Fig. 2.3 Schematic representation of a high-temperature fluidized bed reactor used in the preparation of carbonaceous adsorbents. Fig. 5.4(a) Comparison of calculated equivalence ratio values obtained from dimensionless analysis with the experimental values. Fig. 5.4(b) Comparison of calculated values of Euler's number obtained from dimensionless analysis with the experimental values.
THESIS-SYNOPSIS
The effect of Parameters on the performance of a Fluidized Bed Reactor and Gasifier
Graphical abstract of a fluidized bed reactor
Both theoretical and experimental results show that the system parameters play a crucial role in the optimal design of a fluidized bed reactor. Thus, the current laboratory-level work can be suitably adapted over a wide range of parameters for a commercial or large-scale fluidized bed reactor. C., (2009), Effect of secondary fluidizing medium on the hydrodynamics of gas-solid fluidized bed statistical and ANN approaches, Chemical Engineering Journal.
CHAPTER-1
INTRODUCTION
Activation energy; Higher activation energy for a reaction implies that the reactants need more energy to participate in the reaction than the reactants of a reaction with lower activation energy. A fluidized bed reactor (FBR) is a type of reactor device that can be used to perform a variety of multiphase chemical reactions. The principle behind this is that the solid substrate (the catalytic material upon which chemical substances react) material in the fluid bed reactor is typically supported by a porous plate known as a distributor.
APPLICATIONS OF FLUIDIZED BED REACTOR
The software must solve the mass and energy balance to find a stable operating point. It is essentially an optimization problem to be solved in an iterative process. The first fluidized bed gas generator was developed by Fritz Winkler in Germany in the 1920s.
ADVANTAGES OF FLUIDIZED BED REACTOR
- Experimental
- Computational
In this work, we also tried to study the gasification processes of biomass samples in a fluidized bed reactor. To determine the equivalence ratio and carbon conversion efficiency of biomass samples in the Hot-model gasification unit. MAT LAB coding was developed for a catalytic fluidized bed reactor to know the effects of parameters such as static bed height, residence time, etc.
CHAPTER-2
LITERATURE SURVEYS
PRINCIPLES OF FLUIDIZED BED REACTOR
As the fluid velocity is increased, the reactor will reach a stage where the force of the fluid on the solids is sufficient to balance the weight of the solids. Once this minimum velocity is exceeded, the contents of the reactor bed begin to expand a. As the fluid velocity is increased, the reactor will reach a stage where the on the solids is enough to balance the weight of the solids.
PREVIOUS WORKS
Combustion studies with metallurgical cokes were also carried out in batch experiments in an electrically heated fluidized bed reactor. Kp[kg/(cm2 s atmo2)] = 30 exp(-22,340/RTp) (2.2) The performance of a pilot fluidized bed membrane reactor (FLBMR) was experimentally investigated in comparison with conventional operation as a fluidized bed reactor. (FLBR) for the catalytic oxidative dehydrogenation of ethane using a g-alumina supported vanadium oxide catalyst [9]. A group of authors conducted experiments with eight different coals in batch fluidized bed reactors.
The fluidized bed reactor can also be used for the production of adsorbents in the removal of malachite green. Steam activation was carried out in a high-temperature fluidized bed reactor (FBR), using steam as the quenching medium. Figure 2.3: Schematic representation of a high-temperature fluidized bed reactor used in the preparation of carbonaceous adsorbents.
Figure-2.4: Formation and reduction of NO and N2O during coal combustion Reaction kinetics of conversion of uranium tetrafluoride to uranium hexafluoride has also been studied with fluorine gas in a fluidized bed reactor operating under industrial conditions [27]. Pyrolysis and gasification performed in a fluidized bed reactor (316 stainless steel) are as shown in figure-2.6. Knowledge of the bed pressure drop and fluctuation ratio in gas-solid fluidization is important in the design of fluidized bed reactors and combustors, especially for the calculation of bed height.
The effect of different sized particles on the heat transfer coefficient between biomass particles and a fluidized bed was modeled.
CHAPTER-3
RAW MATERIALS USED 1. Biomass samples
EXPERIMENTAL PROCEDURE 1. Cold Model Experimentation
- Hot model experimentation
The unit consists of an air blower, an air accumulator, U-tube manometer, three reciprocating pumps connected to three screw feeders to feed biomass and bed materials, bubble cap type distribution plate, bed type gasification unit liquid and a cyclone separator. First, the starter fan switch is turned on, so that air passes through the air accumulator to the gasification unit. The gasification unit is composed of mild steel and the insulating material is high aluminum.
Once the bed material is injected, some external heat is given to the bed material by means of liquid petroleum gas at 20 lpm rate for initial heating purposes. When the bed temperature reached 500oC, biomass was fed to the unit at a high speed of about 90 rpm speed to prevent blocking of biomass in the screw feed section. The pipe through steam passages is made of copper material, because it has a high thermal conductivity.
