Flue gas co2 sequestration by turkish coal fly ashes and anotolian geothermal hot waters

Abstract

Depending on the combustion technology, lignite coal ash contains 10–25% free reactive lime. CO2 capturing, transport and sequestration by pressurized water dissolution and reacting by natural alkali lime and magnesia in coal fly ash or other sources becomes an industrial advantageous sequestration option resulting in green waste solutions or solid fines. Reactive Mg and Ca containing ash is sufficiently reacting with flue gas CO2 to form the carbonates. Various types of fly ash materials may react with CO2 to form carbonate regarding the fly ash composition and reaction parameters. Carbonation of CO2 will also allow us to produce fine raw materials for cement production industry or as cement filling material in constructions with low cost. In this study, the fly ash contains 10–25% free lime of Soma, Yatagan, Afşin Elbistanand Silopi Power Stations were received and transported to wet open-air ponds, by a hydraulic system. Main work used 100,0–200,0 cubic meters of ponds with full of slurry fly ash. This slurry will contain Ca2+-ion-saturated alkaline water (pH level 12–13) and easily recycling between the plant and sedimentation ponds. This study discussed the results of tests in that the progress on three consecutive column reactors carbonation achieved and search for fast reaction methods using coal fly ash of Soma, Yatagan, Afşin Elbistan and Silopi Power Stations. Other ash materials containing magnesium and magnesium silicates, supercritical CO2, steam- slurry, and additives were searched for pretreatment methods to enhance mineral reactivity; and in analyzing the structural changes to identify reaction paths and potential barriers.