3rd Generation, High Performance, Water-lean Solvents for Carbon Capture

Commercially available aqueous amine solvents have very high reboiler duty due to significant amount of heat is consumed for the latent heat of vaporization of water, making them quite expensive for carbon capture. Several new systems are being developed and are exclusively focused on water-lean solvents to avoid the latent heat of vaporization of water as well as improve the overall capture efficiency. These water-lean solvents hold great promise, however, they have yet to deliver on significantly lowering the overall capture cost due to the significant increase in viscosity upon the uptake of CO2. This increase in viscosity has a negative impact on the capital cost and it increases the overall cost of capture. Under this SBIR, our goal is to develop and commercialize a 3rd generation water-lean solvent system with high capture capacity (>10wt%), low viscosity (<10 cP at 40 °C) of the rich solvent, and improved thermal and chemical stability over 2nd generation solvents. We will achieve this goal by combining key characteristics of piperazine-based solvents and water-lean solvents. We will also take the advantage of our proprietary additives to mitigate the increase in viscosity of water-lean solvents via hydrogen bonding (HB) disruptor approach. During Phase I of this project, we will select commercially available amine candidates which has similar intrinsic properties of piperazine and formulate them into water-lean solvent systems. We will conduct performance testing to screen and optimize the solvent systems. The down-selected solvent system will be scaled-up and tested in a lab-scale CO2 capture system. The solvent performance data and operating parameters collected will be crucial for scale-up, process simulation, and process implementation for larger scale study. If this project is successfully carried out over into later Phases and commercialization, the new solvent system will not only decrease the regeneration energy compared to current CO2 capture systems but also significantly decrease the capital cost. The water-lean nature of these systems should theoretically provide mitigation for corrosion in capture systems, and the lower viscosities allow the size of the capture units to be considerably smaller, both of which will reduce the cost of CO2 capture. For rapid commercialization, we have identified natural gas sweetening as our beach-head market. If successful, this solvent system can also be deployed with minor modification for a number of applications such as metals production, cement industry, and chemicals production which are also large sources of CO2 emissions. We ultimately believe these materials due to much higher boiling points and lower viscosities can be easily used in direct air capture applications using large surface capture modules. The need for makeup solutions will be minimal due to its high boiling point.