The gasification process was initiated and completed through four steps (i.e. drying, combustion, gasification and pyrolysis) in the gasifier. The resulting flue gases, together with some dust particles, were led to the cyclone separator to separate the flue gas from the dust particles. The carbonization after combustion was analyzed to determine the carbon conversion efficiency.
CHAPTER-4
PROCESS MODELING
COMPUTATIONAL APPROACH USING The graphical abstract of a fluidized bed
- Effect of velocity on rate constant
- Effect of bed height on conversion
- Effect of conversion on selectivity
The MATLAB coding is done by taking the parameters given as Annexure-1 in the Appendix section. the program was executed and. By entering the values of the above parameters and the effects of these parameters on the kinetics of the reaction were observed (E.g. Rate vs. rate constant, height vs. conversion, time vs. conversion and conversion vs. selectivity etc.) and are shown in the figures ( 4.2) in (4.5). By entering the values of the above parameters, the effects of these parameters on the kinetics of the reaction have been observed (Ex.
From this figure it can be seen that as the speed increases, the rate constant also increases for all the different sizes of reactors. Again, it is also observed that for the same flow rate, the rate constant decreases with increasing reactor size. Figure-4.3 depicts the change in bed height conversion for different values of the rate constant.
And it can be seen from the graph that with the increasing value of the rate constant. The effect of time on the conversion for different values of the rate constant is shown in Figure 4.4. It can be seen from the figure that the conversion increases with increasing values of the rate constant.
It can be seen from the figure that the selectivity of the plant decreases with increasing conversion for all values of the reaction rate constant because the conversion is inversely proportional to the selectivity according to eq-(4.18).
CHAPTER-5
OBSERVATION AND RESULTS
- PRELIMINARY ANALYSIS OF THE BIOMASS SAMPLES
- Proximate analysis
- Analysis of other properties
- IMPORTANCE OF CHEMICAL FORMULA
- EXPERIMENTAL RESULTS FOR COLD MODEL UNIT
- EXPERIMENTAL RESULTS FOR HOT MODEL UNIT
The following analyzes were carried out for the preliminary analysis of the different biomass samples. The TGA (Thermo gravimetric analysis) of these biomass samples was carried out and the result is shown in Figure 5.1. The direct analysis for different biomass samples yields the following results, which are listed in Table 5.2.
Figure-5.1: TGA results for different biomass samples Table-5.2: Proximate analysis results for different biomass samples Biomass samples Moisture. Calculation of the chemical formula is important to determine the stoichiometric amount of air required for combustion of biomass samples. In a similar way above, the chemical formulas of all biomass samples were calculated, which are given in table-5.4.
The data observed for the same with different parameters are shown in Table-5.5 and 5.6 respectively. Table-5.5: Comparison between calculated ER values obtained from dimensionless analysis with experimentally observed values. Table-5.6: Comparison between calculated EU values obtained from dimensionless analysis with experimentally observed values.
From the final analysis of biomass samples and using stoichiometric calculations the following product gas compositions were obtained.
CHAPTER-6
DISCUSSION AND CONCLUSION
COLD MODEL
- Effects of individual system parameters on ER
Several experiments were carried out by varying the various system parameters such as density, static bed heights and bed particle diameter etc. It is seen from figure-(6.1) and (6.5) that with increase in static bed height, equivalence ratio and Euler's number both increase gradually with a certain trend and also with the bed particle size, where the equivalence ratio, as in the case of varying density of the bed materials, increases, but the Euler number decreases. The effects of individual parameters on ER and Eu have also been observed by the MAT LAB coding (from Figure (6.2) to (6.4) and Figure (6.6) to (6.8) respectively) and it also shows the similar trends as discussed above.
The calculated values of ER and Eu obtained from the developed correlation were compared with those obtained from the programming. The comparison shows that the percentage deviation is smaller in both cases (i.e. the equivalence ratio and Euler's number), as shown in Table 6.1. The overall changes in the values of equivalence ratio and Euler's number were observed from the developed correlations (equation no. 5.3 and 5.4).
It is observed that with the increase in static bed height and particle size, both equivalence ratio and Euler's number increase, but with varying particle density, ER values increase and Eu values decrease. The comparison graphs for ER and Eu by different methods are shown in Figure 5.4, which shows good agreement. Table 6.1: Comparison of calculated values of the ER and Eu using MAT LAB and the experimental values.
Table-6.2: Percentage deviations of calculated ER and Eu values from experimentally observed values and chi square values for correlation fit.
HOT MODEL
CONCLUSION
The developed correlations can also be used as the basis of designs for the industrial fluid bed gasifier. The carbon conversion efficiency for the hot model experimental setup was found to be 81.7%.
SCOPE OF THE WORK
Kr12 : Effective rate constant for conversion of initial to intermediate product, s-1 KfAR : Final rate constant for the process, s-1. XA : Percent conversion Lf : Static bearing height, m vp : Volume of particle, m3 Dp : Diameter of particle, m Sp : Surface of particle. R., "Utilization of fluidized bed reactor for production of adsorbents for removal of malachite green", Chemical Engineering Journal p.
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