Proses Penghasilan Kitin daripada Kulit Udang

Chitin is produced from prawn shells by removing protein and calcium carbonate. This production process is not well understood and is not amenable to mathematical modelling normally applicable to other chemical processes. The main aim of the present study is to identify process variables such as particle size, concentration of NaOH solution, temperature and protein removal time, concentration of HCl acid, temperature and chalk removal time which have significant effect on the chitin content (an indicator for chalk removal) and nitrogen (an indicator for protein removal) in the product. Factor analysis method is used. This study found that NaOH concentration, temperature and protein removal time affect the protein removal rate whereas the effect of particule size nonexistent. HCl concentration, temperature and chalk removal time are found to affect the chalk removal process. Linear models have been proposed for both cases by using the linear regression method. This process is currently being optimized in a further study

Determination of Optimal Conditions for Extraction of Alcohol-soluble Eugenol Containing Material from Cloves

Clove oleoresin (total soluble extract matter) contains an antioxidant compound eugenol. Extraction of eugenol from cloves was studied using 95% ethanol.Trials varying in particle size, extraction temperature, extraction time and solvent to solid ratio were performed and optimal conditions were evaluated. Refractive index was used to monitor the extraction parameters. Extraction patterns of ground clove fractions with size of 500 pm, 355 pm, 250 pm and less than 250 pm with solvent to solid ratio of 4: 1 at room temperature were studied. Agitation was ensured by a reciprocating shaker. Optimal size for the extraction at room temperature was 250 pm. Trials on extraction temperature were varied from 30°C to 70°C with the same solvent to solid ratio for particle size of 250 pm and 355 pm. Optimal tempel-atures for 250 Fll1 and 355 pm were 50°C and 60°C respectively

Proses Penghasilan Bromelin daripada Batang Nenas

A proteolytic enzyme called bromelin can be produced from pineapple stem by precipitating it from pineapple stem juice and separating the precipitate from the juice. Acetone is used as the precipitant. The precipitating process is performed twice and the second precipitate is taken as the bromelin product. This process is not well understood and is not amenable to mathematical modelling. The main aim of the present study is to identify process variables such as the precipitant: juice ratio, precipitation time and centrifugation time in every stage which have a significant effect on the yield and activity of bromelin. Factor analysis is used. This study found that the centrifugation times in both stages, precipitation and centrifugation times in the second stage affect the yield of bromelin. The enzyme activity is affected by the precipitant: juice ratio, the precipitation and centrifugation times in the first stage,' precipitant: juice ratio and precipitation time in the second stage. This process is currently being optimised

Drying Characteristics of Malaysian Padi

In this paper, the drying behaviour of Malaysian padi was studied using the thin layer method. Characteristic drying curves of padi were determined using an environmental chamber. The experiments were conducted over a temperature range of between 30°C to 70°C, air relative humidity from 30% to 80% and air velocity from 0.12 to 1 m/s. No constant rate periods was observed. Mass loss, temperature, relative humidity and air velocity were monitored on a personal computer. From the drying curves, two falling rate periods were observed, namely an initial rapid drying period and a subsequent gradual drying period. The normalised drying rate versus normalised moisture content was regressed by least square method to fit a new polynomial model for the first falling rate period and a linear model for the second falling rate period. Both the polynomial and linear models estimate the falling rate periods quite wel

The effect of storage on the quality attributes of ultraviolet-irradiated and thermally pasteurised pineapple juices

The effect of storage time on the quality of ultraviolet-irradiated and thermally pasteurised pineapple juice was evaluated. The juices were irradiated with ultraviolet light (UV-C) at wavelength 254 nm (53.42 mJ/cm2, 4.918 s), thermally pasteurised at 800C for 10 minutes and stored at 40C for 13 weeks. There were significant changes in the total soluble solids, pH, titratable acidity and turbidity of UV-irradiated juice during storage, whereas for the same quality attributes of thermally pasteurised juice remained stable throughout the storage time. There were no significant changes in total phenolics for both treatments throughout the storage period. Other quality parameters (ascorbic acid, colour L, hue angle and chroma) were significantly affected by the storage time. Regarding the microbiological analysis, the total plate counts and yeast and mould counts of the UV-irradiated juice increased gradually throughout the 13 weeks of storage while these parameters remained unchanged in the thermally pasteurised juice with almost no microorganism growth. UV-irradiated pineapple juice preserved better quality attributes (TSS, pH, titratable acidity, ascorbic acid, turbidity, total phenolic, L (lightness), hue angle and chroma) than the thermal pasteurised juice during the storage time. Hence, UV irradiation has great potential as an alternative technology to thermal pasteurisation in producing products of high nutritive values

Steam Reforming of Glycerol over Ni Supported Alumina Xerogel for Hydrogen Production

