WR) attained through this study were 1.522 gm-2s-1 and 51.131 %, respectively.

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

Abstract: 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

Abstract: 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.

Application of progressive freezing on forward osmosis draw solute recovery.

Abstract: Progressive freezing is a solvent purification technology with low energy requirements and high concentration efficiency. Although these advantages make it a promising technology, the technique has never been explored for draw solution recovery for forward osmosis (FO). Hence, in this study, the progressive freezing process was used to concentrate three common diluted draw solutions: NaCl, MgCl2, and EDTA-2Na with different ice front speeds, stirring rates, and initial draw solution concentrations. Effective partition and intrinsic partition constants were also evaluated. The results reveal that the freezing process can achieve a draw solution recovery rate of 99.73%, 99.06%, and 98.65% with NaCl, MgCl2, and EDTA-2Na, respectively, using an ice front speed of 0.5 cm/h, a stirring rate of 2.62 m/s, and 30% of percentage of ice phase. Higher concentration efficiency for NaCl and MgCl2 was achieved due to the high solubility of NaCl and MgCl2 increased solute diffusion into the liquid phase solutions. The concentration factors for all three draw solutions exceeded 1.9, indicating that the draw solutes could be reused for the FO process. In addition, the two mass transfer coefficients depended on the ice front speed and the stirring rates were also obtained for scaling up the experiment in the future.

Temperature field distribution of a freeze sinking shaft under seepage conditions in cretaceous formation of Western China

Abstract: Received: 8 January 2018 Accepted: 10 May 2018 This paper attempts to disclose the distribution law of artificial freezing temperature field in Cretaceous sandstone of western China and determine the key parameters of freeze sinking. For this purpose, a numerical model was established in light of the general conditions of freeze sinking project, the model parameters were optimized according to onsite monitored data, and the optimized model was applied to explore the change law of the freezing temperature field. The simulation reveals that the temperature of each measuring point decreased linearly with time, but the mean daily decline differed from point to point: the daily decline is negatively correlated to the distance from the freezing point, i.e. the temperature is positively correlated to the distance from the freezing point at the same time. The freezing time for closure was 79d at the groundwater flow rate of 50m/d. When the freezing intensity was weak (freezing tube temperature: -22°C), the frozen wall failed to achieve closure. This means the groundwater directly bears on the distribution of the temperature field. The freezing intensity has a nonlinear impact on the temperature field. The higher the temperature, the smaller the impact on the closure.

Optimization of progressive freezing on synthetic produced water by circular moving cylindrical crystallizer via Response Surface Methodology

Abstract: Treatment and disposal are two main approaches for water cycle management in the oil and gas industry. Freeze concentration has been identified as one of the methods to separate water from wastewater samples. The conventional method used for solution movement in progressive freezing technique is stirring by a stirrer. However, the stirrer requires frequent maintenance as it needs to be cleaned and requires longer cleaning time due to the complex structure of a stirrer. Thus, the new solution movement for progressive freezing is proposed, which is circular moving progressive freezing. This study aims to remove water from the wastewater sample (i.e., produced water). To optimize and investigate the effect of coolant temperature, freezing time and rotation speed, response surface methodology (RSM) was applied to determine the efficiency of the process and central composite design (CCD) was used to design the experiment. From the results, the optimum parameters were determined at the freezing time of 22.79 min, coolant temperature of −14.89 °C and rotation speed of 59 rpm. To evaluate the accuracy of the optimization process, a validation experiment was performed and water removal value of 89.67% was achieved.

Calcium Soap from Palm Fatty Acid Distillate for Ruminant Feed: The Influence of Initial Mixing Temperature

Abstract: The breastfeeding dairy cows often go through metabolic disturbances and low milk production due to the use of stored body fat and minerals to assist milk production. Those problems can be solved by feeding feed supplement to the dairy lactating cows. Calcium soap is a well-known lactating dairy cattle feed supplement, which gives energy in the form of protected fat so it can increase milk productivity of dairy cattle. This research studied the use of PFAD (Palm Fatty Acid Distillate) as the free fatty acids source and calcium oxide as a calcium source to produce calcium soap using modified fusion method with water as the reaction catalyst. This study evaluated the initial mixing temperature of PFAD as the parameter affecting the conversion of PFAD, which was determined by the product acid value. The result showed that, at the same mole ratio of calcium source to PFAD, the lower initial mixing temperature gave higher reaction conversion of PFAD. The recommended initial temperature for mixing was found to be 60 °C, which gave the acid value of the product in the range of 2.96 - 3.14 mg KOH/g sample for mole ratio of CaO/PFAD 1 - 1.15.