A review of accelerated carbonation technology in the treatment of cement-based materials and sequestration of CO2

Moist calcium silicate minerals are known to readily react with carbon dioxide (CO2). The reaction products can cause rapid hardening and result in the production of monolithic materials. Today, accelerated carbonation is a developing technology, which may have potential for the treatment of wastes and contaminated soils and for the sequestration of CO2, an important greenhouse gas. This paper reviews recent developments in this emerging technology and provides information on the parameters that control the process. The effects of the accelerated carbonation reaction on the solid phase are discussed and future potential applications of this technology are also considered

Expansion of cohesive gas fluidized binary solid systems

The capability to predict the expansion characteristics of cohesive systems is still limited. A cohesive powder is fluidized by means of a second fluidizable solid and the possibility to describe the system with a model is evaluated. A generalized Richardson and Zaki correlation is tested and the form of the correlation is found to be valid as long as lower values of the exponential index are employed. The experimentation conducted in this work can be extended to substantiate preliminary findings and a research path to develop the work further is proposed

Investigation of accelerated carbonation for the stabilisation of MSW incinerator ashes and the sequestration of CO2

Accelerated carbonation has been used for the treatment of contaminated soils and hazardous wastes, giving reaction products that can cause rapid hardening and the production of granulated or monolithic materials. This technology provides a route to sustainable waste management and it generates a viable remedy to the problems of a decreasing number of landfill sites in the UK, global warming (due to greenhouse gas emissions) and the depletion of natural aggregate resources, such as sand and gravel. The application of accelerated carbonation (termed Accelerated Carbonation Technology or ACT) to sequester CO2 in fresh ashes from municipal solid waste (MSW) incinerator/combined heat and power plants is presented. The purpose of this paper is to evaluate the influence of fundamental parameters affecting the diffusivity and reactivity of CO2 (i.e. particle size, the reaction time and the water content) on the extent and quality of carbonation. In addition, the major physical and chemical changes in air pollution control (APC) residues and bottom ashes (BA) after carbonation are evaluated, as are the optimum reaction conditions, and the physical and chemical changes induced by accelerated carbonation are presented and discussed