Widespread industrial use of CFB technology in coal and biomass combustion and gasification depends on improved control of the fluidization process that demands a better understanding of fluidized bed hydrodynamics. Huhnke , and Mark R. Biomass materials exhibit a wide range of moisture content and since this affects its value as a fuel source, it is important that the basis be stated whenever moisture content is measured Sharma, Ajay Kumar, Hasan K. Partial oxidation of fuel is achieved by mixing steam with air or oxygen. Cracking is the process of breaking down large complex molecules such as tar into lighter gases by exposure to heat. The result showed that the Rice Husk gas stoves perform accordingly with the design which can satisfactorily produce a combustible gas.
Or more accurately, they are less strongly bonded in the biomass than the fixed carbon, which is the direct C to C bond. Electricity from Rice Husk: Moisture is of paramount importance in biomass gasification because it drains much of the deliverable energy from a gasification plant, as the energy used in evaporation is not recovered. Reaction zones in a Downdraft Gasifier . Basic Design Formulae In order to achieve the desired design of the gasifier, factors such as:
Moreover, tar evolution was almost completely suppressed during the subsequent flash pyrolysis. International Journal of Energy Research. American Journal of Energy Research7 1 Authors across the world have conducted studies and researches on the design of gasifiers, performed modeling and simulation of biomass gasification  These pyrolysis products can be further reacted in the gasificatioh reaction zones as well.
The main reactions show that heat is required during the reduction process.
It is the amount of water in the material, expressed as a percentage of the materials weight. Journal of Mechanical and Civil Engineering12 4: During the combustion process the organic matter in the husks carbohydrate and carbonaceous fractions is converted to carbon dioxide and water.
Thesls Journal of Research in Applied Sciences, 3: They evaluated various biomass energy conversion technologies and their applications to developing countries such as Nigeria.
Fuel Moisture Content Biomass materials exhibit a wide range of moisture content and since this affects its value as a fuel source, it is important that the basis be stated whenever moisture content is measured The authors provided a full description of the gasifjcation starting from basic understanding and ending by design of gawification gasification unit.
When all the available oxygen is redistributed as single atoms, reduction stops It was found that the blower can sufficiently supply air for a gasifier operation even at high temperature. Published online in Wiley Online Library wileyonlinelibrary. Journal of Food, Agriculture and Environment. Temperature affects not only the amount of tar formed but also the composition of tar by influencing the chemical reactions involved in the gasification network This can be estimated from the energy requirement, thus hhesis amount of fuel to be supplied to the burner, to meet the energy required for cooking or boiling.
Ben Oumarou, Babagana M. RamachandriyaDimple K.
CFD Modeling and Simulation on Hydrodynamics of CFB Biomass Gasifier using FLUENT
Experience on the previous gasifier design revealed that reloading of fuel during operation is only possible when burning of fuel starts from the bottom of the reactor. In addition, designing a shorter chamber will give sufficient height for the gasifier reactor and the burner. Concrete mixed with biomass, at a proportion of 1: Gasificarion The essence of a gasification process is the conversion of solid carbon fuels into carbon monoxide and hydrogen mainly; by a complex thermo chemical process.
In the combustion zone of the gasifier, reactions between char and oxygen played a more dominant role, however Ash thesi removed as liquid phase and due to the fluebt temperature tar content is very low. The heat needed should be supplied by external heat source or by partial oxidation of fuel.
Assessment of Biomass Gasification: A Review of Basic Design Considerations
This study proposes that the operating parameters solid circulation rate and gas velocity and solid inlet geometry may be the critical consideration in order to reduce non-uniform distribution of gas and solid in CFB gasifier. The major components are carbon, gasificqtion, and hydrogen. Ganesh and Chincholhat 7 reviewed the development and performance evaluation of various gasifier cook stoves that uses Rice Hush as fuel.
Optimum amount of biomass consumption rate is not only due to a higher combustion rate, but also due to the enhanced pyrolysis and drying rate. Size and Location of the Char Chamber The size of the chamber for carbonized biomass determines the fluemt of unloading the char or the ash.
The weight loss gives the moisture M of the proximate analysis. To properly discharge the ash or the char from the reactor, the angle of friction at the bottom of the chamber hopper should be at 45 degrees.
This involves some additional cost, but avoids previously mentioned gasiifcation dilution problem and results in medium level of energy content of gas per unit volume.