skip to main content

Title: Reversible Acid Gas Capture Using CO2-Binding Organic Liquids

Acid gas scrubbing technology is predominantly aqueous alkanolamine based. Of the acid gases, CO2, H2S and SO2 have been shown to be reversible, however there are serious disadvantages with corrosion and high regeneration costs. The primary scrubbing system composed of monoethanolamine is limited to 30% by weight because of the highly corrosive solution. This gravimetric limitation limits the CO2 volumetric (≤108 g/L) and gravimetric capacity (≤7 wt%) of the system. Furthermore the scrubbing system has a large energy penalty from pumping and heating the excess water required to dissolve the MEA bicarbonate salt. Considering the high specific heat of water (4 j/g-1K-1), low capacities and the high corrosion we set out to design a fully organic solvent that can chemically bind all acid gases i.e. CO2 as reversible alkylcarbonate ionic liquids or analogues thereof. Having a liquid acid gas carrier improves process economics because there is no need for excess solvent to pump and to heat. We have demonstrated illustrated in Figure 1, that CO2-binding organic liquids (CO2BOLs) have a high CO2 solubility paired with a much lower specific heat (<1.5 J/g-1K-1) than aqueous systems. CO2BOLs are a subsection of a larger class of materials known as Binding Organic Liquidsmore » (BOLs). Our BOLs have been shown to reversibly bind and release COS, CS2, and SO2, which we denote COSBOLS, CS2BOLs and SO2BOLs. Our BOLs are highly tunable and can be designed for post or pre-combustion gas capture. The design and testing of the next generation zwitterionic CO2BOLs and SO2BOLs are presented.« less
Authors:
; ; ; ;
Publication Date:
OSTI Identifier:
989440
Report Number(s):
PNNL-SA-69452
TRN: US201019%%492
DOE Contract Number:
AC05-76RL01830
Resource Type:
Conference
Resource Relation:
Conference: Preprints of Symposia - American Chemical Society Fuel Chemistry Division, 55(1):81-82
Publisher:
American Chemical Society, Washington DC, United States(US).
Research Org:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ACID CARBONATES; CAPACITY; CORROSION; DESIGN; ECONOMICS; GASES; HEATING; ORGANIC SOLVENTS; PUMPING; REGENERATION; SCRUBBING; SOLUBILITY; SOLVENTS; SPECIFIC HEAT; TESTING; WATER; CO2BOL, CO2, ionic liquid