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Home>Products>Journal and Reviews>I.RE.Ch.E.>Latest issue
International Review of Chemical Engineering (Rapid Communications) - July 2009 - Papers
International Review of Chemical Engineering (Rapid Communications) - Papers
by Atul Sharma, C. R. Chen Vol. 1. n. 4, pp. 297-307
Abstract - Thermal energy storage has always been one of the most critical components in residential solar water heating applications. Solar radiation is a time-dependent energy source with an intermittent character. The heating demands of a residential house are also time dependent. However, the energy source and the demands of a house (or building), in general, do not match each other, especially in solar water heating applications. The peak solar radiation occurs near noon, but the peak heating demand is in the late evening or early morning when solar radiation is not available. Thermal energy storage provides a reservoir of energy to adjust this mismatch and to meet the energy needs at all times. It is used as a bridge to cross the gap between the energy source, the sun, the application and the building. So, thermal energy storage is essential in the solar heating system. Therefore, in this paper, an attempt has been taken to summarize the investigation of the solar water heating system incorporating with Phase Change Materials (PCMs). Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Solar Water Heating System, Thermal Energy Storage, Phase Change Material, Solar Energy, Latent Heat.
Vol. 1. n. 4, pp. 308-315
Abstract - Well-shaped spherical magnetic microspheres were prepared using a synthetic polymer of poly-(acrylonitrile-co-acrylamide). Their size varied from 100 up to 1000 μm proportionally to the flow rate of the polymer solution and their density was from 1030 to 1045 kg.m-3, depending on the magnetite content. Trypsin (EC 3.4.21.4) was chosen as model enzyme and immobilized on the acyl azide derivatives of microparticles with diameter approx. 500 μm. The impact of various parameters such as pH, initial protein/support ratio, magnetite content on the immobilization efficiency was investigated. The maximum amount of fixed protein was about 14.4 mg.g-1 dry support. The relative activity of immobilized trypsin represented about 90% of the corresponding activity of free enzyme. Optimal pH for enzyme reaction and Km’ for substrate BAPNA remained unchanged after the immobilization. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Immobilized Trypsin, Magnetic Beads, Synthetic Polymer.
Vol. 1. n. 4, pp. 316-323
Abstract - Direct scaling relationships allowing to fit bed expansion (porosity) curves magnetically assisted gas-fluidized beds (Magnetization FIRST mode) have been tested. Exponential-decay, asymptotic and power-law relationships have been used as approximating functions. The numerical experiments have demonstrated the applicability of the approximating function chosen to predict either the entire expansion curve profiles or the maximum bed expansion through simple asymptotes. The errors of approximations performed revealed less than in all trials and relationships established. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Fluidization, Magnetization FIRST, Tapered bed, Porosity correlations, Scaling relationship.
Vol. 1. n. 4, pp. 324-328
Abstract - Ultrafine particles of nickel carbonate have specific characteristics and important applications as catalysts, and magnetic materials. This study addresses preparation of nano-sized particles of nickel carbonate by chemical reactions in micro- emulsions and possible applications as catalysts. The particles prepared in this way are spherical with a size of about from 10 to 20 nm. The quantity of NiO in the catalysts (NiO/ TiO2 and NiO/ γ-Al2O3) developed have been established by atomic absorption spectroscopy, while both the particle morphology and the structure have been determined by scanning electronic microscopy. The catalytic activity of the composition NiO/ γ-Al2O3 has been studied by oxidative dehydration of ethane to ethene. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Nanoparticles, Nickel carbonate, W/O Microemulsion system, Nanocatalysts.
Vol. 1. n. 4, pp. 329-333
Abstract - Crude palm oil (CPO) is a renewable bio-based resource. It is an attractive alternative fuel which provides the potential to reduce emission problems. CPO is an example of biofuels that can be blended with petroleum distillates as a fuel in mobile engines and industrial processes to help offset the increasing energy demand. This paper highlights the results of blended Crude palm oil (CPO)/Medium fuel oil (MFO) as an alternative environmentally friendly boiler’s fuel. Physical properties and heating values of the blended fuels been presented. Emission test of a blend containing 50% CPO in MFO fuel was also examined using a commercial boiler had been conducted in a local oil palm mill in Malaysia. The blend burned satisfactorily without major modification to the appliance and fuel delivery system. Emission of SO2, H2S and NOx were very much reduced as compared to the combustion of MFO. Results indicate potential replacement for the petroleum distillates with this blend. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Biofuel, Crude palm oil, Emission, Greenhouse gas, MFO.
Abstract - New and renewable fuels are the major alternative to conventional fossil fuels. Biomass is a form of agricultural residues and is becoming popular among new renewable energy sources especially in an agricultural country such as Malaysia. Among the biomass, rice husk represents one of the highest agricultural wastes in Malaysia. Pyrolysis of biomass is one of the most important thermal conversion processes to produce bio-oil. The aim of the present study is to determine the characteristics and thermal degradation behavior of rice husk via thermal gravimetric analysis (TGA). Chemical analyses show that rice husk contains a high amount of organic constituents of hemi-cellulose (24%), cellulose (29%), and lignin (12.2%). Furthermore, the TG results show that the lignin is relatively more thermally stable than hemi-cellulose and cellulose. Evaluation of biomass resources as potential feedstock for conversion to bio-fuel generally requires information about proximate analysis, ultimate analysis, organic component analysis (hemi-cellulose, cellulose and lignin contents), and calorific value determination. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Biomass, Agriculture waste, Pyrolysis, Fuel, Organic Component.
