CO2/CH4 exchange sorption in coal material under confining pressure
NCN, OPUS 12, 2016/23 / B / ST8 / 00744,
Realizing Institute: Strata Mechanics Institute of the Polish Academy of Sciences
Project leader: dr hab. Norbert Skoczylas email@example.com
Awarded amount: PLN 611 500, Start: 2017-10-18, End: 2021-10-17
1. Research objectives / Research hypothesis
The objective of the research is to analyse the course and the mechanism of CO2/CH4 exchange sorption in coal material in the state of confining pressure. The planned studies will cover a number of scientific problems still to be solved. They will allow among others for thorough analysis of the changes of sorption capacities and the volume of the coal sample at various confining pressures for particular point of sorption equilibrium and the analysis of the qualitative and quantitative changes of the mechanism of exchange sorption at various confining pressure and various pressure gradient. The studies will also make it possible to determine the influence of the CO2/CH4 exchange sorption in coal material under confining pressure on the structural properties of the studied material.
2. Research method/ methodology
The research plan includes mainly sorption analyses i.e., the analysis of the course of the processes of CO2/CH4 exchange sorption in a coal sample, sweep efficiency of the sorbed gases, the kinetics of the movement of the exchange zone in the sample under confining pressure, sorption swelling and additional analyses of the changes that took place in the porous structure of the sample. The main sorption studies will be carried out by the use of an isobaric-isothermal volumetric method and a flow method at a constant pressure gradient of the gas. For the purpose of the research original equipment will be constructed, which - realising particular research objectives – will make it possible to comprehensive evaluation of the influence of confining pressure on the parameters of the coal-gas system under isothermal and isobaric conditions.
Before and after the main sorption analyses, selected coal samples will be subjected to technical and structural analyses. The additional studies will be carried out by scanning electron microscopy allowing for the observation of the changes of the surface topography of the samples and determining their phase composition. Mercury porosimetry, low-pressure gas adsorption and helium pycnometry will be used to characterise the changes of the pore structure of the samples. These methods will make it possible to determine the changes in the porosity, the size and the distribution of the pores in the samples after the analyses of the exchange sorption under pressure.
3.The influence of expected results on the development of science, civilisation and society
The mechanism of the sorption processes has been the subject of many research studies for many years. Well investigated are the sorption processes of pure gases and their mixtures in coal material. Studies into sorption in coal material under confining pressure have also been carried out. Thorough review of the literature showed that a subject which is has not been investigated so far is the CO2/CH4 exchange sorption in coal material under confining pressure.
The large number of interdependencies, which during the sorption processes under confining pressure exerted on a coal sorbent can be both observed experimentally and assessed quantitatively, is the missing link in broadly defined analysis of the coal-gas system. Most certainly, the proposition to analyse the CO2/CH4 exchange sorption in coal material under confining pressure taking into account the time and space factor is unique. Such analyses are planned as part of this project. The outcome of the project is a detailed description of the relation of exchange sorption – confining pressure – sorption swelling of sorbent.
Research apparatus built as part of the project.
Sample results recorded during sorption exchange experiments.