Synthesis of Sintering-Resistant Sorbents for CO₂ Capture

Abstract

Sorbents for high temperature CO2 capture are under intensive development owing to their potential applications in advanced zero emission power, sorption-enhanced steam methane reforming for hydrogen production and energy storage systems in chemical heat pumps. One of the challenges in the development is the prevention of sintering of the sorbent (normally a calcium oxide derivative) which causes the CO2 capture capacity of the material to deteriorate rapidly after a few cycles of utilization. Here we show that a simple wet mixing method can produce sintering-resistant sorbents from calcium and magnesium salts of d-gluconic acid. It was found that calcium oxide was well distributed in the sorbents with metal oxide nanoparticles on the surface acting as physical barriers, and the CO2 capture capacity of the sorbents was largely maintained over multiple cycles of utilization. This method was also applied to other organometallic salts of calcium and magnesium/aluminum and the produced sorbents showed similarly high reversibility.

The calcium looping cycle for CO2 capture from power generation, cement manufacture and hydrogen production

“…calcium acetate, calcium ethanoate (Lu et al, 2006;Lu, H. et al, 2008;Liu et al, 2010a) with particular success using a MgO support (Liu et al, 2010b) to similarly enhance the reactive surface area; dispersal of CaO within an inert porous matrix such as mayenite (Li et al, 2005;Li et al, 2006;Pacciani et al, 2008a) to improve mechanical stability; and use of cementitious binders (Manovic and Anthony, 2009a; to improve mechanical stability. Sorbent reactivity can be periodically improved by hydration of calcined sorbent, though this is often at the expense of mechanical strength of the sorbent (Hughes et al, 2004;Fennell et al 2007b;Manovic and Anthony, 2007;Manovic and Anthony., 2008a;Sun et al, 2008;Zeman, 2008).…”

Degradation study of a novel polymorphic sorbent under realistic post-combustion conditions

“…These approaches include: the use of dopants [10] [11] [12]; hydration and steam reactivation [13] [14] [15]; thermal pre-sintering [16] [17]; spacer molecule incorporation [18] and sintering resistant internal supports [19] [20]. Recently, Zhao et al [21] has reported a CaO-based sorbent incorporating a supporting structure composed of dicalcium silicate (Ca2SiO4, from here on referred to as C2S which is common notation of this compound in the cement industry) which enabled the sorbent to retain a very high proportion of its carrying capacity throughout many cycles.…”

Conditional Methods in Modeling CO2 Capture from Coal Syngas

“…Adsorption of N 2 on a sorbent was performed on a TriStar 3000 instrument (Micromeritics Instrument Corporation, Norcross, GA, USA) in order to evaluate its Brunauer, Emmett and Teller (BET) surface area and pore volume, parameters of which were used to calculate the initial surface area and porosity of CaO and CaCO 3 . Before the test, the fresh sorbent was degassed at 250 °C overnight.…”

“…Nevertheless, its performance in the cycling process rapidly decreases due to sintering, attrition and ash fouling [2]. To overcome the loss in CO 2 sorption capacity over cycles, synthetic CaO based sorbents have been developed [3,4] and tested in a laboratory scale process [4]. Note that relatively low CaO content in these samples allows for substantial improve the performance of the synthetic sorbents over many cycles.…”