A Simulation Study for Fluidized Bed Combustion of Petroleum Coke With CO2 Capture

2003 ◽  
Author(s):  
Jinsheng Wang ◽  
Edward J. Anthony ◽  
J. Carlos Abanades
Keyword(s):  
Power Generation ◽  
Fluidized Bed ◽  
Petroleum Coke ◽  
Co2 Capture ◽  
Low Cost ◽  
Volatile Content ◽  
Fluidized Bed Combustion ◽  
High Carbon ◽  
Overall Efficiency ◽  
Fluidized Bed Combustor

Petroleum coke is regarded as a difficult fuel because of its high sulphur content and low volatile content. However, its low price and increased production, means that there is a powerful economic stimulus to use it for power generation. In this work, a process simulation has been performed as part of a feasibility study on the utilization of petroleum coke for power generation with low-cost CO2 capture. The proposed system employs a pressurized fluidized bed combustor and a calciner. In the combustor itself, the petroleum coke is burned and most of the CO2 generated is captured by a CaO sorbent under pressurized condition to form CaCO3. The CaCO3 is transported into the calciner where limited proportion of the petroleum coke is burned with pure O2, and calcines the spent sorbent back into CaO and CO2. A nearly pure CO2 stream is obtained from the calciner for subsequent disposal or utilization. The predicted overall efficiency of the combustion is near 40%. The proposed system would also be suitable for firing other high carbon and low ash fuel, such as anthracite.

Petroleum Coke and Coal Start-Up Testing in Bubbling Fluidized Bed Combustors

1997 ◽  
Vol 119 (2) ◽  
pp. 96-102 ◽  
Author(s):  
E. J. Anthony ◽  
K. Anderson ◽  
R. Carson ◽  
I. T. Lau
Keyword(s):  
Fluidized Bed ◽  
Petroleum Coke ◽  
Bituminous Coal ◽  
Volatile Content ◽  
Fluidized Bed Combustion ◽  
Bench Scale ◽  
Start Up ◽  
Bubbling Fluidized Bed ◽  
Tennessee Valley ◽  
Start Ups

Bench-scale and 160 MWe demonstration tests were conducted for petroleum coke and high volatile bituminous coal blends. The bench-scale apparatus was a 100-mm-dia reactor located at the Canada Centre for Mineral and Energy Technology (CANMET), Energy Research Laboratories. The demonstration tests were conducted on the Tennessee Valley Authority’s (TVA) 160 MWe Shawnee Atmospheric Fluidized Bed Combustion (AFBC) Unit located at Paducah, Kentucky. Five and ten percent nominal volatile petroleum cokes were tested in the bench-scale unit. In addition, for the five-percent petroleum coke blends of 25, 50, and 75-percent petroleum coke, with the balance coal, were also examined at the bench scale. Eight start-up tests have been conducted with 50 percent blend of green delayed petroleum coke at the Shawnee AFBC unit. The bench-scale tests revealed that the volatile content in the petroleum coke was the primary factor affecting start-up. The tests showed that the volatile content from the coke and coal ignited at similar times; the char required longer to ignite. Bench-scale tests showed adequate start-up performance with blends up to 75 percent petroleum coke. Cold start-ups were conducted at the Shawnee AFBC Unit with 7 to 10 percent volatile green delayed petroleum coke. In all the start-ups, the operating temperature of 816°C was reached within 15 min of introducing the petroleum coke blend; this is similar to when high volatile bituminous coal was used. One start-up required a longer time because limestone had to be used to generate the bed. Local hot spots (982°C) were noticed in several start-ups for short periods, but subsided when additional air was supplied. Although more difficult to control, TVA routinely starts the Shawnee AFBC Unit with 50 percent shot petroleum coke and 50 percent high volatile bituminous coal.

