Abstract
Every year, a plethora of studies focused on developing water-lean solvents for CO2 capture is published in the scientific literature. More often than not, these studies lack a satisfactory contextualization with the previous body of work. The reasons for this are manyfold, but perhaps the main culprit is the multitude of possible diluent and amine constituents for water-lean solvent formulation. This multitude of options can render a comprehensive analysis of water-lean solvents and their common properties quite a challenging task. However, precisely because there is such a diversity of results and observations, the ordering and categorization of distinct phenomena involving water-lean solvents is the more essential. Although there are some novel sophisticated deployements for the concept of organo-amine mixtures (such as the CO2BOLs and the NAS for example), many works on water-lean solvents adopt a traditionalistic approach, one that is conceptually based on the mixing of a physical and a chemical absorbent to generate a so-called hybrid solvent. We have demonstrated in this review that this particular class of solvents have more in common than one could be initially led to believe, and set clear guidelines to contextualize past and future results in terms of CO2 solubility, kinetic rates, mass transfer rates and heat of regeneration analyses. By doing this, we have also identified the main knowledge gaps remaining in the field of water-lean solvents – namely, degradation and corrosion data, as well as pilot plant data. We also believe that our comprehensive categorization and discussion of past literature on water-lean solvents delivers an important trove of references for those willing to carry on working with organo-amine mixtures, traditional or otherwise. With this study, we aim to aid future researchers to have easy access to key concepts for discussing their results.
Highlights
The search for plausible solvents for CO2 absorption covers a wide range of investigations, from the typical ones with benchmark aqueous amines [1] to curious alternatives such as human fat [2]
Many of the most promising water-lean solvents, such as the CO2BOLs [3,4] or those developed by Barzagli et al [5,6], rely on alternative mechanisms of reaction other than the ones observed in typical aqueous amines
Water-lean solvents, or rather hybrid solvents, have experienced a history of shifting interests loosely guided by two distinct factors
Summary
The search for plausible solvents for CO2 absorption covers a wide range of investigations, from the typical ones with benchmark aqueous amines [1] to curious alternatives such as human fat [2]. Many of the most promising water-lean solvents, such as the CO2BOLs [3,4] or those developed by Barzagli et al [5,6], rely on alternative mechanisms of reaction other than the ones observed in typical aqueous amines Together with this shift came the gradual changing of nomenclature. This text intends to present overaching ideas regarding a diverse, sometimes contradictory set of experimental data This is a risky endeavor, as one might point out that the available body of work on water-lean solvents is not conclusive enough to warrant general statements on chemical kinetics or CO2 solubility. Bench and pilot-scale operations are ideal for producing insights into real industrial challenges This is the more relevant in at least three particular areas: CO2 absorption rates, energy performance, and solvent degradation phenomena. To facilitate our discussion, a list of abbreviations for amines and diluents can be found at the end of this study
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
