12 research outputs found

    H2 PRODUCTION FROM BIOMASS GASIFICATIONWITH ENRICHED SYN-GAS BY ABSORPTION METHOD

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    oai:ojs.ijitr.com:article/1Hydrogen-enriched syngas(HESG), addresses two dominant energy and environmental issues: decarbonization and improved energy management. Reducing the CO2 content of syn-gas widens our efforts to build a bridge to an ultra-low carbon world. With HESG, it becomes possible to reduce emissions, improve the efficiency of end-use equipment and lower the overall carbon intensity of syngas in the years to come. Higher CO2 content in the syngas also lowers the calorific value. This work is aimed at reducing the CO2 content in the syngas by absorption process. For this purpose we have taken the help of ASPEN PLUS simulator. The rate-based non-equilibrium, RateFrac, model is used for column design. Mono ethanolamine (MEA) is taken as liquid solvent and various parameters like flow rate and temperature of the solvent and number of segments of the absorption column were varied to test the CO2 absorption efficiency of the solvent. Similarly CaO absorption efficiency was found by experimental methods for gasification process carried out under different conditions like variation in temperature, equivalence ratio and steam to biomass ratio. The efficiency was found to be less than 30% due to ineffective fluidization

    Effect of superficial gas velocity and ratio of bed volume to reactor volume of inverse fluidized bed biofilm reactor on the removal of ammonia-nitrogen from wastewater

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    709-716Hydrodynamic parameters of an inverse fluidized bed biofilm reactor (IFBBR) have been studied using spherical polypropylene (PP) particles having average diameter and density of 5.63 mm and 920 kg/m3 respectively. Gas-phase holdup (g) was analyzed for various ratios of settled bed volume to reactor volume (Vb/Vr) and superficial gas velocities (Ug) with a liquid recirculation velocity (Ul) of 0.0021 m/s. The g values were found to increase with Vb/Vr ratios up to a certain limit and then decrease with further increase of Vb/Vr ratios. The effect of Ug, Vb/Vr ratios, and initial concentration of ammonia-nitrogen (NH4 +-N) on the removal of NH4 +-N from synthetic wastewater were studied. The optimal values of Vb/Vr ratio and Ug were found to be 0.380 and 0.0085 m/s respectively for all initial NH4 +-N concentrations. Complete removal of NH4 +-N was achieved in 8 to 44 hours for different initial NH4 +-N concentrations. It was also observed that with the increase in initial NH4 +-N concentrations, the nitrification decreases

    CFD simulation for hydrodynamic behaviour of fine particles in a fluidized bed

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    The fluidization characteristics of fine particles i.e. Geldart–C and A particles are studied in a cylindrical fluidized column. The effects of different system parameters (viz. static bed height, particle density, size of particle, speed of promoter and superficial velocity of the fluidizing medium) on bed dynamics are analyzed. CFD simulation is carried out for the hydrodynamic behaviour of fine powders. The values of these bed dynamics obtained through CFD simulation are compared against the respective experimental values. The comparison results show very good agreement between the experimental and simulated results thereby indicating the possibility of smooth or proper fluidization for fine particles. Thus these findings will be helpful in designing a good fluidized bed reactor for fine particle system can optimize the processes very well

    CFD simulation for hydrodynamic behaviour of fine particles in a fluidized bed

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    253-261The fluidization characteristics of fine particles i.e. Geldart–C and A particles are studied in a cylindrical fluidized column. The effects of different system parameters (viz. static bed height, particle density, size of particle, speed of promoter and superficial velocity of the fluidizing medium) on bed dynamics are analyzed. CFD simulation is carried out for the hydrodynamic behaviour of fine powders. The values of these bed dynamics obtained through CFD simulation are compared against the respective experimental values. The comparison results show very good agreement between the experimental and simulated results thereby indicating the possibility of smooth or proper fluidization for fine particles. Thus these findings will be helpful in designing a good fluidized bed reactor for fine particle system can optimize the processes very well

    Effect of C/N ratio, temperature, and pH on the removal of ammonia-nitrogen from wastewater using inverse fluidized bed biofilm reactor

