Coal, Swelling, Pyrolysis, Pressure


A model was previously developed to describe the decrease in swelling during coal pyrolysis at atmospheric pressure when maximum particle heating rates increase from 104 K/s to 105 K/s. That model included effects of coal type using chemical structure properties. This paper presents results of new experiments to study the effects of elevated pressure and high heating rates on coal pyrolysis. A pressurized flat-flame burner (PFFB) was designed and built to conduct these studies. The pyrolysis experiments reported in this paper were conducted at particle heating rates of ∼105 K/s and maximum gas temperatures of 1700 to 1900 K at pressures of 1 to 15 atm. Residence times of 25−85 ms were used. A new coal swelling correlation was developed that predicts the effects of heating rate, pressure, and coal rank on the swelling ratio at heating rates above ∼104 K/s. The coal rank index parameters from a previously published atmospheric swelling model were used to model the pressurized swelling data, and a new correlation was developed to describe the effects of pressure. The resulting empirical correlation fits pressurized swelling data from a wide range of coals and types of reactors that could not previously be explained by any one model.

Original Publication Citation

Shurtz, R. C., J. W. Hogge, K. C. Fowers, G. S. Sorensen, and T. H. Fletcher, “A Coal Swelling Model for Pressurized High Particle Heating Rate Pyrolysis Applications,” Energy & Fuels, 26, 3612-3627 (2012). DOI: 10.1021/ef300442r

Document Type

Peer-Reviewed Article

Publication Date



American Chemical Society




Ira A. Fulton College of Engineering


Chemical Engineering

University Standing at Time of Publication

Full Professor