Carbon capture and storage (CCS) technologies are a cornerstone for reducing CO2 emissions from energy and energy-intensive industries. Among the various CCS technologies, solid sorbent looping systems are considered to be potentially promising solutions for reducing CO2 capture energy penalty. We present an evaluation module for a carbonator with sorbent looping cycle to calculate the carbonation efficiency. The module incorporates a simple sorbent activity model, and the solid/gas balances are constructed by assuming simple reactor mixing quality. By conducting simulations, we examine the variation in the carbonation efficiencies as a function of the sorbent looping operation factors and discuss an optimum operating strategy.