Vol. 1. n. 4, pp. 339-345
Abstract - The oxidation of phenol solutions (10 g/L) has been studied in a batch reactor. Activity catalytic was performed over two type catalysts: CuO/γ-Al2O3 and NiO/γ-Al2O3 prepared in our laboratory. Isothermal runs between 973K and 1223K were carried out under an oxygen pressure of 25 atm. Phenol conversions as well as pH and temperature effect measurements were recorded. Almost complete phenol conversion was obtained for all catalysts. However, conversion to CO2 was only partial. Laboratory prepared catalysts gave the best performance in terms of activity and selectivity with the lowest induction period. Tests showed that catalysts are active in the conditions of operation. Measurement of titration calorimetric was realized. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Oxidation phenol, Catalyst, γ-Al2O3, pH, Temperature, Titration calorimetry.
Vol. 1. n. 4, pp. 346-356
Abstract - Discriminated dimensional analysis combined with the scale analysis has been implemented to obtain a strong analytical derivation of the correlations describing the pressure drop for low Reynolds number swirl flow in circular tube with twisted-tape insert. This analysis demonstrates a new insight on the phenomenon and reveals the relevant dimensionless parameters that play an independent role in the solution. The scaling by swirl parameter Resw/√y, , proposed previously, has been proved using discriminated dimensional analysis. The validity of the analysis is demonstrated by the excellent agreement between a large experimental data set for isothermal friction factors and the predictions of the π+4-π5 correlations for swirl transition and fully developed swirl-flow regimes. In discriminated dimensional analysis, the classical numbers fsw , Resw , and their product (fRe)sw are not relevant dimensionless parameters, and, consequently, they do not play an independent role in the solutions. Hence, the combination of and is artificial. Furthermore, discriminated dimensional analysis provides the characteristic pressure drop to make it a “discriminated” relevant dimensionless parameter. The π+4-π5 correlations provides a very reliable predictive tool for designing, optimizing, and estimating off-design hydrodynamic performance of tubular heat exchangers in which twisted tapes are employed to promote heat transfer enhancement. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Discriminated dimensional analysis, Swirl flow, Laminar flow, Pressure drop.
Vol. 1. n. 4, pp. 357-368
Abstract - Chemical-looping combustion (CLC), characterized by high efficiency, inherent CO2 separation and low NOX emission, is considered as one promising CO2 sequestration technology. The preparation of a suitable oxygen carrier for CLC is a key issue to realize the CLC technique. Recent advances on preparation and characteristics of oxygen carrier particles were reviewed in this paper. Based on a brief summary of CLC, the preparation materials and methods of oxygen carrier were introduced respectively. Finally, the physical properties of the oxygen carrier and reaction characteristics represented by the thermodynamics and kinetics were discussed. The feasibility of some materials used as oxygen carriers was evaluated through thermodynamic analysis. Three gas-solid reaction models were used to explain the reaction kinetics of the gas fuel combustion with oxygen carriers. It is a new trend to synthesis a preferable oxygen carrier using the low-cost ores and industry products instead of metal oxides and directly using the solid fuel in substitution for gas. Further, this review covers a brief introduction to the further application of CLC, especially chemical-looping hydrogen production. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Chemical looping combustion, Oxygen carriers, Fluidized beds, Preparation, Reaction kinetics, Hydrogen production.
Vol. 1. n. 4, pp. 369-374
Abstract - Effect of a non-uniform basic temperature gradient and magnetic field on the onset of Marangoni convection in a horizontal micropolar fluid layer bounded below by a rigid plate and above by non-deformable free surface subjected to a constant heat flux, is investigated in this study. Six different non-uniform basic state temperature profiles are considered. The resulting eigenvalue problem is solved using the Rayleigh-Ritz technique, and the influence of various parameters on the onset of convection is discussed. It is observed that the micropolar fluid layer heated from below is more stable compared to the classical fluid layer. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Marangoni convection, Non-uniform temperature, Magnetic field, Micropolar fluid.
Vol. 1. n. 4, pp. 375-383
Abstract
- Absorption refrigeration technology presents a promising alternative
for vapor compression cooling system due to the increase of the
environmental problems and electricity cost which made this
heat-operated cycle more attractive for both residential and industrial
applications. In order to assess the viability of these systems
economically, the user needs to assess the effect of some operational
parameters on system’s performance. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Absorption, COP, Thermodynamic model, Packed column absorber, Absorption rate, Packing.
Vol. 1. n. 4, pp. 384-391
Abstract - The biological treatment of an industrial poultry wastewater was studied in a jacketed cylindrical Sequencing Batch Reactor (SBR), in order to verify the effect of the filling step in the process performance. The experiments were carried out in a reactor with 7 L total capacity, starting with 2 L initial volume (activated sludge plus raw wastewater). Thus, the equation of the biomass concentration balance during filling step was solved. This solution allows us to understand the filling kinetic and determining the specific growth rate through the biomass concentration curve, that is a pseudo specific growth rate. Nevertheless, the real specific growth rate was determined from the biomass curve and consequently, the difference between these rates resulted in the dilution rate. Similar interpretation was carried out when the substrate balance was solved but, assuming that the substrate consumption followed a first order kinetic. The results showed the complexity and importance of the filling phase during the SBR operation applied to industrial wastewater. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Filling step, Kinetic parameters, Sequencing batch reactor.
Vol. 1. n. 4, pp. 392-393
This is a book with a multidisciplinary approach to process intensification in chemical industry – from laboratory level to the industrial implementations. 11 chapters written by eminent experts in the fields provide to the readers in industry and academia comprehensive sources of knowledge on hot topics in chemical engineering. The collection emphasizes the necessity for new modelling approaches in case of emerging new reactors , among them : microreactors, membrane reactors, ultrasound assisted reactors, simulated moving-bed chromatography, magnetic field assisted multiphase reactors and those operating with supercritical media.. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
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