Integration of Calcium and Chemical Looping Combustion using Composite CaO/CuO-Based Materials

摘要

Calcium looping cycles (CaL) and chemical looping combustion (CLC) are two new, developing technologies for reduction of CO_2 emissions from plants using fossil fuels for energy production, which are being intensively examined. Calcium looping is a two-stage process, which includes ozy-fuel combustion for sorbent regeneration, U., generation of a concentrated CO_2 stream. This paper discuss the development of composite materials which can use copper(Il)-oxide (CuO) as an oxygen carrier to provide oxygen for the sorbent regeneration stage of calcium looping. In other words, the work presented here involves integration of calcium looping and chemical looping into a new class of postcombustion CO_2 capture processes designated as integrated CaL and CLC (CaL-CLC or Ca-Cu looping cycles) using composite pellets containing lime (CaO) and CuO together with the addition of calcium aluminate cement as a binder. Their activity was tested in a theraiogravimerric analyzer (TGA) during caldnation/reduca'on/oxidatton/carbonation cycles. The calcination/reduction typically was performed in methane (CH_4), and the ondation/carbonation stage was carried out using a gas mixture containing bom CO_2 and O_2. It was confirmed that me material synthesized is suitable for the proposed cycles; with the very favorable rinding mat reduction/oxidation of the oxygen carrier is complete. Various schemes for the Ca-Cu looping process have been explored here that would be compatible with these new composite materials, along with some different possibilities for flow directions among carbonator, caldner, and air reactor.