Новые поступления

Compartmented Fluidized Bed Gasifier compartmented fluidized bed gasifier
Biomass gasification is a set of thermo-chemical reactions that converts biomass to fuel gases using air, oxygen or steam. Oil palm shell is selected as the feedstock due to its abundant availability and favorable chemical properties. Generally, biomass cannot be fluidized solely due to its peculiar shape, size and density; a second fluidizable material, e.g. sand is often required to facilitate fluidization. The hydrodynamics of sand-biomass system depends on the specific biomass used. In conventional fluidized bed gasifier, a single vessel is utilized for combustion and gasification. Air is widely used as oxidant but the flue gas will contaminate the gasification products and reduces its heating value. Dual fluidized bed gasifier separates the combustion and gasification in two vessels, so that the gas from the gasifier is separated from the flue gas. Compartmented fluidized bed gasifier (CFBG) is a single vessel partitioned into two discrete compartments as combustor and gasifier where solid heat carrier is internally circulated between the two compartments. The present work has successfully proved the concept of CFBG as a prospective technology for palm shell gasification.
7890 RUR
Biomass Gasification compartmented fluidized bed gasifier
The book describes fluidized bed gasification of biomass to generate hydrogen rich medium calorific value gas using steam as gasifying medium. Basic studies on steam biomass gasification process have been carried out in a laboratory scale bubbling fluidized bed gasifier and the endothermic heat is supplied by electrical heating. A mathematical model based on thermodynamic equilibrium has been developed to predict the behaviour of thermo-chemical fluidized bed biomass gasification. The subsequent chapters of the work has been devoted to develop a self-sustaining dual fluidized bed gasifier capable of producing medium calorific value gas. The dual bed system has two chambers; bubbling bed gasifier and fast bed combustor. A part of carbon from the gasifier is combusted in the adjoining combustor and the hot bed material from the combustor is circulated back to the gasifier for supplying necessary endothermic heat. The hydrodynamic design of the dual bed system has been carried out through cold model investigation. Based on cold model data, a pilot scale hot dual fluidized bed gasifier has been designed and developed and experiments have been conducted to generate data.
5790 RUR
Hydrodynamic Behavior in Palm Shells and Sand Mixtures Fluidization compartmented fluidized bed gasifier
Utilization of palm shells in gasification technology known as Compartmented Fluidized Bed Gasifier (CFBG) system which uses air as a gasification agent to produce a high heating value of syngas for power generation and chemical processes. Hence, it does not only give the potential source of renewable energy but also utilizing the waste in a sustainable way. Fluidization quality is a determining factor in CFBG to guarantee its well-mixed behavior when gasification is concerned. The fluidized behavior of sand / palm shell binary mixtures of different particles sizes and densities is studied in CFBG of 66 cm ID, consisting of two compartments, combustor and gasifier in a respective ratio of 2:1, fluidized with air. The minimum fluidization velocity (Umf), fluidization quality (Q), incipient bed voidage, incipient and expanded bed height are reported in 2, 5, 10 and 15 weight percentage of palm shells.
4929 RUR
Emissions from Circulating Fluidized Bed compartmented fluidized bed gasifier
In this monograph, gaseous emissions are discussed using the fluidized bed technology to enhance the local coal utilization along with biomass. Design of the circulating fluidized bed combustor is given along with its operation under fast fluidized bed mode at different operating conditions. A fluidized bed model for the steady state combustion and sulphation is also employed to predict the SO2 concentrations in the exit flue gases.
5490 RUR
Circulating Fluidized Bed Boiler Technology compartmented fluidized bed gasifier
Comprehensive understanding of the heat transfer processes that take place during circulating fluidized bed (CFB) combustion is one of the most important issues in CFB technology development. This leads to possibility of predicting, evaluation and proper design of combustion and heat transfer mechanisms. The aim of this work is to develop a model for circulating fluidized bed boiler operation. Empirical correlations are used for determining heat transfer coefficients in each part of the furnace. The proposed model is used both in design and offdesign conditions. During off-design simulations fuel moisture content and boiler load effects on boiler operation have been investigated.In this book fuel properties of most typical classes of biomass are widely reviewed. Various schemes of biomass utilization are presented and, especially, concerning circulating fluidized bed boilers. In addition, possible negative effects of biomass usage in boilers are briefly discussed.