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    429-435Experiments have been carried out in an inverse fluidized bed biofilm reactor (IFBBR) to study the effects of carbon to nitrogen (C/N) ratio, temperature (T), and pH on the removal of ammonia-nitrogen (NH, N) from wastewater using muxed microbial-culture IFBBR is operated at settled bed volume to reactor volume ratio (V/V) of 0.380, superficial gas velocity (U) of 0.0085 m/s, and liquid recirculation velocity (U) of 0.0021 m/s. Three initial NH, -N concentrations (40, 100, and 200 mg/L) are considered here. Effects of different parameters are studied for wastewater treatment by varying C/N ratio from 0.0 to 2.5. T from 26 to 34°C, and pH from 7.5 to 9.0. Maximum NH-N removal is observed at C/N ratio of 0.0, T of 30°C, and pH of 8.3. NHN removal is found to decrease with increase in C/N ratio. Both NO, N formation and nitrification percentage are found to decrease with increase in C/N ratio and initial NH4 N concentration Fractional Factorial Design analysis is used to predict the NH N removal. Average absolute percent deviation is found to be 11.75 implying the proposed correlation is in good agreement with experimental values. Kinetic constants are found to be higher than the values reported in literatures

    Facile Approach to Develop Durable and Reusable Superhydrophobic/superoleophilic Coatings for Steel Mesh Surfaces

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    Oil spills on the surfaces of bodies of water are now a great concern as they affect marine creatures and the ecosystem. Therefore, a facile technique for removal of oil from water is of much interest. In this study, superhydrophobic and superoleophilic coating is synthesized on stainless steel mesh via chemical etching using a mixture of FeCl3 and HCl followed by treatment with hexadecyltrimethoxysilane. Surface morphology analysis shows the presence of flower like microstructures on the surface after treatment. Superhydrophobic and superoleophilic properties have been achieved on stainless steel mesh with water static contact angle of 167° ± 3° water tilting angle of 6° ± 1° and oil static contact angle of nearly 0°. The coating shows excellent thermal, chemical and mechanical stability. Kerosene-water and hexane-water mixtures were successfully separated via a simple filtering process using coated steel mesh with a separation efficiency of more than 98%. This approach can be implemented on any shape or size of stainless steel mesh and will have industrial applications

    Enhancement of spray cooling by modify spray orientation and coolant characteristics

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    In the current work, using upward spray and NaCl added water, the Leidenfrost effect is significantly minimised in an ultrafast regime by cooling on a hot moving plate, and the heat removal enhancement rate is achieved at 2.15 times of water. The salt deposition on the steel augments CHF(Critical Heat Flux) and IHF(Initial Heat Flux) by bridging the droplet and hot plate's air gap and enhancing the momentum diffusivity. With NaCl added to water, the achieved corrosion rate is 0.79 mm/year lower than the SDS and Na2CO3 additives. The mechanical property analysis of the post-treated steel plate ensures significant tensile strength and hardness

    Effect of superficial gas velocity and ratio of bed volume to reactor volume of inverse fluidized bed biofilm reactor on the removal of ammonia-nitrogen from wastewater

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    Hydrodynamic parameters of an inverse fluidized bed biofilm reactor (IFBBR) have been studied using spherical polypropylene (PP) particles having average diameter and density of 5.63 mm and 920 kg/m3 respectively. Gas-phase holdup (g) was analyzed for various ratios of settled bed volume to reactor volume (Vb/Vr) and superficial gas velocities (Ug) with a liquid recirculation velocity (Ul) of 0.0021 m/s. The g values were found to increase with Vb/Vr ratios up to a certain limit and then decrease with further increase of Vb/Vr ratios. The effect of Ug, Vb/Vr ratios, and initial concentration of ammonia-nitrogen (NH4 +-N) on the removal of NH4 +-N from synthetic wastewater were studied. The optimal values of Vb/Vr ratio and Ug were found to be 0.380 and 0.0085 m/s respectively for all initial NH4 +-N concentrations. Complete removal of NH4 +-N was achieved in 8 to 44 hours for different initial NH4 +-N concentrations. It was also observed that with the increase in initial NH4 +-N concentrations, the nitrification decreases
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