5.1.2. CAC + Production Costs

A search with the keywords, calcium aluminate cement, and production costs (CAC + production costs) in the Scopus database yielded 17 results. The number of documents produced per year is presented in Figure 8b. The low production in this topic can be observed in the last 25 years.

M. Erans, et al. [63] oriented their research to the production of improved sorbents, motivated by the fact that the calcium loop (CaL) is a CO<sup>2</sup> capture technology and a fundamental problem for the commercialization of these technologies is to maintain a high level of sorbent reactivity during the long-term cycle, to mitigate the decrease in carrying capacity. A great strength of CaL compared to other carbon capture technologies is the synergy with the cement industry, due to the use of spent sorbent as Clinker raw material.

M. Erans, et al. [63] investigated limestone doped with HBr through a particle surface impregnation technique and granules prepared from limestone and CAC. These were tested in a 25 kWth dual fluidized bed pilot scale reactor to understand their capture performance and mechanical stability under realistic CaL conditions and the spent sorbent was subsequently used as a raw material to make cement. It was found that HBr-doped limestone showed better performance in terms of mechanical strength and stability of CO<sup>2</sup> absorption compared to that of granules prepared from limestone and CAC, and that the cement produced has characteristics and performance similar to that of commercial CEM I cement. This demonstrates the advantages of using spent sorbent as a raw material for cement manufacturing and shows the benefits of synthetic sorbents in CaL and the end-use suitability of spent sorbents for the cement industry. It can be concluded from the work of M. Erans, et al. [63], the feasibility of using various practical techniques to improve the performance of CaL on a pilot scale, and more importantly, it shows that commercial grade cement can be manufactured at from the lime product of this technology.

Abolhasani et al. [3] discusses the results of a comprehensive study incorporating rice husk ash (RHA) in CAC concrete to limit the phase transition of CAC hydration product and stabilize its long-term properties. The findings indicate that, at 90 days, the mechanical strengths of the mixes containing RHA were higher than those of the control mix, with the maximum improvement occurring at the substitution percentage of 5%.
