Innovation in high-temperature CO2-capture Development of novel solid sorbents

The aim of the project is to develop new synthesis and processing methods for synthetic Ca-based CO2 sorbent that will significantly reduce production cost while maintaining previously reported superior chemical and mechanical stability. Most of the resea rch on synthetic sorbents have focused on developing materials with high chemical stability based on the use of solid binders with high thermal stability and, most often, high production costs. This project aims at formulating a synthetic sorbent with su perior chemical and mechanical performance whilst defining a realistic production method that will allow for a future industrial application of the material for post-combustion and pre-combustion CO2 capture. During the first phase of the project, a new synthesis method has been developed based on dissolution and re-precipitation of Anorthosite minerals and limestone. The new sorbent produced from mineral rocks has shown similar long-term chemical stability as the sorbent produced from synthetic precurs ors. This new path for producing CO2-sorbents opens up the possibility for producing the synthetic sorbent at lower cost therefore increasing the potential of the material for high-temperature CO2 capture application based on Calcium-sorbent In the secon d phase of the project,several agglomeration techniques were investigated to determine to optimal method to produce uniformly distributed spherical particles of synthetic sorbent for future fluidized bed applications. Three preferred technologies were tes ted in the coming months: Spray-drying, Shear agglomeration and fluidized bed agglomeration. Based on this assessment study, larger batches of agglomerated particles were produced for testing of the chemical and mechanical properties, first during TGA mul ticycling, fixed bed experiments and fluidized bed reactor.

One of the novel innovative concepts to remove efficiently CO2 from flue gas is a sorption process where a CaO-based solid sorbent is continuously circulating between two fluidized bed reactors. In the first reactor, CO2 is carbonated and captured in a ga s-solid reaction and, in a second step, CO2 is released by heating the formed compound in a regeneration reactor to produce a pure CO2-stream. The key factors in the further development of solid-based CO2-capture processes are the reaction kinetics, the c ost and long-term durability of the reactive solids, along with the development of technology to manage the large solid circulation rates. In the work proposed here, promising high-temperature CO2-sorbents previously studied at Institute for Energy Techno logy (IFE) will be developed further. The primary objectives are to reduce the production cost of the sorbent and improve the long-term mechanical durability of the particles. The work will include the development of a novel synthesis method from cheap an d abundant industrial minerals and the development of novel agglomeration techniques to produce mechanically stable solid particles. The evolution of the chemical and physical properties of the particles during long-term operation in realistic conditions will also be performed to highlight the potential of the material for industrial applications.