The high-temperature, solid chemical looping for CO2capture is a promising technology to mitigate greenhouse gases emission. The choice of a high-performance sorbent is a fundamental need to improve the CO2uptake in solid regeneration systems. Calcium-based sorbents have demonstrated a good compromise between cost, performance and environmental impact. In particular, calcined dolomite is selected as CO2-acceptor in pre-combustion processes due to its good experimental capacity for CO2uptake. Moreover, among the solid acceptors investigated in scientific literature, naturally occurring sorbents (e.g. calcite and dolomite) are not considered as potentially hazardous substances, as they are not toxic either to the environment or to humans. This work presents the effect on CO2carrying capacity of different compositions of the calcination atmosphere, from 100% N2to 50/50% CO2-N2, as well as a novel pre-treatment (here called triggered calcination) by means of half-calcination in CO2with subsequent flash N2calcination. This new decomposition method improves CO2capture up to 24% in prolonged carbonation/calcination cycling (over 150 cycles). Other factors have been studied such as heating rate, CO2concentration and carbonation time, as well as other pre-treatments. Increased and sustained rates of CO2uptake can be explained as a result of changes in the internal structure of sorbent particles. In order to explain them, a study of the surface area has been carried out by means of an indirect method based on TGA experiments.
All Science Journal Classification (ASJC) codes
- Environmental Chemistry
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering