The history of fluidized bed technology dates back 60 years. Gasification of pulverized coal in the Winkler process during the 1920's marked the beginning of fluidized bed application. Consider­ ,able work done during World War II by U.S. oil companies to improve the catalytic cracking of kerosene led to the development of the Fluid Catalytic Cracking process. Fluidized bed technology later exp...

In recent years, coal production and consumption increased dramatically, especially in China. So, more and more attentions have been paid to coal preparation and coal ash utilization with the growing concern about the pollution by fly ash. The unburned carbon in fly ash significantly affects its utilization in many fields, especially in concrete production industry. Technologies such as flotati...

A bench-scale updraft gasifier was used as a fluidized- and fixed-bed gasification unit in three modes (fluidized-bed at equivalence ratios (ER) =0.2 and 0.25, and a mode in fixed-bed). The experiments were done in five different temperatures (650, 700, 750, 800 and 850oC). To obtain the required data to develop a thermodynamic equilibrium model, the proximate and ultimate analysis w...

The aim of this work is to study coal steam gasification with various methods in-core treatment in FB using a newly developed thermodynamic calculation method. A calculational subbituminous non-catalytic was carried out four different single-vessel multisectional fluidized-bed gasifiers. semi-empirical model based on the entropy maximization method and “restricted equilibria” previously obtaine...

This paper presents a comparison of commercial fluidized bed gasifiers and combustors used to recover energy from municipal solid wastes and biomass. The work reported here is excerpted from four case studies prepared for the International Energy Agency’s Bioenergy Agreement, under Task 23 (Energy from Thermal Conversion of MSW and RDF, 1998-2000) and Task 36 (Energy from Integrated Solid Waste...

This paper investigates the synergistic interaction in a gasification of coal and petcoke blends in a 150 kWth pilot scale gasification plant. Petcoke was used either in combination with coal or separately to produce syngas in an atmospheric fluidized bed gasifier using air as gasifying agent. Syngas composition and carbon conversion efficiency were recorded and calculated. The results show tha...

N2O emissions from coal fired fluidized-bed combustion are approximately 30–360 mg/Nm, much higher than that from pulverized coal combustion (less than 30 mg/Nm). One approach to reduce the N2O is to reburn the biomass gasification gas in the coal-fired fluidized bed. In this paper, the effects of gasified biomass reburning on the integrated boiler system were investigated by both simulation an...

In this work we have tested the fluidized bed desulfurization performance of lime particles obtained by means of a proprietary limestone slow calcination pre-treatment technique. This performance was compared to that of the parent untreated limestone particles. The occurrence of particle fragmentation and attrition during the fluidized bed operation was also investigated with a specific test pr...

In this paper computational analysis of circulating fluidized bed combustion using the fluent software is analysed. This work is concerned about gas–solid two-phase mixtures flowing upwards through the fast beds. The procedures studied are applicable to all types of fluidized-bed boilers. The type of information resulting from various ways of analyzing the pressure and temperature in fluidized ...