(45h) Effect of Structural Changes During Partial Calcination of Dolomite-Based Sorbent On CO2 Capture in IGCC

Carbon dioxide emission from fossil fuel combustion and its impact on global warming is one of the most critical environmental issues nowadays. Coal as a main source of produce energy is the most CO₂-intensive fossil fuel. Advanced power generation processes that use gasification technology, such as Integrated Gasification Combined Cycle (IGCC), which offer higher efficiency, are among the leading contenders for power generation in the 21^st century. In an IGCC process, because of high pressure, carbon dioxide in the fuel gas is at higher concentration, which can be captured and sequestered at lower costs.  Utilization of regenerable MgO-based sorbents has been shown to be an effective method for capturing CO₂ from gasification-based processes at high pressures and temperatures. Dolomite, as an abundant mineral is a ideal source of magnesium for the development of MgO-based sorbents for CO₂ capture. Although the sorbent can be regenerated, the cyclic process is hindered by a slow and incomplete regeneration step resulting in decreased CO₂ capture capacity in the cyclic process.

In an effort to develop effective solutions to improve regenerability of dolomite-based sorbents, as a first step the kinetics of partial calcinations of dolomite was studied. A variable grain size model was developed to predict the rate and the extent of decomposition of dolomite. The size distribution of grains was obtained by measuring the pore size distribution and total porosity of the dolomite particles. The model is able to account for changes in the rate and the extent of reaction and provides an excellent fit to the experimental data.