4839 RUR
Circulating Fluidized Bed compartmented fluidized bed gasifier
This book emphasizes the Circulating fluidized bed technology which is one of the most efficient methods of coal burning in boilers for production of electric power. It has many advantages like efficient burning of coal, low emission etc. In recent years, Circulating Fluidized Bed (CFB) boilers are fast gaining importance in power generation due to dwindling reserves of high quality coal and need for abatement of atmospheric pollution due to emission of pollutant gases mainly SOx and NOx. To develop an optimum economic design of boiler, it is necessary to know how heat transfer coefficient depends on different designs and operating parameters.
3549 RUR
Fluidized Bed Adsorber for Gaseous Pollutant Control compartmented fluidized bed gasifier
This book is a compendium of all the important facts, and other information needed to analyze, plan, design,and operate an industrial fluidized bed adsorber for removal of gaseous pollutants from industrial flue gas.This provides the most exhaustive and extensive discussion of fluidization ever done for flue gas treatment. It is recommended for B.Tech & M.Tech students, research scholars and professionals working in the industries.
6890 RUR
CFD Modeling Of Gas-liquid-solid Fluidized Bed compartmented fluidized bed gasifier
Gas–liquid–solid fluidized beds are used extensively in the refining, petrochemical, pharmaceutical, biotechnology, food and environmental industries. Some of these processes use solids whose densities are only slightly higher than the density of water. Because of the good heat and mass transfer characteristics, three-phase fluidized beds or slurry bubble columns have gained considerable importance in their application in physical, chemical, petrochemical, electrochemical and biochemical processing. The first part discusses about importance of gas-liquid-solid fluidized bed, their modes of operation, important hydrodynamic properties those have been studied either related to modeling or experimental analysis and applications of gas-liquid-solid fluidized bed. The second part gives an overview of the methodology used in CFD to solve problems relating mass, momentum and heat transfer. Also comparative study of various CFD related software is given in this section. Third part contains the details about problem description and approach used in FLUENT to get the solution. Finally results of simulation and comparison with experimental results are shown.
4839 RUR
Bubbling Fluidized Bed Hydrodynamics compartmented fluidized bed gasifier
Rising gas bubbles in bubbling fluidized beds are important for all hydrodynamics related phenomena, e.g. mass transfer, gas bypassing, heat transfer, gas-solids mixing, etc. However, still many interactions of bubbles with specific operation conditions in fluidized beds are unknown. In this work, fluidized beds with vertical heat exchangers are investigated. Vertical heat exchangers are in this case used to remove the heat of reaction from the exothermal methanation reaction for the production of synthetic natural gas (SNG) from wood. Several vertical tube bank configurations ? varying in their diameter, tube-to-tube spacing, and arrangement (square vs. triangular) ? have been immersed into a lab-scale fluidized bed. By means of optical probing and pressure fluctuation measurements, their influence on the rising gas bubbles has been evaluated by means of statistical tools. Findings from these experiments are furthermore used to develop a modified approach to scale up fluidized beds with vertical internals.
11490 RUR
Combustion Performance in a Fluidized Bed Combustor compartmented fluidized bed gasifier
This monograph presents the research work carried out in studying the use of air staging technique in a fluidized bed combustor as an effective alternative to control and reduce the emissions from the combustion of industrial and agricultural waste. Fluidized bed combustion has been recognized as a technology that can generate power from solid wastes and more importantly it has been known as a suitable combustion system for biomass. This monograph highlights the influence of applying air staging technique in reducing the gaseous emissions from a fluidized bed combustor. In this investigation, palm shell is used as the source of fuel and silica sand as the inert sand material. This monograph describes the results obtained and the methodology adopted. The outcome of this investigation has shown that the use of the air staging technique has resulted in the reduction of the emission of NOx of more than 50%. This significant reduction is a clear indication of the prospect of using this technology for sustainable management of the environment and a better future for our palm oil industry.
