DBPapers
DOI: 10.5593/sgem2011/s18.111

MATERIAL AND ENERGY BALANCE OF THE UCG PROCESS IN THE LABORATORY CONDITIONS

AUTHOR/S: M. LACIAK, J. KACUR, M. DURDAN
Monday 1 August 2011 by Libadmin2011

11th International Multidisciplinary Scientific GeoConference SGEM2011, www.sgem.org, SGEM2011 Conference Proceedings/ ISSN 1314-2704, June 20-25, 2011, Vol. 3, 69-76 pp

ABSTRACT

Structure of the mathematical model of underground coal gasification process in terms
of material and energy (heat) balance is presented in this paper.

Base inputs of gasification process are coal (coal model) and oxidant (a mixture of
oxygen and air), which appropriate combination has to ensure the best possible
conditions for the gasification process. The expected energy output from coal
gasification process is a synthetic gas - syngas. Components such as ash, tar and
unburned coal are side outputs of the process. All inscribed components create balance
of the heat aggregate respectively process. Energy that enters into process (coal,
oxidizer) is equal to output energy (syngas) and residual energy (unburned coal, ash,
tar).

Control of expenditure and energy consumption (compliance with the law of
conservation of energy) is based on material balance and heat balance of the process
which is used for the purpose of tracking temperature changes. Heat balance allows us
to track the impact of temperature changes on the gasification process and the
proportion of obtained energy in the form of the gas from the process. The physical and
chemical heat input and output components of the process are taken into consideration.
Calculating material and heat balance of the underground coal gasification process is
one of the most important indicators for the evaluation of its effectiveness.

Physical model (experimental equipment), which simulates the conditions of the real
coal-seam in the bearing geometric similarity, has been created for better understanding
and analysis of the gasification process. Several experiments representing specific
conditions of the gasification were performed using created physical model.
Experiments have been carried out at the different arrangements of the coal charge and
regulatory mode. Accomplished experiments were evaluated in terms of gas production
with the greatest heat content, which is represented by the largest share of heating
element in the output part of the heat balance.

Keywords: underground coal gasification (UCG), mathematical model, material and energy balance, physical and chemical heat.