Author: Ernesto Silva MojicaPublisher:
ISBN:
Category : Aliphatic compounds
Languages : en
Pages : 107
Book Description
The emissions of CO2 to the atmosphere have rapidly increased in the last decades due to the industrialization and the increasing energy demand. Due to the potential effect that CO2 has as global warmer, industrialized and emerging countries are putting efforts on developing technologies to reduce emissions. Coal fired power plants produce 55% of U.S. electricity and more than 33% of global CO2 emissions, representing the largest stationary source of CO2. As a co-product of the combustion process of sulfur-containing coal, SO2 is produced and represents between 0.2 and 0.3 v% of the power plant flue gas composition. SO2 is a serious pollutant, precursor of the acid rain and particulate materials. The release of SO2 to the atmosphere can cause respiratory diseases and destruction of eco-systems. Some existing CO2 capture technologies are inefficient to be applied in power plants due to the large flow rates and high concentration of CO2 in the flue gas. Other technologies such as the liquid amine process are not economically viable because the energy requirements for operation and regeneration are excessive. In addition those processes cause rapid corrosion to the equipment. The adsorption on solid sorbents is potentially the most suitable process for the treatment of flue gas from power plants. The development of solid sorbents by functionalization of solid supports with amine functional groups has been recently studied. The goals during the sorbent development are (i) a high CO2 selectivity and adsorption capacity, (ii) the long term stability and cycle life, (iii) resistivity toward thermal and oxidative degradation, (iv) resistance to SO2 and (iv) low cost. In this thesis, the resistance of aliphatic amine and aromatic anime sorbents towards SO2 was studied by in-situ infrared spectroscopy (IR) and mass spectrometry (MS). An operational condition to improve the CO2 adsorption capacity of an amine sorbent was also studied by introducing H2O in the flue gas. The hypothesis included the use of an aromatic amine to prepare a low basicity sorbent for SO2 capture and to reduce the SO2 poisoning on a CO2 capture sorbent. In addition, it is thought that the presence of H2O in the flue gas improves the adsorption capacity of an amine sorbent due to the formation of different adsorbed species. The IR and MS results showed that the aromatic amine sorbent has a weak adsorption capacity of CO2 and SO2, leading to CO2 capture processes at low temperature. SO2 strongly adsorbs on the aliphatic amine sorbent, causing accumulation of sulfate and sulfite species and reducing the availability of amine sites for CO2 adsorption. The performance of CO2 capture in simulated practical conditions showed the improvement in capture capacity of a sorbent by more than 60% when the flue gas is saturated with H2O.
