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Syngas as a Sustainable Carbon Source for PHA Production
Published in Martin Koller, The Handbook of Polyhydroxyalkanoates, 2020
Véronique Amstutz, Manfred Zinn
Fluidized bed reactors are associated with high rates of mass and heat transfer and are therefore more tolerant of feedstock variability. There are two types of fluidized bed reactors: 1) the bubbling fluidized bed gasifier where the gasification agent is supplied from the bottom and contributes to the fluidization of the solid bed and, therefore, the gasification process occurs in the fluidized bed and 2) the dual bed gasifier with two separated chambers in which the process is based on two steps. In the first step, the combustion occurs in the so-called combustion chamber and generates heat. It is followed by the second step, in a second chamber, by the pyrolysis and gasification reactions with a high-speed gas in a bubbling fluidized bed, where the gas is then separated with a cyclone separator. The addition of a catalyst enables the higher oxidation of tar into syngas.
Industrial Fixed Bed Catalytic Reactors: Drawbacks, Challenges, and Future Scope
Published in Devrim Balköse, Ana Cristina Faria Ribeiro, A. K. Haghi, Suresh C. Ameta, Tanmoy Chakraborty, Chemical Science and Engineering Technology, 2019
A fluidized bed reactor is a type of reactor device that can be used to carry out a variety of multiphase reactions. In this type of reactor, a fluid (gas or liquid) is passed through a solid granular material (usually a catalyst possibly shaped as tiny spheres) at high enough velocities to suspend the solid and cause it to behave as though it were a fluid. The process, known as fluidization, imparts many important advantages to the fluidized bed reactor. As a result, the fluidized bed reactor is now used in diverse applications. Scientific vision, deep scientific doctrine, and the need for scientific challenges are today leading a long and visionary way in the true emancipation of both chemical process technology and petroleum engineering. In this well-researched chapter, the author deeply comprehends and lucidly explains the need of fluidized bed reactors in petroleum refining. The efficiency and the scientific vision of fluidized bed reactor operation need to be re-envisioned and deeply restructured as science and engineering steps into a new era.
Future Fuels
Published in Arumugam S. Ramadhas, Alternative Fuels for Transportation, 2016
A fluidized bed reactor is a vessel in which fine solids are kept in suspension by a gas such that the whole bed exhibits a fluid like behavior. This type of reacting system is characterized by high heat and mass transfer rates between the solid and gas. In a fluidized bed gasifier, air, oxygen, or steam is passed through distributor plates at the bottom of the gasifier. Limestone is mixed with coal to remove the sulfur present in the coal. Char/ash taken along with producer gas are pyrolyzed in the hot agglomerating zone. Any ash particles that stick together will fall and are cooled and removed at the bottom of the gasifier. In fluidized bed gasification, rising oxygen enriched gas reacts with suspended coal at a temperature of 950–1100°C and a pressure of 20–30 bar. High levels of back mixing result in fluid bed gasifiers having a uniform temperature distribution. A typical diagram of a fluidized bed gasifier is shown in Figure 13.4.
Improvements in the mechanical behavior of a silty soil treated with rice husk silica, lime, and polypropylene fiber
Published in International Journal of Geotechnical Engineering, 2023
Jessica Leindorf de Almeida, Yeimy Muñoz Ordoñez, Paula Caroline Alves Pudell, Daniel Leal Brandão, Monigleicia Alcalde Orioli, Ronaldo Luis dos Santos Izzo
Rice husk silica (RHS) is a type of reactive pozzolan that is produced under controlled conditions. Production is done through fluidized bed combustion. A fluidized bed reactor consists of a reaction chamber containing particles supported by a distributor plate and suspended by a fluid that crosses them upwards (Angel et al. 2009; Marangon et al. 2013).