Viscoelastic diamine surfactant for stable carbon dioxide/water foams over a wide range in salinity and temperature

Amro S Elhag; Chang Da; Yunshen Chen; Nayan Mukherjee; Jose A Noguera; Shehab Alzobaidi; Prathima P Reddy; Ali M AlSumaiti; George J Hirasaki; Sibani L Biswal; Quoc P Nguyen; Keith P Johnston

doi:10.1016/j.jcis.2018.03.037

Viscoelastic diamine surfactant for stable carbon dioxide/water foams over a wide range in salinity and temperature

J Colloid Interface Sci. 2018 Jul 15:522:151-162. doi: 10.1016/j.jcis.2018.03.037. Epub 2018 Mar 13.

Authors

Affiliations

¹ McKetta Department of Chemical Engineering, The University of Texas at Austin, United States; Petroleum Engineering Department, Khalifa University of Science and Technology, Petroleum Institute, United Arab Emirates.
² McKetta Department of Chemical Engineering, The University of Texas at Austin, United States.
³ Petroleum Engineering Department, Khalifa University of Science and Technology, Petroleum Institute, United Arab Emirates.
⁴ Department of Chemical and Biomolecular Engineering, Rice University, United States.
⁵ Hildebrand Department of Petroleum and Geosystems Engineering, The University of Texas at Austin, United States.
⁶ McKetta Department of Chemical Engineering, The University of Texas at Austin, United States. Electronic address: kpj@che.utexas.edu.

PMID: 29597127
DOI: 10.1016/j.jcis.2018.03.037

Abstract

Hypothesis: The viscosity and stability of CO₂/water foams at elevated temperature can be increased significantly with highly viscoelastic aqueous lamellae. The slow thinning of these viscoelastic lamellae leads to greater foam stability upon slowing down Ostwald ripening and coalescence. In the aqueous phase, the viscoelasticity may be increased by increasing the surfactant tail length to form more entangled micelles even at high temperatures and salinity.

Experiments: Systematic measurements of the steady state shear viscosity of aqueous solutions of the diamine surfactant (C_16-18N(CH₃)C₃N(CH₃)₂) were conducted at varying surfactant concentrations and salinity to determine the parameters for formation of entangled wormlike micelles. The apparent viscosity and stability of CO₂/water foams were compared for systems with viscoelastic entangled micellar aqueous phases relative to those with much less viscous spherical micelles.

Findings: We demonstrated for the first time stable CO₂/water foams at temperatures up to 120 °C and CO₂ volumetric fractions up to 0.98 with a single diamine surfactant, C_16-18N(CH₃)C₃N(CH₃)₂. The foam stability was increased by increasing the packing parameter of the surfactant with a long tail and methyl substitution on the amine to form entangled viscoelastic wormlike micelles in the aqueous phase. The foam was more viscous and stable compared to foams with spherical micelles in the aqueous lamellae as seen with C_12-14N(EO)₂ and C_16-18N(EO)C₃N(EO)₂.

Keywords: CO(2)-in-water foam; High Temperature; High internal phase foam; Viscoelastic surfactant; Wormlike micelles.