Modelling Fuel and Sorbent Attrition During Circulating Fluidized Bed Combustion of Coal

2003 ◽  
Author(s):  
D. Barletta ◽  
A. Marzocchella ◽  
P. Salatino ◽  
S. G. Kang ◽  
P. T. Stromberg
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Surface Wear ◽  
Fluidized Bed Combustion ◽  
Coal Fuel ◽  
Primary Fragmentation ◽  
The Impact ◽  
Constitutive Parameters ◽  
Fluidized Bed Combustor ◽  
Circulating Fluidized Bed Combustion

A simulation model of a circulating fluidized bed combustor, based on a one-dimensional description of bed hydrodynamics and a simplified formulation of the population balance equation on fuel and bed solids, has been set up. The model specifically aims at assessing the extent of fuel and sorbent attrition during circulating fluidized bed combustion of coal. Fuel attrition is modelled as a function of carbon loading and of the relevant operating variables while taking into account primary fragmentation of coal and secondary fragmentation and attrition by surface wear of its char. Modelling of sorbent attrition accounts for primary fragmentation of limestone upon calcination as well as attrition by surface wear of lime. To this end time- and conversion-dependent attrition rate is averaged over the sorbent particle lifetime in the reactor. Attrition submodels and their constitutive parameters are based on previous work by the research group in Naples. Coal char combustion and lime sulphation are modelled considering intrinsic reaction kinetics as well as boundary layer and intraparticle diffusion of reactants. The impact of attrition phenomena on the performance of the fluidized bed combustor is characterized by looking at carbon combustion efficiency, at sulphur capture efficiency, at the balance between bottom and fly ashes. The influence of operating parameters like fuel particle size, Ca/S ratio, gas superficial velocity, extent of air staging is investigated. The sensitivity of results of model computations to the parameters expressing fuel and sorbent attrition is presented and discussed.

Fluidized bed combustion systems for power generation and other industrial applications

2003 ◽  
Vol 217 (1) ◽  
pp. 9-18 ◽  
Author(s):  
A. J. Minchener
Keyword(s):  
Power Generation ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Industrial Applications ◽  
Coal Waste ◽  
Fluidized Bed Combustion ◽  
Bubbling Fluidized Bed ◽  
The Status ◽  
Market Opportunities ◽  
Derivatives Of

Fluidized bed combustion (FBC) in various forms has been used to burn all types of coal, coal waste and a wide variety of other fuels, either singly or cofired with coal. FBC boilers are currently available commercially in the capacity range from 1 MWth to over 250 MWe and continue to be adopted for a variety of commercial, industrial and power generation applications. There are two main derivatives of FBC, namely bubbling fluidized bed combustion (BFBC) and circulating fluidized bed combustion (CFBC). There are also several hybrid systems and pressurized versions of both BFBC and CFBC. The status of these different systems, with some now fully commercial and some still under development, is described, with projections made for future development requirements and market opportunities.

scholarly journals Design and Initial Development of Monolithic Cross-Flow Ceramic Hot-Gas Filters

1999 ◽  
Author(s):  
Virginie Vaubert ◽  
David P. Stinton ◽  
Chris Barra ◽  
Santosh Limaye
Keyword(s):  
Power Generation ◽  
High Efficiency ◽  
Low Cost ◽  
National Laboratory ◽  
Cross Flow ◽  
Combined Cycle ◽  
Fluidized Bed Combustion ◽  
Initial Development ◽  
Oak Ridge ◽  
Hot Gas

