Measurement of carbon dioxide adsorption capacity on selected Turkish lignites

Abstract

In this work, CO2 adsorption capacities of samples from the four coal (lignite) basins: Soma, Tuncbilek, Tekirdag-Saray and Afsin-Elbistan were experimentally determined at 313.15 K using the volumetric method. Four adsorption models, namely: modified Langmuir, modified Langmuir+k, modified Dubinin-Radushkevich (DR) and modified DR +k models, were used to fit experimental data. The modified DR model was found to be the best fit with an average relative error of less than ±6%. The results show that Soma and Tuncbilek samples have the highest maximum adsorption capacities (nmax) as 1.95 mmol/g and 1.90 mmol/g, respectively. A positive correlation between nmax and fixed carbon content of the samples has been observed. Furthermore, using maximum adsorption capacity values, the maximum CO2 storage capacities of the four lignite basins were determined to be: 62.1 Mt CO2 for Soma, 17.73 Mt CO2 for Tuncbilek, 4.91 Mt CO2 for Tekirdag-Saray and 29.89 Mt CO2 for Afsin-Elbistan. It was estimated that the Soma lignite seam could store the CO2 emissions from a theoretical 100 MW coal power plant for about 102 years, Tuncbilek for about 29 years, Tekirdag-Saray for about 8 years, and Afsin-Elbistan for 49 years.