5790 RUR
Fluidized Bed Combustion of High Volatile Matter Fuels compartmented fluidized bed gasifier
This book has covered some essential innovations on Fluidized Bed Combustion (FBC) of high-volatile matter (VM) fuels especially using porous solids as bed material. The delayed onset of devolatilization is expected to broaden the area of devolatilization in the reactor, thus to avoid formation of local VM-rich zone in the freeboard. A new method has been developed to evaluate horizontal dispersion of solids at high bed temperatures that resemble those of commercial operations. As the first step to scaling-up of the FBC system using carbon loaded solids prepared by capacitance effect, the developed model is considered to be applicable to large-scale FBCs if the solid dispersion coefficient can be predicted.
4839 RUR
Fluidized Bed Technique compartmented fluidized bed gasifier
Heat treatment is the most common process used to alter the mechanical properties of aluminum alloys. Traditional heat treatment technology applies circulating air convection furnaces for the purposes of obtaining a T6 or T7 temper. With conventional heat treating systems, however, prolonged solution heat treatment and aging times of over 20 h are required for heat treatment of aluminum casting alloys, entailing high energy costs. The long cycle times required for heat treating with conventional systems go contrary to industry requirements where the goal is to improve the performance of the part and to reduce the time of manufacturing. The fluidized bed (FB) heat-treating process makes it possible to reduce the time required for heat treating significantly (2 h), while at the same time increasing the uniformity of the heat treatment process. The use of fluidized beds is considered to be an innovative technology for the heat treatment process of Al-Si cast alloys and appears to be more effective than conventional furnace techniques. This book,therefore, explains the influence of fluidized bed heat treatment on the performance of aluminum based castings used in automotive industry.
7790 RUR
Experimental Studies on a Circulating Fluidized Bed Biomass Gasifier compartmented fluidized bed gasifier
This work is related to renewable energy technologies which is a hot topic around the world. The fuels prices and demand of fuels forces mankind to search for new technologies which are environment friendly as well as highly efficient. Renewable systems poses no threat to the environment. The raw material is available at free of cost. The process of energy generation is highly dependent on the characteristics of the raw material. Biomass gasification is an established technology for the production of producer gas. Biomass gasification combined with steam reforming can produce hydrogen gas which is considered as one of the clean fuels for the future. Hence this process is highly demanding. By various steam fuel ratios, hydrogen composition can be varied. This work on biomass gasification is a promising technology for future.
7790 RUR
Hydrodynamic study of Three Phase Fluidized Beds compartmented fluidized bed gasifier
The general purpose of the experimental investigations described here has to study the hydrodynamic properties of gas-liquid fluidized beds. Gas –liquid fluidization of or three-phase fluidization is a chemical engineering operation where all the three phases are brought into contact with each other. This contact is brought about by passing the gas and liquid trough the bed of solids. The solids are said to be in a fluidized state when they are suspended in the continuous phase.Hydrodynamic properties such as gas hold-up, liquid hold-up and bed porosity have been studied. These properties depend upon certain independent variables such as gas flow rates, liquid flow rate, particle size, static bed heights, gas density, liquid density, solid density, liquid surface tension, liquid viscosity, gas viscosity and particle shape. During the course of this experimental investigation only four of these parameters have been varied, viz, gas flow rates, liquid flow rates, static bed height and particle size.The result of these experimental investigations is discussed and correlations have also been developed for the hydrodynamics properties studied.
3549 RUR
Numerical Simulation of Two-Phase Turbulent Flows in Ash CFB compartmented fluidized bed gasifier
Current research deals with numerical simulation of two-phase turbulent flows (gas and solid particles), which appear in Circulating Fluidized Bed (CFB) boilers, combusting Estonian local fuel - oil-shale. Many thermal processes in industry take advantage of the significant fluid-solid contacting in fluidized beds to carry out fluid-solid reactions, eterogeneous catalysis and particle drying. Gas-solid fluidization process in circulating fluidized beds is widely applied in many industries. The scientific novelty of the thesis is a gas-solid particle turbulent flow numerical simulation, taking in the advance the real initial data of CFB power plants using Estonian oil-shale ash. The results of the simulation describe the behaviour of oil-shale ash particles in CFB, which could be helpful in improving the efficiency of the combustion process.
4839 RUR