Advanced, coal-fueled, power generation systems utilizing pressurized fluidized bed combustion (PFBC) and integrated gasification combined cycle (IGCC) technologies are currently being developed for high-efficiency, low emissions, and low-cost power generation. In spite of the advantages of these promising technologies, the severe operating environment often leads to material degradation and loss of performance in the barrier filters used for particle entrapment. To address this problem, LoTEC Inc., and Oak Ridge National Laboratory are jointly designing and developing a monolithic cross-flow ceramic hot-gas filter. The filter concept involves a truly monolithic cross-flow design that is resistant to delamination, can be easily fabricated, and offers flexibility of geometry and material make-up. During Phase I of the program, a thermo-mechanical analysis was performed to determine how a cross-flow filter would respond both thermally and mechanically to a series of thermal and mechanical loads. The cross-flow filter mold was designed accordingly, and the materials selection was narrowed down to Ca0.5Sr0.5Zr4P6O24 (CS-50) and 2Al2O3−3SiO2 (mullite). A fabrication process was developed using gelcasting technology and monolithic cross-flow filters were fabricated. The program focuses on obtaining optimum filter permeability and testing the corrosion resistance of the candidate materials.

The Effect of Coal Type on Thermal Balance in a Dense Phase of a Circulating Fluidized Bed Combustor

2003 ◽  
Author(s):  
Mirko S. Komatina ◽  
Xin Liu ◽  
Franz Winter
Keyword(s):  
Fluidized Bed ◽  
Coal Batch ◽  
Circulating Fluidized Bed ◽  
Temperature Drop ◽  
Thermal Balance ◽  
Experimental Investigations ◽  
Volatile Content ◽  
Dense Phase ◽  
Fluidized Bed Combustor ◽  
Coal Type

The results of experimental investigations of the effect of coal type on the thermal balance during early stages in a dense phase of a circulating fluidized bed combustor (CFBC) are presented in this paper. The experimental investigations were performed in a laboratory-scale CFBC. Five coals with three size classes (small 0.5–0.63 mm, medium 2–3.1 mm, and large 7.1–8 mm) were tested. The electrical heating system was used to ensure that the riser has a constant temperature (850°C) before the experiments. Mean velocity was 1.2 m/s. Oxygen concentration was 5%. During the experiments the temperature in the dense phase in the lower part of the riser and the gas concentrations of CO and CO2 were measured continuously. On the temperature histories measured, it can be seen that after feeding the coal batch into the hot CFBC, the temperature in the dense phase decreases, after reaching a minimum value and increases back again. The experimental results were compared to each other on the basis of the maximum temperature drop after feeding the coal batch. It was concluded that the temperature drop depends slightly on coal size and mainly on coal type and its mechanical and physical structure. The temperature drop slightly increases when the particle size of the coal batch increases. The strongest influence on the temperature drop in the dense phase of the CFBC shows the volatile content of the original coal and the temperature drop is directly proportional to the volatile content.

Experimental Studies on Combustion of Cattle Manure in a Fluidized Bed Combustor

1987 ◽  
Vol 109 (2) ◽  
pp. 49-57 ◽  
Author(s):  
K. Annamalai ◽  
M. Y. Ibrahim ◽  
J. M. Sweeten
Keyword(s):  
Fluidized Bed ◽  
Fossil Fuels ◽  
Experimental Studies ◽  
Heat Content ◽  
Fluidized Bed Combustion ◽  
Volatile Solids ◽  
Combustion Technology ◽  
Solids Content ◽  
Combustion Tests ◽  
Fluidized Bed Combustor

Manure from cattle feedlots is a renewable energy source which has the potential of supplementing the existing fossil fuels. But the heat content of manure is rather low. Since, the fluidized bed combustion technology has been used for the energy conversion of marginal fuels, such a technology is being explored for the combustion of feedlot manure. A fluidized bed combustor of 0.15 m (6 in.) diameter was used for the combustion tests on manure. Experiments were conducted with −20 to +20 percent excess air and at bed temperatures ranging from 600°C (1112°F) to 800°C (1472°F). Experimental data revealed that the gasification efficiencies ranged from 90 to 98 percent, while the combustion efficiencies varied from 45 to 85 percent. Higher combustion efficiencies were obtained with decreased volatile solids content of manure. The low combustion efficiencies are attributed to the limited residence time available for the volatiles to burn within the reactor.

Sign in / Sign up

Export Citation Format

Share Document