The study on the effect of the substitution of K2CO3 with Ca(OH)2 on kinetics on CO2–lignite coal gasification

Abstract

Three kinds of lignite were mixed with K 2 CO 3 and Ca(OH) 2 and were gasified with CO 2 to investigate the effect that the addition of Ca(OH) 2 had on the gasification kinetics. K 2 CO 3 and Ca(OH) 2 were impregnated and dried, their mixing ratio was varied, and the gasification experiments were conducted over a temperature range from 850 to 950°C at atmospheric pressure. The modified volumetric reaction model was applied as the gas-solid reaction model to analyze the carbon conversion results and thus obtain the kinetic parameters. The results indicate that the catalytic activity based on carbon conversion followed the order of K 2 CO 3 5 wt% ? Ca(OH) 2 3 wt% [ K 2 CO 3 8 wt% [ K 2 CO 3 3 wt% ? Ca(OH) 2 5 wt% [ K 2 CO 3 1 wt% ? Ca(OH) 2 7 wt%. The reaction rate was also influenced by the type of lignite, with a higher reactivity observed for Adaro lignite. The highest reaction rate constant was of 44.25 min -1 with Adaro lignite and K 2 CO 3 5 wt% ? Ca(OH) 2 3 wt% at 950°C. The lowest activation energy of 44.49 kJ/min was calculated for Mongolia lignite with K 2 CO 3 8 wt%. The reaction rate was enhanced by partly substituting K 2 CO 3 with Ca(OH) 2 , but further substitution resulted in a decrease in the reaction rate compared to that of K 2 CO 3 alone.

The prediction of CO2 emissions in domestic power generation sector between 2020 and 2030 for Korea

“…The ultimate analysis and approximate analysis values for each country that exports anthracite and bituminous coal were investigated. 27–34 By using each data from different coals, average values were obtained, and this is shown in Table 2. Calculation of the calorific value of anthracite and bituminous coal was conducted following the method suggested in Perry's Handbook 35 : …”

“…26 The ultimate analysis and approximate analysis values for each country that exports anthracite and bituminous coal were investigated. [27][28][29][30][31][32][33][34] By using each data from different coals, average values were obtained, and this is shown in Table 2. Calculation of the calorific value of anthracite and bituminous coal was conducted following the method suggested in Perry's Handbook 35 : Here, HHV: Higher calorific value, C: Mole fraction of carbon inside coal, H: Mole fraction of hydrogen inside coal, S: Mole fraction of sulfur inside coal, O: Mole fraction of oxygen inside coal, and N: The mole fraction of nitrogen inside coal.…”