AbstractMomentous amount of glycerol is produced as a by-product during bio-diesel production by the transesterification of vegetable oils, which are available at low cost in large supply from renewable raw materials. As hydrogen is a clean energy carrier, conversion of glycerol to hydrogen is one among the most attractive ways to make use of glycerol. In this study, the catalytic production of hydrogen by steam reforming of glycerol has been experimentally performed in a fixed-bed reactor. The performance of this process was evaluated over 10wt% Ni supported alumina xerogel catalysts. Ni is impregnated over alumina xerogel which was pretreated at different temperatures of 700°C, 800°C, 900°C and 1000°C. For a comparative purpose, the steam reforming experiments were conducted under same operating conditions, i.e., reaction temperature of 600°C, atmospheric pressure and 1:6 glycerol to water molar ratio where we are getting 100% glycerol conversion in all the runs. The results showed that the hydrogen production increased with the increase in the treatment temperature of the support. The highest amount of hydrogen produced was attained over 10wt% Ni doped alumina xerogel pretreated at 1000°C. The catalytic enhancement over the best catalyst system is due to the thermal stability of the support which is treated at highest temperature. Sol gel method of preparation is implemented in the support development and different catalyst systems used in the reforming process were characterized using X-ray powder diffraction, BET surface area and SEM analysis

ENERGY BALANCE OF SOLAR HYDROGEN THE ECO-HOUSE

Energy system of the future will have to be cleaner and mach more efficient, flexible and reliable. Hydrogen is a clean and sustainable form of energy that can be used in mobile and stationary applications and is answer to satisfying many of our energy needs while reducing carbon dioxide and other greenhouse and gas emissions. The paper presents the power and mass balance of Eco-House Solar Hydrogen Energy system (ECO-House SHES). These will pave the way to study of electrolyzer, fuel cell, photovoltaic performance, and also a futuristic sustainable, environment friendly and bioclimatic residential dwellings. Sunlight hits the photovoltaic panels, which convert solar energy into DC electricity. Inverter will convert DC electric to AC electric, and this electricity will be used to run electrolyzer, and over current connected to grid. The hydrogen product of electrolyzer is stored in a storage tank at 150-200 psi pressure. The hydrogen will be converted to electricity by fuel cell unit, and also can supply fuel to household appliances. A data acquisition unit will take data of ambient temperature, PV cell temperature, Wind speed, air humidity, solar radiation, voltage and current of PV, connect to grid, to electrolyzer unit and electrolyzer cells stack, and electrical product of Fuel cell unit. Also flow rate hydrogen product of electrolyzer, hydrogen consumed of Fuel cell unit. The obiective is to improve the efficiency of the solar hydrogen energy system and it reliability

Prediction of Chromatographic Separation of Eugenol by the Fast Fourier Transform Method

The switching time to change from adsorption to desorption in liquid chromatography, which is the time at which the concentration of the effluent reaches the breakthrough value, is important in the operation, scale-up, and optimisation of chromatographic separation. The switching time can be estimated by computer simulation of the chromatographic adsorption column. In this paper, the theoretical simulation of the chromatographic column of Chen and Hsu (1987) based on the Fast Fourier Transform (FFT) method originally proposed for chromatographic systems by Hsu using estimated axial diffusivity, film mass transfer coefficient and pore diffusivity obtained from analytical scale separation, is compared with experimental data of chromatographic separation of eugenol. The use of FIT over more sophisticated techniques such as finite difference or orthogonal collocation methods was dictated by the simpler computation and the availability of better inverting techniques. The model was validated by experimental data on chromatographic separation of eugenol on IBondapak CIS analytical column, mobile phase methanol-water (80:20), and flow rate 0.5 ml/min, at different solution concentration injection at equilibrium condition. Physical property data required for validation such as equilibrium adsorption isotherm data was determined experimentally, and mass transfer data was calculated from normal correlations and from analytical scale separation. The simulation agreed with experimental data at a Peclet number of 6000, a bed length parameter of 3.0 and number of samples 90

Equilibrium Relative Humidity-Equilibrium Moisture Content Isotherms of Oil Palm Kernels

Equilibrium relative humidity-equilibrium moisture content (ERH-EMC) or moisture isotherms of solids is important in the drying, solid mixing, packaging and storage of such material. ERH-EMC isotherms of oil palm kernels are determined by using a constant environmental chamber for several combination of air relative humidity (30-90%) and temperature (30-70°C). The isotherms are found to fit the Hasley and Henderson equations well

The Activity of Ni-Based Catalysts on Steam Reforming of Glycerol for Hydrogen Production

Glycerol, the readily available bio renewable material, is effectively utilized for hydrogen production by a steam reforming reaction. The experiments were carried out in a continuous flow fixed-bed reactor over Nickel supported alumina catalysts under atmospheric pressure at 600°C and three hours reaction time. 5%wt Ni was loaded over γ-Al2O3 and effect of promoter metals such as Fe and Co over Ni/γ-Al2O3 catalytic systems were evaluated. The catalysts were characterized by BET surface area, XRD and SEM techniques. The activity results showed that the addition of Co enhanced the catalyst performance. The catalysts exhibited a good activity and selectivity to hydrogen