Enhancement of sulfur dioxide capture by limestone sorbents in the presence of an acoustic field

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:171593

Nair, R; Yavuzkurt, S ^[1]

---

1. Pennsylvanina State Univ., University Park, PA (United States)

The effect of high intensity acoustic fields on sulfur capture during pulverized coal combustion is investigated. A two-dimensional, steady, axisymmetric code, PCGC-2 (Pulverized Coal Gasification and Combustion-2 Dimensional) developed over ten years at Brigham Young University, was used to simulate the combustion of pulverized coal. The effects of increased heat and mass transfer to a burning particle in the presence of an acoustic field were modeled by modifications made in the code which were obtained from previous studies The code was also used to predict SO{sub 2} levels in the furnace during combustion. A comprehensive single particle model to capture sulfur dioxide using limestone sorbent was developed. Following previous approaches, the particle was modeled as a sphere formed of overlapping grains. Calcination, sintering and sulfation processes occur simultaneously during sulfur capture by limestone. Thermal decomposition of calcium carbonate (calcination) is described by a shrinking core model for a spherical particle. Decomposition begins on the surface and proceeds inwardly in a symmetrical fashion, and the diameter of the unreacted core decreases. At the interface of the two phases, heat is absorbed and CO{sub 2} diffuses out during reaction. The particle is assumed isothermal. Sintering which is melting and sticking of individual grains in the particle is modeled by moving the grain centers in the particle closer to each other, thereby decreasing the porosity and the specific surface area of the particle. For larger particle sizes of the order of 100 {mu}m, which is the range at which acoustic fields and pore diffusion show significant effects, it is shown that an increase in sulfur capture ({approximately} 10-12%) results since pore diffusion includes contributions from both gas-phase diffusion and Knudsen diffusion.

• Research Organization: Coal and Slurry Technology Association, Washington, DC (United States); USDOE Pittsburgh Energy Technology Center, PA (United States)
• OSTI ID: 171593
• Report Number(s): CONF-950313--; ON: TI96120225
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ACOUSTICS
AIR POLLUTION CONTROL
CALCINATION
COAL FINES
COMBUSTION
COMBUSTORS
LIMESTONE
PULVERIZED FUELS
SORPTION
SOUND WAVES
SULFATION
SULFUR DIOXIDE